FULHAM COMPANY LIMITED Patent applications |
Patent application number | Title | Published |
20140339996 | BALLAST AND BALLAST CONTROL METHOD AND APPARATUS, FOR EXAMPLE ANTI-ARCING CONTROL FOR ELECTRONIC BALLAST - 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. | 11-20-2014 |
20140252991 | ELECTRONIC BALLASTS - Methods and apparatus are described that can provide improved power factor correction and total harmonic distortion, efficiency and/or direct feedback of load current variations to a power source inverter. In one example, a power supply, for example, a ballast, can have an input circuit, an output circuit and an inverter circuit coupled between the input circuit and the output circuit. A current feedback circuit is coupled between the output circuit and the inverter circuit and configured to feed current back to the inverter circuit through a transformer stage separate from the inverter as a function of a current level in the output circuit. | 09-11-2014 |
20130307429 | MULTIPLE VOLTAGE BALLAST - A ballast and method for operating a ballast includes a switch or other circuit for connecting and disconnecting a voltage multiplier to a rectifier circuit. A control circuit for controlling the switch senses an input voltage and connects the voltage multiplier to the rectifier circuit when an input voltage falls below a selected voltage level. | 11-21-2013 |