Looking for simple light detector circuit

[sangkeetha]

simple detector circuit

hi,

i would like to construct a simple optical sensor.And for that, i need a simple design of a light detector circuit, using pin photodidode as the detector, with model spec.

thanx.

 

[flatulent]

Re: simple detector circuit

You can probably go to a local Tandy-Radio Shack store and see what they have. Then build an OP AMP circuit with the diode between the inverting input and grould, the noninverting input grounded and a large resistor between the output and the inverting input. Have the diode in the direction so that on the schematic the cross bar of the diode symbol is towards the inverting input.

The light will cause the diode reverse current to flow and it will try to be removed from the inverting terminal. The op amp output will go positive to supply an equal current through the resistor between it and the inverting input.