Voltage amplifier with the 37 tube (T392E)

Found in a modern design book with tubes, this stage with the triode 37 has a plate current of 3.7 mA.

Fluorescent Lamps Night Control (CB4668E)
This circuit triggers a relay when it gets dark, thus enabling the lighting of fluorescent lamps, which...
Audio Visual Output Indicator (CB25193E)
This circuit was obtained from a Radio Electronics issue from January 1989. The indicator is a...
Temperature Sensor II (CB5051E)
The previous circuit (CB5050E) triggers when the temperature exceeds the limit set on the...