Koninklijke Philips Corporation N.V.

Ching-Yao Hung

Robert Alexander Erhardt

Raymond Kulka

Oscar Jan Deurloo

Seymour Perkins, Iii

Steven Pilgrim

Control circuitry for controlling the output power of an electronic ballast system having a power supply branch circuit having power lines comprising a line voltage line and a common line, and a ballast stage having (i) inputs connected to the power lines for providing power to the lamp, (ii) internal power control feedback circuitry that defines a feedback loop for controlling the amount of power applied to the lamp, and (iii) a control signal input for receiving a control signal that affects operation the internal power control feedback circuitry and the level of power outputted by the ballast stage. The control circuitry comprises a first circuit having an input for connection to one of the power lines. The first circuit generates a control signal for input into the control input of the ballast stage. The control circuitry having a first predetermined magnitude when one of the power lines is connected to the input of the first circuit and a second predetermined magnitude when the power lines are isolated from the input of the first circuit. The control circuitry further comprises a second circuit having a first state for reducing the first and second predetermined magnitudes of the control signal by a predetermined increment so as to effect step dimming of the lamp and a second state that maintains the first and second predetermined magnitudes of the control signal.

Electronic ballast system with dual power and dimming capability

An auxiliary lighting system for a high-intensity discharge lamp. In one embodiment, the auxiliary lighting system has an auxiliary light source, an HID lamp status circuit having an input for connection to a status signal representative of the operational state of a high-intensity discharge lamp wherein the HID lamp status circuit determines whether the status signal meets predetermined signal criteria, a switch circuit having a first state that effects application of a voltage source to the auxiliary light source, and a second state that isolates the voltage source from the auxiliary light source, and a control circuit responsive to the HID lamp status circuit for controlling the switch circuit. The control circuit has a first state when the HID lamp status circuit determines that the status signal meets the predetermined signal criteria and a second state when the HID lamp status circuit determines that the status signal does not meet the predetermined signal criteria. When the control circuit is in the first state, the control circuit outputs a control signal for input into the switch circuit that configures the switch circuit into the first state. When the control circuit is in the second state, the control circuit outputs a control signal for input into the switch circuit that configures the switch circuit into the second state.

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Palatine, IL, United States of America

Ching-Yao Hung