Patent ID: 7692337

Claim:
A pulse width modulation switching circuit, responsive to a voltage demand signal, for controlling current supplied to an inductor from a direct current (DC) supply voltage, said switching circuit comprising: a bridge circuit, said bridge circuit comprising: an input operable to receive a direct current, DC, supply of nominal voltage +V S , an output connected to said inductor, said output having opposed ends; and first and second bridge arms, said arms having corresponding first and second switches operable in response to first and second switching signals to be switched between on and off states, wherein switching between various combinations of on and off states produces an electrical signal at the opposed ends of said output with voltage pulses at levels of nominally +V S , 0V, and −V S ; a voltage sensor for producing a signal indicative of said DC supply voltage; and a switching signal generator, responsive to said DC supply voltage signal and said voltage demand signal, for generating said first and second switching signals.