This circuit was found in a documentation from 1948. There are 5 valves with push-pull output. The source uses a transformer, and the indicated application is with turntables.
Suggested by National Semiconductor in a documentation of the 90s, this circuit uses a power...
This circuit was obtained from an American 1980s documentation. The frequency depends on the...
The sensor of this circuit is a large surface diode. We believe that a small solar cell can also...