IR remote control. Simple Infrared Control Circuit DIY IR Control

An interesting and informative scheme for a beginner radio designer on organizing sound transmission over a distance in the infrared (IR) range of light. A great starter kit for experimenting and building your own optical phone. Do you want to establish a "closed" communication channel, for example, with your friend who lives in direct line of sight in a nearby high-rise? To start designing, this diagram is for you! Below is the process of assembling two base boards - an IR audio transmitter and an IR audio receiver. The sound receiver has a loudspeaker output. Block diagrams, photo assembly of blocks and video demonstration of performance are presented. DIY purchase price Kit set in an online store will not affect your budget in any way.

How to assemble an infrared receiver and sound transmitter with your own hands

Description:
The kit implements the functions of amplitude modulation by electrical signals of the brightness of the infrared LED and the reception of modulated infrared radiation, its conversion into an electrical signal, signal amplification to ensure the operation of the connected speaker. The signal transmission range in this embodiment depends on the accuracy of pointing the diodes at each other and can reach several meters without the use of additional optics.

1. Electrical characteristics dialing boards
infrared transmitter
Working voltage: 12V
The size printed circuit board: 19*25mm

infrared receiver
Working voltage: 4~12V
Connected speaker power: 0.5W-10W
PCB size: 17*39mm

2. Working principle
IR transmitter: The audio signal through the 3.5 mm jack and the electrolytic capacitor C3 is fed to the transistor Q1 type S8050, the transistor modulates the electrical signal, which leads to the modulation of the IR radiation emitted by the LED D2.
IR receiver: IR LED receives radiation, converts it into an electrical signal, the signal through the capacitor C1 is fed to the input of the ULF assembled on the LM386 microcircuit, the signal from the microcircuit is fed to the speaker.

3. List of components

IR receiver

amount
2	×	620 kΩ, 1K resistor R1 and R2 respectively
3	×	0.22uF, 0.1uF and 0.1uF capacitors C1, C4 and C6 respectively
3	×	10 uF, 100 uF and 100 uF capacitors C2, C3 and C7 respectively
1	×	Red LEDs D1
1	×	IR receiving LED D2
1	×
1	×	speaker terminal block
1	×	LM386 chip U1
1	×	printed circuit board

IR transmitter

amount		Designation and marking of the part on the diagram
2	×	100 Ohm, 51K resistor R1 and R2 respectively
3	×	0.001uF, 100uF and 4.7uF capacitors C1, C2 and C3 respectively
1	×	S8050 transistor Q1
1	×	Red LEDs D1
1	×	IR transmitting LED D2
1	×	power supply pin block
1	×	3.5mm audio input jack
1	×	Printed circuit board

Assembling the IR receiver and IR transmitter

The design of the circuits is simple, any novice electronics engineer can handle the assembly. When assembling, you must be careful and accurate.

• it is necessary to check the contents of the packages and their compliance with the specification;
  
  
• determine the resistor values ​​with a tester or by color code;
• start installing parts and soldering them to the board, during assembly, you must observe the polarity of the installation of the transistor and the microcircuit block are installed by key on the board, see photos and videos;
  
  
  
  
  
  

  Good luck with your assembly and long-range communication in the IR range

Remote control of a VCR, TV, stereo or satellite receiver can be used to turn off and on various household electrical appliances, including lighting.

Do-it-yourself remote control, the diagram of which is given in this article, will help us with this.

Description of the operation of the IR remote control system

The following mechanism is used for remote control of devices. On the remote control, press and hold an arbitrary button for 1 second. The system does not respond to a short press (for example, while controlling the music center).

In order to exclude the response of the TV to the control of devices, it is necessary to select unused buttons on the remote control or use the remote control from the device turned off at this time.

circuit diagram remote control is shown in Figure 1. A special chip DA1 amplifies and generates the electrical signal of the photodiode BL1 into electric pulses. A comparator was built on radio elements DD1.1 and DD1.2, and a pulse generator was built on radio elements DD1.3, DD1.4.

The state of the control system (on or off load) controls the trigger DD2.1. If the direct output of this trigger is log 1, the generator will operate at a frequency of approximately 1 kHz. Pulses will appear on the emitters of transistors VT1 and VT2, which will go through the capacitance C10 to the control output of the triac VS1. It will fire at the beginning of each mains voltage half cycle.

In the initial position, on pin 7 of the DA1 chip, there is a log 1, the capacitance C5 is charged through the resistances R1, R2 and at the input C of the trigger DD2.1 log 0. If IR radiation signals from the remote control go to the BL1 photodiode, pin 7 of the DA1 chip will be signals, and the capacitance C5 will be discharged through the diode VD1 and the resistance R2.

When the potential at C5 drops to the lower level of the comparator (after 1 second or more), the comparator will switch and a signal will be sent to the trigger input DD2.1. The state of the trigger DD2.1 will change. This is how devices switch from one state to another.

Microcircuits DD1 and DD2 can be used similar from the series K564, K176. VD2 - a zener diode for a voltage of 8-9 volts and a current of more than 35 mA. Diodes VD3 and VD4 - KD102B or similar. Oxide tanks - K50-35; C2, C4, C6, C7 - K10-17; C9, C10 - K73-16 or K73-17.

Setting up the IR remote control system

It consists in selecting the resistance R2 of such a value that the switching takes place after 1 ... 2 s. If an increase in the value of this resistance will lead to the fact that the capacitance C5 will not be discharged to the threshold voltage, it is necessary to double the capacitance C5 and re-adjust.

Capacitance C6 should be set if the duration of the front of the pulse going from the comparator to the trigger is excessively large and it will switch unstably.

If the remote control used does not allow you to control the device without interfering with the TV, it is possible to assemble a home-made remote control, which is a generator of rectangular signals with a repetition rate of 20 ... 40 kHz, operating on an IR emitting diode. Variants of a similar remote control on the timer KR1006VI1 (

Below are schematic diagrams and articles on the topic "IR rays" on the site on radio electronics and the radio hobby site.

What is "IR rays" and where it is used, circuit diagrams homemade devices which relate to the term "IR rays".

Schematic diagram. Like the previous version, this transmitter provides a short range (up to 10 m). In addition, the LEDs used as emitters have a directivity, which allows you to control the model only within the irradiation zone ... IR radiation pulses modulated by a command signal are fed to the VD1 photodiode. The changing current of the photodiode through the emitter follower VT2 is fed to the input of the three-stage amplifier VT3-VT5. On the transistor VT1, a node is assembled to compensate for interference from ... In this shooting range, pulses of infrared radiation are fired. The gun contains a power source and a converter constant voltage into rectangular pulses, the duration and amplitude of which is determined by the capacitance of capacitors C2-C5. A packet of pulses is fed to an infrared emitter ... Wireless headphones allow you to receive the sound of a TV, a radio signal, a tape recorder within one medium-sized room. The device operates on the basis of the transmission of a frequency-modulated infrared light signal. Included in the kit... Thanks to the use of specialized coded integrated circuits this device can be used to control car central locking, car alarm, garage doors, gates, lighting, etc. The kit consists of two parts: a transmitter and ... The infrared receiver circuit is designed so that it can work with any remote control: from the TV receiver, satellite tuner, VCR. The device works with most remote control buttons. The receiver operates as follows: the signal from the receiving diode... The optoelectronic barrier serves to protect objects. Thanks to him, you can turn on the alarm when an unauthorized person approaches the object. The barrier uses infrared radiation, the beam of which is transmitted from the transmitter to the receiver. Beam interruption causes a change in the output state ... Standard remote control systems used in video technology are made on specialized microcircuits and provide a very large set of commands. But, to control simple devices, such a large number of commands is not required. In principle, even for the operational control of a TV ... The TRC1300N chip is an encoder / decoder for remote control systems operating via an infrared communication channel or via a radio channel. Depending on the logic level at pin 2 of the microcircuit, it works either as an encoder that generates pulses, or as ... Light can be used as an information transmission medium. It can be ordinary (visible) light or infrared radiation - infrared rays. Schemes of simple optical transmitters for light telephones (phototelephones) are considered using simple lamps incandescent, as well as ... Domestic semiconductor TVs of the USCT line have already been completely out of service, many have been thrown away, disassembled into parts. But someone still had quite working copies, operated exclusively in the country. Indeed, our dachas are usually guarded very poorly (if at all ... The device is designed to signal the passage of a person into the room through the front door or passage. The circuit works on the principle of crossing an infrared beam. When it is crossed, a musical signaling device is turned on, warning personnel that they have come visitor or client... Diagram of a simple homemade photo sensor to control objects on the conveyor. This device is designed to turn on the load when a crate or box enters the certain area conveyor or conveyor belt, and turn off the load when the box leaves this area. The device is very ... Homemade sensor for the intersection or reflection of the IR beam on the K561LP2 chip. In many amateur radio circuits automation uses infrared sensors for reflection or beam intersection, built on the basis of the element base of remote control systems for household electronics ... Diagram of a simple home-made set-top box connected to a COM port to control a computer using a remote control. Modern Personal Computer, with the necessary peripherals and software able to replace the home audio-video center. You must have ... A diagram of a simple home-made signaling device for crossing the border or entering a room using infrared rays. In some cases, it is required to signal the passage of a person into the premises, the passage of a car into the territory, the movement or entry of any object into a box, box ... The following is a description of a simple two-command remote control system on IR beams that can be used to control various devices as well as burglar alarms, electronic lock with remote control. The circuit is based on three LM567 chips and one... The system is designed for independent control of four objects. There are four buttons on the remote and four outputs on the receiver. Each remote control button is responsible for its own receiver output, each button press changes the state of the corresponding receiver output. The outputs of the receiver are equipped with ... Everyone knows why a microcalculator exists, but it turns out that, in addition to mathematical calculations, it is capable of much more. Please note that if you press the "1" button, then "+" and then press "=", then with each press of the "=" button, the number on the display will be ... The device is designed to turn on or switch something when brought to the sensor hand or other reflective surface. Sensitivity can be adjusted over a wide range, while the response range varies from a few meters to several centimeters. The idea is basically...

At the end of the USSR, domestic semiconductor TVs of the USCT series appeared and were very popular, some of them are still in service. Particularly durable were televisions with a screen size of 51 cm diagonally (the kinescope was very reliable). Of course, they no longer meet modern requirements at all, but as a “country option” they are still quite suitable.

Somehow, having nothing to do, there was a desire to improve the old, already long "dacha" "Rainbow-51ТЦ315", supplementing it with a remote control system. Now it is already impossible to purchase a “native” module, so it was decided to make a simplified one-command system that allows at least switching programs “in a ring”. Microcontrollers and special microcircuits were immediately rejected due to unprofitability, and the system was made from what was available.

Namely, an integrated timer 555, an IR LED LD271, an integrated photodetector TSOP4838, a counter K561IE9 and plus some other little things.

Control panel diagram

The remote control is a pulse generator with a frequency of 38 kHz, at the output of which an infrared LED is switched on through a key. The generator is built on the basis of the "555" microcircuit, the so-called "integral timer". The generation frequency depends on the circuit C1-R1, when adjusting the selection of the resistor R1, you need to set the frequency of 38 kHz at the output of the microcircuit (pin 3).

Fig.1. Schematic diagram of an IR transmitter for remote control of a TV.

Rectangular pulses with a frequency of 38 kHz are fed to the base of the transistor VT1 through the resistor R2. Diodes VD1 and VD2, together with resistor R3, form a current control circuit through the IR LED HL1.

With increased current, the voltage at R3 increases, and the voltage at the emitter VT1 also increases accordingly. And when the voltage at the emitter approaches in magnitude the drop voltage on the diodes VD1 and VD2, the voltage at the base of VT1 decreases relative to the emitter, and the transistor is covered.

IR light pulses following at a frequency of 38 kHz are emitted by an infrared LED HL1.

Control - one button S1, which supplies power to the control panel circuit. As long as the button is pressed, the remote control emits infrared pulses.

Receiving block scheme

The receiver is installed inside the TV, it is powered by + 12V from the power supply of the TV, and the cathodes of the diodes VD2-VD9 are connected to the contacts of the buttons of the USU-1-10 program selection module.

Fig.2. Schematic diagram of an IR receiver for remote control of a TV.

The IR pulses emitted by the remote control are received by the integral photodetector HF1 type TSOP4838. This photodetector is widely used in remote control systems for various household electronic equipment. When a signal is received, its output 1 contains a logical zero, and in the absence of a received signal, a unit.

Thus, when the remote control button is pressed, its output is zero, and when it is not pressed, it is one.

TSOP4838 should be powered by 4.5-5.5V, and no more. But, to control the TV program selection module, you need to apply 12V voltage to the buttons of the transistor 8-phase trigger. Therefore, a voltage of 12V is applied to the D1 chip, and a voltage of 4.7-5V is applied to the photodetector HF1 through a parametric stabilizer on the VD10 zener diode and resistor R4.

The transistor VT1 serves as a matching cascade for the levels of logical units. In doing so, it inverts logic levels. The voltage from the collector VT1 through the circuit R3-C2 is supplied to the counting input of the counter D1, designed to receive positive pulses. The R3-C2 circuit serves to suppress errors from the bounce of the contacts of the S1 button of the control panel.

Counter D1 K561IE9 is a three-digit binary counter, with a decimal decoder circuit at the output. It can be in one of eight states from 0 to 7, while only one output corresponding to its state has a logical unit. The rest of the outputs are zero.

With each press - release of the remote control button, the counter goes up one state, while switching the logical unit on its outputs. If the countdown started from zero, then after eight button presses, on the ninth, the counter will return to the zero position. And further, the process of switching the logical unit on its outputs will be repeated.

The LD271 IR LED can be replaced with any IR LED that can be used for home appliance remote controls. The TSOP4838 photodetector can be replaced with any complete or functional analogue.

Details and installation

The K561IE9 chip can be replaced with a K176IE9 or a foreign analogue. You can use the K561IE8 chip (K176IE8), while there will be 10 control outputs. To limit them to 8, you need to connect the output number "8" to the input "R" (at the same time, the input "R" should not be connected to a common minus, as it is in the diagram).

Diodes 1N4148 can be replaced by any analogues, for example, KD521, KD522. The remote is powered by Krona. Housed in a toothbrush case. Mounting - volumetric on the terminals of the A1 microcircuit.

The receiver circuit is also assembled by volumetric installation and glued with BF-4 glue to wooden case TV from the inside. For the eye of the photodetector, I used a hole for a connector for connecting headphones (the hole in the TV was empty, closed with a plug, there was no connector itself).

By selecting R1 (Fig. 1), you need to tune the remote control to the frequency of the photodetector. This can be seen from the longest receiving range.

If the scheme is of interest, but the old "Rainbow" is not, it can also be used to switch something more modern. It is possible to connect transistor switches through resistors to the outputs of the D1 chip, with electromagnetic relays on collectors or LEDs of powerful optocouplers.

Kotov V.N. RK-2016-04.

The design is a so-called infrared barrier and can be used to protect the perimeter, windows, balconies and other poorly protected openings. The author used a similar design to protect the loggia and was satisfied with the stability of the work and the absence of false positives. According to him, the device worked reliably at temperatures from -25 to +30 °C.

Structurally, the security system consists of two blocks - an IR transmitter and a receiver, which should be located on the sides of the opening, while the width of the opening itself can reach 9 m. no worries either. As soon as the invisible beam is crossed by the intruder, the alarm is activated.

The transmitter is an asymmetric multivibrator assembled on transistors VT1 and VT2. The frequency and duty cycle of the pulses depends on the ratings of the R1C1 chain and, with the values ​​\u200b\u200bspecified in the diagram, is approximately equal to 10 kHz. Resistor R2 is current limiting for infrared LED HL1.

The receiver is assembled on the timer KR1006VI1 (foreign analogue 555), the role of the IR receiver is performed by the VT3 phototransistor, which has a sufficiently large current gain. For use in the design, it will have to be slightly modified - carefully cut with a needle file upper part case so that the light hits the crystal. In principle, the FD-24K photodiode can be a good alternative to a phototransistor, but its cost is much higher.

The sensitivity of the start input Z of the timer depends on the value of the resistor R3, which is the load of the phototransistor VT3 - the higher the value, the higher the sensitivity of the receiver. The DA1 timer itself is enabled by classical pattern missed pulse detector. While pulses from the photosensor pass to the input 2 of the microcircuit, the timer is constantly restarted without completing the duty cycle. On his way out constantly high level. Transistor VT4 is open, trinistor VS1 is closed, relay K1 is de-energized.

As soon as the IR beam is blocked by the intruder, the pulses at the reset input will disappear, the counting cycle will be normally completed and the pin 3 of the timer will go low. Transistor VT4 will close, trinistor VS1 will open and turn on relay K1, which, with its normally open contacts, will turn on an alarm or any other actuator. It is worth noting that the R4R5C3 chain is selected in such a way that to complete the timer's working cycle, it is enough to skip a few pulses from the transmitter - the alarm is triggered when a tennis ball passes between the transmitter and the receiver. To reduce the sensitivity, it is enough to increase the value of the resistor R6 or capacitor C3. After the restoration of the passage of the IR beam, the circuit will return to its original state, with the exception of the trinistor, which will remain open and will not remove the alarm until its supply circuit is briefly interrupted by the SA1 switch.

About the details. The transmitter can use transistors KT315A - B, KT375A-B, KT3102B-E (VT1). KT3107A or KT361A - G will work in place of VT2. Capacitor C2 is an oxide type K50-20. The transmitter circuit practically does not need to be adjusted. In the receiver, you can use transistors KT312B - V, KT315A - B or any other low-power n-p-n structures(VT4). Relay RES15 passport RS4.591.004 or RES10 with passport RS4.524.302 is used as K1. Trinistor - KU101 or KU201 with any letter index. In the second case, you may have to choose the value of the resistor R7.

Oxide capacitors - K50-20 for an operating voltage of at least 25 V, the rest - KM5, KM6-B. Resistors - MLT-0.25. Any stabilized voltage source of 9-15 V is suitable as a power source for the system. Current consumption in armed mode (receiver + transmitter) is 25-30 mA.

When you turn it on for the first time, due to the discharged capacitor C3, the timer will immediately start and the alarm will turn on, to turn off which it is enough to briefly turn off switch SA1.

A.P. Kashkarov "Photo and thermal sensors in electronic circuits", 2004