LAMP_SWITCHING_CIRCUIT

Published:2009/6/16 2:49:00 Author:May | From:SeekIC

A normally open pushbutton switch (51) delivers a positive input pulse to pin 4 of U1, triggering the IC into action. The output of U1 at pin 6 supplies base-drive current to a Darlington pair comprised of Q1 and Q2, activating K1. A 10-μF capacitor and any resistor value of from 1 to 10 MΩ can be used as the timing components.To use the circuit on an auto's headlights, connect the relay's normally open contacts across the car's headlight switch and press S1 to extend the on time. In connecting the circuit to control an acoperated lamp, turn off the ac power and connect the relay contacts in parallel with the lamp's power switch contacts.



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