Patent ID: 8199024

Claim:
A safety circuit for use in establishing connections between low-voltage systems to transfer energy from a first low-voltage system to a second low-voltage system, comprising: a pair of input terminals; a pair of output terminals; a detection circuit operatively connected to the input terminals and the output terminals for detecting whether the input terminals and the output terminals are properly connected to first and second low-voltage systems, respectively; a connection-controlling circuit configured to electrically connect the input terminals to the output terminals only when a proper connection has been detected and using a soft start procedure that reduces inductive voltage spikes; and a transistor protection s stem for protecting transistors used to electrical connect the input terminals to the output terminals, the transistor protection system comprising a microcontroller that maintains a thermal model of heating of the transistors when power is flowing and a thermal model of cooling of the transistors when power is not flowing, that monitors for over-current conditions that could destroy the transistors, and that monitors for under-voltage conditions on the supply side.