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 is a commercial circuit found in Radio Electronics magazine from September 1960. The circuit has...
A TTL NAND trigger is the basis of this oscillator which, with the indicated components, can...
Using a 4046 PLL we found this circuit in the December 1989 issue of Radio Electronics magazine. The...