Electronic Security Door Key

Circuit

Description

A different circuit of electronic lock very simple, one and does not need a lot of materials in order to it is manufactured. The right keys of code should be stepped with the right line, so that is activated the optocupler IC2. If from error is stepped switch that does not belong in the combination, then the lock is trapped. In order to we restore the regular operation of lock, it should we press switches S1 or S12. Switch S1 makes Reset of lock externally and the S12 internally, the door. The Code the circuit as he is connected it is 147 and it can change, very easily, changing the connections in the switches of keyboard. The optocupler IC2, can drive any exterior circuit as Relay etc, ensuring simultaneously electric isolation the two circuits. The circuit can be also supplied from a battery 9V..

Part List

• R1-7-9=1Kohm
• R2-3-4-5=100Kohm
• R6 =10Kohm
• R9 =47Kohm
• IC1 = 4066
• IC2 =4N25
• Q1-2=BC550
• S1...11=Push button sw or keyboard
• S12=Push button normal closed
• All resistors is 1/4W 5% 

Sourec  Sam Electronic Circuits