Periodic Switch In The Primary Circuit Of The Supply Transformer Patents (Class 315/219)
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Patent number: 8680835Abstract: A buck DC-to-DC converter having a novel output protection mechanism, comprising: a buck converter circuit, having a line input end, a DC output end, a first feedback end, and a second feedback end; a voltage divider, having an input terminal and an output terminal, the input terminal being coupled to the DC output end of the buck converter circuit, and the output terminal coupled to the first feedback end of the buck converter circuit for providing a first feedback voltage; and an output current sensing resistor, having one end coupled to the DC output end of the buck converter circuit, and another end coupled to the second feedback end of the buck converter circuit for providing a second feedback voltage; wherein the buck converter circuit uses the first feedback voltage and the second feedback voltage to generate a protection signal.Type: GrantFiled: February 2, 2012Date of Patent: March 25, 2014Assignee: Immense Advance TechnologyInventors: Chia-Chieh Hung, Chung-Han Wu, Feng-Jung Huang
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Patent number: 8680787Abstract: An LED driver for controlling the intensity of an LED light source includes a power converter circuit for generating a DC bus voltage, an LED drive circuit for receiving the bus voltage and controlling a load current through, and thus the intensity of, the LED light source, and a controller operatively coupled to the power converter circuit and the LED drive circuit. The LED drive circuit comprises a controllable-impedance circuit coupled in series with the LED light source. The controller adjusts the magnitude of the bus voltage to a target bus voltage and generates a drive signal for controlling the controllable-impedance circuit. To adjust the intensity of the LED light source, the controller controls the magnitudes of both the load current and the regulator voltage. The controller controls the magnitude of the regulator voltage by simultaneously maintaining the magnitude of the drive signal constant and adjusting the target bus voltage.Type: GrantFiled: March 9, 2012Date of Patent: March 25, 2014Assignee: Lutron Electronics Co., Inc.Inventor: Dragan Veskovic
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Patent number: 8674615Abstract: A control apparatus for LED diodes includes a dimmer TRIAC electrically connected in series between a power supply and a LED lighting converter. The converter comprises a transformer, with a primary winding coupled with an input terminal and a secondary winding coupled with an output terminal, and a switch coupled to the primary winding to regulate the current through the primary winding and regulate the output voltage. The apparatus comprises a control device adapted to control said switch determining the on period and the off period of the switch to maintain constant the output current to supply said LED diodes. The apparatus comprises a detector connected to the secondary winding of the transformer and adapted to detect the conduction angle of the TRIAC; the control device is adapted to regulate the output current to supply said LED diodes in response to the TRIAC conduction angle detected by the detector.Type: GrantFiled: January 9, 2012Date of Patent: March 18, 2014Assignee: STMicroelectronics Design and Application S.R.O.Inventors: Pavel Koutensky, Ales Loidl, Jiri Smutka, Jakub Hajek
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Patent number: 8664893Abstract: The present invention provides a feedback control circuit and an LED driving circuit for using the same, wherein the feedback control circuit receives a dimming signal. The dimming signal is changed between a first state and a second state. When being in the first state, the feedback control circuit controls a converter circuit to drive the LED module for lighting stably. When being in the second state, the feedback control circuit controls the converter circuit to maintain the power conversion of the converter circuit to have an output voltage outputted by the converter circuit maintained at a level close to a lighting threshold voltage of the LED module.Type: GrantFiled: August 25, 2011Date of Patent: March 4, 2014Assignee: Green Solution Technology Co., Ltd.Inventors: Li-Min Lee, Shian-Sung Shiu, Chung-Che Yu, Hai-Po Li
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Patent number: 8659238Abstract: A power supply and methods are provided. In one implementation, the power supply includes a switching converter with power feedback circuit to output constant power to keep lamp at constant brightness. The power feedback circuits include a current feedback circuit and a voltage feedback circuit. The power supply further includes a controller operable to adjust on time or duty cycle of main switch to keep the output power constant.Type: GrantFiled: April 20, 2011Date of Patent: February 25, 2014Assignees: Xi' An Upright Photoelectric Technology Co., Ltd, Upright Lighting LLCInventor: Liang Chen
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Patent number: 8654485Abstract: A control signal interface circuit includes a line voltage protection circuit coupled to first and second input terminals. The protection circuit provides an input DC voltage across the input terminals within a predetermined range (i.e., 0-10 Vdc) and prevents the application of an input line voltage (i.e., 347 Vac) across the input terminals. A first current source circuit is coupled to the protection circuit, an isolation circuit is coupled to the first current source circuit and a second current source circuit is coupled to the isolation circuit. The first and second current source circuits collectively provide a linear output DC voltage with respect to the input DC voltage. At least one of the first and second current source circuits include circuitry wherein the linear conversion of the input DC voltage to the output DC voltage is independent of the temperature.Type: GrantFiled: March 31, 2011Date of Patent: February 18, 2014Assignee: Universal Lighting Technologies, Inc.Inventor: James Koehler
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Patent number: 8643297Abstract: The present invention provides a control circuit for dimming LED lighting. The control circuit comprises a voltage divider, a controller and an adaptive bleeder. The voltage divider receives an input voltage from an input terminal to generate a dimming signal. The controller generates a switching signal in response to the dimming signal. The controller further generates a control signal in response to the input voltage. The adaptive bleeder receives the control signal and draws a bleeder current from the input terminal in response to the control signal.Type: GrantFiled: September 1, 2011Date of Patent: February 4, 2014Assignee: System General CorporationInventors: Ta-Yung Yang, Li Lin, Chi-Yin Lo, Kuo-Hsien Huang, Hung-Chun Chen
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Patent number: 8643289Abstract: A Pulse Width Modulation (PWM) controlling circuit and a Light Emitting Diode (LED) driver circuit having the same are provided. An LED driver circuit includes a voltage detector connected to a plurality of LED arrays, the voltage detector being configured to determine a connection status of each of the LED arrays according to a corresponding level of the feedback voltage, and detect a minimum feedback voltage from feedback voltages of the LED arrays that are determined to be connected, a controller configured to output a control signal to one of abort and control boosting of the LED arrays according to the detected minimum feedback voltage, and a Pulse Width Modulation (PWM) signal generator configured to output a PWM signal corresponding to the outputted control signal according to an on/off state of a dimming signal that drives the LED arrays that are determined to be connected.Type: GrantFiled: February 16, 2012Date of Patent: February 4, 2014Assignee: Magnachip Semiconductor, Ltd.Inventors: Beom-seon Ryu, Chang-sik Lim, Jin-wook Kim
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Publication number: 20140021880Abstract: An electric lighting driver circuit for driving an illuminating unit to emit light includes a flyback converting unit for converting a DC input voltage to a low ripple DC voltage, and a half-bridge converting unit electrically connected to the flyback converting unit, for converting the low ripple DC voltage to a low frequency, rectangular wave output voltage to drive the illuminating unit to emit light. The flyback converting unit includes a dual-output winding transformer connected to the half-bridge converting unit. The dual-output winding transformer includes a first winding at a primary side of the dual-output winding transformer and a second winding and a third winding at a secondary side of the dual-output winding transformer. The third winding converts leakage inductance attributed to the first winding and the second winding to electrical energy that is provided to the half-bridge converting unit.Type: ApplicationFiled: July 20, 2012Publication date: January 23, 2014Inventors: Chun-An Cheng, Chen-Wei Ku
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Patent number: 8633659Abstract: A lighting device includes: a power converting unit; a voltage measuring unit for measuring an output voltage from the power converting unit or a value equivalent to the output voltage; a current measuring unit for measuring an output current from the power converting unit or a value equivalent to the output current; and a control unit for controlling the power converting unit. When one of the output voltage and the output current of the power converting unit is changed by a specific magnitude per unit hour, the control unit determines that a change in a load status has occurred and controls the power converting unit by switching constant current control in which a measurement value of the current measuring unit is kept at a specific current designated value to constant voltage control in which a measurement value of the voltage measuring unit is kept at a specific voltage designated value.Type: GrantFiled: April 22, 2011Date of Patent: January 21, 2014Assignee: Panasonic CorporationInventor: Toshifumi Tanaka
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Publication number: 20140009078Abstract: In accordance with these and other embodiments of the present disclosure, a system and method for providing compatibility between a load and a secondary winding of an electronic transformer driven by a trailing-edge dimmer may include predicting based on an electronic transformer secondary signal an estimated occurrence of a high-resistance state of the trailing-edge dimmer, wherein the high-resistance state occurs when the trailing-edge dimmer begins phase-cutting an alternating current voltage signal and operating the load in a high-current mode for a period of time immediately prior to the estimated occurrence of the high-resistance state.Type: ApplicationFiled: March 13, 2013Publication date: January 9, 2014Applicant: Cirrus Logic, Inc.Inventors: Yanhui Xie, Eric Jerome King, John L. Melanson, Michael A. Kost
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Publication number: 20140009079Abstract: A system and method for providing compatibility between a load and a secondary winding of a magnetic transformer driven at its primary winding by a trailing-edge dimmer may include determining from a magnetic transformer secondary signal a period of a half-line cycle of an output signal of the dimmer, determining from the magnetic transformer secondary signal an estimated occurrence of an end of a phase-cut angle of the dimmer, and generating a driving signal to the load based on the period and the estimated occurrence of the end of the phase-cut angle. A lamp assembly may include a lamp for generating light and a controller for controlling operation of the lamp, the controller comprising a timing control circuit for determining a period of a periodic signal received by the lamp assembly.Type: ApplicationFiled: March 13, 2013Publication date: January 9, 2014Applicant: CIRRUS LOGIC, INC.Inventors: Yanhui Xie, Eric Jerome King, John L. Melanson
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Patent number: 8624516Abstract: A power supply apparatus for LED is provided. The power supply apparatus for LED includes a detector, a voltage dropper, and a control switch. The detector detects whether an LED is connected to the power supply apparatus. The voltage dropper drops a voltage applied to the LED. The control switch is connected to the voltage dropper in parallel, and changes a path of a power applied to the LED according to the detected result of the detector. Accordingly, the power supply apparatus for LED compensates for a low impedance of an LED to an impedance equal to or higher than a predetermined impedance at a time when connection of the LED is detected, thereby inhibiting an overcurrent from flowing in the LED.Type: GrantFiled: June 20, 2011Date of Patent: January 7, 2014Assignee: LG Innotek Co., Ltd.Inventors: Ui Jong Kim, Min Ho Kim
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Patent number: 8615339Abstract: An electric vehicle control device comprises: a smoothing capacitor to be charged from a DC power supply via a charging resistor; an inverter converting a DC power having been charged in the smoothing capacitor to an AC power to supply it to a load; and a discharging switch causing a voltage having been charged in the smoothing capacitor to discharge via a discharging resistor, and in which a resistor is used as both charging resistor and discharging resistor to simplify a circuit arrangement. In the electric vehicle control device, there are provided a main switch inserted into a main circuit to which a DC power is supplied from the DC power supply, and an auxiliary switch that is connected in parallel to the discharging switch, and is in inverted switching states with respect to the main switch.Type: GrantFiled: April 12, 2006Date of Patent: December 24, 2013Assignee: Mitsubishi Electric CorporationInventors: Yutaka Higuchi, Toshiaki Takeoka
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Patent number: 8604707Abstract: A power supply includes: a step-down chopper unit for stepping down a DC voltage from a DC power source to a voltage required for lighting; and a dimming control unit which dims the light source by alternately repeating a switching ON period during which a drive signal having a frequency higher than that of the dimming signal is supplied to the switching element and a switching OFF period during which the supply of the drive signal to the switching element is stopped. Further, the power supply includes an inrush current prevention unit for preventing an inrush current occurring when the DC power source is turned on, and a compensation unit which applies a drive voltage to the thyristor in the switching OFF period.Type: GrantFiled: April 18, 2012Date of Patent: December 10, 2013Assignee: Panasonic CorporationInventors: Kazuhiro Kumada, Yosikazu Kado, Satoru Nagata, Kazuhiro Nisimoto
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Patent number: 8593069Abstract: A method for use in a power converter includes generating a peak input voltage signal that is representative of a peak value of the input voltage for phase angles less than a phase angle threshold and is representative of a value that is less than the peak value of the input voltage for phase angles greater than the phase angle threshold. The method also includes controlling a switching of a switch to regulate an output current of the power converter in response to the peak input voltage signal and the feedback signal. A compensation current is then added to the peak input voltage signal when the phase angle is greater than the phase angle threshold to allow for natural dimming at an output of the power converter.Type: GrantFiled: March 18, 2013Date of Patent: November 26, 2013Assignee: Power Integrations, Inc.Inventors: Douglas Kang, John A. Carpenter, Taher M. Savliwala
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Publication number: 20130307434Abstract: Aspects of the disclosure provide a method. The method includes detecting a dimming characteristic in an energy source that provides energy to be transferred to a load via a magnetic component, receiving a dimming control signal, and controlling a switch in connection with the magnetic component based on the dimming characteristic and the dimming control signal to transfer energy to the load via the magnetic component.Type: ApplicationFiled: May 21, 2013Publication date: November 21, 2013Applicant: Marvell World Trade Ltd.Inventors: Wanfeng ZHANG, Pantas SUTARDJA, Yonghua SONG
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Patent number: 8587209Abstract: A method of operating an LED driver including a power converter to generate an output current for powering an LED and to provide active power factor correction is disclosed. The power converter is coupled between an input to receive a rectified AC voltage and an output for providing the output current to the LED. The method includes operating the power converter at a substantially fixed frequency in an open loop mode based on a current through the inductive element and the rectified AC voltage. LED drivers operable in accordance with the disclosed method are disclosed.Type: GrantFiled: December 7, 2010Date of Patent: November 19, 2013Assignee: Astec International LimitedInventor: Antonio R. Soleño
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Patent number: 8587207Abstract: An electronic ballast for a light emitting load is provided, and includes a transformer module, a resonance module, a high-frequency push-pull inverter and a driving controller module. The high-frequency push-pull inverter includes a first switch component and a second switch component. The driving controller module is used for generating and providing an asymmetric driving waveform to the first switch component and the second switch component. The asymmetric driving waveform includes a first discharging waveform portion for discharging and turning off the first switch component, and also a second discharging waveform portion for discharging and turning off the second switch component. The first and second discharging waveform portions are different in current amplitudes and time spans.Type: GrantFiled: April 19, 2012Date of Patent: November 19, 2013Assignee: Delta Electronics, Inc.Inventors: Ching-Ho Chou, Tsung-Yu Ou
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Patent number: 8587210Abstract: An electronic ballast for operating at least one discharge lamp may include an input having a first and a second input connection for coupling to a DC supply voltage; a load circuit having an output; a constant-current transformer which includes a converter throttle, a converter diode and a converter switch, whereby the converter throttle is coupled serially between the first input connection and the load circuit; an activation circuit which is configured to activate the converter switch during operation with an HF signal; wherein at least one component across which a second voltage which is opposite in phase to the first voltage drops during operation is coupled between the internal and the external reference potential.Type: GrantFiled: June 21, 2010Date of Patent: November 19, 2013Assignee: Osram AGInventors: Maximilian Gerber, Wolfram Sowa, Arwed Storm
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Publication number: 20130300307Abstract: A controller for controlling a power converter includes a signal generator and a driver. The power converter receives an input voltage and provides an output voltage to power a load. The signal generator receives a sense signal indicating a current flowing through the power converter, receives a detection signal indicating whether the power converter operates in a predetermined state, and generates a square wave signal according to the sense signal and the detection signal. The square wave signal has a first voltage level proportional to a peak level of the current when the power converter operates in the predetermined state; otherwise, the square wave signal has a second voltage level. The driver generates a driving signal based on the square wave signal to control a current flowing through the load.Type: ApplicationFiled: September 10, 2012Publication date: November 14, 2013Inventors: Zhimou REN, Yunning XIE, Jun REN, Ching-Chuan KUO
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Patent number: 8581505Abstract: A power control system includes a transformer and a controller regulates a current on a secondary-side of the transformer based on a primary-side signal value. In at least one embodiment, the secondary-side current is a current out of a filter coupled to a rectifier and the secondary-side of the transformer and into a load. In at least one embodiment, the primary-side signal value is a sample of a current in the primary-side windings of the transformer. In at least one embodiment, the primary-side signal value represents a sample value of a primary-side transformer current. Proper timing of sampling the primary-side signal value substantially eliminates contributions of a transformer magnetizing current from the primary-side transformer current sample. Sampling the primary-side signal value when contributions of the transformer magnetizing current are substantially eliminated allows at least an average of the secondary-side current to be determined from the primary-side signal value.Type: GrantFiled: September 5, 2012Date of Patent: November 12, 2013Assignee: Cirrus Logic, Inc.Inventor: John L. Melanson
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Patent number: 8581515Abstract: The present invention relates to a light emitting diode driver that integrates a light emitting diode control function and a power switching control function at a secondary side insulated from a primary side in a power supply circuit, without using a photo coupler to control power switching at the primary side.Type: GrantFiled: May 27, 2011Date of Patent: November 12, 2013Assignee: Samsung Electro-Mechanics Co., Ltd.Inventors: Dae Hoon Han, Jeong In Cheon, Jae Shin Lee
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Publication number: 20130293119Abstract: A universal ballast. The ballast includes a power converter, a transformer, a current sensor, and a controller. The power converter is configured to receive an input signal and convert the input signal to a direct current (DC) voltage having a first magnitude. The transformer has a center-tapped primary winding coupled to the power converter and a secondary winding coupled to a lamp. The current sensor is configured to sense a current in the secondary winding. And the controller is configured to receive an indication of the detected current from the current sensor and to determine correct operating parameters for the lamp.Type: ApplicationFiled: May 4, 2012Publication date: November 7, 2013Applicant: ROBERT BOSCH GMBHInventors: Scott Averitt, Paul Wickett
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Patent number: 8575901Abstract: An auto-selecting holding current circuit is applicable to a converter. A primary side of the converter has a Triode for Alternating Current (TRIAC) and a bleeder circuit. The auto-selecting holding current circuit includes a first sensor module, a second sensor module and a reference voltage selecting circuit. The first sensor module detects an input current drop time or an input voltage drop time to output a sense signal. The second sensor module receives a current detector signal and outputs a critical current signal to detect a holding-current value range of the TRIAC. The reference voltage selecting circuit outputs a reference current signal to the bleeder circuit, and the reference current signal corresponds to a holding-current value of the TRIAC. Therefore, the bleeder circuit maintains normal operation of the TRIACs with different holding-current values.Type: GrantFiled: March 1, 2012Date of Patent: November 5, 2013Assignee: Macroblock, Inc.Inventors: Lon-Kou Chang, Hsing-Fu Liu, Chang-Yu Wu, Li-Wei Yen
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Patent number: 8575849Abstract: A driver circuit, solid state light (SSL) source assembly including same, and a method of driving an SSL source are provided. The driver circuit includes a rectifier, an inverter, a transformer, a PFC circuit, and a frequency control. The rectifier receives an AC voltage and provides an unregulated DC voltage. The inverter includes two switches, and receives respective control signals to operate these, to generate a resonate AC signal from the unregulated DC voltage. The transformer includes a primary winding coupled to the inverter, a secondary winding to be coupled to an SSL source through an output stage, and a feedback winding. The PFC circuit controls the inverter in response to signals representative of the unregulated DC voltage and the inverter's current. The frequency control generates the control signals to control the inverter's switching frequency in response to signals representative of the output stage's current and the feedback winding's current.Type: GrantFiled: July 15, 2011Date of Patent: November 5, 2013Assignee: Osram Sylvania Inc.Inventor: Victor M. Simi
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Patent number: 8575847Abstract: A control circuit of a light-emitting element comprises a rectifying unit (30), a switching element (38), a transformer (48) having a first winding (L1) which generates a magnetic field using a current controlled by switching of the switching element (38), a second winding (L2) which is magnetically coupled to the first winding (L1) and which generates a current flowing to an LED (102), and a third winding (L3) which is magnetically coupled to the first winding (L1) and which generates a voltage (Sfbk), and an averaging capacitor (32) which averages a voltage derived by superposing a voltage (Srec) rectified by the rectifying unit (30) and the voltage (Sfbk), and a voltage averaged by the averaging capacitor (32) is applied to the first winding (L1), so that light is emitted from the LED (102).Type: GrantFiled: April 22, 2011Date of Patent: November 5, 2013Assignee: ON Semiconductor Trading, Ltd.Inventors: Yoshio Fujimura, Shinichi Yamamoto, Feng Xu
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Patent number: 8575850Abstract: An apparatus is disclosed for supplying power to a luminous load. The apparatus includes a transformer having a primary winding, and a control circuit adapted to generate an alternating current through the primary winding to develop an alternating voltage. The alternating current is based on a first signal derived from the input voltage, a second signal derived from the current, and a third signal varying substantially in-phase with the input voltage. The first and second signals are used to regulate the power delivered to the load, and the third signal is used to improve the power factor. A load interface circuit is provided to generate an output voltage for the luminous load based on the alternating voltage from the transformer. An over-temperature sensor may be provided to cause a reduction in power to the load when the ambient temperature exceeds a threshold.Type: GrantFiled: November 14, 2011Date of Patent: November 5, 2013Assignee: Ace Power International, Inc.Inventor: Chunghang Peng
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Patent number: 8569970Abstract: An LED package containing integrated circuitry for matching a power source voltage to the LED operating voltage, LEDs containing such integrated circuitry, systems containing such packages, and methods for matching the source and operating voltages are described. The integrated circuitry typically contains a power converter and a constant current circuit. The LED package may also contain other active or passive components such as pin-outs for integrated or external components, a transformer and rectifier, or a rectifier circuit. External components can include control systems for regulating the LED current level or the properties of light emitted by the LED. Integrating the power supply and current control components into the LED can provide for fabrication of relatively small LEDs using fewer and less device-specific components.Type: GrantFiled: June 25, 2012Date of Patent: October 29, 2013Assignee: Cree, Inc.Inventors: Robert Underwood, Yifeng Wu
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Patent number: 8536793Abstract: A process for controlling a current supplied to a load includes, in at least one aspect, detecting input to control a current supplied to a load operated by a driving signal, and in response to detecting the input, modifying the driving signal to control the current supplied to the load, wherein modifying the driving signal comprises alternately applying a first duty cycle and a second duty cycle to the driving signal.Type: GrantFiled: October 11, 2012Date of Patent: September 17, 2013Assignee: Marvell World Trade Ltd.Inventors: Hubertus Notohamiprodjo, Radu Pitigoi-Aron
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Patent number: 8525428Abstract: A power supply system includes a transformer having a primary winding on its primary side for coupling to a power source and one or more secondary windings on its secondary side. A first control circuit is disposed on the primary side of the transformer for controlling a current flow in the primary winding. A second control circuit disposed on the secondary side of the transformer, and the second control circuit is configured to provide a regulated output voltage. In the power supply system, the first control circuit is configured to generate a control signal for controlling the current flow in the primary winding without using a feedback control signal from the secondary side of the transformer.Type: GrantFiled: January 7, 2011Date of Patent: September 3, 2013Assignee: BCD Semiconductor Manufacturing Co. Ltd.Inventors: Fan Chen, Xin Wu, Chaoqun Sun, Qanqing Wu
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Patent number: 8525429Abstract: A method and a device for controlling gas discharge lamps using a direct current/alternating current inverter (DC/AC inverter) that is operated at a predetermined frequency and that generates an AC output voltage U for operating the gas discharge lamps from a DC input voltage which has a residual ripple. The DC/AC inverter is operated in zero voltage switching (ZVS) mode, wherein the DC input voltage is used as the control variable for the lamp current IL, wherein fluctuations in the lamp current IL caused by the residual ripple of the DC input voltage are compensated by a variation in the switch-on times and/or switch-off times of the switching elements QH, QL of the DC/AC inverter.Type: GrantFiled: June 22, 2010Date of Patent: September 3, 2013Assignee: Minebea Co., Ltd.Inventors: Manfred Schlenk, Robert Weger, Hans Hoffmann, Mykhaylo Raykhman, Michael Herfurth, Martin Feldtkeller
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Patent number: 8487540Abstract: A wake-up lighting device is described, comprising a gas discharge lamp (10) and a lamp driver (1; 2) comprising a power source (100) capable of generating spaced-apart current bursts (51) of alternating lamp current (I). The wake-up lighting device is capable of operating in an off-mode in which no lamp current is generated, and is adapted to switch from its off-mode to a wake-up mode in which the power source (100) operates to:—initially generate an alternating lamp current (I) with a minimum duty cycle value (?T) and a reduced current amplitude (IR) close to zero;—subsequently gradually increase the current amplitude while keeping the duty cycle (?) constant at the minimum duty cycle value (?T), until the current amplitude reaches a nominal current amplitude (IM);—subsequently gradually increase the duty cycle (?) while keeping the current amplitude constant at the nominal current amplitude (IM).Type: GrantFiled: December 12, 2008Date of Patent: July 16, 2013Assignee: Koninklijke Philips Electronics N.V.Inventors: Jacob Dijkstra, Wilhelmus Ettes, Schelte Heeringa, Petrus Johannes Bremer
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Publication number: 20130169182Abstract: Disclosed herein are a PWM control circuit, a flyback converter, and a PWM control method. The PWM control circuit includes: a peak storing and reference signal generating unit storing a peak value of one period of a feedback signal from a secondary side output and inverting the peak signal arid outputting the inverted peak signal as a reference signal; and a PWM control signal generating unit generating a PWM control signal by using an output obtained by comparing the reference signal with a reference waveform from the peak storing and reference signal generating unit. In addition, the flyback converter including the same and the method for controlling PWM are proposed.Type: ApplicationFiled: January 4, 2013Publication date: July 4, 2013Applicant: SAMSUNG ELECTRO-MECHANICS CO., LTD.Inventor: SAMSUNG ELECTRO-MECHANICS CO., LTD.
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Patent number: 8466628Abstract: A load control circuit, such as a light-emitting diode (LED) driver, for controlling the amount of power delivered to an electrical load, such as an LED light source, comprises a regulation transistor adapted to be coupled in series with the load, and a feedback circuit coupled in series with the regulation transistor, whereby the load control circuit is able to control the magnitude of a load current conducted through the load from a minimum load current to a maximum load current, which is at least approximately one thousand times larger than the minimum load current. The feedback circuit generates at least one load current feedback signal representative of the magnitude of the load current. The regulation transistor operates in the linear region to control the magnitude of the load current conducted through the load in response to the magnitude of the load current determined from the load current feedback signal.Type: GrantFiled: June 11, 2010Date of Patent: June 18, 2013Assignee: Lutron Electronics Co., Inc.Inventors: Thomas M. Shearer, Matthew W. Nuhfer, Venkatesh Chitta, Kartik Iyer, Nicholas A. Hoerter, Mark S. Taipale
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Patent number: 8466632Abstract: An LED device is provided. The LED device implements an efficient dimming operation. The LED device includes a triac dimmer for receiving an AC voltage and adjusting an angle of the AC voltage, a ballast for receiving the AC voltage from the triac dimmer and generating an AC voltage pulse, a bridge diode unit for generating a DC voltage pulse using the AC voltage pulse, an LED for receiving a DC current and emitting a light, an LED drive controller for receiving a dimming signal and controlling the DC current passing through the LED, and a dimming signal generator for receiving the AC voltage pulse from the ballast and generating a pulsating dimming signal for compensating an output of the triac dimmer and providing the dimming signal to the LED drive controller.Type: GrantFiled: August 13, 2010Date of Patent: June 18, 2013Assignee: LG Electronics Inc.Inventor: Sang Hyun Park
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Patent number: 8461766Abstract: An 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. Specifically, the estimator circuit includes a capacitance having a first terminal coupled to a comparator input of a pulse width modulation controller, and a second terminal coupled to an error input of an error amplifier, and a switching device having a first power terminal coupled to the second terminal of the capacitance, a second power terminal coupled to the circuit ground, and a control input terminal coupled to a drive output of the pulse width modulation controller.Type: GrantFiled: December 9, 2010Date of Patent: June 11, 2013Assignee: General Electric CompanyInventor: Louis Robert Nerone
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Patent number: 8456096Abstract: Circuits for regulating and/or controlling integrated circuits such as drivers and switching regulators generally include a first switch configured to control or regulate a current, voltage drop or voltage boost; a first regulator or driver configured to transmit first pulses to the first switch, the pulses having a first pulse width; and pulse width modulation circuitry configured to (i) reduce the first pulse width when a first thermal threshold is met and (ii) increase the first pulse width when a second thermal threshold is met, the second thermal threshold being less than the first thermal threshold.Type: GrantFiled: June 15, 2010Date of Patent: June 4, 2013Assignee: Dongbu HiTek Co., Ltd.Inventors: Kenneth Kwok, Jan Krellner, Steven Ulbrich, Joon Park
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Publication number: 20130119884Abstract: The present invention provides a light source module, including at least a LED and a switching power supply. The switching power supply has an input port, an output port, a transforming unit, and a switching unit. An external power source is connected to the input port, the LED is electrically connected to the output port, and the transforming unit is between the input port and the output port to receive power of the external power source through the input port, transform the power, and send the power to the light emitting diode through the output port. The switching unit includes a ringing choke converter electrically connected to the transforming unit to make the transforming unit provide a constant current to the LED by turning on and turning off the power outputting from the transforming unit.Type: ApplicationFiled: December 29, 2011Publication date: May 16, 2013Applicant: HEP TECH CO., LTD.Inventors: TA-SHENG HUNG, Lien-Ta Chien
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Patent number: 8436540Abstract: A multi-lamp driving system includes a pulse width modulation (PWM) controller, transformers, a current difference detection circuit, a lighting detection circuit, a frequency scanning detection circuit, a frequency regulating circuit, and a duty cycle regulating circuit. The current difference detection circuit detects difference among current flowing through lamps to determine if the current fluctuates. The lighting detection circuit determines if the lamps are lit according to the current, and generates a lighting indication signal after the lamps are lit. The frequency scanning detection circuit determines if the multi-lamp driving system is in a frequency scanning process according to the lighting indication signal, and generates a frequency scanning indication signal if the multi-lamp driving system is in the frequency scanning process.Type: GrantFiled: May 18, 2011Date of Patent: May 7, 2013Assignee: Ampower Technology Co., Ltd.Inventors: Chin-Po Cheng, Yong-Long Lee
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Publication number: 20130093345Abstract: Solid state light sources are compatible with AC phase-cut dimmers. The light sources may have switching mode power supplies having primary and secondary sides that are in first and second circuit parts that are electrically isolated from one another. Information regarding a waveform of input electrical power is extracted in the first circuit part and passed to a controller in the second circuit part by way of a galvanic isolator. Additional isolated paths may be provided to provide bi-directional exchange of information between the first and second circuit parts and/or to provide for the exchange of additional information relevant to control. The signal path from the first side to the second side may have a low latency.Type: ApplicationFiled: December 5, 2012Publication date: April 18, 2013Applicant: LIGHT-BASED TECHNOLOGIES INCORPORATEDInventor: LIGHT-BASED TECHNOLOGIES INCORPORATE
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Patent number: 8415890Abstract: A power converter for constant loads includes an energy transfer element, a switch, a controller, and a compensation circuit. The energy transfer element is coupled to receive a rectified voltage having a blocked portion that corresponds to a phase angle. The controller is coupled to control switching of the switch to regulate an output current of the power converter in response to a plurality of signals. The plurality of signals includes a peak input voltage signal and a feedback signal. The compensation circuit is coupled to output a compensation signal to adjust at least one of the plurality of signals in response to the phase angle exceeding a phase angle threshold. The compensation circuit does not output the compensation signal and does not adjust the at least one of the plurality of signals when the phase angle is less than the phase angle threshold.Type: GrantFiled: September 25, 2012Date of Patent: April 9, 2013Assignee: Power Integrations, Inc.Inventors: Douglas Kang, John A. Carpenter, Taher M. Savliwala
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Patent number: 8410721Abstract: An electronic ballast for operating at least one discharge lamp may include an input for coupling to an input voltage; a load circuit with an output, the load circuit having a bridge circuit; an intermediate circuit capacitor that is coupled to the input of the load circuit; a transformer that is coupled between the input of the ballast and the capacitor, the transformer having a transformer switch; a control apparatus for driving the switch; and a monitoring apparatus for monitoring at least one value correlated with the input voltage, the control apparatus being designed to deactivate the driving of the switch upon detection of a deactivation criterion; and a voltage measuring apparatus for measuring the intermediate circuit voltage, the control apparatus being designed to reactivate the driving of the switch after a deactivation phase when the sum of input and intermediate circuit voltage has dropped below a prescribable threshold value.Type: GrantFiled: June 1, 2010Date of Patent: April 2, 2013Assignee: OSRAM Gesellschaft mit beschraenkter HaftungInventors: Olaf Busse, Siegfried Mayer
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Patent number: 8400072Abstract: The present invention discloses a light emitting device driver circuit and a method for driving a light emitting device. In the present invention, the secondary windings of a transformer provide positive and negative secondary voltages, so as to generate positive and negative output voltages. A light emitting device circuit is coupled between the positive and negative output voltages. As such, the specification to withstand high voltage for a device in the circuit is reduced.Type: GrantFiled: November 9, 2010Date of Patent: March 19, 2013Assignee: Richtek Technology Corporation, R.O.C.Inventors: Pei-Cheng Huang, Jing-Meng Liu, Roland Van Roy
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Patent number: 8384295Abstract: A ballast circuit for a light emitting diode (LED) based lamp including power factor correction with protective isolation. The circuit includes a transformer with electrically isolated windings and a power factor correction circuit that receives no feedback from a secondary winding side of the transformer. An LED-based lamp assembly and a method of driving an LED-based light source are also provided.Type: GrantFiled: November 11, 2009Date of Patent: February 26, 2013Assignee: OSRAM SYLVANIA Inc.Inventor: Victor M. Simi
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Patent number: 8373351Abstract: A driver circuit includes a plurality of switches, forming two switching legs, each of at least two switches and connected between two DC voltage buses. The switches are matched to form diagonal pairs. The driver circuit also includes a load circuit connecting the legs, with a first inductor connected between one leg's switches, and a second inductor connected between the other leg's switches, and lamp terminals between the inductors and in series with the second inductor. The driver circuit also includes a capacitor in parallel with the series-connected lamp terminals and the second inductor, and a control circuit connected to the plurality of switches. During a commutation period, a diagonal pair operates in a non-conductive state and the other in a conductive state, until a current through the first inductor reaches a predefined value. Then the other operates in a non-conductive state until the current through the first inductor reaches zero.Type: GrantFiled: December 8, 2010Date of Patent: February 12, 2013Assignee: OSRAM SYLVANIA Inc.Inventors: Sivakumar Thangavelu, Afroz M. Imam
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Publication number: 20130026936Abstract: A driving circuit system for a gas discharge lamp includes a power circuit having a switch for converting an input voltage into a lamp voltage for driving the gas discharge lamp, a lamp current detecting circuit connected to the power circuit or the gas discharge lamp for detecting a lamp current, a feedback circuit connected to the lamp current detecting circuit for generating a lamp current feedback signal, a constant power control circuit for generating a corrected current reference signal, and a power control circuit connected to the feedback circuit, the constant power control circuit, and the switch of the power circuit for generating a first modulating signal in accordance with the lamp current feedback signal and the corrected current reference signal for driving the switch to turn on or off, thereby substantially maintaining a lamp power of the gas discharge lamp at a constant value.Type: ApplicationFiled: September 23, 2011Publication date: January 31, 2013Applicant: DELTA ELECTRONICS (SHANGHAI) CO., LTD.Inventors: Qi Zhang, Weiqiang Zhang, Jianping Ying
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Patent number: 8354795Abstract: A program start ballast powers multiple lamps coupled in parallel. A first inverter and a primary winding of a first transformer form a main circuit. A second inverter and a primary winding of a second transformer form a preheat circuit. One or more lamps are coupled in parallel across a secondary winding of the first transformer, and secondary windings of the second transformer are coupled across filaments at either end of the one or more lamps. The main circuit is configured to disable power across the first transformer during a preheat mode of operation and to provide power across the first transformer during a steady-state mode of operation. The preheat circuit is configured to provide power across the second transformer during the preheat mode of operation and to disable power across the second transformer during the steady-state mode of operation.Type: GrantFiled: May 24, 2010Date of Patent: January 15, 2013Assignee: Universal Lighting Technologies, Inc.Inventor: Wei Xiong
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Patent number: 8350488Abstract: A lighting arrangement constituted of: a power factor correction circuit; a lighting controller operative at an electrical potential consonant with the electric potential of the output of the power factor correction circuit; a switching network, coupled to the output of the power factor correction circuit and to respective outputs of the lighting controller; a transformer, a primary winding of the transformer coupled to the output of the switching network; and at least one luminaire coupled to at least one secondary winding of the transformer and arranged to be driven by the at least one secondary winding, the lighting controller operative to control the switching network via the respective outputs to switchably pass current from the power factor correction circuit through the primary winding, thereby powering the at least one luminaire.Type: GrantFiled: June 15, 2010Date of Patent: January 8, 2013Assignee: Microsemi CorporationInventor: Xiaoping Jin
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Patent number: RE44101Abstract: A fluorescent lamp assembly includes a fluorescent lamp ballast capable of detecting at least one of a plurality of input signals and generating an output signal. The output signal is associated with a power level that is based on the at least one detected input signal. The fluorescent lamp assembly also includes a fluorescent lamp capable of receiving the output signal and generating light. An intensity of the light is based on the power level associated with the output signal.Type: GrantFiled: March 31, 2011Date of Patent: March 26, 2013Assignee: STMicroelectronics, Inc.Inventor: Thomas L. Hopkins