Light Detector


Posted on Sep 27, 2012

The circuit`s threshold is set by resistor R2. When the intensity of the light falling on the LDR is lowered, resistance of


Light Detector
Click here to download the full size of the above Circuit.

that unit increases, and lowers the voltage applied to the inverting input of the 741. The reference voltage at the noninverting input of the 741 is set (via R2) so that the comparator switches from low to high when the light falling on the LDR is reduced. That high activates transistor Ql, which causes the relay contacts to close.




Leave Comment

characters left:

New Circuits

.

 


Popular Circuits

Colpitts oscillator FM transmitter
Robot eyes
Audio booster
High-level four-channel mixer
Remotely Programmable RTC-Interfaced Microcontroller for Multiple Device Control
overheating
variable voltage and current power supply
PWM LED Dimmer/ Brightness Control by 555 Timer With Video Simulation
LED light
DIGITAL pH METER
Circuit power audio amplifier stereo with LM1875 and preamp for NE5532 2 x 20 Watts
Alarm interface circuit



Top