Ground-fault-protected series-resonant ballast

Claim 1

An arrangement comprising: an electric utility power line having power line conductors electrically connected with ground; a power conditioner means connected with the electric utility power line and operative to provide a DC voltage at a set of DC terminals; and inverter means connected with the DC terminals by way of an EMI filter means, the inverter means having control means receptive of a control signal and, in absence of the control signal, being: (i) operative to provide a high-frequency AC voltage at a set of AC output terminals, which AC voltage is suitable for powering a load means such as a gas discharge lamp; (ii) apt to produce a flow of ground-fault current if one of the AC output terminals were to be electrically connected with ground, which ground-fault current would then flow between the electric utility power line and the inverter means by way of the power conditioner means and the EMI filter means; and (iii) apt to generate electro-magnetic interference which in the absence of the EMI filter means would flow from the inverter means to the electric utility power line by way of the power conditioner means, the EMI filter means: (i) being operative significantly to reduce the amount of electro-magnetic interference that would flow from the inverter means to the electric utility power line compared to what such amount would have been in the absence of the EMI filter means, (ii) being connected in circuit with said . control means, and (iii) having an auxiliary output operative to provide said control signal in response to the flow of groundfault current.