6VDC Amplifier (T485E)

This drum amplifier was found in an American documentation from 1947. It makes use of a mechanical vibrator to generate high voltage for the tubes.

| Clique na imagem para ampliar |

Precision Current Drain (CB14077E)
This circuit is from the 1994 Linear Applications Handbook. The operational circuit can be...
Adjustable Current Regulator (CB17583E)
This circuit is suggested by National Semiconductor (now Texas) in an old manual. The circuit...
Phone circuit (CB8709E)
With this circuit, found in a 80s Popular Electronics, it is possible to use two ordinary phones in a...