This circuit is from the time when cars used contact breakers. This 80's version measures the dwell angle of the contact breaker for dwell adjustment using an era integrated circuit, the LM3917.
We found this circuit in an American 1980s documentation. The circuit uses a piezoelectric transducer...
A ring and pendulum of stripped wires form the sensor for this alarm. Once triggered, to reset, you...
Other operational amplifiers in the series, such as the MC34072, MC34074, MC35071, MC35072,...