Circuit diagram of memorial anti-toll-fraud alarm

Published:2011/8/9 20:47:00 Author:Vicky | Keyword: memorial anti-toll-fraud alarm | From:SeekIC

Memorial anti-toll-fraud alarm Despite the functions of general anti-toll-fraud telephone, the telephone anti-toll-fraud alarm has functions of alarm for toll fraud by doubling the line, and alarm for toll fraud by breaking the line. In addition, it does not need external power supply. The telephone anti-toll-fraud alarm is mainly composed by CMOS integrated circuit. The composition is very simple. It is mainly polarity reversing circuit (Q1 and Q2), voltage detection circuit (R2, VD1 and VD2), logic-judging circuit (A1), memory display circuit (A2 and V1), and alarm-driving circuit (V2 and V3 buzzer) etc.



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