| 摘要 |
<p>Module serves for connecting a housephone to a phone line after ringing to telephone user, whereby a housephone is connected only for a limited time. The module also serves for easy identification of persistent command for electric lock with possibility its switch-off until fault clearing. The module consists of a jack (CH) connected with an emitter of a transistor (T 1), condenser (C2), resistor (R) and with negative pin of condenser (C1). The positive pin of the condenser (C1) is connected with a cathode of diode (D1), anode of which is connected to jack (A), a positive pin of condenser (C) is connected trough resistor (R1) with potentiometer, the second pin and a follower of which are connected to the second pin of resistor (R2), the second pin of condenser (C2) and a base of transistor (T1), collector of which is connected to a coil of a relay (RE1). The first switch contact of the relay (RE1) connects jacks (E, H), whereby the second pin of the coil of the relay (RE1) is connected with a cathode of diode (D1), whereby jack (B) is connected through switch (V1) and resistor (R3) to jack (C), whereby a cathode of diode (D2) is connected to the second pin of switch (V1) and anode of diode (D2) is connected to jack (C).</p> |
