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: 3631
Print version: 
Other electronic circuits and schematics from Motor, light and power control
-
Running Message Display
-
Knightrider lights for model cars
-
LED Chaser
-
Bicycle back Safety Light
-
Unipolar Stepper Motor Controller
-
Audio Light Modulator
-
25 Light Sequencer using Xmas lamps
-
Brightness of multiple displays control circuit
-
12 Stage Neon Sequencer (NE-2 / NE-51)
-
PWM Motor/Light Controller