Lie Detector (T1534E)

This circuit was found in a Popular Electronics from December 1956. Power is provided by batteries.

TV Transmitter (CB15706E)
The circuit shown in the figure generates a signal between 50 and 100 MHz and can therefore be...
Simplified Alarm (CB16418E)
We found this simple alarm circuit in a 1981 documentation. As we can see, it is a car alarm...
0 to 20 second timer (CB20370E)
This simple timer with unijunction transistor was found in an old American technical...