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 |
20120032608 | LIGHTING SYSTEM COMMUNICATIONS APPARATUS AND METHOD - A communications apparatus and techniques are presented for communicating with ballasts or drivers through lighting system power connections in which the power connections are energized with low levels of power to power communications components in the ballast/drivers while the light sources are off and low frequency AC communications signals are transmitted through the power connections. | 02-09-2012 |
20120086353 | END-OF-LIFE CIRCUIT FOR FLUORESCENT LAMP BALLASTS - A ballast and method are presented for detecting end-of-life conditions of fluorescent lamps in which a ballast output is controlled according to a dimming input when a DC voltage or current of the lamp is in a predefined range or when the AC lamp current is below a predefined threshold, and the output is reduced to an EOL protection level when the lamp DC voltage or current is outside the predefined range and the AC lamp current is above the predefined threshold. | 04-12-2012 |
20120104947 | COMPACT FLUORESCENT LAMP AND LED LIGHT SOURCE WITH ELECTRONIC COMPONENTS IN BASE - Light sources are presented in which lamp ballast or LED driver circuitry is disposed within a base assembly using integrated boards with components embedded between board layers and or circular flex boards with pot core magnetic components and/or ASICs and thermally conductive board core materials with thermal vias, reflective mirrors, and/or potting materials to conduct heat out through the base to facilitate reduced form factors for lamps and/or LED light sources. | 05-03-2012 |
20120146538 | 3-WAY, PHASE-CUT DIMMABLE LED DRIVER - An LED driver is presented with a sensing circuit and attenuator circuits to provide three-way switched dimming as well as phase-cut dimming to control the output power driving an LED load. | 06-14-2012 |
20120146545 | DRIVER CIRCUIT WITH PRIMARY SIDE STATE ESTIMATOR FOR INFERRED OUTPUT CURRENT FEEDBACK SENSING - A LED driver circuit and an isolated DC-DC converter therefor are presented, in which a primary side state estimator circuit is provided for inferred output current sensing for closed loop control of pulse width modulated flyback or buck converters. | 06-14-2012 |
20120229044 | AUTO-SWITCHING TRIAC COMPATIBILITY CIRCUIT WITH AUTO-LEVELING AND OVERVOLTAGE PROTECTION - Drivers and ballast circuits are presented having a boost converter with a triac compatibility circuit providing regulated current load to accommodate phase-cutting triac circuit holding current requirements, including auto switching driver circuit with overvoltage protection and an auto leveling circuit to regulate against thermal and load fluctuations. | 09-13-2012 |
20120235597 | LIGHTING POWER CIRCUIT WITH PEAK CURRENT LIMITER FOR EMI FILTER - Light e power circuits and EMI filters therefor are presented in which a depletion mode field effect transistor is connected in series with an EMI filter capacitor following an input rectifier to allow filtering of EMI and to limit capacitive currents during triac switching when powered through a phase-cutting dimmer circuit. | 09-20-2012 |
20140103820 | Boost Converter of Driver Circuit With Thermal Compensation - A circuit for providing thermal compensation for a driver circuit used to drive light emitting diodes (LEDs) is provided. The driver circuit can include a rectifier circuit configured to rectify an AC power source into a DC power source providing a DC source voltage. The driver circuit can further include a boost circuit configured to boost the DC source voltage to provide a drive voltage for driving the light emitting diodes. The boost circuit can include a switching element that is controlled based at least in part on a current sense circuit having a sense transistor. A thermal tracking transistor is provided as part of the reference to the sense circuit. | 04-17-2014 |