How to make a remote IR switch. IR receiver circuit for remote control of electrical devices. Using sensors to control lighting
Nowadays, it is almost impossible to imagine equipment without remote control... But, unfortunately, not all devices are equipped with such remotes yet ...
Chinese manufacturers, however, have already started producing chandeliers equipped with remote controls with radio signal control, but the cost of such devices is quite high.
This article suggests a fairly simple scheme such a switch. Unlike the industrial one, which includes one LSI, it is mainly assembled on discrete elements, which, of course, increases the dimensions, but, if necessary, it can be easily repaired. But if you chase the dimensions, then in this case you can use planar parts. This circuit also has a built-in transmitter (there is no industrial one), which saves you from having to carry a remote control with you all the time or look for it. It is enough to bring your hand to the switch at a distance of up to ten centimeters and it will work. Another advantage is that the DU any remotes from any imported or domestic radio equipment are suitable.
Transmitter
Figure 1 shows a diagram of a short-pulse emitter. This allows you to reduce the current consumed by the transmitter from the power source, and therefore extend the life of one battery. On the elements DD1.1, DD1.2, a pulse generator is assembled, following with a frequency of 30 ... 35 Hz. Short, 13 ... 15 μs duration, pulses are formed by the C2R3 differentiating circuit. Elements DD1.4-DD1.6 and normally closed transistor VT1 form a pulse amplifier with an IR diode VD1 on the load.
The dependence of the main parameters of such a generator on the supply voltage Usup are shown in the table.
| Upit, V Iimp, A Ipot, mA |
4.5 0.24 0.4 |
5 0.43 0.57 |
6 0.56 0.96 |
7 0.73 1.5 |
8 0.88 2.1 |
9 1.00 2.8 |
Here: Iimp is the amplitude of the current in the IR diode, Ipot is the current consumed by the generator from the power source (with the nominal resistors R5 and R6 indicated in the diagram).
Any remote control from domestic or imported equipment (TV, VCR, music center) can also serve as a transmitter.
The printed circuit board is shown in Fig. 3. It is proposed to be made of double-sided foil fiberglass with a thickness of 1.5 mm. The foil from the side of the parts (not shown in the figure) performs the function of the common (negative) wire of the power source. Around the holes for the passage of the leads of the parts in the foil, areas with a diameter of 1.5 ... 2 mm are etched. The leads of the parts connected to the common wire are soldered directly to the foil on this side of the board. The VT1 transistor is attached to the board with an M3 screw, without any heat sink. The optical axis of the VD1 IR diode must be parallel to the board and spaced 5 mm from it.
Receiver
The receiver is assembled according to the classical scheme adopted in the Russian industry (in particular, in TV sets Rubin, Temp, etc.). Its circuit is shown in Figure 2. The pulses of IR radiation fall on the IR photodiode VD1, are converted into electrical signals and amplified by transistors VT3, VT4; An emitter follower is assembled on transistor VT2, which matches the resistance of the dynamic load of the photodiode VD1 and the transistor VT1 with the input resistance of the amplifier stage on the transistor VT3. Diodes VD2, VD3 protect the switching amplifier on the VT4 transistor from overloads. All front-end amplifier stages of the receiver are covered by a deep feedback by current. This ensures a constant position of the operating point of the transistors regardless of the external light level - a kind of automatic gain control, especially important when the receiver is operated in rooms with artificial lighting or outdoors in bright daylight, when the level of extraneous IR radiation is very high.
Further, the signal passes through an active filter with a double T-shaped bridge, assembled on a VT5 transistor, resistors R12-R14 and capacitors C7-C9. Transistor VT5 must have a current transfer ratio H21e = 30, otherwise the filter may start to be excited. The filter removes network interference from the transmitter signal alternating current which are emitted by electric lamps. The lamps create a modulated radiation flux with a frequency of 100 Hz and not only in the visible part of the spectrum, but also in the IR region. The filtered code message signal is formed on the VT6 transistor. As a result, short pulses are obtained on its collector (if received from an external transmitter) or proportional with a frequency of 30 ... 35 Hz (if received from a built-in transmitter).
The pulses coming from the receiver go to the buffer element DD1.1, and from it to the rectifier circuit. The rectifier circuit VD4, R19, C12 works like this: When the output of the element is logical 0, then the diode VD4 is closed and the capacitor C12 is discharged. As soon as pulses appear at the output of the element, the capacitor begins to charge, but gradually (not from the first pulse), and the diode prevents it from discharging. Resistor R19 is selected so that the capacitor has time to charge to a voltage equal to logical 1 only with 3 ... 6 pulses coming from the receiver. This is another protection against interference, short IR flashes (for example, from a camera flash, lightning discharge, etc.). The discharge of the capacitor occurs through the resistor R19 and takes 1 ... 2 s in time. This allows you to prevent crushing and arbitrary turning on and off the light. Next, an amplifier DD1.2, DD1.3 is installed with capacitive feedback (C3) to obtain sharp rectangular drops at its output (when turned on and off). These drops are fed to the trigger input of the divider by 2 assembled on the DD2 microcircuit. Its non-inverted output is connected to an amplifier on a VT10 transistor, which controls the VD11 thyristor, and a VT9 transistor. The inverted one is fed to the VT8 transistor. Both of these transistors (VT8, Vt9) serve to light the corresponding color on the VD6 LED when the light is turned on and off. It also performs the function of a "beacon" when the lights are off. An RC circuit is connected to the R input of the divider flip-flop, which performs a reset. It is needed so that if the voltage in the apartment is turned off, then after turning on the light does not accidentally come on.
The built-in transmitter is used to turn on the light without a remote control (by bringing your palm to the switch). It is assembled on elements DD1.4-DD1.6, R20-R23, C14, VT7, VD5. The built-in transmitter is a pulse generator with a repetition rate of 30 ... 35 Hz and the amplifier is connected to the load by an IR LED. The IR LED is installed next to the IR photodiode and must be directed in the same direction with it, and they must be separated by an opaque partition. Resistor R20 is selected in such a way that the sensing distance, when holding the palm, is 50 ... 200 mm. In the built-in transmitter, you can use an IR diode such as AL147A or any other. (I, for example, used an IR diode from an old floppy drive, but the resistor R20 = 68 ohms).
The power supply is assembled according to the classical scheme on KREN9B and the output voltage is 9V. It includes DA1, C15-C18, VS1, T1. Capacitor C19 serves to protect the device from power surges in the power supply. The load in the diagram is shown by an incandescent lamp.
The printed circuit board of the receiver (Fig. 4) is made of one-sided foil fiberglass with a size of 100X52 mm and a thickness of 1.5 mm. All parts, with the exception of the VD1, VD5, VD8 diode, are installed as usual, the same diodes are installed from the mounting side. Diode bridge VS1 is assembled with discrete rectifier diodes often used in imported equipment. The diode bridge (VD8-VD11) is assembled on diodes of the KD213 series (others are indicated in the diagram), when soldering, the diodes are located one above the other (column), this method is used in order to save space.
Literature:
1. Radio No. 7 1996 p. 42-44. "IR sensor in burglar alarm".
This remote control system (CRY) allows you to use infrared (IR) beams from a distance of up to five meters to cycle through the TV programs, adjust the volume up and down, and turn off the TV when you finish watching programs. The system has 16 levels of volume control and eight positions of the program selector. The unit installed in the TV is powered from a 12V power source of the TV, so the TV is turned on by its switch from which the latch is removed, and turned off using the remote control.The schematic diagram of the control panel is shown in Figure 1. The control panel consists of a rectangular clock generator, a counter with a variable division ratio, a control device for this counter, and an output stage with an infrared LED at the output.
The clock generator is made on the elements D1.1 and D1.2 of the K561LE5 microcircuit. Items included for inverter operation. The pulse repetition rate is 1 kHz. Since the switching voltage of CMOS elements is not equal to half of the supply voltage, a correction circuit R1VD1 is introduced in the generator to balance the shape of the output pulses.
The generator pulses are fed to the input of the binary counter 02, which is switched on for operation in the countdown mode. The counter has the ability to block the clock generator with a negative pulse from its carry output "P". At the same time, the pulses from the clock generator output are fed to the output amplifier at the output of which the VD8 infrared emitter is turned on.
The principle of operation of the circuit is that the counter D2 limits the number of pulses at the output of the generator to the number - one, two, four or eight, respectively, according to the high inputs of the counter preset. Thus, four types of bursts of pulses are formed, which include four commands: "programs", "volume -", "volume +" and "off".
The circuit works this way. In the initial state, at the output of the transfer of the counter, a logical zero, which, through the diode VD2, blocks the clock generator. When you press one of the buttons, for example, the SA3 button at the input of the preset-counter 4, a unit is set, and the number code "4" is 0100.
Through one of the VD4-VD7 diodes, a logical unit is fed to the one-shot on the elements D1.3 and D1.4. This one-shot generates a short positive pulse, the duration of which is much less than the button holding time, which is fed to the input for enabling the counter preset "S" and the number 0100 is written into the counter.
At this time, the counter goes from zero to the set value and a logical unit appears at its transfer output "P", which enables the operation of the clock generator, pulses from it are fed to the output amplifier at VT1 and VT2 and to the counter input of the counter.
The counter counts in the downward direction, and after four pulses it goes back to the zero state, the zero from its carry output blocks the clock generator and the circuit, by transmitting one command, goes into the waiting mode for the next pressing of one of the buttons. Thus, each time you press one of the buttons, one packet is transmitted, which changes the positions of the knobs by one step, or by one program.
The actuator circuit is shown in Figure 2. Any photodetector can be used, but it provides negative pulses at its output.
The executive device consists of an informal pulse generator and a command end signal, an information pulse counter, a register-decoder-command pulse generator, a counter-decoder for switching programs, a reversible volume control and a TV power switch.
The information pulse generator is made on the elements D1.1 and D1.2, the resistor R1 and the capacitor C1. The device has the properties of an integrating circuit and a Schmitt trigger. Its output pulses are somewhat delayed relative to the input ones and have steep edges regardless of the duration of the edges of the input pulses. In addition, such a shaper suppresses short-duration impulse noise.
The generator of the command end signal is made on the elements D1.3 and D1.4, resistor R2 and diode VD1, capacitor C2. The principle of operation of this shaper is that in the intervals between the information pulses C2 does not have time to discharge, and at the end of the message, the voltage at the input D1.3 reaches the threshold value and it switches like an avalanche into a single state. In this case, its output is one - the signal of the end of the message.
The pulses from the output of the element D1.2 are fed to the counting input D2 and after the end of the burst it is set to the state corresponding to the number of pulses in it. In our case, the AZ button was pressed, and the remote control generated four pulses. Counter D2 is set to "4" (0100). Under the action of the burst end signal, counter D3, which performs the functions of a register, transfers the code from the D2 output to its outputs, in our case, a unit appears at the "4" D3 output. This unit is kept until the counter D2 is reset to zero through the R3 C2 circuit.
Thus, at the output "4" of the counter D3, a command pulse appears, the duration of which depends on the time constant of the circuit R3 C3. In this case, this pulse is fed to the input of the counter D6, which, together with the resistive matrix at its outputs, acts as a volume control. In this case, the volume increases by one level.
To decrease or increase by one more step, you need to press the corresponding button on the remote control. Each time you press the control button, the volume changes by one level. When the power is turned on, the capacitor C7 sets the regulator to the middle position.
In the case of decreasing the volume to zero and then pressing the volume down button, thanks to the D1.5 element, the regulator goes not to the maximum, but to the middle position. Instead of the middle position, you can set the code for the number of any other step, respectively, by unsoldering the terminals 4,12,13,3 of the D6 counter.
To switch programs, press the first button. A positive pulse from the sixth pin D3 goes to the D4 counter input and switches the D4 counter to the next position. The code of the number of the included program enters the binary-decimal decoder on the R5 microcircuit, a positive pulse appears at the corresponding output R5, the duration of which is determined by the parameters of the R5 C5 circuit, which, some time after the end of the packet, transfers the decoder to the area that is not accessible for the program selection unit, (programs 9 to 16). The switching of programs occurs only in one direction, ascending.
To turn off the TV, use the second button. When you turn on the power of the TV, its switches, converted into a button (the latch is removed), the supply voltage is supplied to the control unit and the D3 counter is set to zero. The zero level from its second output opens the key to VT1 and passes current through the relay P, the contacts of which close the wires going to the TV power button.
After that, the button can be released and the TV will remain turned on. When you turn off the TV from the remote control, a unit appears at pin 11D3, which turns the key into a closed state, the relay contacts open and the TV turns off.
The connection diagram of the receiving unit (Fig. 2) is shown in Fig. 3 for the TV "Raduga 61 TC-311".
The receiver of IR commands of the remote control for controlling household appliances can be easily made using the decimal counter CD4017, timer NE555 and infrared receiver TSOP1738.
Using this IR receiver circuit, you can easily control your household appliances using the remote control from the TV, DVD player, or using the remote control circuit described at the end of the article.
IR receiver circuit for remote control
Pins 1 and 2 of the TSOP1738 IR receiver are used to power it. Resistor R1 and capacitor C1 are designed for stable operation and suppression of various noise in the power supply circuit.
When IR rays at a frequency of 38 kHz fall on the TSOP1738 IR receiver, a low voltage level appears at its output 3, and a high level reappears when the IR rays disappear. This negative pulse is amplified by Q1, which feeds the amplified frequency signal to the CD4017 decimal counter. Counter pins 16 and 8 are designed to power it. Pin 13 is connected to ground, thereby allowing its operation.
Output Q2 (pin 4) is connected to the reset pin (pin 15) to make the CD4017 work in bistable multivibrator mode. During the first pulse, log1 appears on Q0, the second clock signal causes log1 to appear on Q1 (Q0 becomes low), and on the third signal it again outputs log 1 to Q0 (Q2 is connected to MR, so the third clock signal resets the counter).
Let's assume the counter is reset (Q0 is high and the rest are low). When you press the button on the remote control, the clock signal affects the counter, which leads to the appearance high level on Q1. Thus, LED D1 is on, transistor Q2 turns on and the relay is activated.
When the remote control button is pressed again, log 1 appears on pin Q0, the relay turns off and LED D2 lights up. LED D1 indicates when the device is on and LED D2 indicates when the device is off.
You can use your TV remote to control it or assemble a separate one according to the diagram below.
Electronic technology encompasses a wide range of household applications. There are practically no restrictions. Even the simplest functions of a lamp switch for a household lamp are now increasingly performed by touch-sensitive devices, and not technologically outdated ones - manual ones.
Electronic devices, as a rule, are classified as complex structures. Meanwhile, as practice shows, it is not difficult to build a touch switch with your own hands. Minimal experience in designing electronic devices is enough for this.
We offer you to understand the device, functionality and the rules for connecting such a switch. For lovers of homemade products, we have prepared three working schemes for assembling a smart device that can be implemented at home.
The term "sensory" carries a fairly broad definition. In fact, under it should be considered a whole group of sensors capable of responding to a variety of signals.
However, in relation to switches - devices endowed with the functionality of switches, the sensory effect is most often considered as the effect obtained from the energy of the electrostatic field.
Such, approximately, it is necessary to consider the design of the light switch, created on the basis of the sensor mechanism. A light touch of the pad of your finger to the surface of the front panel turns on the lighting in the house
It is enough for an ordinary user to touch such a contact field with his fingers and in response, the same switching result will be obtained as a standard familiar keyboard device.
Meanwhile, the internal structure of the sensor equipment differs significantly from a simple manual switch.
Typically, such a design is built on the basis of four working nodes:
- protective panel;
- contact sensor-sensor;
- electronic board;
- device body.
The variety of sensor-based instruments is extensive. Models available with conventional switch functions. And there are more advanced developments - with dimmers that monitor the temperature of the environment, raise the blinds on the windows and others.
Traditional characteristics are present here, such as:
- noiselessness of action;
- interesting design;
- safe use.
In addition to all this, another useful feature is added - a built-in timer. With its help, the user gets the opportunity to control the switch programmatically. For example, set the on and off times in a certain time range.
Instrument connection rules
The technology of installation of such devices, despite the perfection of designs, has remained traditional, as it is provided for standard light switches.
Usually, there are two terminal contacts on the back of the product case - input and load. They are designated on foreign-made devices by markers "L-in" and "L-load".
Conclusions and useful video on the topic
This overview allows you to take a closer look at light switches that are rapidly gaining popularity in society.
Touch switches marked with the Livolo product brand - what these designs are and how attractive they are to the end user. A video guide to the new type of switches will help you get answers to your questions:
Completing the topic of touch switches, it is worth noting active development in the development and production of switches for household and industrial use.
Light switches, seemingly the simplest designs, are already so perfect that now you can control the light with a voice code phrase and at the same time receive complete information about the state of the atmosphere inside the room.
Do you have something to add, or have questions about the assembly of the touch switch? You can leave comments on the publication, participate in discussions and share your own experience of using such devices. The contact form is in the lower block.
The proposed device is designed to turn on and off (including remote) incandescent lamps, heaters and other devices powered by a 220 V household network and representing a purely active load with a power of up to 500 W. The circuit breaker is shown in Fig. 1.
An alternating voltage of 220 V is fed through the FU1 fuse to the power unit, assembled from the elements VD3, VD4, СЗ, С5, С7, R7 and R9. The stabilized voltage of 5 V from the capacitor C5 feeds the microcontroller DD1 and the photodetector B1. The microcontroller, working according to the program recorded in it, analyzes the signals coming from the photodetector to the RB5 input and from the SB1 button to the RB1 input, as well as from the zero phase sensor mains voltage(resistor R6, diodes VD1, VD2) to input RA1. The signals generated at the RB0 and RB4 outputs, the microcontroller controls the VS1 triac and the HL1 LED, respectively. The switch changes its state to the opposite each time you press the SB1 button or the remote control button. There are two options for the program. Working according to the first of them (file irs_v110.hex), the microcontroller remembers the current state of the switch and, in the event of a temporary disconnection of the mains voltage when its supply is resumed, it restores this state. When using the second version of the program (file irs_v111.hex), restoration of the mains voltage always turns the circuit breaker off. The HL1 LED is on when the load circuit is open. This is useful for controlling lighting fixtures. The circuit of the remote control switch is shown in Fig. 2.
It is powered by two AAA cells. When you press the SB1 button, a pulse generator with a duration of about 18 ms, assembled on logical elements DD1.1 and DD1.2, starts to work. These pulses control a 36 kHz pulse generator on elements DD1.3, DD1.4. Bursts of pulses from the output of this generator are fed to the gate of the transistor VT1, in the drain circuit of which the IR emitting diode VD1 is connected. Setting up the remote control is reduced to tuning the generator on the elements DD1.3, DD1.4 to a frequency of 36 kHz (resonant frequency of the photodetector B1 in the switch) by selecting the resistor R4. With the correct setting, the maximum range of the remote control of the circuit breaker is achieved. The circuit board of the switch is shown in Fig. 3.
The VT137-600 triac is installed on a heat sink made of an aluminum plate with dimensions of 65x15x1 mm. A replacement for this triac can be selected from among similar devices of the VT136, VT138 series. Zener diode BZV85C5V6 is replaced by another small one with a stabilization voltage of 5.6 V, for example KS156G. Instead of the TSOP1736 photodetector, another of the TVs and other household electronic devices used in remote control systems is also suitable. The central frequency of the passband of such a photodetector can lie in the range of 30 ... 56 kHz, so the remote control will have to be tuned to this frequency. If it is necessary to expand the sensitivity zone of the switch in the horizontal plane, instead of one photodetector, you can install two, pointing them in different directions. In this case, pins 1 and 2 of the two photodetectors are connected in parallel directly, and pin 3 is connected through 1 kΩ resistors. The common point of the resistors is connected to pin 3 of the X1 block, and the resistor R3 in the switch is replaced with a jumper. Printed circuit board the remote control is made according to the drawing shown in Fig. 4.
Here, as VD1, you can use any IR emitting diode from the remote control of a household appliance. It is undesirable to replace the HEF4011 microcircuit with a similar domestic K561LA7. When the supply voltage is too low, it works unstably. In fig. 5 shows appearance circuit breaker and remote control boards.
Radio No. 5, 2009
List of radioelements
| Designation | A type | Denomination | Quantity | Note | Score | My notebook | |
|---|---|---|---|---|---|---|---|
| Circuit breaker | |||||||
| DD1 | MK PIC 8-bit | PIC16F628A | 1 | Into notepad | |||
| VD1, VD2 | Diode | KD522B | 2 | Into notepad | |||
| VD3 | Rectifier diode | 1N4007 | 1 | Into notepad | |||
| VD4 | Zener diode | BZV85-C5V6 | 1 | KS156G | Into notepad | ||
| VS1 | Triac | BT137-600 | 1 | Into notepad | |||
| C1 | 47 uF 10 V | 1 | Into notepad | ||||
| C2 | Capacitor | 0.022 uF | 1 | Into notepad | |||
| C3 | Capacitor | 0.1 uF | 1 | Into notepad | |||
| C4, C6 | Capacitor | 22 pF | 2 | Into notepad | |||
| C5 | Electrolytic capacitor | 470 uF 16 V | 1 | Into notepad | |||
| C7 | Capacitor | 0.47 μF 630 V | 1 | Into notepad | |||
| R1, R5 | Resistor | 10 kΩ | 2 | Into notepad | |||
| R2 | Resistor | 220 ohm | 1 | Into notepad | |||
| R3 | Resistor | 1 kΩ | 1 | Into notepad | |||
| R4, R8 | Resistor | 100 ohm | 2 | Into notepad | |||
| R6 | Resistor | 4.7 MOhm | 1 | 0.5 watts | Into notepad | ||
| R7 | Resistor | 47 Ohm | 1 | 1 watt | Into notepad | ||
| R9 | Resistor | 300 kΩ | 1 | 0.5 watts | Into notepad | ||
| IN 1 | Photodetector | TSOP1736 | 1 | Into notepad | |||
| HL1 | Light-emitting diode | AL307BM | 1 | Into notepad | |||
| ZQ1 | Quartz | 4 MHz | 1 | Into notepad | |||
| FU1 | Fuse | 5 A | 1 | Into notepad | |||
| SB1 | Button | 1 | Into notepad | ||||
| X1 | Connector | 1 | Into notepad | ||||
| X2 | Connector | 1 | Into notepad | ||||
| Circuit breaker remote control | |||||||
| DD1 | Chip | HEF4011 | 1 | Into notepad | |||
| VT1 | Field-effect transistor | KP505A | 1 | Into notepad | |||
| C1 | Electrolytic capacitor | 100uF 6.3V | 1 | Into notepad | |||
| C2 | Capacitor | 0.047 uF | 1 | Into notepad | |||
| C3 | Capacitor | 47 pF | 1 | ||||