This circuit generates rectangular signals from 2 Hz to 20 kHz using an operational amplifier. The circuit is from 1984 Radio Electronics. The power supply must be symmetrical.
This circuit is from an American 80's documentation. The transistor is general purpose,...
We found this circuit in the September 1971 issue of Radio Electronics magazine. The sensor is an...
This old configuration, using a unijunction transistor (UJT) controls a LED than blinks if an...