Found in documentation from the 1980s, this highly sensitive circuit is based on the conduction by the presence of gas from an ionization chamber. The components are from the time.
This current meter with many scales was found in a 80s American documentation. The operational amplifier...
This dimmer, from an old publication, can use almost any triac and in shooting a neon lamp. The...
We found this circuit in a 1975 publication. The circuit can be made with more modern equivalent...