This circuit triggers a buzzer or other warning device when the light falling on the sensor is cut off. We found it in the Encyclopedia of Electronic Circuits Volume 5 of 1995.
The purpose of this 1967 Philips circuit is to produce a rectangular signal from a sharp pulse....
This circuit allows you to read capacitances on a common analog instrument. It is part of an...
The idea of this circuit is to use an AM radio with headphones to receive sound signals...