This is the circuit diagram electronic door lock security key system. It means that this security system circuit is the combination of pressed key itself (not the mechanical). The output can be connected to drive the relay to open the door (usually using motor).

It is a quite simple circuit of electronic door lock with security code of 7 digits. Attention must be paid in time we pressed the keys forming the code and there is no delay. With the right keys and if the correct code will activate the output Q7 for about 4 seconds, driving the transistor Q2, which can be used to activate a relay and opening the door, or can be used for any other circuit. The LED used for visual indication of activation. The seven-digit combination code of the above circuit is: 1704570, but can be changed the combination of secure key by exchange the connections between the outputs of the counter IC1 and switches.

Electronic Door Lock Security Key Components List