Multi Tube Amplifier (T446E)

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

EMP Detector (CB23889E)
Originally intended to detect EMPs produced by tests or atomic blasts, this interesting circuit...
Automatic plant sprinkler (CB20778E)
This circuit triggers a small water pump when the humidity detected by the sensor is reduced in a...
Remote power sensor amplifier (CB7444E)
This circuit was found in Maxim's documentation from the 90's. The configuration uses components...