Leak Detector (CB22456E)

We found this circuit in a Popular Electronics from 1992. The transistor is general purpose, assuming equivalent.

DC Motor and Stepper Controls with the A3906 (CB12513E)
The A3906 integrated circuit from Allegro MicroSystems (www.allegro.com) consists of a single-step motor...
UHF Digital TV Booster (CB12593E)
This circuit, ideal for those who have signal problems in the UHF band, mainly in the reception of digital...
Modulator with TAA111 (CB19432E)
This circuit is suitable for modulating small FM transmitters for eavesdropping or espionage. The...