Patent application number | Description | Published |
20100052569 | ELECTRONIC DEVICE FOR DRIVING LIGHT EMITTING DIODES - The present invention relates to an electronic device for driving a light emitting diode, which includes a switch (Ts) being adapted to switch a switch-mode power converter, and controlling means (CNTL) being adapted for controlling the switch (Ts) in response to a sensing value (Vs) indicative of a current of the switch-mode power converter and for controlling by the switch (Ts) the output voltage of the switched power converter and a current (Iout) through the light emitting diode. | 03-04-2010 |
20110068713 | METHOD AND CIRCUIT ARRANGEMENT FOR CYCLE-BY-CYCLE CONTROL OF A LED CURRENT FLOWING THROUGH A LED CIRCUIT ARRANGEMENT, AND ASSOCIATED CIRCUIT COMPOSITION AND LIGHTING SYSTEM - The invention provides a method for cycle-by-cycle control of a LED current (ILED) flowing through a LED circuit arrangement (LEDCIRC) at a mean LED current level. The method comprises a) establishing a converter current (IL), b) establishing an oscillation of the converter current (IL) between substantially a valley current level and substantially a peak current level, c) feeding the LED circuit arrangement (LEDCIRC) with the converter current (IL) as the LED current during a part of an oscillation cycle of the oscillation of the converter current, d) determining a current level correction for compensating a current level error between an integral over an oscillation cycle of the LED current and a reference, the reference being representative of the mean LED current level, and e) adjusting at least one of the valley current level and the peak current level with the current level correction for use in a successive cycle of the oscillation of the converter current. The invention also provides a circuit arrangement operable for using the method, a LED driver IC using the circuit arrangement, a circuit composition with at least one LED and the circuit arrangement, and a lighting system with the circuit composition. | 03-24-2011 |
20110164339 | SURGE PROTECTION CIRCUIT - A surge protection circuit for a circuit having a rectification module. The surge protection circuit includes a first diode, a second diode, a capacitor and a discharge device. The anode of the first diode is connected to a first input of the rectification module, and the anode of the second diode is connected to a second input of the rectification module. The cathodes of the first and second diodes are both connected to the first plate of the capacitor. The second plate of the capacitor is connected to the negative output of the rectification module. The capacitor is configured such that it is consistently charged to substantially the peak value of a supply voltage during normal operation between surge events. The discharge device is connected to the first plate of the capacitor and is configured to discharge the capacitor when the voltage across the capacitor is in excess of the peak of the maximum value of the normal supply voltage and not discharge the capacitor when the voltage across the capacitor is not in excess of the peak of the maximum value of the normal supply voltage. | 07-07-2011 |
20110187335 | CONTROL OF A HALF RESONANT CONVERTER FOR AVOIDING CAPACITIVE MODE - This invention relates to improved methods of preventing MOSFET damage in a resonant switched mode power converter ( | 08-04-2011 |
20110188270 | CIRCUIT - A circuit comprising a power factor correction stage having a DC input, a ground input, a DC output and a ground output; a capacitor; a diode; and discharge means. A first terminal of the diode is connected to an input of the power factor correction stage, a second terminal of the diode is connected to the first plate of the capacitor; and the second plate of the capacitor is connected to the other input of the PFC stage. The discharge means is connected to the capacitor and is configured to discharge the capacitor such that it contributes to the output of the PFC stage when the level of a signal at the input of the PFC stage falls below a threshold value. | 08-04-2011 |
20110188273 | POWER FACTOR CORRECTION STAGE - A power factor correction stage comprising: an input terminal configured to receive an input signal; an output terminal configured to provide an output signal; a first converter stage and one or more further converter stages, wherein each of the converter stages is connected to the input terminal and the output terminal, and each converter stage comprises a switch; and a controller configured to operate the switches of the converter stages. The controller is configured to operate the switch of the one or more further converter stages at a period of time after operation of the switch of the first converter stage for a current switching cycle, wherein the period of time corresponds to a proportion of the switching frequency for an earlier switching cycle that does not correspond to substantially the period of the earlier switching cycle divided by the number of converter stages. | 08-04-2011 |
20110193612 | METHODS OF CONTROLLING A SYNCHRONOUS RECTIFIER - Consistent with an example embodiment, there is a method of controlling a synchronous rectifier having an input signal having oscillations therein and a switch which is switchable between an open state and a closed state. The method comprises filtering the input signal to produce a filtered signal, comparing the filtered signal with a reference value, and opening the switch in response to the comparison, in which the filtering is active filtering. | 08-11-2011 |
20110261599 | CONTROLLER FOR A POWER CONVERSION CIRCUIT - A power conversion controller for controlling the operation of a switch in a power conversion circuit, wherein the power conversion controller is configured to operate the switch according to: a variable frequency mode of operation for switching frequencies greater than a minimum threshold value; and a fixed frequency mode of operation at a switching frequency equal to the minimum threshold value. | 10-27-2011 |
20110267856 | PFC WITH HIGH EFFICIENCY AT LOW LOAD - A Power Factor Corrector (PFC), typically used as the first stage of switched mode power supplies, particularly suited for Universal Mains inputs, is disclosed, along with methods for controlling a switched mode power supply having power factor correction. In order to increase efficiency, particularly under low load conditions, without undue degradation of the Power Factor, the switching of the PFC circuit is confined to one or more operating windows within each half-cycle. In embodiments, the operating window comprises a small time window centred around the peak of the mains voltage. The higher the power level, the wider the switching window. | 11-03-2011 |
20110280050 | POWER CONVERTER - The invention refers to a power converter and to a method for power conversion. The power converter includes a primary winding adapted to receive a primary alternating voltage. The converter further includes a first secondary circuit magnetically coupled to the primary winding, the first secondary circuit generating a first secondary output signal, the power converter further includes a second secondary circuit magnetically coupled to the primary winding. The power converter includes a post regulator adapted to be coupled to the second secondary circuit, the post regulator having a switch which is opened at every zero-crossing of the first output signal. | 11-17-2011 |
20120014146 | POWER-DEPENDANT MAINS UNDER-VOLTAGE PROTECTION - A method and controller for power dependant mains under-voltage (“brown-out”) protection is disclosed. Brown-out protection is meant for protection against overheating due to low mains voltage and associated high mains current. Usually this is coupled to the absolute value of the mains voltage, but for devices operating at low power this is not necessary, as overheating will not occur. The disclosed method and controller allow for lower mains voltages at low load by comparing the mains voltage with a signal indicating the actual power level of the power supply. | 01-19-2012 |
20120112711 | POWER FACTOR CONTROLLER WITH ERROR FEEDBACK, AND A METHOD OF OPERATING SUCH A POWER FACTOR CONTROLLER - A power factor controller is disclosed, in which error feedback is provided my means of a parallel combination of at least two error feedback channels. By providing at least two error feedback channels, the stability associated with, for instance, a continuously integrated feedback loop with relatively long time constant, may be combined with a fast transient response associated with, for instance, a sample-and-hold error feedback. | 05-10-2012 |
20120127761 | CIRCUIT FOR A RESONANT CONVERTER - A circuit ( | 05-24-2012 |
20120217898 | ELECTRICAL LOAD DRIVING CIRCUIT - Circuits and methods for driving electrical loads, where each is driven according to a desired current. A circuit comprising a switch mode converter comprising a transformer with primary and secondary windings, the primary connected to a voltage supply via one or more input control switches; output circuits, each comprising a switch connecting a load to an output of the secondary, each load series connected with a respective switch and in parallel with a capacitor; and a switching control circuit for control of each of the output circuit switches and for sensing a current through the loads. The switching control circuit operates the output circuit switches to maintain set current through the loads, the switching control circuit configured in successive output cycles of the switch mode converter to operate each output circuit switch in an order dependent on a forward voltage of each of the respective loads. | 08-30-2012 |
20130154494 | ELECTRONIC DEVICE FOR DRIVING LIGHT EMITTING DIODES - The present invention relates to an electronic device for driving a light emitting diode, which includes a switch (Ts) being adapted to switch a switch-mode power converter, and controlling means (CNTL) being adapted for controlling the switch (Ts) in response to a sensing value (Vs) indicative of a current of the switch-mode power converter and for controlling by the switch (Ts) the output voltage of the switched power converter and a current (Tout) through the light emitting diode. | 06-20-2013 |
20130301176 | PROTECTION CIRCUIT FOR A CASCODE SWITCH, AND A METHOD OF PROTECTING A CASCODE SWITCH - A circuit arrangement is disclosed comprising: a normally-on transistor (such as a HEMT) having first and second transistor main terminals and a non-insulated control terminal, the non-insulated control terminal being electrically coupled to a ground; a normally-off switch having first and second switch main terminals and a switch control terminal, the normally-off switch being arranged in a cascode configuration with the normally-on transistor, the first switch main terminal being electrically coupled to the second transistor main terminal, the switch control terminal being electrically coupled to the second switch main terminal and to the ground; and a control circuit configured to switch on the normally-off switch in response to the voltage at the first switch main terminal being negative relative to the ground. | 11-14-2013 |
20140071719 | NOISE FILTERING - A noise filter circuit uses open loop signal processing to process the signal that causes the noise and generate a signal to be fed back into the system to cancel noise currents. | 03-13-2014 |
20140146428 | CASCODED SEMICONDUCTOR DEVICES - The invention provides a cascode transistor circuit with a main power transistor and a cascode MOSFET formed as an integrated circuit, packaged to form the cascode transistor circuit. A control and protection circuit is integrated into the integrated circuit together and a storage capacitor provides an energy source to drive the control and protection circuit. A charging circuit is also integrated into the integrated circuit for charging the storage capacitor. | 05-29-2014 |
20140210370 | RESONANT CONVERTER CONTROL - The invention relates to methods of controlling operation of a resonant power converter and to controllers configured to operate according to such methods. Embodiments disclosed include a method of controlling a power output of a resonant power converter comprising first and second switches (S | 07-31-2014 |
20140218048 | NOISE SENSOR - The present invention relates to a noise sensor for an alternating or direct current power supply. The sensor comprises a noise sensing unit and a noise separator. The noise separator is configured to receive first, second and third input signals and provide a first output signal representative of the common mode noise and a second output signal representative of the differential mode noise. The noise sensing unit comprises a first capacitive element, a second capacitive element, a first resistive element and a second resistive element. | 08-07-2014 |
20140320096 | Voltage Generator - The disclosure relates to a voltage generator for providing an output voltage in accordance with a received target signal, the voltage generator comprising: a resonant converter configured to receive an input voltage, the resonant converter comprising: a first switch; a second switch connected in series with the first switch between the input voltage and ground (GND); a resonant tank associated with the second switch; an output capacitor coupled to the resonant tank and configured to provide an output voltage; and a rectifier configured to allow charge to flow in a single direction between the resonant tank and the output capacitor; and a controller configured to receive the target signal and to set an operating parameter of the resonant converter in accordance with a difference between an output value which is related to the output voltage and the target signal. | 10-30-2014 |
20150015155 | ELECTRONIC DEVICE FOR DRIVING LIGHT EMITTING DIODES - The present invention relates to an electronic device for driving a light emitting diode, which includes a switch (Ts) being adapted to switch a switch-mode power converter, and controlling means (CNTL) being adapted for controlling the switch (Ts) in response to a sensing value (Vs) indicative of a current of the switch-mode power converter and for controlling by the switch (Ts) the output voltage of the switched power converter and a current (Tout) through the light emitting diode. | 01-15-2015 |