This circuit for car engine spot adjustment was found in an 80's Radio Electronics. The circuit makes use of a xenon lamp and the pulse transformer must have a turn ratio of 1:50.
Old phones with dials can be used in a simple home intercom system, as this circuit from Popular...
This circuit was found in the July 1992 issue of Radio Electronics magazine. The circuit has a...
This simple circuit indicates if the polarity of a load is reversed when it is connected to a...