This circuit is from an old American amateur radio manual. The circuit shows how to use a Varicap on a high power frequency doubler circuit.
This circuit is for a siren that can be used with any of the above alarms and also other types. The...
This circuit can be used on a 0 to 14 V source with a current of 1 A. The PNP power transistor can be the...
This TTL circuit was found in the February 1973 issue of Radio Electronics magazine. The power...