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.
We found this circuit in an old documentation. The indicated solenoid is of low current type,...
This commercial circuit of 3 transistors was found in Japanese documentation from the 1960s. The...
This circuit was found in National Semiconductor documentation from the 90s. The circuit uses two...