Telephony. Telephony For the "power surge protection"

When used as a listening device (eg rooms). One of the options is connected in parallel with the lighting lamp under the ceiling.

Circuit diagram 1

For transmission, frequency modulation and a carrier frequency of 94 kHz are used. The device is powered from the mains. The excess is extinguished by a capacitor and the undervoltage is rectified by a diode bridge. Then it is filtered and limited by the KS520 Zener diode and used to power the output stage at VT1. The voltage taken from the KS210 Zener diode is used to power the rest of the device. The low frequency signal from the microphone is amplified in a cascade at VT2 and fed to a voltage-controlled square-wave generator at DD1 (FM modulator). The initial frequency of the generator is set, in the absence of a signal from the microphone, equal to 94 kHz using a trimming resistor.

Further, the signal from the generator is fed to the output stage at VT1. A transformer is included in the collector circuit, the primary winding of which is tuned to the carrier frequency. The transformer core and windings are insulated with fluoroplastic or something similar. The transformer on the W-iron worked very badly!

The adjustment is carried out using an IP in the region of 27 volts, connected with a plus to point A on the diagram. Having short-circuited the VT2 base, the tuning resistor sets the generator frequency to 94 kHz. The output stage is tuned by selecting a capacitor in the collector circuit to minimize the distortion of the sine wave or, if there is no oscilloscope, to the maximum signal on the secondary winding of the transformer (DO NOT FIT THE SECOND HARMONIC!).

RECEIVER

It was too lazy to invent anything and therefore a converted car VHF radio was used. The first local oscillator with quartz stabilization at 10.794 (10.606) kHz. Quartz at 10800 took 6 kHz lower. The standard piezofilter with a passband of 300 kHz (a small one with three legs! :-)) was replaced by a filter from the Len radio station with a bandwidth of 15 kHz to suppress the mirror reception channel. Instead of a phase-shifting circuit K174UR3 used quartz at a frequency of 10700 kHz (deviation is less). UHF was not used, and the signal to the mixer was fed through a double-loop band-pass filter at a frequency of 94 kHz, made on rings with data similar to the transmitter transformer.

For trial, ready-made coils for this frequency from the army r / receivers r-155 (or r-873) were tested. It is she who is used in the synthesizers of these receivers in one of the PLL rings. The results were better (most likely due to the higher Q factor).

This scheme was originally conceived for communication over a radio network. That is why the carrier is 94 kHz and is located between the frequencies of the second (78 kHz) and third (120 kHz) programs. True, the power supply was done separately, and the output stage of the transmitter was loaded onto an additional winding of a standard transformer from a subscriber radio receiver. Well, I don’t remember how many turns! The receiver was connected to the existing secondary winding. Then the desire to invent and improve was gone.

BE CAREFUL WITH THE TRANSMITTER! POWER SUPPLY IS TRANSFORMER FREE!

220 VN MARUSHKEVICH, 220040, Minsk, Vostochnaya st., 38 - 314. The use of such devices justifies itself in negotiations within the same house or neighboring houses, because it is impractical to use a radio station at such distances, and the telephone is now paid by the minute. The principle of operation of these devices is based on the fact that electric wires networks Electromagnetic vibrations with a frequency of 10 kHz to 100 kHz can be transmitted, and they can propagate unhindered to the nearest transformer. In its simplest form, this is an RF generator (Fig. 1) and a detector receiver with an ULF (Fig. 2). The auto-generator is assembled according to the usual push-pull circuit. Triac ts106-10 voltage regulator circuit It is modulated in amplitude by a carbon microphone VM1, included in the supply circuit of the VT2, VT3 collectors. Coils L1 ... L4 are placed in cores SB-12 or similar. It is important that L1 and L4 are identical in the number of turns, wire diameter and winding method. L1 contains 100 turns with a center tap. Wire - 0.1 ... 0.15 mm in diameter. Both halves of the coil are wound in different sections of the bobbin, i.e. half - in one section and half - in the other. L2 contains about 50 turns of wire with a diameter of 0.1 ... 0.15 mm and is wound over L1.L4 - 100 turns; is wound similarly to L1, but without a tap. L3 - 50 turns, on top of L4. To increase the operating range ...

For the diagram "Indication of connecting electrical appliances to a 220 V network"

For "Switching device with automatic charger"

A diagram of a switching device with a charger is shown in the figure. In the presence of mains voltage by contacts K1.1 and K1.2, the load is connected to the network, by contact K3.1 the battery is connected to the charger. If contacts K1.1 and K1.2 fail, the load is connected to the secondary winding of the transformer T1 of the voltage converter. With contacts K2.1, the converter is connected to the battery. ...

For the "OVERVOLTAGE PROTECTION DEVICE" circuit

For the circuit "Voltage level indicator in the network"

I offer the simplest signaling device of voltage out of the established limits. Its circuit is shown in the figure. Resistor R2 is selected so that the HL1 neon lamp is turned on only at a voltage of more than 190 V. And by selecting the resistor R4, the HL2 lamp is turned on only at a voltage exceeding 240 V. Thus, at a voltage of less than 190 V, the lamps are turned off, in the interval 190. ..240 V one of them shines, and at an even higher voltage - both. In the device, you can use neon lamps not only of the type indicated in the diagram, but also any others with an operating current of no more than 1 ... 2 mA Ya. MANDRIK, Chernivtsi, Ukraine ...

For the scheme "Home network overvoltage protection circuit breaker"

Due to electrical instability (especially in rural areas) and overvoltage, household appliances can get out of order: electric bulbs, various heating devices, electric motors of refrigerators and other devices, radio equipment, etc. I offer an automatic machine that monitors the state of electrical networks and automatically disconnects and shuts down the load. The load will be put into operation only in the normal state of the electrical network. The threshold circuit is powered from networks through damping resistors R3, R4 and diodes VD1 ... VD4. Zener diode VD8 serves to stabilize the supply voltage of the circuit. Changing voltage networks goes through the diode bridge VD1 ... VD4 to the divider R1, R2. From the slider of the resistor R2, which sets the trigger voltage of the device, the control voltage is supplied through the VD5 diode to the base of the transistor VT1. Do-it-yourself charger for a miner's lantern The VD6 Zener diode serves to protect the transistor from high voltages. With a voltage of networks more than normal, the voltage at the base of the transistor rises, it opens and turns on relay K1. Contacts K1.1 close, relay K2 is activated and disconnects the load by contacts K2.1. After the voltage is restored in the electrical relay, K1 de-energizes, disconnects relay K2, which by contacts K2.1 turns on the load. LEDs VD10, VD12 serve to indicate the state of the device. Relay K2 - any with an operating voltage of the winding of 220 V, K1 - also any of the RES-9 series; Applying the device is reduced to the setting by the resistor R2 of the voltage of the circuit breaker. Basenkov, Dobrush ...

For the scheme "Protection device"

For the "FUSE BURNT INDICATOR" circuit

FUSE BURNING INDICATOR Fuse and thermal fuses are used to protect electronic equipment from current overloads. After the fuse has blown, the equipment turns out to be inoperative, therefore, a timely response to the protection operation allows you to quickly eliminate the cause of the malfunction and start the equipment again. The suggested one indicates the blown fuse with short sound and light signals. The indicator is made in the form of a two-terminal device connected in parallel to the fuse in a circuit of a continuous or alternating current with a frequency of up to 1 kHz and a voltage of 10 ... 1000 V. The device includes a current limiter on resistors R1 and R2, a bridge diode rectifier (VD1 ... VD4 ), elements of sound (BQ1) and light (HL1) indication and negatron, made on transistors VT1, VT2 and resistors R3, R4. Intercom electronics PU-02 As a timing capacitor, the device uses a piezoceramic emitter BQ1, which, if only LED indication is used, can be replaced by a capacitor with a capacity of 0.022 .., 0.5 μF. When the fuse blows, the mains voltage is applied to the indicator and generates intermittent light and sound signals (clicks). It is assumed that the load resistance is finite and does not exceed several megohms. To indicate that the fuse has blown when the load is interrupted, a resistor of 1 ... 2 MΩ can be connected in parallel with RH. The residual current flowing through the load and indicator at a voltage of 220 V does not exceed 0.5 mA A. M. SHUSTOV, A. SHUSTOV, Tomsk (RL 2-99) ...

For the scheme "PROTECTION OF REA AGAINST VOLTAGE SURGE"

Power supply PROTECTION OF REA AGAINST VOLTAGE SURGE device protection of equipment from power surges. Unlike those described earlier, the proposed device does not turn on again when the normal mains voltage is restored. Switching on occurs only after pressing the "ON" button. This is necessary when the equipment is in the on state without supervision, and the mains supply at this hour starts to "jump" or turn off many times. We will consider the operation of the device according to the principle diagram. The C1-R1 chain creates, when the SB1 button is closed, the starting current of the relay K1. The current through the C2-R3 chain keeps the relay energized. The capacitance C2 is selected so that when the voltage drops to 160 V. The relay is disconnected when the voltage rises to 250 V. An emergency shutdown when the voltage rises to 250 V occurs due to the shunting of the relay coil by the thyristor VS1. VS1 opens under the management of the VU1 optocoupler. Elshemes of voltage converters Zener diodes VD10, VD11 and resistor R4 are selected so that VS1 opens at a voltage higher than 250 V. Optocoupler VU1 should be with a management current of approximately 20 mA. It can be replaced with a small isolation transformer. It is switched on by the secondary winding instead of R2. Relay K1 can be of any type with contacts that can withstand the maximum load current (RES9, RES22, RENZZ). For each type of relay, it is necessary to select capacities: C1 - for reliable switching on of the device and C2 - for shutdown when the voltage drops to 160 ... 170 V. The total stabilization voltage VD10, VD11 should be approximately 330 ... 340 V. You can use other zener diodes types, for example D817. Instead of the VD6 ... VD9 bridge, you can use one diode (KD209), connected in series with VD 10, VD 11. At the same time, it is controlled ...

Tell in:
Intercom over a 220 V network When used as a listening device (for example, premises). One of the options is connected in parallel with the lighting lamp under the ceiling. circuit diagram 1
circuit diagram 2 For transmission, frequency modulation and a carrier frequency of 94 kHz are used. The device is powered from the mains. The excess is extinguished by a capacitor and the undervoltage is rectified by a diode bridge. Then it is filtered and limited by the KS520 Zener diode and used to power the output stage at VT1. The voltage taken from the KS210 Zener diode is used to power the rest of the device. The low frequency signal from the microphone is amplified in a cascade at VT2 and fed to a voltage-controlled square-wave generator at DD1 (FM modulator). The initial frequency of the generator is set in the absence of a signal from the microphone equal to 94 kHz using a trimming resistor. Further, the signal from the generator is fed to the output stage at VT1. A transformer is included in the collector circuit, the primary winding of which is tuned to the carrier frequency. The transformer core and windings are insulated with fluoroplastic or something similar. The transformer on the W-iron worked very badly! The adjustment is carried out using an IP in the region of 27 volts connected with a plus to point A on the diagram. Short-circuiting the VT2 base with a trimming resistor, set the generator frequency to 94 kHz. The output stage is tuned by selecting a capacitor in the collector circuit to minimize the distortion of the sinusoid or if there is no oscilloscope for the maximum signal on the secondary winding of the transformer (DO NOT FIT THE SECOND HARMONY!). RECEIVER It was too lazy to invent something and therefore a converted VHF car radio was used. The first local oscillator with quartz stabilization at 10 794 (10 606) kHz. Quartz at 10800 took 6 kHz lower. The standard piezofilter with a passband of 300 kHz (a small one with three legs! :-)) was replaced by a filter from the Len radio station with a bandwidth of 15 kHz to suppress the mirror reception channel. Instead of a phase-shifting circuit K174UR3 used quartz at a frequency of 10700 kHz (deviation is less). UHF was not used and the signal to the mixer was fed through a double-loop bandpass filter at a frequency of 94 kHz, made on rings with data similar to the transmitter transformer. For trial, ready-made coils for this frequency from the army r / receivers r-155 (or r-873) were tested. It is she who is used in the synthesizers of these receivers in one of the PLL rings. The results were better (most likely due to the higher Q factor). This scheme was originally conceived for communication over a radio network. That is why the carrier is 94 kHz and is located between the frequencies of the second (78 kHz) and third (120 kHz) programs. True, the power was made separately and the output stage of the transmitter was loaded onto an additional winding of a standard transformer from a subscriber radio receiver. Well, I don’t remember how many turns! The receiver was connected to the existing secondary winding. Then the desire to invent and improve was gone. BE CAREFUL WITH THE TRANSMITTER! POWER SUPPLY IS TRANSFORMER FREE! Everything within the building worked with a bang! We did not try further. I do not pretend to be the author. the scheme uses standard solutions that are given in many reference publications. Alexey Koscheev UA4NFX
2:5056/16.13
[email protected] Section:

When used as a listening device (eg rooms). One of the options is connected in parallel with the lighting lamp under the ceiling.

For transmission, frequency modulation and a carrier frequency of 94 kHz are used. The device is powered from the mains. The excess is extinguished by a capacitor and the undervoltage is rectified by a diode bridge. Then it is filtered and limited by the KS520 Zener diode and used to power the output stage at VT1. The voltage taken from the KS210 Zener diode is used to power the rest of the device. The low frequency signal from the microphone is amplified in a cascade at VT2 and fed to a voltage-controlled square-wave generator at DD1 (FM modulator). The initial frequency of the generator is set, in the absence of a signal from the microphone, equal to 94 kHz using a trimming resistor.

Circuit diagram 1

Circuit diagram 2

Further, the signal from the generator is fed to the output stage at VT1. A transformer is included in the collector circuit, the primary winding of which is tuned to the carrier frequency. The transformer core and windings are insulated with fluoroplastic or something similar. The transformer on the W-iron worked very badly!

The adjustment is carried out using an IP in the region of 27 volts, connected with a plus to point A on the diagram. Having short-circuited the VT2 base, the tuning resistor sets the generator frequency to 94 kHz. The output stage is tuned by selecting a capacitor in the collector circuit to minimize the distortion of the sine wave or, if there is no oscilloscope, to the maximum signal on the secondary winding of the transformer (DO NOT FIT THE SECOND HARMONIC!).

RECEIVER

It was too lazy to invent anything and therefore a converted car VHF radio was used. The first local oscillator with quartz stabilization at 10.794 (10.606) kHz. Quartz at 10800 took 6 kHz lower. The standard piezofilter with a passband of 300 kHz (a small one with three legs! :-)) was replaced by a filter from the Len radio station with a bandwidth of 15 kHz to suppress the mirror reception channel. Instead of a phase-shifting circuit K174UR3 used quartz at a frequency of 10700 kHz (deviation is less). UHF was not used, and the signal to the mixer was fed through a double-loop band-pass filter at a frequency of 94 kHz, made on rings with data similar to the transmitter transformer.

For trial, ready-made coils for this frequency from the army r / receivers r-155 (or r-873) were tested. It is she who is used in the synthesizers of these receivers in one of the PLL rings. The results were better (most likely due to the higher Q factor).

This scheme was originally conceived for communication over a radio network. That is why the carrier is 94 kHz and is located between the frequencies of the second (78 kHz) and third (120 kHz) programs. True, the power supply was done separately, and the output stage of the transmitter was loaded onto an additional winding of a standard transformer from a subscriber radio receiver. Well, I don’t remember how many turns! The receiver was connected to the existing secondary winding. Then the desire to invent and improve was gone.

BE CAREFUL WITH THE TRANSMITTER! POWER SUPPLY IS TRANSFORMER FREE!