Telephone electronic coded lock circuit

Published:2011/7/27 8:27:00 Author:Fiona | Keyword: electronic coded lock | From:SeekIC

Telephone electronic coded lock circuit is shown as above,the electronic coded lock is suitable for double audio circuits.After the phone adds this coded lock, when you call out,you must use the buttons on the phone to press the four pre-programmed password,then you can make a call.If the password is error, the phone can not dial out. When the exterior line is incoming call,the phone can receive the ring signal normally,picking machine can response.When the electronic coded lock circuitis connected toexterior line to be used,we mustmeasure the positive and negative polarities of outside feeder,then connect the positive pole to L1 and connect L2 to the negative pole,the phone is connected to the the phone location in electronic coded lock circuit.



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