Capacitive closing switch circuit composed of the division devices

Published:2011/6/24 23:46:00 Author:TaoXi | Keyword: Capacitive closing switch, division devices | From:SeekIC

The capacitive closing switch circuit is composed of a RF oscillator circuit and a detection board. The capacitive sensing type controller principle diagram (composed of the division devices) is as shown in the figure. In the figure, the RF oscillator circuit is composed of the transistor VT1 and the surrounding components; the metal induction electrode plate is connected with the collector of VT1 that can be used as the detector. When there is no conductor closing the induction electrode plate, the oscilation circuit which is composed of the VT1 oscillates normally, at this time the RF voltage signal which is output by the VT1 emitter is changed into the DC control signal after it is detected by VD1 and VD2, this signal conducts the switching tube VT2, the relay closes to connect the power supply of the controlled circuit.



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