Radio control equipment diagram. RC Models - Electronic Toys - Beginner's Diagrams

Dear 4uvak. Collected the other day this miracle on 4 channels. I used the FS1000A radio module, Plows, of course, everything is as written, except for the range, but I think this radio module is simply not a fountain, from which it costs $ 1.5.
But I collected it in order to bind it to the broadlink rm2 pro and then I didn't succeed. Broadlink rm2 pro saw him, read his command and kept it in himself, but when he sends a command to the decoder, the latter does not react in any way. Broadlink rm2 pro is designed according to the declared characteristics to work in the 315/433 MHz range, but he did not accept this miracle into his ranks. This was followed by dances with a tambourine ..... In broadlink rm2 pro there is a function as a timer for several commands and I decided to set broadlink rm2 pro a task to send the same command several times with an interval of 0 seconds, BUT !!! Having written down one command to write down further, he refused, arguing that there was no more space in memory to save commands. Then I tried to do the same operation with the commands from the TV and he recorded 5 commands without problems. From here I concluded that in the program you wrote, very informative and large in volume commands are sent by the encoder to the decoder.

I am an absolute zero in MK programming and your project is the first assembled and working remote control in my life. I have never been friends with radio technology and my profession is far from electronics.

Now the question is:

If, nevertheless, as I believe, the signal sent by the encoder is long and large, then you can make it as scanty as possible ???, with the same base, so as not to change the MK harness and circuit.

I understand that any unpaid work is considered slavery :))))), and therefore I am ready to pay for your work. Of course, I don't know how much it will cost, but I think the price will be adequate for the work done. I wanted to transfer money to you, but where it was written, it was in rubles and it was not clear where to send it. I am not a resident of the Russian Federation and I live in Kyrgyzstan. I have a master card $. If there is an option to send you money to your card, then it will be good. In rubles, I don't even know how to do it. There are probably other easy options.

I thought this because after I bought a broadlink rm2 pro I connected a TV and an air conditioner for free, but the rest of the radio gadgets we have are not cheap. There are 19 light switches in the house, 3-4-5 pieces per room and it is very expensive to buy everything. Yes, and I would like to redo the sockets on the control, otherwise what kind of smart home it turns out.

In general, my task is to make the remotes with my own hands, so that they do not confuse each other and the main thing is that broadlink rm2 pro understands them. At the moment, he does not understand the remote control according to your scheme.

In the discussion, I could not write, only registered users write there.

Waiting for your reply.

In this article, you will see how to make a radio control for 10 commands with your own hands. The range of this device is 200 meters on the ground and more than 400 meters in the air.

The scheme was taken from the site vrtp.ru
Transmitter

Receiver

Pressing the buttons can be done in any sequence, although everything at once everything works stably. It can be used to control various loads: garage doors, lights, aircraft models, cars, and so on ... In general, anything, it all depends on your imagination.

To work, we need a list of parts:
1) PIC16F628A-2 pcs (microcontroller) (link to aliexpress pic16f628a )
2) MRF49XA-2 pcs (radio transmitter) (link to aliexpress MRF 49 XA )
3) Inductor 47nH (or wind it yourself) -6pcs
Capacitors:
4) 33 uF (electrolytic) -2 pcs
5) 0.1 uF-6 pcs
6) 4.7 pF-4 pcs
7) 18 pF-2 pcs
Resistors
8) 100 Ohm - 1 pc
9) 560 Ohm-10 pcs
10) 1 Com-3 pcs
11) 1 x LED
12) buttons - 10 pcs
13) Quartz 10MHz-2 pcs
14) Textolite
15) Soldering iron
As you can see, the device consists of a minimum of parts and everyone can do it. One has only to want. The device is very stable, it works immediately after assembly. The circuit can be done as on a printed circuit board. So also by mounting (especially for the first time, it will be easier to program this way). First, we make a fee. We print

And we poison the board.

We solder all the components, it is better to solder the PIC16F628A with the very last one, since it will still need to be programmed. The first step is to solder the MRF49XA

The main thing is very careful, she has very subtle conclusions. Capacitors for clarity. The most important thing is not to confuse the poles on the 33 uF capacitor, since its conclusions are different, one +, the other -. Solder all other capacitors as you wish, they have no polarity at the terminals

You can use purchased coils 47nH, but it is better to wind it yourself, they are all the same (6 turns of 0.4 wire on a 2 mm mandrel)

When everything is soldered, we check everything well. Next, we take PIC16F628A, it needs to be programmed. I used a PIC KIT 2 lite and a homemade socket
Here is the link to the programmer ( Pic kit2 )

Here is the connection diagram

It's all simple, so don't be alarmed. For those who are far from electronics, I advise you not to start with SMD components, but buy everything in DIP size. I did it myself the first time

And it all really worked the first time

We open the program, select our microcontroller

For radio control of various models and toys, discrete and proportional equipment can be used. The main difference between the proportional action equipment and the discrete one is that it allows, according to the operator's commands, to deflect the rudders of the model to any required angle and smoothly change the speed and direction of its movement, "Forward" or "Backward". The construction and adjustment of proportional action equipment is quite complicated and. not always within the power of a novice radio amateur. Although the discrete-action equipment has limited opportunities, but using special technical solutions, you can embroider them. Therefore, further we will consider a single-command control equipment suitable for wheeled, flying and floating models.

Radio controlled model transmitter.

Experience shows that to control models within a radius of 500 m, it is sufficient to have a transmitter with an output power of about 100 mW. Transmitters of radio-controlled models, as a rule, operate in a range of 10 m. One-command control of the model is carried out as follows. When the control command is given, the transmitter emits high-frequency electromagnetic oscillations, in other words, generates one carrier frequency. The receiver, which is on the model, receives the signal sent by the transmitter, as a result of which the actuator is triggered. As a result, the model, obeying the command, changes the direction of movement or carries out one pre-set in the design of the model indication. Using a single command control model, you can make the model perform fairly complex movements. A schematic of a single-command transmitter is shown in Fig. 22.4. The transmitter includes a master oscillator high frequency and a modulator. The master oscillator is assembled on a transistor VT1, according to the capacitive three-point circuit. The L2..C2 circuit of the transmitter is tuned to a frequency of 27.12 MHz, which is allocated by the State Telecommunications Supervision Authority for radio-controlled models. The mode of operation of the generator for direct current is determined by the selection of the value of the resistance of the resistor R1. The high-frequency oscillations created by the generator are radiated into space by an antenna connected to the circuit through a matching inductor L1. The modulator is made on two transistors VT1, VT2 and is a symmetrical multivibrator. The modulated voltage is removed from the collector load R4 of the transistor VT2 and supplied to the common power supply circuit of the transistor VT1 of the high-frequency generator, which provides 100% modulation. The transmitter is controlled by the SB1 button included in the common power supply circuit. The master generator does not work continuously, but only when the SB1 button is pressed, when current pulses generated by the multivibrate appear.

Figure: 22.4. Schematic diagram radio-controlled model transmitter

rum. The high-frequency oscillations created by the master oscillator are sent to the antenna in separate portions, the repetition rate of which corresponds to the pulse frequency of the modulator.
The transmitter uses transistors with a base current transfer ratio of at least 60. Resistors of the MLT-0.125 type, capacitors-K10-7, KM-6. The matching antenna coil L1 has 12 turns of PEV-1 0.4 and is wound on a unified frame from a pocket receiver with a tuning ferrite core brand 100NN with a diameter of 2.8 mm. The L2 coil is frameless and contains 16 turns of PEV-1 0.8 wire wound on a mandrel with a dimatrix of 10 mm. The MP-7 microswitch can be used as a control button. The parts of the transmitter are mounted on a printed circuit board made of foil-clad fiberglass. The antenna of the transmitter is a piece of steel elastic wire 0 1 ... 2 mm and about 60 cm long, which is connected directly to the XI socket located on the printed circuit board. All parts of the transmitter must be enclosed in an aluminum housing. There is a control button on the front panel of the case. A plastic insulator must be installed where the antenna passes through the housing wall to socket XI to prevent the antenna from touching the housing.
With known serviceable parts and correct installation, the transmitter does not require special setup. It is only necessary to make sure that it works and, by changing the inductance of the L1 coil, achieve the maximum transmitter power. To check the operation of the multivibrator, you need to turn on high-impedance headphones between the VT2 collector and the plus of the power source. When the SB1 button is closed, a low-tone sound should be heard in the headphones, corresponding to the frequency of the multivibrator. To check the performance of the HF generator, it is necessary to assemble a wavemeter according to the diagram in Fig. 22.5. The circuit is a simple detector receiver in which the L1 coil is wound with a PEV-1 wire 1 ... 1,2 and contains 10 turns with a tap from 3 turns. The coil is wound with a pitch of 4 mm on a plastic frame Ø 25 mm. A DC voltmeter with a relative input resistance is used as an indicator.

Figure: 22.5. Schematic diagram of the wavemeter for tuning the transmitter
10 kOhm / V or microammeter for a current of 50 ... 100 μA. The wavemeter is collected on a small plate of foil-clad fiberglass with a thickness of 1.5 mm. After turning on the transmitter, place a wave meter from it at a distance of 50 ... 60 cm. With a working HF generator, the wavemeter needle deviates at a certain angle from the zero mark. By tuning the RF generator to a frequency of 27.12 MHz, shifting and expanding the turns of the L2 coil, the maximum deflection of the voltmeter needle is achieved. The maximum power of the high-frequency oscillations emitted by the antenna is obtained by rotating the core of the coil L1. The transmitter setting is considered complete if the voltmeter of the wave meter at a distance of 1 ... 1.2 m from the transmitter shows a voltage of at least 0.05 V.
Radio-controlled model receiver.

To control the model, radio amateurs quite often use receivers built according to the super-regenerator scheme. This is due to the fact that a super-regenerative receiver, having a simple design, has a very high sensitivity, of the order of 10 ... 20 μV. The super-regenerative receiver circuit for the model is shown in Fig. 22.6. The receiver is assembled on three transistors and is powered by a "Krona" battery or another 9V source. The first stage of the receiver is a self-extinguishing super-regenerative detector based on a VT1 transistor. If a signal is not received at the antenna, then this stage generates pulses of high-frequency oscillations, following with a frequency of 60 ... 100 kHz. This is the quenching frequency, which is set by the capacitor C6 and the resistor R3. Gain you-

Figure: 22.6. Schematic diagram of a super-regenerative receiver of a radio-controlled model

the divided command signal by the super-regenerative detector of the receiver is as follows. Transistor VT1 is switched on according to a common base circuit, and its collector current pulsates with a blanking frequency. In the absence of a signal at the input of the receiver, these pulses are detected and create a certain voltage across the resistor R3. At the moment the signal arrives at the receiver, the duration of individual pulses increases, which leads to an increase in the voltage across the resistor R3. The receiver has one input circuit LI, C4, which is tuned to the transmitter frequency by means of the L1 coil core. The connection of the loop with the antenna is capacitive. The control signal received by the receiver is isolated at the resistor R4. This signal is 10 ... 30 times less than the blanking frequency voltage. To suppress interfering voltage with a quenching frequency, a filter L3, C7 is included between the super-regenerative detector and the voltage amplifier. In this case, the voltage of the quenching frequency at the filter output is 5 ... 10 times less than the amplitude of the useful signal. The detected signal through the blocking capacitor C8 is fed to the base of the transistor VT2, which is a low-frequency amplification stage, and then to electronic relaycollected on a transistor VT3 and diodes VD1, VD2. The signal amplified by transistor VT3 is rectified by diodes VD1 and VD2. The rectified current (negative polarity) is supplied to the base of the transistor VT3. When a current appears at the input of the electronic relay, the collector current of the transistor increases and relay K1 is activated. A 70 ... 100 cm long rod can be used as a receiver antenna. The maximum sensitivity of a super-regenerative receiver is set by selecting the resistance of the resistor R1.
The receiver is mounted in a printed manner on a board made of foil-clad fiberglass with a thickness of 1.5 mm and dimensions of 100x65 mm. The receiver uses the same types of resistors and capacitors as the transmitter. The coil of the superregenerator circuit L1 has 8 turns of PELSHO 0.35 wire, wound turn to turn on a polystyrene frame Ø 6.5 mm, with a 100NN trimmer ferrite core 2.7 mm in diameter and 8 mm long. The inductors have inductance: L2 - 8 μH, and L3 - 0.07 ... 0.1 μH. Electromagnetic relay K1 type RES-6 with a winding resistance of 200 Ohm. Receiver tuning begins with a super-regenerative stage. Connect high-impedance headphones in parallel with the capacitor C7 and turn on the power. The noise that appears in the headphones indicates that the super-regenerative detector is working properly. By changing the resistance of the resistor R1, the maximum noise in the headphones is achieved. The voltage amplification cascade on the VT2 transistor and the electronic relay do not require special adjustment. By selecting the resistance of the resistor R7, the sensitivity of the receiver is about 20 μV. The final setting of the receiver is done together with the transmitter. If you connect headphones in the receiver parallel to the winding of the K1 relay and turn on the transmitter, then a loud noise should be heard in the headphones. Tuning the receiver to the transmitter frequency causes the noise in the headphones to disappear and the relay is triggered.

Basic technical data

The radio control system allows you to remotely control the toy at a distance of up to 10 meters.
The working frequency of the transmitter is 27.12 MHz.
The transmitter power is within 4-10 mW.
Current consumption by the transmitter is not more than 20 mA.
The weight of the transmitter with antenna and power supply is not more than 150 g.
Receiver sensitivity in the operating frequency band is not worse than 100 μV.
The current consumption of the receiver is not more than 20 mA.
Receiver weight no more than 70 g.
The command apparatus provides the execution of four different commands, which are repeated periodically.
The weight of the command apparatus is not more than 70 g.
The receiver and transmitter are powered by Krona-VTs batteries.

Principle of operation

The transmitter consists of a modulator and a high frequency generator (Fig. 1). The transmitter modulator is a symmetrical multivibrator assembled on low-frequency transistors VT2 and VT3 of the MP40 type.

The high-frequency generator is assembled on a VT1 transistor of the P416 type according to the circuit with a capacitive feedback... When the VT2 modulator transistor is open, the generator circuit is closed to the battery plus, the generator is excited at the operating frequency, the high frequency signal is emitted by the antenna.

The receiver consists of a high frequency stage, a low frequency amplifier and an electronic relay.

The high-frequency stage of the receiver is a super-regenerator. The super-regenerator is assembled on a high-frequency transistor VT1 of the P416 type (Fig. 2).

In the absence of a signal on the emitter chain C5 R3, fluctuations in the quenching frequency are observed. The quenching frequency determines the sensitivity of the super-regenerator at its operating frequency and is selected by elements C5, R3.

The transmitter command signal is selected by the L1-C4 circuit, amplified and detected by the super-regenerator. The R4-C8 filter passes the low-frequency command signal to the input of the amplifier VT2, while separating the quenching frequency of a higher order.

The electronic relay is assembled on transistors VT3-VT4 of the MP40 type, and the collector of the VT4 transistor is connected to the executive relay KR of the RSM-1 type.

The low-frequency voltage of the command signal is amplified by transistors VT3-VT4 and fed through the capacitor C13 to the rectifying cell UD1, UDZ.

The rectified voltage through the resistor R9 is fed to the base of the transistor VT3. In this case, the emitter current of the transistor VT3 increases sharply, the transistor VT4 opens. The relay is energized, closing the power supply of the controller motor.

The command device consists of an electric motor, a ratchet mechanism, a program disk and distribution sliding contacts. The program disk, the side of which is a system of jumpers, commutes through the distribution sliding contacts the power supply of the drive motors and other electrical elements of the toy.

Description electrical circuit radio controlled toy

The diagram (Fig. 3) shows one of the options for the electrical equipment of a radio-controlled toy.

The toy has two drive motors that provide forward movement and turns left and right. The toy's rear light bulbs serve as turn signals. Two headlights create the effect of illuminating the path of the toy.

Fig. 3

To receive command signals from the transmitter, a receiver and a Command device are mounted in the toy. The drive motor and the controller, as well as the light bulbs, are powered by two series-connected batteries of type 3336L (U) (GB1). The receiver is powered by the Krona-VTs battery (GB2). A two-pole switch S is used to turn off the battery. When a command signal is received from the transmitter, the relay KR, the receiver, and its contacts turn on the electric motor of the controller (Fig. 4) of the MZ.

Fig. 4. Command apparatus

The electric motor МЗ, using a ratchet mechanism, rotates the program disk by 30 °, which corresponds to switching one command.

The program disc, through the distribution sliding contacts, switches on the drive motors and the toy bulbs as follows:

In the forward position, contacts 1, 2, 3, 4 are closed, while motors M1 and M2 are on, as well as lamps H1, H2, NC, H4.

In the "right" position, contacts 1, 2 are closed, while the M1 motor and the NC light are on.

In the stop position, all contacts are open.

In the "left" position, contacts 1, 3 are closed, while the M2 motor and the H4 lamp are on.

The teams change periodically. The diagram shows a sequence of commands in one cycle.

Installation and commissioning instructions

It is advisable to place the receiver in the toy at the maximum distance from the email. motors and electromagnets. To protect the receiver from interference caused by electric motors, it is recommended to connect electrolytic capacitors of 10-20 microfarads with an operating voltage of 10-12 volts in parallel to the electric motors, observing the polarity of switching on. An antenna must be connected to the receiver. A pin or wire with a diameter of 1.0-2.0 mm and a length of at least 20 cm can be used as an antenna. The antenna must be isolated from the toy body. Parts made of ceramics, fluoroplastic, plexiglas or polystyrene can be used as insulators. With increasing antenna length, the control range increases. The receiver must be covered with an insulating cover to protect it from dust and moisture. The distance from the printed circuit board to the base on which the receiver is mounted must be at least 5 mm.
After installing the electrical circuit and checking the functionality (the order of switching on is indicated below), it is necessary to adjust the receiver to the maximum sensitivity. The adjustment is carried out using a capacitor C4 (see the schematic diagram and drawing of the receiver). Turning the capacitor rotor with an insulating screwdriver, it is necessary to find the position at which the relay is activated at the maximum distance from the transmitter toy.

The commander is fixed on a horizontal platform using legs.

For radio control of various models and toys, discrete and proportional equipment can be used.

The main difference between the proportional and discrete equipment is that it allows the operator to deflect the rudders of the model to any required angle and smoothly change the speed and direction of its movement "Forward" or "Backward".

The construction and adjustment of proportional action equipment is rather complicated and not always within the power of a novice radio amateur.

Although the discrete-action equipment has limited capabilities, it is possible to expand them using special technical solutions. Therefore, further we will consider a single-command control equipment suitable for wheeled, flying and floating models.

Transmitter circuit

Experience shows that to control models within a radius of 500 m, it is enough to have a transmitter with an output power of about 100 mW. The transmitters of radio-controlled models typically operate in the 10m range.

One-command model control is carried out as follows. When the control command is given, the transmitter emits high-frequency electromagnetic waves, in other words, generates one carrier frequency.

The receiver, which is on the model, receives the signal sent by the transmitter, as a result of which the actuator is triggered.

Figure: 1. Schematic diagram of the transmitter of the radio-controlled model.

As a result, the model, obeying the command, changes the direction of movement or carries out one pre-set in the design of the model indication. Using a single command control model, you can make the model perform fairly complex movements.

A schematic of a single-command transmitter is shown in Fig. 1. The transmitter includes a master oscillator of high frequency and a modulator.

The master oscillator is assembled on a VT1 transistor according to the capacitive three-point circuit. The L2, C2 circuit of the transmitter is tuned to the frequency of 27.12 MHz, which is allocated by the State Communications Supervision of Telecommunications for radio control of models.

The mode of operation of the generator for direct current is determined by the selection of the value of the resistance of the resistor R1. The high-frequency oscillations created by the generator are radiated into space by an antenna connected to the circuit through a matching inductor L1.

The modulator is made on two transistors VT1, VT2 and is a symmetrical multivibrator. The modulated voltage is removed from the collector load R4 of the transistor VT2 and supplied to the common power supply circuit of the transistor VT1 of the high-frequency generator, which provides 100% modulation.

The transmitter is controlled by the SB1 button included in the common power supply circuit. The master generator does not work continuously, but only when the SB1 button is pressed, when current pulses generated by the multivibrator appear.

The high-frequency oscillations created by the master oscillator are sent to the antenna in separate portions, the repetition rate of which corresponds to the pulse frequency of the modulator.

Transmitter parts

Transistors with base current transfer ratio h21e not less than 60 are used in the transmitter. Resistors of MLT-0.125 type, capacitors - K10-7, KM-6.

The matching antenna coil L1 has 12 turns of PEV-1 0.4 and is wound on a unified frame from a pocket receiver with a tuning ferrite core brand 100NN with a diameter of 2.8 mm.

The L2 coil is frameless and contains 16 turns of PEV-1 0.8 wire wound on a mandrel with a diameter of 10 mm. The MP-7 microswitch can be used as a control button.

The parts of the transmitter are mounted on a printed circuit board made of foil-clad fiberglass. The antenna of the transmitter is a piece of elastic steel wire 1 ... 2 mm in diameter and about 60 cm long, which is connected directly to the X1 socket located on the printed circuit board.

All parts of the transmitter must be enclosed in an aluminum housing. There is a control button on the front panel of the case. A plastic insulator must be installed where the antenna passes through the housing wall to socket XI to prevent the antenna from touching the housing.

Establishing a transmitter

With known serviceable parts and correct installation, the transmitter does not require special setup. It is only necessary to make sure that it works and, by changing the inductance of the L1 coil, achieve the maximum transmitter power.

To check the operation of the multivibrator, you need to turn on high-impedance headphones between the VT2 collector and the plus of the power source. When the SB1 button is closed, a low-tone sound should be heard in the headphones, corresponding to the frequency of the multivibrator.

To check the performance of the RF generator, it is necessary to assemble a wavemeter according to the diagram in Fig. 2. The circuit is a simple detector receiver in which the L1 coil is wound with a PEV-1 wire with a diameter of 1 ... 1.2 mm and contains 10 turns with a tap from 3 turns.

Figure: 2. Schematic diagram of the wave meter for tuning the transmitter.

The coil is wound with a pitch of 4 mm on a plastic frame with a diameter of 25 mm. A DC voltmeter with a relative input resistance of 10 kΩ / V or a microammeter for a current of 50 ... 100 μA is used as an indicator.

The wavemeter is collected on a small plate of foil-clad fiberglass with a thickness of 1.5 mm. Having turned on the transmitter, place a wavemeter from it at a distance of 50 ... 60 cm. With a working HF generator, the wavemeter arrow deviates by a certain angle from the zero mark.

By tuning the RF generator to a frequency of 27.12 MHz, shifting and expanding the turns of the L2 coil, the maximum deflection of the voltmeter needle is achieved.

The maximum power of the high-frequency oscillations emitted by the antenna is obtained by rotating the core of the coil L1. The transmitter setting is considered complete if the voltmeter of the wave meter at a distance of 1 ... 1.2 m from the transmitter shows a voltage of at least 0.05 V.

Receiver circuit

To control the model, radio amateurs quite often use receivers built according to the super-regenerator scheme. This is due to the fact that a super-regenerative receiver, having a simple design, has a very high sensitivity, of the order of 10 ... 20 μV.

The super-regenerative receiver circuit for the model is shown in Fig. 3. The receiver is assembled on three transistors and is powered by a battery of the "Krona" type or another 9 V source.

The first stage of the receiver is a self-extinguishing super-regenerative detector based on a VT1 transistor. If a signal is not received at the antenna, then this stage generates pulses of high-frequency oscillations, following with a frequency of 60 ... 100 kHz. This is the quenching frequency, which is set by the capacitor C6 and the resistor R3.

Figure: 3. Schematic diagram of a super-regenerative receiver of a radio-controlled model.

The amplification of the selected command signal by the super-regenerative detector of the receiver is as follows. Transistor VT1 is switched on according to a common base circuit and its collector current pulses with a blanking frequency.

In the absence of a signal at the input of the receiver, these pulses are detected and create a certain voltage across the resistor R3. At the moment the signal arrives at the receiver, the duration of individual pulses increases, which leads to an increase in the voltage across the resistor R3.

The receiver has one input circuit L1, C4, which is tuned to the transmitter frequency with the help of the L1 coil core. The connection of the loop with the antenna is capacitive.

The control signal received by the receiver is isolated at the resistor R4. This signal is 10 ... 30 times less than the blanking frequency voltage.

To suppress interfering voltage with a quenching frequency, a filter L3, C7 is included between the super-regenerative detector and the voltage amplifier.

In this case, the voltage of the quenching frequency at the filter output is 5 ... 10 times less than the amplitude of the useful signal. The detected signal through the blocking capacitor C8 is fed to the base of the transistor VT2, which is a low-frequency amplification cascade, and then to an electronic relay assembled on the ТЗ transistor and diodes VD1, VD2.

The signal amplified by the истТЗ transistor is rectified by the diodes VD1 and VD2. The rectified current (negative polarity) is fed to the base of the ѴТЗ transistor.

When a current appears at the input of the electronic relay, the collector current of the transistor increases and relay K1 is activated. A 70 ... 100 cm long rod can be used as a receiver antenna. The maximum sensitivity of a super-regenerative receiver is set by selecting the resistance of the resistor R1.

Receiver parts and mounting

The receiver is mounted in a printed manner on a board made of foil-clad fiberglass with a thickness of 1.5 mm and dimensions of 100x65 mm. The receiver uses the same types of resistors and capacitors as the transmitter.

The coil of the superregenerator circuit L1 has 8 turns of PELSHO 0.35 wire, wound to turn on a polystyrene frame with a diameter of 6.5 mm, with a 100NN trimmer ferrite core with a diameter of 2.7 mm and a length of 8 mm. The inductors have an inductance: L2 - 8 μH, and L3 - 0.07 ... 0.1 μH.

Electromagnetic relay K1 type RES-6 with a winding resistance of 200 Ohm.

Receiver setup

Receiver tuning begins with a super-regenerative stage. Connect high-impedance headphones in parallel with the capacitor C7 and turn on the power. The noise that appears in the headphones indicates that the super-regenerative detector is working properly.

By changing the resistance of the resistor R1, the maximum noise in the headphones is achieved. The voltage amplification cascade on the VT2 transistor and the electronic relay do not require special adjustment.

By selecting the resistance of the resistor R7, the sensitivity of the receiver is about 20 μV. The final setting of the receiver is done in conjunction with the transmitter.

If you connect headphones in the receiver in parallel with the coil of relay K1 and turn on the transmitter, then a loud noise should be heard in the headphones. Tuning the receiver to the transmitter frequency causes the noise in the headphones to disappear and the relay is triggered.