Tone detector

Posted on Apr 1, 2012

The detector circuit is made up a two-amplifier multiple feedback bandpass filter followed by an ac-to-dc detector section and a Schmitt Trigger. The bandpass filter (with a Q of greater than 100) passes only 5Q0 Hz inputs whch are in turn rectified by Dl and filtered by R9 and Ca

Tone detector
Click here to download the full size of the above Circuit.

This filtering action in combination with the trigger level of 5 V for the Schmitt device insures that at least 55 cycles of 500 Hz input must be present before the output will react to a tone input.

Leave Comment

characters left:

New Circuits



Popular Circuits

Two line intercom
50 Watt Power Amplifier
Ultrasonic switch circuit
Scope calibrator
RTD thermometer
LM555 interlocked monostable timer circuit
Schematic Diagram Basic Levitation and Magnetic Levitation Circuit Project
Super bright LED night light
Pulse Circuits for Infrared LEDs and Visible Diode Lasers
You can set 1 10 100 1000 times magnification programmable amplifier