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AssigneeFulham Company Limited
InventorsNing ZHAI, Xingwei HU
Estimating the term…
A technique for providing control for an electronic ballast by responding to the current in the common bus (DC power rail) betweeen a boost circuit such as a power factor circuit (PFC) and an output (such as a high frequency (HF) inverter) circuit, and adjusting, changing or shutting down either the power factor control circuit or the inverter circuit when the power going into the inverter circuit is above a threshold. Power going into the inverter circuit may be measured by a resistor, and temperature compensation may be provided. Excess power indicative of a spark is detected in such a way that normal starting of a lamp load connected to the ballast occurs without triggering the change/shutdown but an external arc will trigger the change/shutdown. For example, the output circuit may be shut down and the external arc curtailed within 200 msecs.
An electronic ballast comprising:
A method of providing external arcing protection for an electronic ballast, comprising:
Apparatus for providing external arcing protection for an electronic ballast, comprising:
A ballast comprising an input circuit and an output circuit and a sensing and control circuit, wherein the output circuit includes an input for receiving a DC input and wherein the sensing and control circuit includes an input coupled to the DC input for the output circuit and wherein the sensing and control circuit is configured to sense the power going into the input to the DC input for the output circuit and also configured to cause a change in the input to the DC input for the output circuit when the DC input for the output circuit reaches a selected level.
A ballast circuit comprising an input circuit, a boost circuit coupled to the input circuit, an inverter circuit having an input and an output for driving a load, and a sensing circuit coupled to the inverter circuit input and wherein the sensing circuit includes an output coupled to the boost circuit for changing the boost circuit when an electrical signal on the input to the inverter circuit changes a selected amount.
A ballast circuit comprising an AC input, an inverter circuit having an input for receiving an electric current and having an output circuit configured to be coupled to a load, a boost circuit between the AC input and the inverter circuit, and a sensing circuit for sensing a characteristic of the electric current received at the input of the inverter circuit and configured to apply a control signal to the boost circuit when the characteristic of the electric current received at the input of the inverter circuit becomes a predetermined characteristic.
A method of controlling a ballast comprising applying a current signal to an inverter, producing a high frequency AC signal in the inverter and driving a load with the high frequency AC signal, sensing a characteristic of the current signal applied to the inverter and changing the current signal applied to the inverter when a characteristic of the current signal changes to a selected characteristic.
Dependencies are inferred from the claim text.