Switching device having a feedback means for rendering a control circuit inoperative in response to a current supply circuit being inoperative

摘要

A switching device includes a current supply circuit, a control circuit, and means for feedback from the current supply circuit to the control circuit. The current supply circuit supplies current to a load. The control circuit controls operating and non-operating of the current supply circuit. When the current supply circuit is inoperative, means for feedback renders the control circuit inoperative.