Amplifier stage with the T411E (T411E)

The pentode tube used in this circuit has 1.5 V filament. The circuit is a voltage amplifier with the 1U5 tube.

Power control with triac (CB21467E)
Found in a 1967 RCA power manual, this circuit uses an ordinary neon lamp to fire a triac. The...
Biestable CMOS x TRIAC (CB12322E)
This circuit is from an English publication from 1978, but it can be assembled with BC548 for TR2...
Programmable Frequency Divider 1 to 9999 (CB419)
The input frequency of a signal applied to this circuit will be divided by one to 9999 in this...