Patent ID: 8781764

Claim:
A system for detecting a short circuit associated with a direct current bus, the system comprising: a direct current bus having a positive terminal and a negative terminal; a first switching transistor and a second switching transistor with their respective switched terminals connected in series with respect to each other between the positive terminal and the negative terminal; a biasing network for providing signals the first switching transistor and the second switching transistor, wherein during a test mode the first switching transistor, the second switching transistor, or both are selectively activated such that a detected short circuit may be identified within a switching section that comprises the first switching transistor and the second switching transistor; a primary supply for generating a test voltage that is lower than an operational voltage of the direct current bus in an operational mode, during the test mode the test voltage applied between the positive terminal and the negative terminal of the direct current bus; a primary thermal circuit associated with the primary supply for detecting whether the primary supply exceeds an operational temperature threshold, the primary thermal circuit providing a signal or logic level state indicative of the detected short circuit in the direct current bus or in the switching section if the primary supply exceeds the operational temperature threshold; and a first blocking device coupled between one of the terminals of the direct current bus and the primary supply, the first blocking device preventing a flow of current from the direct current bus into the primary supply.