Multi Tube Amplifier (T446E)

Obtained in MIT documentation this circuit uses several tubes to obtain a large gain in the amplification of small signals.

Touch Switch (CB11266E)
With this circuit we can activate a relay with a simple touch on the sensor. The relay can be 6 or...
Instrumentation AC Amplifier (CB12124E)
This circuit was obtained in a 1979 publication. The operational amplifier is of the type with...
Battery Tester (CB6517E)
Found in a 1980s German publication, this circuit tests batteries by type. The circuit is based on a...