This circuit uses a diode as a radiation sensor. The operational ones are old because the publication is from the 80's, but modern low voltage equivalents can be tested.
This circuit already explored in several diagrams in this section was found in a 90’s Popular...
Found in old documentation, this circuit has a configuration already explored in many of our...
Found in a 90s Elektor, the purpose of this circuit is to protect a speaker in case of amplifier...