Freeze Alarm (CB14454E)

The circuit of a 1968 publication can be implemented with more modern transistors such as BC548 for NPN and BC558 for PNP.

Switching Power Supplies Tests Resistive Load (CB18730E)
This resistive load circuit for source testing was found in a 1991 publication. Power transistors must be...
Musical Horn (CB23653E)
This circuit was found in a Radio Electronics from May 1965. The transistor is a power transistor and in...
Electrifier (CB26135E)
This circuit was obtained from the Radio Electronics Experimenter magazine in a special edition of 1990....