Telephone electronic lock circuit

Posted on Dec 11, 2010

Electronic lock using the telephone key (resistor connected plug) is inserted after the oscillator circuit start-up circuit, and the oscillation frequency is accurate or not to

Telephone electronic lock circuit
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decide whether to open the phone for outgoing calls, and answering external calls are not affected, which may ensure that only the person holding the lock key to use the telephone. Telephone electronic lock circuit is shown, it is mainly by the frequency key to unlock circuit, unlocking ring portion of the signal recognition circuit and self-locking circuit.

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