10 W Amplifier (T353E)

This 10 W portable amplifier was obtained in the 1937 RCA valve manual. The power supply was not included. The circuit makes use of double tubes.

Tic Tac Toe with LEDs (CB4322E)
We found this circuit in a 1986 documentation. It uses only LEDs, batteries, resistors and the...
Light Beam Operated Relay (CB4956E)
This circuit was found in an old American magazine and could make use of more modern components...
15 V Symmetrical Power Supply from 5 V with the 555 I (CB1480E )
This circuit, found in a 1978 publication, converts 5 V into a symmetrical 15 V output under low...