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.
Charcoal microphones are rare today. In the figure we have a circuit that shows the use of one of...
This triac circuit was taken from an article in the July 1970 Radio Electronics magazine. Note the...
This power supply can provide 10 A currents. Its regulation is made by 7812 integrated circuit. The...