741 - LM386 Dual Light Wave Receiver Circuit
This light wave receiver circuit consists of a 741 operated as a
preamplifier and a LM386 audio amplifier operated as a power amplifier
circuit. Potentiometer 10K is the gain control. Various kinds of
detectors can be used as the front end of the receiver.
Phototransistors are very sensitive, but they do not work well in the presence of too much ambient light.
A 100-kQ series resistor is required if you use a phototransistor.
Solar cells, photodiodes, and LEDs of the same semiconductor as the
transmitter all work well in this circuit. The unit can receive
transmissions from any type of transmitter, including laser beams,
light wave voice transmitters, I.E. and is very wide range. The 8 Ohm
speaker can be replaced with a set of 8 Ohm earphones when used as some
sort of Spy device.