Found in the American 73 magazine for radio amateurs, this circuit can test common quartz crystals. The circuit includes the power supply.
This is the basic configuration of a voltage comparator with the Norton LM3900 amplifier. The...
This circuit was found in the April 1993 Electronics Now magazine. With it, it is possible to...
This circuit for the power grid was found in the June 1969 Radio Electronics magazine. The load is...