| 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 |
