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.
The figure shows how to implement an alarm buzzer in an LM3914 to warn about crossing the scale...
This circuit can act as a shield being controlled by a microcontroller by pin 1 or 2. The...
This circuit was obtained from a 1980's QST magazine. The circuit can generate 1 to 15 MHz signals...