Homemade products from an energy-saving lamp with your own hands. Instructions for making a switching power supply from an energy-saving lamp

Modern fluorescent light bulbs are a real find for economical consumers. They shine brightly, last longer than incandescent bulbs and consume much less energy. At first glance, there are only pluses. However, due to the imperfection of domestic power grids, they exhaust their resource much earlier than the deadlines announced by the manufacturers. And often they do not even have time to "cover" the cost of their acquisition.
But do not rush to throw out the failed "housekeeper". Given the high initial cost fluorescent lamps points, it is advisable to "squeeze" the maximum out of them, using to the last all their possible resources. Indeed, right under the spiral, a compact high-frequency converter circuit is installed in it. For a knowledgeable person, this is a whole “Klondike” of various spare parts.

Disassembled lamp

General information

Battery

In fact, such a circuit is an almost ready-made switching power supply. It lacks only an isolation transformer with a rectifier. Therefore, if the flask is intact, you can, without fear of mercury fumes, try to disassemble the case.
By the way, it is the lighting elements of light bulbs that most often fail: due to resource burnout, merciless operation, too low (or high) temperatures, etc. The internal boards are more or less protected by a hermetically sealed case and parts with a margin of safety.
We advise you to save up a certain number of lamps before starting repair and restoration work (you can ask around at work or with friends - usually there is enough of this stuff everywhere). After all, it is not a fact that all of them will be maintainable. In this case, it is the performance of the ballast (that is, the board built inside the light bulb) that is important to us.

You may have to dig a little for the first time, but then in an hour you will be able to assemble a primitive power supply for devices that are suitable in terms of power.
If you plan to create a power supply, choose models of fluorescent lamps more powerful, starting from 20 watts. However, less bright light bulbs will also be used - they can be used as donors of the necessary details.
And as a result, from a couple of burnt housekeepers, it is quite possible to create one completely capable model, whether it be a work light, a power supply or a battery charger.
Most often, self-taught masters use housekeeper ballast to create 12-watt power supplies. They can be connected to modern LED systems, because 12 V is the operating voltage of most common household appliances, including lighting.
Such blocks are usually hidden in furniture, so the appearance of the node does not really matter. And even if outwardly the craft turns out to be sloppy - it's okay, the main thing is to take care of maximum electrical safety. To do this, carefully check the created system for operability, leaving it to work in test mode for a long time. If power surges and overheating are not observed, then you did everything right.
It is clear that you will not extend the life of an updated light bulb much - anyway, sooner or later the resource is exhausted (the phosphor and the filament burn out). But you must admit, why not try to restore the failed lamp within six months or a year after purchase.

We disassemble the lamp

So, we take a non-working light bulb, we find the junction of the glass bulb with the plastic case. Gently pry the halves with a screwdriver, gradually moving along the "belt". Usually these two elements are connected by plastic latches, and if you are going to use both components in some other way, do not put much effort - a piece of plastic can easily break off, and the tightness of the light bulb housing will be broken.

After opening the case, carefully disconnect the contacts going from the ballast to the filaments in the bulb, because. they block full access to the board. Often they are simply tied to the pins, and if you do not plan to use the failed bulb anymore, you can safely cut off the connecting wires. As a result, you should see something like this scheme.

Lamp disassembly

It is clear that lamp designs from different manufacturers may differ in "stuffing". But general scheme and the basic constituent elements have much in common.
Then you need to scrupulously inspect each part for blisters, breakdowns, make sure that all elements are soldered securely. If any of the parts burned out, it will be immediately visible by the characteristic soot on the board. In cases where no visible defects are found, but the lamp is not working, use the tester and “ring out” all the elements of the circuit.
As practice shows, resistors, capacitors, dinistors most often suffer due to large voltage drops that occur with unenviable regularity in domestic networks. In addition, frequent flicking of the switch has an extremely negative effect on the duration of the operation of fluorescent bulbs.
Therefore, in order to extend their operating time as long as possible, try to turn them on and off as little as possible. The pennies saved on electricity will eventually result in hundreds of rubles to replace a burnt-out light bulb ahead of time. .

Disassembled lamps

If, as a result of the initial inspection, you find scorch marks on the board, swelling of parts, try replacing the failed blocks by taking them from other non-working donor bulbs. After installing the parts, once again “ring” all the components of the board with the tester.
By and large, from non-working ballast fluorescent light bulb it is possible to make a switching power supply with a power corresponding to the initial power of the lamp. As a rule, low-power power supplies do not require significant modifications. But over blocks of greater power, of course, you have to sweat.
To do this, it will be necessary to slightly expand the capabilities of the native choke by providing it with an additional winding. You can adjust the power of the created power supply by increasing the number of secondary turns on the inductor. Do you want to know how to do it?

Preparatory work

As an example, below is a diagram of a Vitoone fluorescent light bulb, but in principle the composition of boards from different manufacturers does not differ much. In this case, a light bulb of sufficient power is presented - 25 watts, it can make an excellent 12 V charging unit.

Vitoone 25W lamp circuit

Power supply assembly

The red color in the diagram indicates the lighting unit (i.e., the bulb with filaments). If the threads in it are burned out, then we will no longer need this part of the light bulb, and we can safely bite off the contacts from the board. If the light bulb still burned before the breakdown, albeit dimly, you can then try to revive it for a while by connecting it to the working circuit from another product.
But it's not about that now. Our goal is to create a power supply from a ballast extracted from a light bulb. So, we delete everything that is between points A and A´ in the above diagram.
For a low-power power supply (approximately equal to the original one of the donor bulb), only a small alteration is enough. A jumper must be installed in place of the remote lamp assembly. To do this, simply wind a new piece of wire to the released pins - at the place of attachment of the former filaments of an energy-saving light bulb (or to the holes for them).

In principle, you can try to slightly increase the generated power by providing an additional (secondary) winding to the choke already on the board (it is indicated on the diagram as L5). Thus, its native (factory) winding becomes primary, and another layer of secondary provides the same power reserve. And again, it can be adjusted by the number of turns or the thickness of the wound wire.

Connecting the power supply

But, of course, it will not be possible to significantly increase the initial capacity. Everything depends on the size of the "frame" around the ferrites - they are very limited, because. originally intended for use in compact lamps. Often it is possible to apply turns in only one layer, eight to ten will be enough for a start.
Try to apply them evenly over the entire area of ​​the ferrite to get the best performance. Such systems are very sensitive to the quality of the winding and will heat up unevenly, and eventually become unusable.
We recommend that you unsolder the inductor from the circuit for the duration of the work, otherwise it will not be easy to wind it. Clean it from factory glue (resins, films, etc.). Visually assess the condition of the primary winding wire, check the integrity of the ferrite. Since if they are damaged, there is no point in continuing to work with it in the future.
Before starting the secondary winding, lay a strip of paper or electrical cardboard on top of the primary winding to eliminate the possibility of breakdown. Adhesive tape in this case is not the best the best option, since over time the adhesive composition is on the wires and leads to corrosion.
The scheme of the modified board from the light bulb will look like this

Scheme of a modified board from a light bulb

Many people know firsthand that making the winding of a transformer with their own hands is still a pleasure. This is more of an occupation for the diligent. Depending on the number of layers, this can take from a couple of hours to a whole evening.
Due to the limited space of the throttle window, we recommend using a varnished copper cable with a cross section of 0.5 mm to create a secondary winding. Because there is simply not enough space for wires in insulation to wind any significant number of turns.
If you decide to remove the insulation from your existing wire, do not use a sharp knife, because. after the violation of the integrity of the outer layer of the winding, the reliability of such a system can only be hoped for.

Cardinal transformations

Ideally, for the secondary winding, you need to take the same type of wire as in the original factory version. But often the "window" of the throttle magnetic pickup is so narrow that it is not even possible to wind one full layer. And yet, it is imperative to take into account the thickness of the gasket between the primary and secondary windings.
As a result, it will not be possible to radically change the power output by the lamp circuit without making changes to the composition of the board components. In addition, no matter how carefully you wind up, you still won’t be able to make it as high-quality as in factory-made models. And in this case, it’s easier then to assemble an impulse block from scratch than to remake the “good” obtained for free from a light bulb.
Therefore, it is more rational to look for a ready-made transformer with the desired parameters at the dismantling of old computer or television and radio equipment. It looks much more compact than the "homemade". Yes, and its margin of safety cannot be compared.

Transformer

And you do not have to puzzle over the calculations of the number of turns to obtain the desired power. Soldered to the circuit - and you're done!
Therefore, if the power of the power supply is needed more, say, about 100 W, then you have to act radically. And only the spare parts available in the lamps are indispensable here. So if you want to increase the power of the power supply even more, you need to unsolder and remove the native choke from the bulb board (indicated in the diagram below as L5).

Detailed UPS Diagram

Connected transformer

Then, in the area between the former location of the throttle and the reactive midpoint (in the diagram, this segment is located between the isolation capacitors C4 and C6), a new powerful transformer is connected (denoted as TV2). If necessary, an output rectifier is connected to it, consisting of a pair of connecting diodes (they are indicated in the diagram as VD14 and VD15). It does not hurt to replace the diodes on the input rectifier with more powerful ones (in the diagram, this is VD1-VD4).
Do not forget to also install a larger capacitor (shown as C0 in the diagram). You need to select it from the calculation of 1 microfarad per 1 W of output power. In our case, a 100 mF capacitor was taken.
As a result, we get a fully capable switching power supply from energy saving lamp. The assembled circuit will look something like this.

Trial run

Trial run

Connected to the circuit, it serves as something akin to a stabilizer fuse and protects the unit during current and voltage fluctuations. If everything is good, the lamp does not particularly affect the operation of the board (due to low resistance).
But with jumps of high currents, the resistance of the lamp increases, leveling the negative impact on the electronic components of the circuit. And even if the lamp suddenly burns out, it will not be as pitiful as the impulse block assembled by your own hand, over which you pored over for several hours.
The simplest test circuit diagram looks like this.

After starting the system, observe how the temperature of the transformer (or the inductor wound with the secondary) changes. In the event that it starts to get very hot (up to 60ºС), de-energize the circuit and try replacing the winding wires with an analogue with a large cross section, or increase the number of turns. The same applies to the heating temperature of transistors. With its significant growth (up to 80ºС), each of them should be equipped with a special radiator.
That's basically it. Finally, we remind you of the observance of safety rules, since the output voltage is very high. Plus, the components of the board can get very hot without changing their appearance.

We also do not recommend using such impulse blocks when creating chargers for modern gadgets with fine electronics (smartphones, electronic clock, tablets, etc.). Why take such a risk? No one will guarantee that the "home-made" will work stably, and will not ruin an expensive device. Moreover, there are more than enough suitable goods (meaning ready-made chargers) on the market, and they are quite inexpensive.
Such homemade block power supply can be fearlessly used to connect light bulbs of various types, to power LED strips, simple electrical appliances that are not so sensitive to current (voltage) surges.

We hope you were able to master all the material presented. Perhaps he will inspire you to try to create something similar yourself. Even if the first power supply you make from a light bulb board will not be a real working system at first, you will acquire basic skills. And most importantly - the excitement and thirst for creativity! And there, you see, it will turn out to make a full-fledged power supply for LED strips, highly popular today. Good luck!

"Angel eyes" for a car with your own hands How to make it right homemade lamp from ropes Device and adjustment of dimmable LED strips

Energy-saving lamps are widely used in everyday life and in production, over time they become unusable, and meanwhile, many of them can be restored after a simple repair. If the lamp itself failed, then from the electronic “stuffing” you can make a fairly powerful power supply for any desired voltage.

What does a power supply from an energy-saving lamp look like?

In everyday life, a compact, but at the same time powerful low-voltage power supply is often required; this can be done using a failed energy-saving lamp. In lamps, lamps most often fail, and the power supply remains in working condition.

In order to make a power supply, you need to understand the principle of operation of the electronics contained in an energy-saving lamp.

Advantages of switching power supplies

In recent years, there has been a clear trend towards moving away from classic transformer power supplies to switching ones. This is due, first of all, to the large disadvantages of transformer power supplies, such as large mass, low overload capacity, low efficiency.

The elimination of these shortcomings in switching power supplies, as well as the development of the element base, made it possible to widely use these power units for devices with power from a few watts to many kilowatts.

Power Supply Diagram

Principle of operation impulse block The power supply in an energy-saving lamp is exactly the same as in any other device, such as a computer or TV.

In general terms, the operation of a switching power supply can be described as follows:

• Alternating mains current is converted into direct current without changing its voltage, i.e. 220 V.
• A transistor-based pulse-width converter converts DC voltage into rectangular pulses, with a frequency of 20 to 40 kHz (depending on the lamp model).
• This voltage is fed through the choke to the lamp.

Consider the scheme and operation of the switching lamp power supply (figure below) in more detail.

Scheme of the electronic ballast of an energy-saving lamp

The mains voltage is supplied to the bridge rectifier (VD1-VD4) through a limiting resistor R 0 of small resistance, then the rectified voltage is smoothed on the filtering high-voltage capacitor (C 0), and is fed through the smoothing filter (L0) to the transistor converter.

The start of the transistor converter occurs at the moment when the voltage across the capacitor C1 exceeds the opening threshold of the VD2 dinistor. This will start the generator on transistors VT1 and VT2, due to which auto-generation occurs at a frequency of about 20 kHz.

Other circuit elements such as R2, C8 and C11 play a supporting role, making it easier to start the generator. Resistors R7 and R8 increase the closing speed of the transistors.

And the resistors R5 and R6 serve as limiting resistors in the transistor base circuits, R3 and R4 protect them from saturation, and in the event of a breakdown they play the role of fuses.

Diodes VD7, VD6 are protective, although in many transistors designed to work in such devices, such diodes are built-in.

TV1 - transformer, from its windings TV1-1 and TV1-2, voltage feedback from the output of the generator is fed into the base circuits of transistors, thereby creating conditions for the operation of the generator.

In the figure above, the parts to be removed when reworking the block are highlighted in red, points A–A` must be connected with a jumper.

Block rework

Before proceeding with the alteration of the power supply, you should decide what current power you need to have at the output, the depth of modernization will depend on this. So, if a power of 20-30 W is required, then the alteration will be minimal and will not require much intervention in the existing circuit. If you need to get a power of 50 or more watts, then a more thorough upgrade will be required.

It should be borne in mind that the output of the power supply will be a constant voltage, not an alternating one. It is impossible to get an alternating voltage with a frequency of 50 Hz from such a power supply.

We determine the power

Power can be calculated using the formula:

Р – power, W;

I - current strength, A;

U - voltage, V.

For example, let's take a power supply with the following parameters: voltage - 12 V, current - 2 A, then the power will be:

Taking into account the overload, 24-26 W can be accepted, so that the manufacture of such a unit will require minimal intervention in the circuit of a 25 W energy-saving lamp.

New details

Adding New Parts to a Schematic

Added parts are highlighted in red, these are:

• diode bridge VD14-VD17;
• two capacitors C 9, C 10;
• additional winding placed on the L5 ballast choke, the number of turns is selected empirically.

The added winding to the inductor plays another important role of an isolation transformer, preventing mains voltage from entering the output of the power supply.

To determine the required number of turns in the added winding, do the following:

1. a temporary winding is wound on the inductor, about 10 turns of any wire;
2. connected to a load resistance, with a power of at least 30 W and a resistance of about 5-6 ohms;
3. plug into the network, measure the voltage at the load resistance;
4. the resulting value is divided by the number of turns, find out how many volts per 1 turn;
5. calculate the required number of turns for a permanent winding.

A more detailed calculation is given below.

Test inclusion of a converted power supply

After that, it is easy to calculate the required number of turns. To do this, the voltage that is planned to be received from this block is divided by the voltage of one turn, the number of turns is obtained, about 5-10% is added to the result in reserve.

W \u003d U out / U vit, where

W is the number of turns;

U out - the required output voltage of the power supply;

U vit - voltage per turn.

Winding an additional winding on a standard choke

The original inductor winding is under mains voltage! When winding an additional winding over it, it is necessary to provide interwinding insulation, especially if a PEL-type wire is wound in enamel insulation. For winding insulation, you can use PTFE thread sealing tape, which is used by plumbers, its thickness is only 0.2 mm.

The power in such a block is limited by the overall power of the transformer used and the allowable current of the transistors.

High Power Power Supply

This will require a more complex upgrade:

• additional transformer on a ferrite ring;
• replacement of transistors;
• installation of transistors on radiators;
• increasing the capacitance of some capacitors.

As a result of such an upgrade, a power supply unit with a power of up to 100 W is obtained, with an output voltage of 12 V. It is capable of providing a current of 8-9 amperes. This is enough to power, for example, a medium power screwdriver.

The diagram of the upgraded power supply is shown in the figure below.

100 W power supply

As you can see in the diagram, the resistor R 0 has been replaced with a more powerful one (3-watt), its resistance has been reduced to 5 ohms. It can be replaced by two 2-watt 10 ohm ones by connecting them in parallel. Further, C 0 - its capacitance is increased to 100 microfarads, with an operating voltage of 350 V. If it is undesirable to increase the dimensions of the power supply, then you can find a miniature capacitor of this capacity, in particular, you can take it from a soap camera.

To ensure reliable operation of the unit, it is useful to slightly reduce the values ​​​​of the resistors R 5 and R 6, up to 18–15 Ohms, and also increase the power of the resistors R 7, R 8 and R 3, R 4. If the generation frequency turns out to be low, then the values ​​\u200b\u200bof the capacitors C 3 and C 4 - 68n should be increased.

The most difficult may be the manufacture of the transformer. For this purpose, in impulse blocks, ferrite rings of appropriate sizes and magnetic permeability are most often used.

The calculation of such transformers is quite complicated, but there are many programs on the Internet with which it is very easy to do this, for example, "Lite-CalcIT Pulse Transformer Calculation Program".

What does a pulse transformer look like?

The calculation carried out using this program gave the following results:

For the core, a ferrite ring is used, its outer diameter is 40, its inner diameter is 22, and its thickness is 20 mm. Primary winding PEL wire - 0.85 mm 2 has 63 turns, and two secondary ones with the same wire - 12.

The secondary winding must be wound in two wires at once, while it is advisable to twist them slightly beforehand along the entire length, since these transformers are very sensitive to the asymmetry of the windings. If this condition is not observed, then the VD14 and VD15 diodes will heat up unevenly, and this will further increase the asymmetry, which, in the end, will disable them.

But such transformers easily forgive significant errors when calculating the number of turns, up to 30%.

Since this circuit was originally designed to work with a 20 W lamp, transistors 13003 were installed. In the figure below, position (1) is medium power transistors, they should be replaced with more powerful ones, for example, 13007, as in position (2). They may have to be installed on a metal plate (radiator), with an area of ​​\u200b\u200babout 30 cm 2.

Trial

A trial run should be carried out with some precautions in order not to damage the power supply:

1. The first test switching on should be done through a 100 W incandescent lamp in order to limit the current to the power supply.
2. Be sure to connect a load resistor of 3-4 ohms, with a power of 50-60 watts, to the output.
3. If everything went well, let it run for 5-10 minutes, turn it off and check the degree of heating of the transformer, transistors and rectifier diodes.

If no mistakes were made during the replacement of parts, the power supply should work without problems.

If the trial run showed the unit to work, it remains to test it in full load mode. To do this, reduce the resistance of the load resistor to 1.2-2 ohms and plug it into the network directly without a light bulb for 1-2 minutes. Then turn off and check the temperature of the transistors: if it exceeds 60 0 C, then they will have to be installed on radiators.

The failure of the battery of a cordless screwdriver or other power tool is not the most pleasant event, especially considering that the cost of replacing this element is commensurate with the price of a new device. But maybe unplanned expenses can be avoided? This is quite possible if you replace the battery with a simple self-made energy-saving power supply of a switching type, with which the tool can be charged from the mains. And the components for it can be found in an affordable and ubiquitous product - this.

Energy saving light bulb ballast source

Do-it-yourself UPS from a fluorescent lamp

In most cases, to assemble the UPS, the electronic choke of the epra should only be slightly changed (with a two-transistor circuit) by a jumper, and then connected to a pulse transformer and a rectifier. Some components are simply removed as unnecessary.

Homemade power supply

For weak power supplies (from 3.7 V to 20 watts), you can do without a transformer. It will be enough to add a few turns of wire to the magnetic circuit of the inductor lamp in the ballast, if, of course, there is room for this. A new winding can be done directly on top of the existing one.

For this, the MGTF brand wire with PTFE insulation is perfect. Usually, little wire is required, while almost the entire gap of the magnetic circuit is occupied by insulation, which causes the low power of such devices. To increase it, you need a pulse transformer.

pulse transformer

A feature of the described version of the UPS is the ability to adapt to the parameters of the transformer to some extent, as well as the absence of a feedback circuit passing through this element. Such a connection scheme eliminates the need for a particularly accurate calculation of the transformer.

As practice has shown, even with gross errors (deviations of more than 140% were allowed), the UPS can be given a second life and it turned out to be efficient.

The transformer is made on the basis of the same inductor, on which the secondary winding is wound from varnished winding copper wire. At the same time, it is important to pay special attention to the winding insulation from the paper gasket, because the “native” winding of the inductor will operate under mains voltage.

Even if it's covered in synthetic protective film, it is still necessary to wind several layers of electric cardboard or at least plain paper with a total thickness of 100 microns (0.1 mm) on top of it, and the varnished wire of the new winding can already be laid on top of the paper.

The wire diameter should be the largest possible. There will not be many turns in the secondary winding, so their optimal number can be selected empirically.

Using these materials and technology, you can get a power supply with a power of 20 or a little more watts. In this case, its value is limited by the area of ​​the magnetic circuit window and, accordingly, by the maximum diameter of the wire that can be placed there.

Rectifier

To avoid saturation of the magnetic circuit, the UPS uses only full-wave output rectifiers. In the event that the pulse transformer works to lower the voltage, the zero-point circuit is the most economical, but for its implementation it will be necessary to make two completely symmetrical secondary windings. With manual winding, two wires can be wound.

A standard rectifier, assembled according to the “diode bridge” scheme from ordinary silicon diodes, is not suitable for a switching UPS, because out of 100 W of transmitted power (at a voltage of 5 V), about 32 W or more will be lost on it. It will be too expensive to assemble a rectifier on powerful pulsed diodes.

UPS setup

After assembling the UPS, it must be connected to the maximum load and check how hot the transistors and transformer are. The limit for the transformer is 60 - 65 degrees, for transistors - 40 degrees. When the transformer overheats, the wire cross-section or the overall power of the magnetic circuit are increased, or both actions are performed together. If the transformer is made from a lamp ballast inductor, it is most likely impossible to increase the wire cross section and you will have to limit the connected load.

How to make an LED PSU with increased power

Sometimes the standard power of the electronic lamp ballast is not enough. Imagine a situation: there is 23 W, and you need to get a power source for charger with parameters 12V/8A.

In order to carry out the plan, you will have to get computer block food, which turned out to be unclaimed for some reason. From this block, the power transformer should be removed along with the chain R4C8, which performs the function of protecting power transistors from overvoltage. The power transformer should be connected to the electronic ballast instead of the choke.

It has been experimentally established that given type The UPS allows you to remove power up to 45 W with a slight overheating of transistors (up to 50 degrees).

To avoid overheating, it is necessary to install a transformer with an increased core section in the bases of transistors, and install the transistors themselves on a radiator.

Possible mistakes

As already mentioned, the inclusion in the circuit as an output rectifier of a conventional low-frequency diode bridge inappropriate, and increased power The UPS should not do this all the more.

It is also pointless to try to wind the base windings directly on the power transformer for the sake of simplifying the circuit. In the absence of a load, significant losses will occur due to the fact that the maximum current will flow into the bases of the transistors.

The applied transformer with an increase in the load current also increases the current in the bases of the transistors. Practice shows that when the load power reaches 75 W, saturation occurs in the magnetic circuit of the transformer. This leads to a deterioration in the characteristics of the transistors and their overheating.

To avoid this, you can wind the current transformer yourself by doubling the cross section of the core or by adding two rings together. You can also double the diameter of the wire.

There is a way to get rid of the basic transformer that performs an intermediate function. To do this, the current transformer is connected through a powerful resistor to a separate winding of the power heater, implementing a voltage feedback circuit. The disadvantage of this option is that the current transformer is constantly operating in saturation mode.

It is impossible to connect the transformer in parallel with the inductor present in the ballast converter. Due to the decrease in the total inductance, the frequency of the power supply will be increased. This phenomenon will lead to an increase in losses in the transformer and overheating of the output rectifier transistors.

Consideration should be given to the increased sensitivity of Schottky diodes to excess reverse voltage and current values. Attempting to install, say, a 5 volt diode in a 12 volt circuit will most likely cause the element to fail.

Do not try to replace transistors and diodes with domestic ones, for example, KT812A and KD213. This clearly leads to a deterioration in the performance of the device.

How to connect a UPS to a screwdriver

The power tool must be disassembled by unscrewing all the screws. Usually the body of a screwdriver consists of two halves. Next, you should find the wires with which the engine is connected to the battery. You can connect these wires to the UPS output using soldering or heat shrink tubing, the twisted option is undesirable.

To enter the wire from the power supply, a hole must be made in the tool case. It is important to provide measures to prevent the wire from being pulled out in the event of careless movements or accidental jerks. The easiest option is to crimp the wire inside the case at the very hole with a clip from a short piece of soft wire folded in half (aluminum will do). Having dimensions exceeding the diameter of the hole, the clip will not allow the wire to come off and fall out of the case in case of a jerk.

As you can see, an energy-saving light bulb, even if it has worked out its due date, can bring considerable benefits to its owner. The UPS assembled on the basis of its components can be successfully used as an energy source for a cordless power tool or charger.

Video

This video will tell you how to assemble a power supply unit (PSU) from energy-saving lamps.

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. With driver supply voltage direct current is fed 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 against human contact with 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 coated in series with a phosphor are fixed and connected. 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 bare areas of a circuit connected to electrical network 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.

One side printed circuit board driver, 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 the contact was missing, 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 electric 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 ratio 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 that exceeds the power consumption of the LEDs and place it in a small package LED lamps, due to the release of more heat, will be unacceptable.

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 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 check of the LEDs showed their serviceability, then it means that 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 the printed circuit board under it was charred, 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.

Examination LEDs corn lamps do not differ from the technology described above, but it must be taken into account that three LEDs are placed in the SMD5050 LED housing, 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 circuit, without an isolation transformer, so touching the LED leads 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 into place with transparent Moment 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 in such a way 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 that had to be done 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 the plastic with the 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. The LED lamp 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 slightly 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 right place and heat 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 in appearance the capacitor looks without external defects, then the repair is still led light bulb with a stroboscopic effect, you need to start 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.

Not so long ago, the demand for energy-saving lamps was huge, but despite the promises of manufacturers, their service life turned out to be no more than half a year, and the price is 10 times more than incandescent lamps. Therefore, if you still have non-working energy-saving lamps, you can convert them into LED ones with your own hands. Converting an energy-saving lamp into an LED one is not such a difficult task, this article describes in detail the conversion process and the circuit.

First, you need to remove the internal converter board from the energy-saving lamp and replace it with a voltage reduction circuit to power the LEDs. The LED supply current is set by a 100-200 Ohm resistor, within 20-50mA.

So, we disassemble the lamp, removing the converter board and the glass bulb (as a rule, it is she who burns out the fastest). There remains a cartridge with a capacious base. There we will place assembled circuit with LEDs and reflector.

LEDs, of course, will not give the same brightness as a fluorescent lamp, but if you buy good ones, then the brightness of 6 pieces will be at a fairly decent level. Bright LEDs can also be ordered on Aliexpress, since there are a lot of them and they are not so expensive.

Of course, you can just buy an LED lamp, but it’s much more interesting to make it yourself, while enjoying the process and having a good time.