coll circuit

This is a touch circuit that is used as a latching circuit to switch a LED ON and OFF by physically touching the ON metal plate or OFF metal plate. This circuit is based on logic gate for control the operation. This is the figure of the circuit.


It is important to ensure that 9V battery is used as its DC source. If one uses the mains supply to step down the voltage using a transformer for rectification and filtering to get the 9V DC supply, ensure that the transformer is designed in such a way that it follows the safety standard requirement of UL. This is important to ensure the safety of the user that is using the metal contacts to ON/OFF the LED.[Schematic diagram source: Electronics Project Design].