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.

Timer 4049 (CB15094E)
This simple timer uses one of the six inverter ports on a CMOS integrated circuit. Rx and Cx...
Doorbell Tone Generator (CB18473E)
This circuit can be used as a residential doorbell. We found it in an English publication from...
Strobe 7400 (CB22418E)
In the old original version of this circuit from 1989, the LED is common (we recommend 330-ohm...