We found this circuit in a 1991s PE Hobbyst Handbook. The circuit fires 10 LEDs that can control incandescent lamps according to their maximum current.
This simple circuit controls the signal amplitude through a photoresistor optical coupler. The...
This circuit can be implemented with standard photodiodes consisting of a two input optical AND gate....
In the figure we have the basic configuration of an operational amplifier for audio signals. The...