Telephone electronic coded lock circuit


Posted on Feb 4, 2014

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..


Telephone electronic coded lock circuit
Click here to download the full size of the above Circuit.




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