We found this version of the automotive tachometer in a 1980s publication. Variations from other sources appear elsewhere in this section. The indicator is a 0 to 1 mA milliammeter.
This oscillator circuit for sinusoidal audio signals with operational 741 requires a symmetrical power...
Found in a 1974 Radio Shack documentation. This circuit must have a connection to the ground of...
This sensitive circuit detects the live pole of a power grid or outlet. The circuit makes use of a high...