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 current meter with many scales was found in a 80s American documentation. The operational amplifier...
This circuit was found in the February 1971 issue of Radio Electronics magazine. It is designed to power...
This circuit is old, causing LEDs to be lit sequentially. Several types of games can be programmed using...