This alarm goes off if someone leaves a door open. We found it in the Encyclopedia of Electronic Circuits Volume 5 from 1995. The circuit uses components that are still common today.
This circuit was found in a 90s Radio Electronics. The integrated circuit admits an equivalent. The...
Suggested by Radio Electronics from the 90s, this circuit is suitable for NiCAd batteries with a...
To control direct current loads, under voltages between 12 and 200 V, and currents up to 3 A, we...