This 4093 IC continuity tester was found in the November 1986 Radio Electronics magazine. The circuit powers a ceramic buzzer with a frequency setting.
We found this voltmeter in a 1977 Radio Shack documentation. The integrated circuit can be the...
This circuit with a maximum current of 50 mA was found in the August 1998 issue of Electronics Now magazine....
This circuit was found in the July 1994 issue of Electronics Now magazine. The relay can be rated...