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.
This is an old configuration that can be modified to operate with 5 V (use 1k on the base...
This receiver is from European documentation from the 90s. The integrated circuit is uncommon, and the coil...
This circuit is from an American technical documentation from the 70s, but it can be easily...