This is Simple Code Lock circuit. This circuit will turn on a relay when the 8-way DIP switches receives the correct code. Here is the schematic diagram of the circuit:
There are two different types of DIP, they are piano-key DIP sw and 8-way DIP sw. This circuit will not draw the current if the switch is kept off. This circuit can give 256 different combination because the combination is in binary. So it would be very difficult for a burglar to keep up with the settings of the switches. [Source: talkingelectronics.com]
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