LED Photo Sensor
Here's a circuit that takes advantage of the photo-voltaic voltage of an ordinary LED. The LED voltage is buffered by a junction FET transistor and then applied to the inverting input of an op-amp with a gain of about 20. This produces a change of about 5 volts at the output from darkness to bright light. The 100K potentiometer can be set so that the output is around 7 volts in darkness and falls to about 2 volts in bright light.
LED Photo Sensor circuit
Title: LED Photo Sensor
electronic circuit
Source: unknown
Published on: 2007-07-21
Reads: 3722
Print version: 
Other electronic circuits and schematics from Motor, light and power control
-
Touch Activated Light
-
Discrete component motor direction controller
-
12 Volt Lamp Dimmer
-
Knightrider lights for model cars
-
IR Remote Control Jammer
-
Dancing LEDs
-
Emergency Light
-
High And Low Voltage Cut Off With Time Delay
-
Light Flasher
-
Super simple stepper motor controller