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How to make an LED from a regular light bulb. DIY LED light bulb

Making a 220 V LED lamp with your own hands is an interesting activity that requires patience. Additionally, you need a little knowledge of physics, and the ability to solder. The main task is to create a circuit for an AC-to-DC 12 V converter that powers an LED lamp.

LED lamp

Represents a small luminous diode element, powered by direct current mostly 12v. To create lamps, they are collected several times, depending on the required light intensity.. The advantages of such lighting:

meager electricity consumption;
service life from 100,000 hours;
can work for days without shutting down;
There is a wide range of different models available for sale.

The main disadvantage in high cost prefabricated LED luminaires. Sellers are not well versed in the issue and can not competently answer your questions. In the very characteristics of the lamp losses due to the passage of light through the scatterer are not taken into account, frosted glass and reflector properties.

The packaging of the luminaire contains calculated data based on the characteristics and number of LED elements. Therefore, in fact the luminous flux of the purchased lamp is significantly lower than required and the lighting is poor. The lamps themselves and the parts for creating circuits cost a penny. Therefore, it is easiest for craftsmen to do everything with their own hands.

Use of LED lights

In houses and apartments, constant lighting of a place is often necessary. It can be stairs and children's rooms, toilets where there are no windows, and a child lives in the house who cannot reach the switch.

Dim light and low energy consumption make it possible to install lighting in entrances and on the porch, in front of the gate and garage doors. Luminaires with a soft glow due to glare damping, used to illuminate desktops in offices and kitchens.

Making an LED lamp with your own hands

Many are tormented by the question of how to make an LED lamp with your own hands and is it possible. There are many schemes for creating LED lighting powered by 220 V AC, they all solve a number of common tasks:

When creating LED lighting with your own hands, you also have to solve problems:

where to put circuits and LEDs;
how to isolate the lighting structure;
correct heat transfer.

Schemes of LED lamps

Variable sweat alignment and creation required power and resistance for LED lamps is solved in two ways. Schemes can be conditionally divided into:

with diode bridge;
resistor, with an even number of LED elements.

Each option has simple schemes and its own advantages.

Scheme of a converter with a diode bridge

The diode bridge consists of 4 diodes directed in different directions. Its task is to turn a sinusoidal alternating current into a pulsating one. Each half wave passes through two elements, and the minus changes its polarity.

In the circuit, for an LED lamp, a capacitor C10.47x250 v is connected to the positive side of the bridge from the AC source. A resistance of 100 ohms is placed in front of the negative terminal. Behind the bridge, parallel to it, another capacitor is installed - C25x400 v, which smooths out the voltage drop. It is easy to make such a scheme with your own hands, it is enough to have the skills to work with a soldering iron.

LED element

The board with LED elements is used standard, from a failed lamp. It is necessary to check before assembly that all parts are working. For this, a 12 V battery is used, it can be from a car. Non-working elements can be replaced by carefully unsoldering the contacts and putting in new ones. Pay close attention to the location of the anode and cathode legs. They are connected in series.

When replacing 2 - 3 parts, you simply solder them in accordance with the position that the failed elements occupied.

When assembling a new LED lamp with your own hands, you need to remember a simple rule. Lamps are connected 10 in series, then these circuits are connected in parallel. In practice, it looks like this:

Put 10 LEDs in a row and solder the legs of the anode of one with the cathode of the second. It turns out 9 connections and one free tail at the edges.
Solder all chains to the wires. To one cathode ends, to the other anode.

In texts, verbal designation of contacts is often used, icons on diagrams. Reminder for novice electricians:

cathode, positive - "+", joins the minus;
The anode is negative - "-", joins the plus.

When assembling circuits with your own hands, make sure that the soldered ends do not touch others. This will lead to a short circuit and burn out the entire circuit that you managed to make.

Schemes for a softer glow

In order for the LED lamp not to irritate the eyes by blinking, several details must be added to the assembly diagram. In general, the current converter consists of:

diode bridge;
400 nF and 10 uF capacitors;
100 and 230 ohm resistors.

To protect against power surges, a 100 ohm resistor is placed first, and then a 400 nF capacitor is soldered. In the previous version, they are installed at different ends of the entrance. Behind the capacitor after the diode bridge, another 230 ohm resistor is installed. It is followed by a series of LEDs (+).

Resistor circuits

The simplest circuit for those who want to do everything with their own hands consists of two 12 k resistors and two chains with the same number of LED elements, lamps connected in series with different directions are soldered. From the R 1 side, one strip is soldered by the cathode, the second - by the anode. Another layer to R 2 is the other way around.

This creates a softer glow of the lamps, since the LED elements are lit alternately and the pulsation of the flashes is almost imperceptible to the eyes. Such lamps can even be used as local lighting when working at a table, thus replacing an ordinary table lamp.

Experts who have made more than one lamp with their own hands recommend collecting at least 20 LEDs for this circuit. 40 is more commonly used. This provides good lighting and the circuit is easy to assemble. For more it is difficult to produce high-quality soldering of the circuit without hitting neighboring contacts. Yes, and it is difficult to collect it in the case.

You can make a lamp from 4 or 6 more powerful LEDs. To calculate the schemes, use a special calculator that can be found on the Internet.

When creating various circuits with your own hands from LED devices and others, you can use an online calculator for the correct calculation. It is easy to find on sites that are dedicated to electrical appliances and descriptions of how to make them. Its use will greatly simplify the process of calculating the current strength, resistance and will allow you to check the correct selection of parts.

Housings for LED lamps

For convenient inclusion of a do-it-yourself LED lamp in ordinary lighting devices, use:

socles of conventional incandescent lamps;
housings from energy-saving lamps;
halogen lamps;
homemade fixtures.

Each specialist, making an LED lamp with his own hands, chooses the most suitable option. The base makes it possible to screw the lamp into a conventional cartridge and at the same time provides heat transfer. Overheating, the LED lamp fails faster.

Base with incandescent lamps

Carefully separate the glass flask and remove the spiral. Then a circuit is placed inside the base and lamps are attached to the top of the board. The disadvantage of such a base is in an unsightly appearance and poor insulation.

Energy saving lamp housing

The most convenient and practical option for creating an LED lamp with your own hands. Methods for mounting diodes can be different. First, the burned-out lamp is carefully disassembled. Then the converter board is removed from it. Next, there are options.

It can be placed in the holes of the lid, which are made for glass flasks. This is in the version of the lamp with three arc-shaped light elements. The circuit is located inside the base providing heat transfer. LEDs are inserted into ready-made holes and mounted in them.

The finished board with LEDs can be placed in the base using a simple plastic water bottle cap. You can use a self-made circle and drill holes for the diodes in it. As a result, it is convenient to use and aesthetic appearance.

Some craftsmen, making their own hands, use the body halogen lamp. The inconvenience of this option is the absence of the usual opportunity for a base to screw the lamp into a cartridge. This option is more suitable for creating do-it-yourself indicators and DC lamps.

An LED is a semiconductor device that can convert electricity into light emission. One 220 volt LED lamp saves a huge amount of electricity. Savings come out 2 times more than the lamp daylight and 10 times than incandescent lamp. If you use parts from a burned-out lamp to make such a lamp, you can significantly reduce costs. Do-it-yourself LED lamp can be assembled quite simply. But do not forget that for this you must have the appropriate qualifications, as you will have to work with high voltage.

Benefits of LEDs

Nowadays, you can find a huge number of types of chandeliers with LED lamps in stores. They have different advantages and disadvantages. Modernization of energy saving lamps allows you to take advantage of all the benefits of fluorescent light. This applies to the most common fixtures with an E 27 base. And the old representatives of this family were endowed with an unpleasant flicker. Fluorescent light sources are truly a miracle. Compared to them, incandescent lamps are losing ground very much. Their high power consumption and low light output are not offset by their high color rendering index.

Durability is their main advantage. It is mechanically strong and reliable.. It is known that its life can reach up to 100,000 hours. And they are also considered environmentally friendly light sources, unlike fluorescent lamps, which, in turn, contain mercury. But as you know, fluorescent lamps have some disadvantages:

The vapors contained in the tubes are quite poisonous.
Due to frequent switching on and off, they can quickly fail.
The design itself requires a certain amount of recycling.

The LED lamp can be considered the second revolution in the field of lighting. It works 5-10 times longer, is more economical and does not require any special disposal. Although there is a minor drawback - it is much more expensive.

In order to remove this small minus and turn it into a good plus, you can build a lamp from an LED strip with your own hands. In this way, the cost of the light source can be reduced. It will be much lower than that of luminescent counterparts . Also, this lamp will have several advantages:

Lamp life will be a record 100,000 hours, but only if properly assembled.
Price homemade device no higher than that of a fluorescent lamp.
The watt/lumen efficiency is far superior to all analogues.

But there is also one drawback - this product does not have a warranty. It must be compensated by the skill of the electrician and the exact observance of the instructions.

Homemade lamps

To create a lamp with your own hands, there are a huge number of ways. Using an old base from a burned-out fluorescent lamp is the most common method. Such resources are available in every home, so there will be no problems finding them. And you will also need:

In some schemes, one or two items from this list may not be useful. However, in others, on the contrary, new links in the chain may be needed, for example: drivers or electrolytes. In each specific case, you need make a list of required materials.

How to make a DIY LED lamp

To proceed with the installation of the lamp, it is necessary to prepare two damaged fluorescent lamps with a power of 13 W and a length of half a meter. There is no point in buying new ones, it is best to find broken old ones. But they must be checked for cracks and chips.

Next in the store you need to purchase led strip. This must be approached responsibly, as the choice is very large. Ribbons with natural or pure white light work best. Since they do not change the shades of surrounding objects and are super-bright. Usually in these tapes the LEDs are assembled in groups of three. The power of one group is 14 watts, and the voltage is 12 volts per meter tape.

After that, you need to disassemble the fluorescent lamps into their component parts. It is necessary to act very carefully - do not damage the wires and do not break the tube, as in this case toxic fumes will escape. All extracted entrails should not be thrown away. They may come in handy later. Next, you need to cut the tape into sections of 3 diodes. After that, it is worth getting expensive and unnecessary converters. Large, sturdy scissors or wire cutters are best for cutting the tape.

As a result, there should be 22 groups 3 leds or 66 leds, which must be connected in parallel along the entire length. To convert alternating current to direct current, it is necessary to increase the standard voltage of 220 volts to 250 in the electrical network. This is due to the straightening process. The next step is to figure out the number of LED sections. To do this, you need to divide 250 volts by 12 volts (voltage for 1 group of 3 pcs.). Having received as a result 20.8 (3), you need to round up - you get 21 groups. It is best to add another group, as the total number of LEDs will be divided into two lamps. And dividing an even number is much easier.

Next, you need a DC rectifier, which can be found in the extracted insides of a fluorescent lamp. Using wire cutters, we remove the capacitor from the common converter circuit. It is quite easy to perform this action, since it is separate from the diodes, you just have to break off the board.

Using superglue and soldering, it is necessary to assemble the entire structure. You should not try to fit all 22 sections into one lamp. As mentioned above, you need to find 2 half-meter lamps, since it is simply impossible to place all the LEDs in one. You do not need to rely on the self-adhesive layer, which is located on the back of the tape. He can't serve for a long time. Therefore, to fix the LEDs, it is better to use superglue or liquid nails.

Summing up, you can make out all the advantages of the assembled product. The amount of light from the resulting lamps is 1.5 times greater than that of analogues. But the power consumption is much less than that of fluorescent lamps. The service life of this light source will be about 10 times longer. And also one of the advantages - is the direction of the light. It is directed strictly downward and does not have the ability to dissipate. Therefore, it will be best used at the desktop or in the kitchen. However, the emitted light is not high brightness, but has low power consumption.

Constant use of the lamp in the on state will consume only 4 kW of energy per year. The cost of electricity consumed per year can be compared with the cost of a ticket in public transport. Therefore, such light sources are often used where constant illumination is required, for example:

The outside.
The corridor.
Utility room.
Emergency lighting.

Simple LED light bulb

There is another way to create a lamp. A table lamp, chandelier or lantern needs an E14 or E27 socket. Accordingly, the diodes used and the circuit will be different. Compact fluorescent lamps are now common . For installation you will need one burned out cartridge, as well as a modified list of materials. Necessary:

Let's move on to creating an LED module with our own hands. First you need to disassemble the old lamp. In fluorescent lamps, the base is attached to a plate with tubes and secured with latches. The plinth can be detached quite simply. It is necessary, having found places with latches, pry them with a screwdriver. You need to do everything quite carefully so as not to damage the tubes. When opening, it is necessary to ensure that the electrical wiring that leads to the base remains intact.

From the upper part with gas discharge tubes, you need to make a plate to which the LEDs will be attached. To do this, disconnect the bulb tubes. The rest of the plate has 6 holes. In order for the LEDs to fit tightly in it, you need to make a cardboard or plastic “bottom” that will also isolate the LEDs. You need to use NK6 LEDs, they are multi-chip (6 crystals per diode) with parallel connection.

Because of this, the light source is ultra-bright at minimum power. In the cover you need to make 2 holes for each LED. Holes should be pierced carefully and evenly so that their location matches each other and the intended pattern. If you use a piece of plastic as a “bottom”, then the LEDs will be fixed firmly. But in the case of using a piece of cardboard, you will need to glue the base with LEDs using superglue or liquid nails.

Since the light bulb will be used on a 220 volt network, an RLD2-1 driver is required. You can connect 3 diodes of 1 watt to it. For this lamp, it took 6 LEDs with a power of 0.5 watts. From this it follows that the connection circuit will be formed from two parts connected in series from three LEDs connected in parallel.

Before proceeding with the assembly, you need to isolate the driver and the board from each other. To do this, you can use a piece of cardboard or plastic. This will avoid a short circuit in the future. There is no need to worry about overheating, as the lamp does not heat up at all. It remains to assemble the design and test it in action. The white light makes the bulb appear much brighter. Light flow assembled lamp equals 100-120 lumens. This may be enough to illuminate a small room (corridor or utility room).

Types of fixtures

Lamps on LEDs can be divided into two groups: indicator (LED) - are used as indicators, because they are low-power and dim. The green lights on the router are indicator LEDs. Such diodes are also on the TV. Their application is quite varied. For example:

Car dashboard lighting.
Various electronic devices.
Illumination of computer displays.

Their colors have a huge variety: yellow, green, red, purple, blue, white and even ultraviolet. It is worth remembering that the color of the LED does not depend on the color of the plastic. It is determined by the type of semiconductor material from which it is made. In most cases, you need to turn it on to know the color, as they are made of colorless plastic.

A lighting design is used to illuminate something. It differs in its power and brightness. It also has a very reduced price, so it is often used in domestic and industrial lighting. This type of lighting is considered productive, environmentally friendly and cheap. To date, the level of development of technology can allow the production of lamps with a high level of light output per 1 watt.

In this article, we will look at examples of making homemade LED lamps for various needs.

1. The simplest lamp for domestic needs.

To begin with, it is worth deciding which LEDs are best to use. If you choose between powerful and low-power - the first is better in terms of labor intensity. To replace one powerful 1W LED, you need 15-20 low power 5mm or smd LEDs. Accordingly, soldering with low-power is much larger. Let's focus on the powerful ones. Usually they are divided into two types - output and surface mount. To make life easier, it is better to use output. The power of the LED is better to choose no more than 1 watt.

We also need a current driver so that the LEDs receive the necessary voltage and serve for a long time.
In addition, a heatsink is needed for long-term operation of the LED (especially for a powerful one). Aluminum is best suited for its manufacture. For each one-watt LED, you need a piece of aluminum 50x50 mm, about 1 mm thick. The piece may be smaller if bent. If you take a piece of 25x25 mm and 5 mm thick, you will not get the desired effect. To dissipate heat, you need area, not thickness.

Consider the model of the simplest lamp. We will need: three 1 W LEDs, a 3x1 W driver, double-sided heat-conducting tape, a radiator (for example, a piece of a U-shaped profile 1 mm thick and 6-8 cm long).

Thermally conductive tape can conduct heat. Therefore, the usual double-sided tape from will not work. Cut off a strip of adhesive tape 6-7 mm wide.

We degrease the radiator and the bottoms of the LEDs. It is undesirable to use acetone for this - the plastic lens of the LED may become cloudy.

Stick tape on the radiator. Then we mark the radiator to install the LEDs evenly.

We install the LEDs on the adhesive tape. At the same time, we observe the polarity - all LEDs must be deployed in the same way so that the "plus" of one LED looks at the "minus" of the neighboring one. Lightly press them for better contact. After that, we apply tin to the leads of the LEDs to facilitate further soldering. If you have a fear that the adhesive tape may burn out, just lift the LED leads so that they do not touch the adhesive tape. In this case, the LED housing must be held with a finger so that it does not come off the adhesive tape. However, you can bend the conclusions in advance.

We connect the LEDs together. For this, a vein from any stranded wire is quite enough.

Solder the driver.

The simplest lamp model is ready. Now you can insert it into any suitable case. Of course, you can make a more powerful lamp, only you need more diodes and a more powerful driver, but the principle remains the same. This technique is suitable both for the manufacture of a single lamp, and for small-scale production.

2. Chandelier based on LEDs.

We will need:
1. Base from a burned-out energy-saving lamp.
2. Two grips (to connect to the LED);
3. Powerful ten-watt LED, color of your choice;
4. Two small screws;
5. One ten watt LED driver;
6. Thermal paste;
7. Radiator;
8. Heat shrink tube (or insulating tape);
9. wires with a cross section of 2 mm.

First you need to disassemble the old or burnt energy saving lamp. It is important to be careful not to damage the glass bulb. Otherwise, mercury gas, which is very harmful to health, will come out of it.

We only need a part of the body with a plinth. We cut off the leads from the board going to the base and solder our own leads from the LED driver, insulating them with heat shrink tubes.

With a soldering iron, we will make a couple of holes for the wire, which will hold the entire structure.

Next, use the terminals, crimp, connect to the LED, observing the polarity. We check. It is not recommended to look at the on LED. The intensity of the light is very strong and can harm your eyes. If everything works, we assemble the lamp into a single whole.

The LED is very bright and casts harsh shadows. You can make the light smoother and softer by using a DIY diffuser. Many different materials can be used as a diffuser. The simplest one is to cut the bottom out of a two-liter plastic bottle, sand it on all sides to give full opacity to direct light. We make four holes and attach it to the radiator with wire.

3. Home LED lamp.

We use Cree MX6 Q5 LEDs with a power of 3 W and a light output of 278 lm as a light source. The LED will be placed on a 5x5 cm heatsink removed from an old processor. motherboard.

For simplicity, we will use a switching source along with an electronic adapter, which will provide the necessary voltage and current to power the LEDs. For this purpose, in our case, a non-working charger was chosen. mobile phone having, according to the manufacturer, an output voltage of 5 V and a current of 420 mA.

For protection from external influences the entire electronic part will be placed in the socket from the old lamp.

According to the manufacturer's instructions, Cree MX6 Q5 LEDs can operate at a maximum current of 1 A at 4.1 V. Logically, for normal operation, we need a 1 ohm resistor to reduce the voltage by about one volt of the five that the charger gives to get the desired 4.1 V, and this is only if the charging produces a maximum current of 1 A. However, as it turned out later, a charger with a design current limit of 0.6 A works without problems. Testing in the same way charging for other mobile phones, it was found that they all have a current supply limit that is 20-50% higher than that indicated by the manufacturer. The meaning of this is that any manufacturer will strive to develop a power supply so that it does not overheat even if the powered device is damaged or a short circuit occurs, and the easiest way in this case is to limit the current.

Thus, we have a direct current source limited to 0.6 A, powered by alternating current 230 V, made by a factory method and having a small size. At the same time, during operation, it only slightly heats up.

Let's move on to assembly. First you need to open the power supply in order to remove the parts that will be inserted into the body of the new lamp. Since most power supplies are connected by soldering, we open the unit with a hacksaw.

In order to fix the board in the lamp housing, in our case, sanitary silicone was used. Silicone was chosen for its resistance to high temperatures.

Before closing the lamp, we fasten the radiator to the cover (using bolts), to which the LED was attached.

The lamp is ready. The power consumption is just under 2.5 W and the luminous flux is 190 lm, which is ideal for an economical, durable and strong table lamp.

4. Lamp in the corridor.

To illuminate the hallway with LED lights, we used two Cree MX6 Q5 LEDs, each of which has a power of 3 W and a light output of 278 lm and is powered by an old mobile power supply. Samsung phone. And although the manufacturer in the specification indicates a current strength of 0.7 A, after measurements it was found that it is limited to 0.75 A.

The scheme for manufacturing the base of the lamp is similar to the previous version. The entire external structure is assembled using textile Velcro, glue and plastic washers from motherboards.

The total consumption of this design is about 6 W with a luminous flux of 460 lm.

5. Light fixture in the bathroom.

For the bathroom, I used a Cree XM-L T6 LED powered by two LG phone chargers.

Each of chargers can deliver 0.9 A according to the manufacturer, but I found that the actual current is 1 A. Both power supplies are connected in parallel to obtain a current of 2 A.

With such indicators, the LED lamp will produce a luminous flux of 700 lm with a power consumption of 6 watts.

6. Lamp for the kitchen.
If for the hallway and bathroom there was no need to provide a certain minimum of illumination, then in the kitchen this is not the case. Therefore, it was decided to use not one, but two series-connected Cree XM-L T6 LEDs for the kitchen, each of which has a maximum power consumption of 9 W and a maximum luminous flux of 910 lumens.

For effective cooling, in our case, we used a heatsink removed from Slot 1 of a Pentium 3 processor, to which both LEDs were attached using ArcticAlumina hot melt adhesive. Although Cree XM-L T6 LEDs can draw up to 3A, the manufacturer recommends using 2A for reliable operation, at which they produce a luminous flux of about 700 lumens. A generating 12V at a current of 1.5A was used as a power source. After testing it with resistors, it was found that the current was limited to a value of 1.8 A, which is very close to the desired value of 2 A.

To protect the heatsink and two LEDs, we used two plastic washers from the motherboard and two neodymium magnets removed from a damaged DVD drive, securing them with superglue and textile Velcro.

I expected this LED fixture to deliver 1200 lumens, which is comparable to the lumen output of a replacement 23W fluorescent lamp, but it was found that the actual light emitted is even more intense, with a power consumption of around 12W - almost half the amount of the old light bulb. .

7. Office lamp
We will need:

1. LED rulers 4 pcs (on powerful American CREE diodes)
2. Suitable driver (power supply) 1pc
3. The metal case of the future lamp.
4. Wiring, soldering iron, hand tools and fasteners.th lamp.

Can be used to make the body of an old lamp

Or use a special aluminum profile with glass. In this case, the driver is installed inside the profile.

We install diode lines 4 pcs.

We make a ceiling mount (on cables) + put frosted glass.

Version of the LED lamp in the housing (from fluorescent 2x36W)

with glass

Or you can put everything in an office lamp 600x600 mm.

Well, as a bonus, consider a few examples of decorative lamps based on LEDs.

For a decorative lamp we need:
- 4 wooden planks of the same size;
- drill with a drill 15 mm;
- glue for wood;
- wood stain;
- a brush with a pencil;
- sandpaper;
- LED candles.
First of all, it is necessary to make several holes in each plank with a drill, having previously made markings with a pencil - this is how we get a kind of pattern from circles.

We put stain on the tree.

Using glue, we connect 4 planks into a lamp.

We pass sandpaper over the lamp to give it a vintage look.

We put LED candles inside the lamp.

The nightlight is ready.

9. Lamp in oriental style.
As ceiling lamps for lamps, we use cans of pva glue.

We will need:
- 2-3 cans of PVA glue
- cartridges, wire
- scissors, sharp knife
- hot glue gun
- bamboo placemats or straw ceiling tiles

First you need to cut the napkins into pieces of the desired size.

On the base of the can, circle the cartridge with a 1 watt LED with a marker and cut a circle with a knife.

Then, using a hot glue gun, glue the napkins to the jars.

We glue the braid to the empty places.

At this stage, you can already see how it will glow.

It remains to decorate the braid with wooden beads at the joints.

For safety reasons, holes must be drilled for ventilation. Maybe more, they still won't be visible.

That's all, the lamp is ready.

10. Unusual decorative lamp.

Making a lamp with your own hands began with drawing preliminary sketches on paper. There was a desire that the lamp not only be curved in a plane, but also in space, and have a bizarre 3d wave shape.

After the sketch on paper is ready, we proceed to the manufacture of the lamp. Each pipe in the figure was measured and the pipes were cut to those dimensions. To get the necessary angles, templates were cut out of paper and fastened with tape on the pipe.

All tubes have been laid out on the table and adjustments have been made to the waveform.

The cuts were made on a stationary circular saw. Thus, smooth cuts without burrs with a width of 2 mm are obtained.

Now you need to connect all the pipes into one. The main task is to make smooth bends, for this it does not hurt to apply a template (fiberboard sheet) on the table.

Since the pipes are cardboard, they can be connected accordingly with PVA glue, but I would recommend using adhesives that are stronger and harden faster (moment, superglue).

On the reverse side, wooden planks were screwed onto the screws to homemade lamp could be hung on the wall. And holes were drilled in each pipe for the output of wires from the LED strips.

The pipes were painted with ordinary paint in a spray can. Red was used, since the wall on which the lamp should be located was white, I wanted to get some contrast.

The paint dries very quickly, so you can proceed with the installation of LEDs. The main thing to remember is that you can cut the LED strip only in specially marked places. The tape must be marked in advance so that it is enough for all 12 pipes.

We solder red wires to the “+” contact, and black wires to the “-” contact, so as not to confuse the polarity later.

We place the LED strips inside the pipes and fix them with the adhesive side to the pipe wall, and we bring the wires out through the holes made in advance. It remains only to connect all the wires in parallel (connect red to red, and black to black) and connect to the power supply.

Now it's time to hang the homemade lamp on the wall.
The lamp is ready.

Due to low power consumption, theoretical durability and lower prices, incandescent and energy-saving lamps are rapidly replacing. But, despite the declared service life of up to 25 years, they often burn out without even having served the warranty period.

Unlike incandescent lamps, 90% of burned-out LED lamps can be successfully repaired with your own hands, even without special training. The presented examples will help you to repair failed LED lamps.

Before undertaking the repair of an LED lamp, you need to present its device. Regardless of the appearance and type of LEDs used, all LED lamps, including filament bulbs, are arranged in the same way. If you remove the walls of the lamp housing, then inside you can see the driver, which is a printed circuit board with radio elements installed on it.

Any LED lamp is arranged and works as follows. The supply voltage from the contacts of the electric cartridge is supplied to the terminals of the base. Two wires are soldered to it, through which voltage is applied to the input of the driver. From the driver, a DC supply voltage is supplied to the board on which the LEDs are soldered.

The driver is an electronic unit - a current generator that converts the mains voltage into the current required to light the LEDs.

Sometimes, to scatter light or protect a person from touching the unprotected conductors of a board with LEDs, it is covered with a diffusing protective glass.

About filament lamps

By appearance A filament lamp is similar to an incandescent lamp. The device of filament lamps differs from LED ones in that they do not use a board with LEDs as light emitters, but a glass sealed bulb filled with gas, in which one or more filament rods are placed. The driver is located in the base.

The filament rod is a glass or sapphire tube with a diameter of about 2 mm and a length of about 30 mm, on which 28 miniature LEDs are fixed and connected in series coated with a phosphor. One filament consumes about 1 W of power. My operating experience shows that filament lamps are much more reliable than those made on the basis of SMD LEDs. I think over time they will replace all other artificial light sources.

Examples of repair of LED lamps

Attention, the electrical circuits of the LED lamp drivers are galvanically connected to the phase of the electrical network and therefore care must be taken. Touching exposed parts of a circuit connected to an electrical outlet may result in electric shock.

LED Lamp Repair
ASD LED-A60, 11 W on SM2082 chip

Currently, powerful LED bulbs have appeared, the drivers of which are assembled on microcircuits of the SM2082 type. One of them worked less than a year and got me to repair. The light bulb flickered randomly and came on again. When tapped on it, it responded with light or extinction. It became obvious that the problem was a bad connection.

To get to the electronic part of the lamp, you need to use a knife to pick up the diffusing glass at the point of contact with the body. Sometimes it is difficult to separate the glass, since silicone is applied to the retaining ring when it is seated.

After removing the light-scattering glass, access to the LEDs and the microcircuit - the current generator SM2082 was opened. In this lamp, one part of the driver was mounted on an aluminum printed circuit board of LEDs, and the second on a separate one.

External inspection did not reveal defective rations or broken tracks. I had to remove the board with LEDs. To do this, the silicone was first cut off and the board was pushed over the edge with a screwdriver blade.

To get to the driver located in the lamp housing, I had to unsolder it, heating two contacts at the same time with a soldering iron and moving it to the right.

On one side of the driver PCB, only an electrolytic capacitor with a capacity of 6.8 microfarads for a voltage of 400 V was installed.

On the reverse side of the driver board, a diode bridge and two series-connected resistors with a nominal value of 510 kOhm were installed.

In order to figure out which of the boards was losing contact, they had to be connected, observing the polarity, using two wires. After tapping the boards with a screwdriver handle, it became obvious that the fault lies in the board with the capacitor or in the contacts of the wires coming from the LED lamp base.

Since soldering did not arouse suspicion, I first checked the reliability of the contact in the central terminal of the base. It is easily removed by prying it over the edge with a knife blade. But the contact was reliable. Just in case, I tinned the wire with solder.

It is difficult to remove the screw part of the base, so I decided to solder the solder wires suitable from the base with a soldering iron. When touching one of the rations, the wire was exposed. Found "cold" soldering. Since it was not possible to get to strip the wire, I had to lubricate it with the FIM active flux, and then solder it again.

After assembly, the LED lamp emitted light steadily despite being hit with a screwdriver handle. Checking the luminous flux for pulsations showed that they are significant at a frequency of 100 Hz. Such a LED lamp can only be installed in luminaires for general lighting.

Driver circuit diagram
LED lamp ASD LED-A60 on the chip SM2082

The electrical circuit of the ASD LED-A60 lamp, thanks to the use of a specialized SM2082 microcircuit in the driver to stabilize the current, turned out to be quite simple.

The driver circuit works as follows. The AC supply voltage is fed through fuse F to the rectifier diode bridge assembled on the MB6S microassembly. The electrolytic capacitor C1 smooths out the ripple, and R1 serves to discharge it when the power is turned off.

From the positive terminal of the capacitor, the supply voltage is applied directly to the LEDs connected in series. From the output of the last LED, the voltage is applied to the input (pin 1) of the SM2082 microcircuit, the current in the microcircuit stabilizes and then from its output (pin 2) it goes to the negative terminal of the capacitor C1.

Resistor R2 sets the amount of current flowing through the LEDs HL. The amount of current is inversely proportional to its nominal value. If the value of the resistor is reduced, then the current will increase, if the value is increased, then the current will decrease. The SM2082 chip allows you to adjust the current value from 5 to 60 mA with a resistor.

LED Lamp Repair
ASD LED-A60, 11W, 220V, E27

Another LED lamp ASD LED-A60, similar in appearance and with the same technical specifications, as above repaired.

When turned on, the lamp lit up for a moment and then did not shine. This behavior of LED lamps is usually associated with a driver malfunction. Therefore, I immediately began to disassemble the lamp.

The diffusing glass was removed with great difficulty, since it was heavily lubricated with silicone along the entire line of contact with the case, despite the presence of a retainer. To separate the glass, I had to look for a pliable place along the entire line of contact with the body with a knife, but still there was a crack in the body.

To gain access to the lamp driver, the next step was to remove the LED printed circuit board, which was pressed into the aluminum insert along the contour. Despite the fact that the board was aluminum, and it was possible to remove it without fear of cracking, all attempts were unsuccessful. The pay was held tight.

It also failed to remove the board together with the aluminum insert, since it fit snugly against the case and was planted on silicone by the outer surface.

I decided to try to remove the driver board from the side of the base. To do this, first, a knife was pulled out of the base, and the central contact was removed. To remove the threaded part of the base, it was necessary to slightly bend its upper shoulder so that the punching points disengaged from the base.

The driver became accessible and freely extended to a certain position, but it was not possible to completely remove it, although the conductors from the LED board were soldered.

There was a hole in the center of the board with the LEDs. I decided to try to remove the driver board by hitting its end through a metal rod threaded through this hole. The board advanced a few centimeters and rested against something. After further blows, the lamp body cracked along the ring and the board with the base of the base separated.

As it turned out, the board had an extension, which rested against the lamp body with its hangers. It looks like the board was shaped in such a way to restrict movement, although it was enough to fix it with a drop of silicone. Then the driver would be removed from either side of the lamp.

The voltage of 220 V from the lamp base through the resistor - fuse FU is fed to the MB6F rectifier bridge and after it is smoothed by an electrolytic capacitor. Next, the voltage is supplied to the SIC9553 chip, which stabilizes the current. Resistors R20 and R80 connected in parallel between terminals 1 and 8 MS set the amount of current to supply the LEDs.

The photo shows a typical electrical circuit diagram given by the manufacturer of the SIC9553 chip in the Chinese datasheet.

This photo shows the appearance of the LED lamp driver from the installation side of the output elements. Since space allowed, to reduce the ripple coefficient of the light flux, the capacitor at the output of the driver was soldered to 6.8 microfarads instead of 4.7 microfarads.

If you have to remove the drivers from the body of this lamp model and you cannot remove the LED board, then you can use a jigsaw to cut the lamp body in a circle just above the screw part of the base.

In the end, all my efforts to extract the driver turned out to be useful only for knowing the device of the LED lamp. The driver was correct.

The flash of the LEDs at the moment of switching on was caused by a breakdown in the crystal of one of them as a result of a voltage surge when the driver was started, which misled me. We had to ring the LEDs first.

An attempt to test the LEDs with a multimeter did not lead to success. The LEDs didn't light up. It turned out that two series-connected light-emitting crystals are installed in one housing, and in order for the LED to start flowing current, it is necessary to apply a voltage of 8 V to it.

A multimeter or tester, switched on to the resistance measurement mode, outputs a voltage in the range of 3-4 V. I had to check the LEDs using the power supply, supplying 12 V to each LED through a 1 kΩ current-limiting resistor.

There was no replacement LED available, so the pads were shorted with a drop of solder instead. It is safe for the driver to work, and the power of the LED lamp will decrease by only 0.7 W, which is almost imperceptible.

After the repair of the electrical part of the LED lamp, the cracked body was glued with Moment quick-drying superglue, the seams were smoothed by melting the plastic with a soldering iron and smoothed out with sandpaper.

For interest, I performed some measurements and calculations. The current flowing through the LEDs was 58 mA, the voltage was 8 V. Therefore, the power supplied to one LED is 0.46 W. With 16 LEDs, it turns out 7.36 watts, instead of the declared 11 watts. Perhaps the manufacturer indicates the total power consumption of the lamp, taking into account losses in the driver.

The service life of the LED lamp ASD LED-A60, 11 W, 220 V, E27, declared by the manufacturer, is very doubtful to me. In a small volume of a plastic lamp housing with low thermal conductivity, significant power is released - 11 watts. As a result, the LEDs and the driver operate at the maximum allowable temperature, which leads to accelerated degradation of their crystals and, as a result, to a sharp decrease in their MTBF.

LED Lamp Repair
LED smd B35 827 ERA, 7 W on BP2831A chip

A friend shared with me that he bought five light bulbs as in the photo below, and all of them stopped working after a month. He managed to throw away three of them, and, at my request, he brought two for repair.

The light bulb worked, but instead of a bright light, it emitted a flickering weak light at a frequency of several times per second. I immediately assumed that the electrolytic capacitor was swollen, usually if it fails, the lamp begins to emit light, like a stroboscope.

The light-diffusing glass was removed easily, it was not glued. It was fixed by a slot on its rim and a protrusion in the lamp body.

The driver was fixed with two solders to the printed circuit board with LEDs, as in one of the lamps described above.

A typical driver circuit on a BP2831A chip taken from the datasheet is shown in the photo. The driver board was removed and all simple radio elements were checked, everything turned out to be in good order. I had to check the LEDs.

The LEDs in the lamp were installed of an unknown type with two crystals in the case and the inspection did not reveal any defects. Using the method of serially connecting the leads of each of the LEDs to each other, he quickly identified the faulty one and replaced it with a drop of solder, as in the photo.

The lamp worked for a week and again got into repair. Shorted the next LED. A week later, I had to short-circuit another LED, and after the fourth I threw out the bulb, because I was tired of repairing it.

The reason for the failure of light bulbs of this design is obvious. LEDs overheat due to insufficient heat sink surface, and their life is reduced to hundreds of hours.

Why is it permissible to close the terminals of burned-out LEDs in LED lamps

Driver for LED lamps, as opposed to a power supply constant voltage, the output produces a stabilized current value, not voltage. Therefore, regardless of the load resistance within the given limits, the current will always be constant and, therefore, the voltage drop across each of the LEDs will remain the same.

Therefore, with a decrease in the number of series-connected LEDs in the circuit, the voltage at the output of the driver will also decrease proportionally.

For example, if 50 LEDs are connected in series to the driver, and a voltage of 3 V drops across each of them, then the voltage at the output of the driver was 150 V, and if 5 of them were shorted, the voltage would drop to 135 V, and the current would not change.

But the coefficient useful action(Efficiency) of a driver assembled according to such a scheme will be low and power losses will be more than 50%. For example, for an MR-16-2835-F27 LED bulb, you will need a 6.1 kΩ resistor with a power of 4 watts. It turns out that the driver on the resistor will consume power exceeding the power consumption of the LEDs and it will be unacceptable to place it in a small LED lamp housing, due to the release of more heat.

But if there is no other way to repair the LED lamp and it is very necessary, then the driver on the resistor can be placed in a separate case, all the same, the power consumption of such an LED lamp will be four times less than incandescent lamps. At the same time, it should be noted that the more LEDs connected in series in the light bulb, the higher the efficiency will be. With 80 serially connected SMD3528 LEDs, you will need an 800 ohm resistor with a power of only 0.5 watts. Capacitor C1 will need to be increased to 4.7 µF.

Finding faulty LEDs

After removing the protective glass, it becomes possible to check the LEDs without peeling off the printed circuit board. First of all, a careful inspection of each LED is carried out. If even the smallest black dot is detected, not to mention the blackening of the entire surface of the LED, then it is definitely faulty.

When examining the appearance of the LEDs, you need to carefully examine the quality of the rations of their conclusions. In one of the light bulbs being repaired, four LEDs were poorly soldered at once.

The photo shows a light bulb that had very small black dots on four LEDs. I immediately marked the faulty LEDs with crosses so that they could be clearly seen.

Faulty LEDs may or may not change appearance. Therefore, it is necessary to check each LED with a multimeter or arrow tester included in the resistance measurement mode.

There are LED lamps in which standard LEDs are installed in appearance, in the case of which two crystals connected in series are mounted at once. For example, lamps of the ASD LED-A60 series. To make such LEDs ring, it is necessary to apply a voltage of more than 6 V to its outputs, and any multimeter gives out no more than 4 V. Therefore, such LEDs can only be checked by applying a voltage of more than 6 (9-12) V through a 1 kΩ resistor from the power source. .

The LED is checked, like a conventional diode, in one direction the resistance should be equal to tens of megaohms, and if you swap the probes (this changes the polarity of the voltage supply to the LED), then it is small, while the LED may glow dimly.

When checking and replacing LEDs, the lamp must be fixed. To do this, you can use a suitable size round jar.

You can check the health of the LED without an additional DC source. But such a verification method is possible if the light bulb driver is working. To do this, it is necessary to apply a supply voltage to the LED bulb base and short the leads of each LED in series with each other with a wire jumper or, for example, metal tweezers sponges.

If suddenly all the LEDs light up, then the shorted one is definitely faulty. This method is useful if only one LED out of all in the circuit is faulty. With this method of verification, it must be taken into account that if the driver does not provide galvanic isolation from the mains, as, for example, in the diagrams above, then touching the LED solderings with your hand is unsafe.

If one or even several LEDs turned out to be faulty and there is nothing to replace them with, then you can simply short-circuit the contact pads to which the LEDs were soldered. The light bulb will work with the same success, only the luminous flux will decrease slightly.

Other malfunctions of LED lamps

If the test of the LEDs showed their serviceability, then the reason for the inoperability of the light bulb lies in the driver or in the places where the current-carrying conductors are soldered.

For example, in this light bulb, a cold soldered conductor was found that supplies voltage to the printed circuit board. The soot released due to poor soldering even settled on the conductive tracks of the printed circuit board. The soot was easily removed by wiping with a rag soaked in alcohol. The wire was soldered, stripped, tinned and re-soldered into the board. Good luck with this lamp.

Of the ten failed light bulbs, only one had a faulty driver, the diode bridge fell apart. The repair of the driver consisted in replacing the diode bridge with four IN4007 diodes, designed for reverse voltage 1000 V and current 1 A.

Soldering SMD LEDs

To replace a faulty LED, it must be desoldered without damaging the printed conductors. From the donor board, you also need to solder the replacement LED without damage.

It is almost impossible to solder SMD LEDs with a simple soldering iron without damaging their case. But if you use a special tip for a soldering iron or put on a standard tip a nozzle made of copper wire, then the problem is easily solved.

The LEDs have polarity and when replacing, you need to correctly install it on the printed circuit board. Typically, printed conductors follow the shape of the leads on the LED. Therefore, you can make a mistake only if you are inattentive. To solder the LED, it is enough to install it on a printed circuit board and heat its ends with contact pads with a soldering iron with a power of 10-15 W.

If the LED burned out to charcoal, and printed circuit board charred under it, then before installing a new LED, it is imperative to clean this place of the printed circuit board from burning, since it is a current conductor. When cleaning, you may find that the pads for soldering the LED are burned or peeled off.

In such a case, the LED can be installed by soldering it to adjacent LEDs if the printed tracks lead to them. To do this, you can take a piece of thin wire, bend it in half or three, depending on the distance between the LEDs, tin and solder to them.

Repair LED lamp series "LL-CORN" (corn lamp)
E27 4.6W 36x5050SMD

The device of the lamp, which is popularly called the corn lamp, shown in the photo below, differs from the lamp described above, therefore the repair technology is different.

The design of LED SMD lamps of this type is very convenient for repair, as there is access for LED continuity and replacement without disassembling the lamp housing. True, I still dismantled the light bulb for interest in order to study its device.

Checking the LEDs of the LED corn lamp does not differ from the technology described above, but it should be noted that three LEDs are placed in the SMD5050 LED housing at once, usually connected in parallel (three dark dots of crystals are visible on the yellow circle), and when checking, all three should glow.

A defective LED can be replaced with a new one or shorted with a jumper. This will not affect the reliability of the lamp, only imperceptibly to the eye, the luminous flux will decrease slightly.

The driver of this lamp is assembled according to the simplest scheme, without an isolation transformer, so touching the LED terminals when the lamp is on is unacceptable. Lamps of this design are unacceptable to be installed in fixtures that can be reached by children.

If all the LEDs are working, then the driver is faulty, and in order to get to it, the lamp will have to be disassembled.

To do this, remove the bezel from the side opposite the base. With a small screwdriver or a knife blade, you need to try in a circle to find a weak spot where the bezel is glued the worst. If the rim succumbed, then working with the tool as a lever, the rim will easily move away around the entire perimeter.

The driver was built wiring diagram, like the MR-16 lamp, only C1 had a capacity of 1 µF, and C2 - 4.7 µF. Due to the fact that the wires from the driver to the lamp base were long, the driver was easily pulled out of the lamp housing. After studying his circuit, the driver was inserted back into the case, and the bezel was glued in place with Moment transparent glue. The failed LED was replaced with a good one.

Repair of LED lamp "LL-CORN" (corn lamp)
E27 12W 80x5050SMD

When repairing a more powerful lamp, 12 W, there were no failed LEDs of the same design, and in order to get to the drivers, I had to open the lamp using the technology described above.

This lamp gave me a surprise. The wires from the driver to the base were short, and it was impossible to remove the driver from the lamp housing for repair. I had to remove the plinth.

The base of the lamp was made of aluminium, rounded and held tight. I had to drill out the attachment points with a 1.5 mm drill. After that, the plinth, which was hooked with a knife, was easily removed.

But you can do without drilling the base, if you pry the edge of the knife around the circumference and slightly bend its upper edge. A mark should first be placed on the plinth and body so that the plinth can be easily installed in place. To securely fix the base after repairing the lamp, it will be enough to put it on the lamp body so that the punched points on the base fall into their old places. Next, push these points with a sharp object.

Two wires were connected to the thread with a clamp, and the other two were pressed into the central contact of the base. I had to cut these wires.

As expected, there were two identical drivers, feeding 43 diodes each. They were covered with heat shrink tubing and taped together. In order for the driver to be placed back into the tube, I usually carefully cut it along the printed circuit board from the side where the parts are installed.

After repair, the driver is wrapped in a tube, which is fixed with a plastic tie or wrapped with several turns of thread.

In the electrical circuit of the driver of this lamp, protection elements are already installed, C1 for protection against impulse surges and R2, R3 for protection against current surges. When checking the elements, resistors R2 were immediately found on both drivers in the open. It appears that the LED lamp was supplied with a voltage exceeding the allowable voltage. After replacing the resistors, there was no 10 Ohm at hand, and I set it to 5.1 Ohm, the lamp worked.

Repair LED lamp series "LLB" LR-EW5N-5

The appearance of this type of light bulb inspires confidence. Aluminum case, high-quality workmanship, beautiful design.

The design of the light bulb is such that it is impossible to disassemble it without the use of significant physical effort. Since the repair of any LED lamp begins with checking the health of the LEDs, the first thing to do was to remove the plastic protective glass.

The glass was fixed without glue on a groove made in the radiator with a shoulder inside it. To remove the glass, you need to use the end of a screwdriver, which will pass between the radiator fins, to lean on the end of the radiator and, as a lever, lift the glass up.

Checking the LEDs with a tester showed their serviceability, therefore, the driver is faulty, and you need to get to it. The aluminum board was fastened with four screws, which I unscrewed.

But contrary to expectations, behind the board was the plane of the radiator, lubricated with heat-conducting paste. The board had to be returned to its place and continue to disassemble the lamp from the side of the base.

Due to the fact that the plastic part to which the radiator was attached was very tight, I decided to go the proven way, remove the base and remove the driver for repair through the opened hole. I drilled out the punching points, but the base was not removed. It turned out that he was still holding on to the plastic due to the threaded connection.

I had to separate the plastic adapter from the radiator. He held, as well as protective glass. To do this, washed down with a hacksaw at the junction of plastic with a radiator and by turning a screwdriver with a wide blade, the parts were separated from each other.

After soldering the leads from the printed circuit board of the LEDs, the driver became available for repair. The driver circuit turned out to be more complex than previous light bulbs, with an isolation transformer and a microcircuit. One of the 400 V 4.7 µF electrolytic capacitors was swollen. I had to replace it.

A check of all semiconductor elements revealed a faulty Schottky diode D4 (pictured below left). There was a SS110 Schottky diode on the board, I replaced it with the existing analog 10 BQ100 (100 V, 1 A). The forward resistance of Schottky diodes is two times less than that of ordinary diodes. Light lit up. The same problem was with the second bulb.

Repair LED lamp series "LLB" LR-EW5N-3

This LED lamp is very similar in appearance to the "LLB" LR-EW5N-5, but its design is somewhat different.

If you look closely, you can see that at the junction between the aluminum radiator and the spherical glass, unlike LR-EW5N-5, there is a ring in which the glass is fixed. To remove the protective glass, just use a small screwdriver to pick it up at the junction with the ring.

There are three nine super-bright crystal LEDs mounted on an aluminum circuit board. The board is screwed to the heatsink with three screws. Checking the LEDs showed their serviceability. Therefore, you need to repair the driver. Having experience in repairing a similar LED lamp "LLB" LR-EW5N-5, I did not unscrew the screws, but soldered the current-carrying wires coming from the driver and continued to disassemble the lamp from the side of the base.

The plastic connecting ring of the plinth with the radiator was removed with great difficulty. At the same time, part of it broke off. As it turned out, it was screwed to the radiator with three self-tapping screws. The driver is easily removed from the lamp housing.

The self-tapping screws that screw the plastic ring of the base cover the driver, and it is difficult to see them, but they are on the same axis with the thread to which the adapter part of the radiator is screwed. Therefore, a thin Phillips screwdriver can be reached.

The driver turned out to be assembled according to the transformer circuit. Checking all the elements, except for the microcircuit, did not reveal any failed ones. Therefore, the microcircuit is faulty, I did not even find a mention of its type on the Internet. The LED bulb could not be repaired, it will come in handy for spare parts. But studied her device.

Repair LED lamp series "LL" GU10-3W

It turned out, at first glance, that it was impossible to disassemble a burned-out GU10-3W LED bulb with a protective glass. An attempt to remove the glass led to its puncture. With the application of great effort, the glass cracked.

By the way, in the marking of the lamp, the letter G means that the lamp has a pin base, the letter U means that the lamp belongs to the class of energy-saving light bulbs, and the number 10 means the distance between the pins in millimeters.

LED bulbs with a GU10 base have special pins and are installed in a socket with a turn. Thanks to the expanding pins, the LED lamp is clamped in the socket and is held securely even when shaking.

In order to disassemble this LED light bulb, I had to drill a hole with a diameter of 2.5 mm in its aluminum case at the level of the surface of the printed circuit board. The drilling location must be chosen in such a way that the drill does not damage the LED when exiting. If there is no drill at hand, then the hole can be made with a thick awl.

Next, a small screwdriver is threaded into the hole and, acting like a lever, the glass is lifted. I removed the glass from two light bulbs without problems. If the test of the LEDs by the tester showed their serviceability, then the printed circuit board is removed.

After separating the board from the lamp housing, it immediately became obvious that the current-limiting resistors burned out in both one and the other lamp. The calculator determined their denomination from the bands, 160 ohms. Since the resistors burned out in LED bulbs of different batches, it is obvious that their power, judging by the size of 0.25 W, does not correspond to the power released when the driver is operating at maximum ambient temperature.

The printed circuit board of the driver was solidly filled with silicone, and I did not disconnect it from the board with LEDs. I cut off the leads of the burnt resistors at the base and soldered more powerful resistors to them, which were at hand. In one lamp, a 150 Ohm resistor with a power of 1 W was soldered, in the second two in parallel 320 Ohm with a power of 0.5 W.

In order to prevent accidental contact with the output of the resistor, to which the mains voltage is connected with metal case lamp, it was insulated with a drop of hot melt adhesive. It is waterproof and an excellent insulator. I often use it for sealing, insulating and securing electrical wires and other parts.

Hot melt adhesive is available in the form of rods with a diameter of 7, 12, 15 and 24 mm different colors, transparent to black. It melts, depending on the brand, at a temperature of 80-150 °, which allows it to be melted with an electric soldering iron. It is enough to cut off a piece of the rod, place it in the right place and heat it up. The hot melt will take on the consistency of May honey. After cooling it becomes solid again. When reheated, it becomes liquid again.

After replacing the resistors, the performance of both bulbs was restored. It remains only to fix the printed circuit board and the protective glass in the lamp housing.

When repairing LED lamps, I used liquid nails "Installation" moment to fix printed circuit boards and plastic parts. The glue is odorless, adheres well to the surfaces of any materials, remains plastic after drying, has sufficient heat resistance.

It is enough to take a small amount of glue on the end of a screwdriver and apply it to the places where the parts come into contact. After 15 minutes, the glue will already hold.

When gluing the printed circuit board, in order not to wait, holding the board in place, as the wires pushed it out, fixed the board additionally at several points with hot glue.

The LED lamp began to flash like a strobe

I had to repair a pair of LED lamps with drivers assembled on a microcircuit, the malfunction of which consisted in flashing light at a frequency of about one hertz, like in a strobe.

One instance of the LED lamp began to flash immediately after being turned on for the first few seconds and then the lamp began to glow normally. Over time, the duration of the lamp flashing after switching on began to increase, and the lamp began to flash continuously. The second copy of the LED lamp began to flash continuously all of a sudden.

After disassembling the lamps, it turned out that the electrolytic capacitors installed immediately after the rectifier bridges failed in the drivers. It was easy to determine the malfunction, since the capacitor cases were swollen. But even if the capacitor looks without external defects in appearance, it is still necessary to start repairing the LED light bulb with a stroboscopic effect by replacing it.

After replacing the electrolytic capacitors with serviceable ones, the stroboscopic effect disappeared and the lamps began to shine normally.

Online calculators for determining the value of resistors
by color coding

When repairing LED lamps, it becomes necessary to determine the value of the resistor. According to the standard, the marking of modern resistors is carried out by applying colored rings to their cases. 4 colored rings are applied to simple resistors, and 5 to high-precision resistors.

Attention! This design does not have galvanic isolation from the high voltage AC network. Strictly observe safety precautions. When repeating the design, you do everything at your own peril and risk. The author is not responsible for your actions.

The article considers the design of an LED lamp powered by an AC mains with a voltage of up to 240 V and a frequency of 50/60 Hz. This lamp has been serving me for more than two years and I want to share this design with you. The lamp has a very a simple circuit current limitation, which makes it possible to repeat the design for beginner radio amateurs. It has low power and can be used as a night light or to illuminate a room where high brightness is not needed, but such a factor as low power consumption and long service life is important. You can hang it in the entrance or on the landing and not worry about turning off or high electricity consumption - its service life is practically limited by the service life of the LEDs used, since this lamp does not have a pulse converter, which often fail faster than the LEDs themselves, and the radio elements are here selected in such a way that the rated voltages and operating currents of both capacitors with diodes and the LEDs themselves are not exceeded, even at the maximum allowable voltage and frequency in the supply network.

The lamp has the following characteristics:

The lamp uses three-crystal warm white LEDs of the smd5050 type:

When a rated current of 20 mA flows, a voltage of about 3.3 V drops on one LED chip. These are the main parameters for calculating a quenching capacitor to power the lamp.

The crystals of all nine LEDs are connected in series with each other and thus the same current flows through each crystal. This achieves the same glow and maximum life of the LEDs and therefore the entire lamp. The LED connection diagram is shown in the figure:

After soldering, this LED matrix is obtained:

This is what it looks like from the front:

I present to you a schematic diagram of this LED lamp:

The lamp uses a full-wave rectifier on diodes D1-D4. Resistor R1 limits the inrush current when the lamp is turned on. Capacitor C2 is a filter capacitor and smooths out current ripples through the LED matrix. For this case, its capacitance in microfarads can be approximately calculated by the formula:

where I is the current through the LED array in milliamps and U is the voltage drop across it in volts. You should not chase too much capacity of this capacitor, since the current-quenching capacitor acts as a current limiter, and the connected LED matrix is a voltage stabilizer.

In this case, you can use a capacitor with a capacity of 2.2-4.7 microfarads. Parallel to it, the installed resistor R3 ensures that this capacitor is completely discharged after the power is turned off. Resistor R2 plays the same role for current-quenching capacitor C1. Now the main question is how to calculate the capacitance of the quenching capacitor? There are many formulas and online calculators on the Internet for this, but they all underestimate the result and give a lower capacity, which was confirmed in practice. When using formulas from various sites and after using online calculators, in most cases, a capacitance of 0.22 microfarads was obtained. When installing a capacitor with this capacity and measuring the current flowing through the LED matrix, a result of 12 mA was obtained at a mains voltage of 240 V and a frequency of 50 Hz:

Then I went the longer way and first calculated the required quenching resistance, and then derived the capacitance of the quenching capacitor. For the initial data we have:

Supply voltage: 220 V. Let's take the maximum possible - 240 V.
I took the network frequency at 60 Hz. At a frequency of 50 Hz, less current will flow through the matrix and the lamp will shine less brightly, but there will be a margin.
The voltage drop on the LED matrix will be 27 * 3.3 = 89.1 V, since we have 27 LED crystals connected in series and each of them will drop approximately 3.3 V. Let's round this value to 90.
At a maximum frequency of 60 Hz and a mains voltage of 240 V, the current flowing through the matrix must not exceed 20 mA.

The calculations use the effective values of currents and voltages. According to Ohm's law, the damping resistance should be:

where Uc - network voltage (V)

U m - LED matrix voltage (V)

I m - current through the matrix (A).

Since we use a capacitor as a damping resistance, then X c = R and according to the well-known formula for capacitance:

we calculate the required capacitance of the capacitor:

where f - mains frequency (Hz)

Xc - required capacitance (Ohm)

I remind you that the value of the capacitance of the capacitor obtained in this case is valid for a power supply frequency of 60 Hz. For a frequency of 50 Hz, according to calculations, a value of 0.42 microfarads is obtained. To check the validity, I temporarily put two 0.22 uF capacitors connected in parallel with the resulting total capacitance of 0.44 uF, and when measuring the current flowing through the LED matrix, a value of 21 mA was recorded:

But for me, durability and versatility were important, and based on the calculation for a frequency of 60 Hz with the result of the required capacitance of 0.35 microfarads, I took a close rating with a capacitance of 0.33 microfarads. I also advise you to take a capacitor with a slightly smaller capacity than the calculated one, so as not to exceed the allowable current of the LEDs used.

Next, substituting the formula for calculating the resistance into the formula for determining the capacitance and reducing the entire expression, I derived a universal formula into which, by substituting the initial values, you can calculate the required capacitance of the capacitor for any number of LEDs in the lamp and any supply voltage:

The final formula takes the following form:

Where C - capacitance of the quenching capacitor (uF)

I d - permissible rated current of the LED used in the lamp (mA)

f - mains frequency (Hz)

Uc - supply voltage (V)

n - number of LEDs used

U d - voltage drop on one LED (V)

Maybe someone will be too lazy to make these calculations, but this formula can be used to determine the capacitance for any LED lamp with any number of series-connected LEDs of any color. For example, you can make a lamp from 16 red LEDs by substituting the voltage drop corresponding to the red LEDs into the formula. The main thing is to stick to reasonable limits, do not exceed the number of LEDs with a total voltage on the matrix up to the mains voltage and do not use too much powerful LEDs. Thus, it is possible to manufacture a lamp with a power of up to 5-7 watts. AT otherwise a capacitor of too large a capacity may be needed and strong current ripples may occur.

Let's go back to my lamp and the photo below shows the radio elements that I used:

I did not find a capacitor with a capacity of 0.33 microfarads and I put two capacitors connected in parallel with a capacitance of 0.22 and 0.1 microfarads. With such a capacitance, the current flowing through the matrix will be slightly less than the calculated one. The filter capacitor in my case is for a voltage of 250 V, but I strongly recommend using a capacitor for a voltage of 400 V. Although the voltage drop across my LED matrix does not exceed 90 V, but in the event of a break or burnout of at least one of the LEDs, the voltage across the filter capacitor reaches the amplitude value, which is more than 330 V at an operating voltage in the supply network of 240 V. (U a \u003d 1.4U)

As a housing, I used a part of a compact energy-saving fluorescent lamp, pulling out the electronic stuffing from it:

I made the board by surface mounting and it easily fit into the specified case:

I glued the LED matrix with double tape to a round piece of getinax, which I screwed to the body with two screws and nuts:

I also made a small reflector by cutting it out of a tin can:

I've spent real measurements at a supply voltage of 240 V and a frequency of 50 Hz:

The constant current through the LED matrix took on a value of 16 mA, which does not exceed the rated current of the LEDs used:

I also designed a printed circuit board for radio elements in the Sprint-Layout program. All parts fit on an area of 30x30 mm. You can see the view of this printed circuit board in the figures:

I provided this PCB in PDF formats, Gerber and Sprint-Layout. You can freely download these files. Although KD105 diodes are indicated on the diagram, since they are currently rare, the printed circuit board is divorced for 1N4007 diodes. You can also use other medium power rectifier diodes for a voltage of 600 V and a current 1.5-2 times greater than the current consumption LED matrix. I will give a recommendation on the account of the assembly of this matrix. I temporarily glued all the LEDs with the front side to the masking tape and soldered all the leads according to the diagram, after which I glued the finished matrix from the side of the leads onto double-sided tape and removed the paper masking tape from the front side. If you have the opportunity, I recommend placing the LEDs at a greater distance from each other, as they will generate heat and from close proximity can overheat and degrade quickly.

Personally, this lamp has been shining for me for seven hours a day for the third year and so far there have been no problems. I also attach an Excel spreadsheet with a formula for the calculation to the article. In it, you just need to substitute the initial values \u200b\u200band as a result you will get the required capacitance of the quenching capacitor. All bright and durable light bulbs. Leave feedback and share the article, as there are many incorrect formulas and calculators on the Internet that give the wrong result. Here everything is tested by experience and confirmed by time and real measurements.