We found this circuit in the November 1974 Radio Electronics magazine. The capacitors determine the output time, and it is normal to obtain 1 second for each uF used.
With this circuit, obtained from an American publication for radio amateurs in 1976, it is...
Small variations in the resistance of the skin of a person holding the electrodes can be detected by...
This circuit was found in a 1967 American documentation. The circuit uses components of the time,...