TIME_ON_TOUCH_SWITCH

Published:2009/7/11 1:23:00 Author:May | From:SeekIC

The circuit is built around a 555 oscillator (U1), which is tumed on when a trigger is applied by touching the touch terminal to pin 2 of U1. When activated, LED1 and BZ1 (a piezoelectric buzzer) tum on for the time period set by the values of R2 and C1. The ON-time of the touch circuit can be altered by changing the values of Q and R2.This touch switch can be powered from batter-ies so that it need not be near a 60-Hz power source for triggering. The extremely small amount of current supplied to the trigger input through the 10-MΩ resistor. R1, makes the input circuitry very sensitive to any external loading, and it is easily triggered by touching the pickup.



Reprinted Url Of This Article:
http://www.seekic.com/circuit_diagram/Control_Circuit/Switch_Control/TIME_ON_TOUCH_SWITCH.html

Print this Page | Comments | Reading(3)