Lie Detector (T1534E)

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

TPA3244 Class D Amplifiers Ultra HD
March 2017 - The new Texas Instruments TPA3244 class D amplifiers with power ratings from 60 to...
Pulse Delay (CB19492E)
This circuit slows down a pulse applied to its input. The delay depends on the capacitor and...
Audio Peak VU (CB12436E)
We found this peak audio indicator in a 1980 publication. The M1 indicator can be 200 uA with the...