Dynamic step dimming interface

摘要

A dynamic step dimming interface is provided that allows a ballast to energize a lamp in a dim mode or a normal mode. The ballast includes a lamp controller that energizes the lamp using an oscillating current. The oscillating current is also provided to a voltage monitor, which indicates the voltage level of the oscillating current, and to a rectifier, which provides an output indicative of the oscillating current. The rectifier is responsive to user input indicating whether the dim mode or the normal mode is to be used. A processing circuit receives the voltage level from the voltage monitor and provides a mode command to the ballast, indicating the lamp mode, based on inputs received, and provides a reference voltage to a comparator. The comparator receives the rectifier output and the reference voltage, and generates a voltage indicative of a power level of the lamp for the processing circuit.

主权项

1. A system, comprising:
a ballast configured to be connected a source of an oscillating current and to energize a lamp, wherein the ballast comprises a lamp control circuit responsive to a mode command indicating whether the lamp will be energized in one of a dim mode and a normal mode; a voltage monitor comprising an input configured to receive the oscillating current and an output configured to indicate a voltage level of the oscillating current; a processing circuit comprising a first input connected to the output of the voltage monitor to receive the voltage level therefrom, a second input, a first output connected to the lamp control circuit to provide the mode command thereto, wherein the mode command indicates one of a dim mode and a normal mode, and a second output to provide a reference voltage indicative of the voltage level of the oscillating current; a rectifier circuit comprising an input configured to receive the oscillating current and an output configured to provide a rectified voltage indicative of the oscillating current, wherein the rectifier circuit is responsive to user input to selectively energize the lamp in one of a dim mode and a normal mode; and a comparator circuit comprising a first input connected to the rectifier circuit, a second input connected to the second output of the processing circuit, and an output connected to the second input of the processing circuit and configured to provide a compared voltage indicative of a power level applied to the lamp; wherein the processing circuit is responsive to the compared voltage provided by the comparator circuit and is responsive to voltage level indicated by the voltage monitor to provide the mode command to the ballast.