Electronic Code Lock With 1 Transistor

This is of advance the simplest electronic code lock circuit one can make. The circuit uses one transistor, a broadcast and few acquiescent components. The artlessness does not accept any access on the achievement and this ambit works absolutely fine.

The circuit is annihilation but a simple transistor about-face with a broadcast at its beneficiary as load. 5 switches (S0 to S4) abiding in alternation with the accepted attached resistor R2 is affiliated beyond the abject of the transistor and absolute accumulation rail. Another 5 switches (S5 to S9) abiding in alongside is affiliated beyond the abject of the transistor and ground. The transistor Q1 will be ON and broadcast will be activated alone if all the switches S0 to S4 are ON and S5 to S9 are OFF.

Arrange these switches in a confused address on the console and that it. The broadcast will be ON alone if the switches S0 to S9 are either OFF or ON in the actual combination. The accessory to be controlled application the lock circuit can be affiliated through the broadcast terminals. Transformer T1, arch D1, capacitor C1 forms the ability accumulation area of the circuit. Diode D2 is a freewheeling diode. Resistor R1 ensures that the transistor Q1 is OFF if there is no affiliation amid its abject and absolute accumulation rail.