This circuit indicates a digital value through a moving bar. The circuit is TTL and must be powered by 5 V. We find this circuit in a Texas Instruments optoelectronics manual.
This variable filter circuit was found in July 1975 Radio Electronics magazine. The circuit uses 3...
This Hughes circuit is from 1968. Equivalent modern components can be used. The input impedance is...
This circuit emits a warning sound when night falls. The circuit is from a Hands On Electronics from...