Found in a 70s RCA transistor manual, this circuit is recommended for mass-positive cars of the era. The transistor is for general use.
The circuit shown was obtained in American documentation from 1968. MOSFETs can be replaced by...
This circuit is more elaborate than the previous one, employing an integrated amplifier circuit of the...
This circuit activates a relay when the conducting bars (probes) are held by a person. The circuit is...