Electronic Lock
Here is an electronic code lock, which can be used as a door latch or key for ignition, etc. Operation is fairly tricky and there lies the beauty of the circuit. There are a number of switches, actually nine, which should be operated in a particular and owner – configured -sequence, or else the circuit [...]
Light Sensitive Staircase Switch with Triac
Operation of the third circuit is much similar except that it has photo sensitivity. The circuit is shown in Schematic When there is no sufficient light/the reset pin is held low by R14 (4.7K resistor) and the circuit works as it is described in the earlier paragraph. But if there is sufficient light, resistance of [...]
