Lie Detector (T1534E)

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

Bipolar Digital Amplifier (CB25627E)
This high-gain digital amplifier uses general-purpose transistors. The supply voltage is logic...
Indicator without lock (CB6685E)
Obtained from a 1969 neon lamp documentation, this circuit shows how to assemble an indicated...
CA3080 Amplitude Modulator (CB25134E)
This 2-quadrant modulator circuit was found in the May 1988 issue of Radio Electronics magazine. The...