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.
Using the Texas Instruments SN75489P this circuit was found in June 1978 Radio Electronics...
We found this circuit, which should only be used with incandescent lamps. In the Motorola Linear...
Found in Electronics Now from the 1980s, this amplifier can also be seen in commercial amplifiers...