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.
This control for 12 V drills was found in a 90s Elektor. The components are current, and Q1 can be...
This circuit was obtained from an American documentation from the 1970s. Information on the...
The integrated circuit used in this 1990 project is uncommon in our market, and transistors...