Abstract: A power switching apparatus comprising a current transformer with coupled primary and secondary windings, the primary windings being adapted for series connection between alternate current power source and load, the primary windings comprising first and second sub-primary windings of different number of turns of windings and respectively of a larger and a smaller core diameter, a current conduction path being provided from intermediate the first and the second sub-primary windings to the power switching means so that upon detection of a current exceeding the current rating of the second sub-primary windings, current will be caused to flow from alternate current power source to load via a current loop comprising the power switching means and the first sub-primary windings only.

Abstract: This invention relates to an electrical power switch which is a two-terminal electrical power switch having a line-powered switching control mechanism. The electrical power switch is provided with first and second shunt circuits between the terminals of the power outlet. This switch for power to operate through the outlet is included in a first shunt circuit that also contains a power supply operating from current flowing through the switch when in the “ON” condition. This first power supply can power a control means to control the operative state of the switch while current flows through. When the switch is in the “OFF” state, a second power supply contained in a second shunt circuit provides power to the control means.