Found in American documentation from the 1980s, this circuit uses common components. The operating frequency range depends on the plug-in coils.
This 4-competitor TTL speed game was obtained in a 1980s documentation, but can still be easily...
This powerful sound emitter used in defense to intimidate people was found in a 90s Popular...
This circuit triggers an alarm when the mains power is cut off. The circuit was found in the July...