This control for 12 V drills was found in a 90s Elektor. The components are current, and Q1 can be replaced by a TIP42 mounted on a heat radiator.
This circuit was found in a Popular Electronics from the 90s. The circuit uses general purpose...
Found in Raytheon's 1960s transistor circuit manual, this circuit employs the CK722, one of the...
This encoded lock circuit with alarm for use in homes was found in a publication from the 90s. The...