This circuit was found in an 80's General Electric documentation. The circuit uses uncommon components today like the PUT. Unijunction admits equivalent.
This circuit is based on the light comparison of two LDR sensors. We found it in a 90s Popular...
We found this crystal AM radio using a germanium diode in a Japanese magazine in 1967. The circuit...
When a model train crosses a level crossing, interrupting the light on the sensor, this circuit...