This circuit was found in a Popular Electronics from the 90's. Its purpose is to detect the ionization of the air. The meter can be replaced by the current scale of an ordinary multimeter.
What differentiates this circuit from the previous one (CB15613E) is the non-need to use a...
Using a 74123 TTL this circuit was found in the Radio Elecronics magazine of June 1975. The power...
The difference between this oscillator in relation to the previous one is the use of emitter...