TONE_ACTUATED_RELAY

Published:2009/6/29 3:57:00 Author:May | From:SeekIC

The circuit is built around the LM567 tone decoder IC that requires about 100 millivolts at its operating frequency. The frequency is set by a 10 K variable resistor and can be between 700 and 1500 Hz. When a tone at the set fre-quency is present, the 567's output goes low to energize a relay through a 2N3906 PNP transistor.



Reprinted Url Of This Article:
http://www.seekic.com/circuit_diagram/Control_Circuit/Relay_Control/TONE_ACTUATED_RELAY.html

Print this Page | Comments | Reading(3)