The proposed switch (Fig.1) smoothly lights the incandescent lamp EL1 when you receive a call signal and gradually extinguish its completion. Alarm does not respond to the dialing and other impulse noise, which may be a telephone line. In order not to complicate the diagram, used a specialized chip CRM designed to work in phase power regulators. This chip allows you to control incandescent lamps up to 150 watts and can withstand without damage the effective value of voltage of up to 280 V. the Chip requires a minimum of hinged elements, and to increase the maximum power you can use the load parallel switching of several chips.
Fig. 1. A schematic diagram of a light switch phone calls
Impulse voltage ringing frequency 13...50 Hz and an amplitude of 80...200 via protective resistors R1, R2 and coupling capacitors C1, C2 is supplied to the rectifier bridge VD1. The pulses of the rectified voltage smoothing capacitor NW, led lights HL1. The inclusion of current-limiting resistors R1, R2 in both wires of the telephone line to prevent damaging of the telephone devices and PBX equipment in the breakdown of isolation optocoupler VU1, the likelihood of which cannot be completely eliminated.
For a sufficiently large amplitude of the input signal as a phototransistor optocoupler VU1. Thus shunted circuit gate-source n-channel field-effect transistor VT2, and it closes. Capacitor C8 smoothly is charged up to voltage 2...4 internal current source circuits DA1. At this time, gently lit the lamp load EL1. The power supplied to the load, depends on the difference of the voltages of the pins 3 and 6 DA1. At the end of the call or during pauses between calls, capacitor C3 is discharged, the current through the led of the optocoupler is terminated, the phototransistor is closed, the transistor VT2 opens and discharges through resistor R8 and capacitor C8, lamp EL1 goes off smoothly.
Transistor VT1 works as Micropower voltage reference diode with voltage stabilization 6...10 V. the Varistor R10 prevents damage to the chip during high-power pulsed interference in lighting network or when a significant emergency increase of the supply voltage. Dwukrotnie led HL2 indicates the presence of supply voltage is 220 V. the Elements R3, C4, L1, C7, L2 reduce the level of interference that can penetrate the lighting network when the detector.
Fig. 2. The Pinout of the transistors and current keys
The device can be used fixed resistors S1-4, S2-23 MLT appropriate power. The trimmer - type GPA-386, RP1-63 or imported compact. Varistor - type FNR-20K431, FNR-10K431, FNR-20K39 or semiconductor voltage limiter XAS. Oxide capacitors - type K50-35, C50-24, K53-19, K53-4 or import, for example, firms "Rubycon", "DON". Capacitors C1, C2, C4, C11 - film, type K73-17, K73-24V, K73-39, on the operating voltage of not lower than 400 V; C7 - ceramic K15-5; C9, XU can be of any type, including oxide. To ensure an earlier opening of the thyristor chip keys, the capacitance of these capacitors is reduced to half. VD1 diode bridge can be replaced by CZW...G, DB102...DB107, RW152...RW157. Diode VD2 - any of the series KD, KD, KD...AND G, CDG...WELL, n4004 cameras and 1... 1 N4007. Led L1543SRC/E high-brightness red glow can be replaced by any similar, for example, series L1503S, L1513S, L383S, CIPD, CIPD, CIPD.
Dwukrotnie HL2 will replace any of the series L117, L57, L937, CIPD, CIPD. OPTRON AOTA, having a voltage galvanic isolation 1500 V, can be replaced by 4N35, 4N26, TIL111. Transistor VT1 you can install any of the series KT315, CT, CT, or apply in its place Micropower voltage reference diode SC, SC, SC. N-channel field effect transistor enriched type VT2 can be replaced by CPB, CPV, VN2120, ZVN2120 or current keys CCT, KR1014KT1, KRKT. Their Pinout is shown in Fig.2. Inductors L1, L2 can be fabricated on a ferrite ring cores MNM-AND with an outer ring diameter of at least 24 mm coils contain 90 turns of wire sew-2 mm. 00,37 Ferrite ring before winding pre-varnished cloth or wrapped PTFE film. Ready chokes impregnated with varnish or compound. The device is mounted on the PCB size 100x75 mm from unilateral foiled fiberglass (Fig.3). The configuration comes down to setting a resistance of the trimming resistor R5 that the lamp was lit only when you receive a ringing signal.
Fig. 3. The printed circuit Board of the light switch phone calls
Because the device is electrically connected to the voltage lighting network, for configuration and operation must comply with the adopted in such cases security measures.
Literature
Author: A. Butov, This email address is being protected from spambots. You must have JavaScript enabled to view it. , S. CORBA, Yaroslavl region; Publication: www.radioradar.net