Precision Light Alarm With Hysteresis Circuit


Posted on Dec 17, 2012

The TL081 is used as a comparator in a Wheatstone bridge circuit. When the CDS cell resistance decreases due to exposure to light, the output from IC2 cause the low-frequency oscillator (a) and (b) to generate a 10-Hz square wave, gating the 1000 Hz oscillator (c) and (d) on and off. This signal drives an amplifier.


Precision Light Alarm With Hysteresis Circuit
Click here to download the full size of the above Circuit.

R3 controls hysteresis, which reduces on-off triggering near the threshold set by R4.




Leave Comment

characters left:

New Circuits

.

 


Popular Circuits

Optical communication system
LCD monitor Switched Mode Power Supply
power electronic design
usb audio multiplexer
new 4 channel portable audio mixer
Cat and Dog Repeller
Batteries charger & PSU - ideal for digital camerass
TDA8920BTH 200 watts d class amplifier circuit diagram
Automatic street light circuit
Transmitting Audio Streams in Automotive Applications Using the MAX9205/MAX9206 LVDS SerDes
A circuit diagram of a phase comparator
Tube amplifier input voltage input



Top