| Patent application number | Description | Published |
|---|
| 20090058302 | THERMAL FOLDBACK FOR LINEAR FLUORESCENT LAMP BALLASTS - A ballast circuit that facilitates providing thermal protection for a fluorescent lamp includes a coupling transformer that couples an inverter circuit to a control circuit. First and second transformer windings in the inverter circuit, and a third transformer winding in the control circuit, are wound around a common ferrite core. The ferrite core has a Curie temperature that approximates a maximum allowable threshold temperature for the lamp. When the temperature of the ballast approaches the Curie temperature of the ferrite core, its permeability, and thus inductance, drops dramatically, causing an increase in operating frequency in the inverter circuit. This increased operating frequency causes a capacitor in the control circuit to charge to a threshold voltage, at which power to the inverter circuit is reduced. The lamp then dims without turning off until the temperature is reduced to an acceptable level. | 03-05-2009 |
| 20090059448 | RISK OF SHOCK PROTECTION CIRCUIT - A risk of shock (ROS) protection circuit is disclosed, which comprises a capacitor that charges whenever there is a voltage between a ground on a lamp ballast and earth ground. If the capacitor exceeds a predetermined threshold voltage, the capacitor causes a gate to shunt current away from a tertiary winding in a control circuit, which in turn reduces impedance reflected by the tertiary winding back on to primary and secondary windings in the ballast circuit. The reduced reflected impedance causes the operating frequency of the ballast to increase, reducing the voltage between the ballast ground and earth ground until it is safe for human contact. In this manner, a human replacing a lamp connected to the ballast can be protected from shock despite a failure to disconnect the power to the lamp ballast prior to lamp replacement. | 03-05-2009 |
| 20090108764 | Starting fluorescent lamps with a voltage fed inverter - A lamp ballast includes an inverter circuit, a resonant circuit, a control circuit, and a startup circuit. When the DC bus reaches its final value, a capacitor in the startup circuit charges to a predetermined voltage, at which point a pulse is sent to start a gate drive circuit in the inverter. Additionally, a gate in the control circuit is initially OFF, allowing full power to the lamp, and a capacitor in the control circuit charges to a predetermined voltage, at which point a gate is turned ON. When the gate is ON, power to the lamp is reduced. The control circuit capacitor is selected so that it charges for a sufficient period to allow the lamp to complete a glow phase of startup before turning on the gate and reducing power as the lamp transitions into an arc phase. | 04-30-2009 |
| 20100138069 | PRE-PROGRAMMED ENERGY MANAGEMENT BALLAST OR DRIVER - A pre-programmed energy saving ballast or driver is presented, having a pre-defined energy profile to which the output power is controlled in accordance with the current time ascertained from the input power connection via simplex clock information or from received broadcast time signals, and which allows a user to select from a number of pre-programmed profiles and/or to modify and store user-defined energy profiles. | 06-03-2010 |
| 20100244702 | PROTECTING BALLAST CIRCUITRY AGAINST MISWIRING - A circuit for protecting an electronic ballast for use with a remote controller for gas discharge lamps against miswiring to a power source. Depletion mode MOSFETS are employed in both sides of the circuit to the controller and the MOSFETS respond to overvoltage, including polarity reversal to create an open circuit condition in the circuit to the controller. | 09-30-2010 |
| 20100244730 | DIMMING INTERFACE FOR POWER LINE - An interface circuit for a lamp ballast includes first and second input power lines, L | 09-30-2010 |
| 20100308751 | LED POWER SOURCE AND DC-DC CONVERTER - Isolated LED power sources and DC-DC converters therefor are presented in which the DC-DC converter includes a self-oscillating inverter driving an output rectifier for operating an LED array of one or more LEDs, where the inverter uses a control transformer with core having a Curie temperature set to a maximum operating temperature of one or more power supply components to reduce inductances of secondary windings in the inverter oscillation circuitry to lower the power supplied to the load so as to prevent the inverter from overheating. | 12-09-2010 |
| 20110089867 | HIGH EFFICIENCY LOW POWER CAPACITOR CHARGED DC DRIVER - A high efficiency low power DC driver apparatus is presented for powering a light source, with a capacitive divider circuit receiving an AC input and providing a divided AC output, a rectifier provide a DC output below ten watts, output terminals coupleable to one or more light sources, and a linear regulator coupled in series with the light source to regulate a drive current flowing through the series circuit. | 04-21-2011 |
| 20110095693 | FLUORESCENT LAMP BALLAST WITH ELECTRONIC PREHEAT CIRCUIT - Fluorescent lamp ballasts and methods are disclosed in which a resonant impedance of a self-oscillating inverter is modified to control the inverter frequency to selectively preheat lamp cathodes using power from the inverter output during a preheating period after power is applied and to change the inverter frequency to a different range following ignition of the lamp. | 04-28-2011 |
| 20110144821 | PRE-PROGRAMMED ENERGY MANAGEMENT BALLAST OR DRIVER - A pre-programmed energy saving ballast or driver is presented, having a pre-defined energy profile to which the output power is controlled in accordance with the current time ascertained from the input power connection via simplex clock information or from received broadcast time signals, and which allows a user to select from a number of pre-programmed profiles and/or to modify and store user-defined energy profiles. | 06-16-2011 |
