HIGH_OUTPUT_PULSED_TONE_LIGHT_ACTIVATED_ALARM

Published:2009/6/14 22:58:00 Author:May | From:SeekIC

This circuit can produce up to 1 W of audio power to drive a speaker or horn. When the CDS cell is struck by light, its resistance decreases thus activating NOR gate(a) thereby causing(a) and(b) to produce a low-frequency(10-Hz) square wave. This pulses the 1-kHz oscillator(c) and(d), caus-ing it to generate a pulsed 1-kHz tone at a 10-Hz rate. Q1 and Q2 amplify this signal. Q2(2N3055) drives the speaker.



Reprinted Url Of This Article:
http://www.seekic.com/circuit_diagram/Control_Circuit/Alarm_Control/HIGH_OUTPUT_PULSED_TONE_LIGHT_ACTIVATED_ALARM.html

Print this Page | Comments | Reading(3)