This circuit is from a Radio Electronics from August 1992. The transistor used allows the control of motors up to about 5 A. It must be equipped with a heat sink.
This circuit is from Popular Electronics from the 90's. The circuit discharges the battery with a...
We found this time base circuit in a timer project from the August 1972 Radio Electronics...
This sonic switch, vox or sonic relay uses a Darlington of the time that has a gain of 10,000. The...