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

Rain Detector
Oscilloscope triggered sweep circuit
Video Line Bar Generator Circuit
R-C Twin-Tee Circuit Reduces Power-Supply Hum
H-Bridge Motor Driver using MOSFETs and Transistors
isp flash microcontroller programmer
automatic street light control system
multi sound for guitars
10W Audio Amplifier with Bass-boost
Dodd Station
Attaching a GPS module to the EB675001DIP
TDS9092 TDS971 IEEE-488/RS232C
Regency ATC-1 Converter
A CMOS the spot welding time adjustment circuit b
DC panel battery uninterrupted power supply switching circuit