This circuit was found in the July 1978 issue of Radio Electronics magazine. The circuit uses a common digital voltmeter as the indicator. The sensors are integrated circuits of the time.
This wired intercom circuit was found in an English publication from the 80's. The integrated...
This triac temperature control circuit was found in an 80s power semiconductor documentation. The circuit...
This circuit is from 1998 documentation. The coils consist of the number of turns indicated on...