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.

Complementary Tourch Switch (CB3852E)
The four gates of a 40111 IC are used in thes two-out circuit. The output chages their state in a...
Transistor Intercom (CB16408E)
This circuit was found in a 1980 publication. It uses only 3 easily obtainable transistors. It is a...
Low Voltage Oscillator (CB6188E)
This circuit operates at a voltage of 1.3 V from a single mercury cell. We found in an old...