This low frequency oscillator circuit was found in an Electronic Design from the 90s. The transistors are common types, and the frequency is given by the crystal.
Found in a Philips documentation from 1968, this circuit detects the trimpot set input voltage....
This circuit can be connected to the output of alarms or sirens with the 555, CMOS or TTL,...
This simple capacitor tester, already covered in other articles in this section and on the...