Dual Switcher Flyback Structure for LED Driver
First Claim
1. A controller for controlling a power converter to convert electrical power at an input voltage into electrical power at an output voltage;
- whereinthe power converter comprisesa first switcher stage comprising a primary winding of a transformer which is arranged in series with a first power switch;
wherein the first switcher stage is arranged in parallel to the input voltage at an input of the power converter;
a second switcher stage comprising an auxiliary winding of the transformer which is arranged in series with a second power switch;
wherein the second switcher stage is arranged in parallel to a reservoir capacitor; and
a secondary winding of the transformer which is arranged in parallel to the output voltage at an output of the power converter;
the controller is configured todetermine whether the input voltage is greater or smaller than a pre-determined voltage threshold;
operate the first switcher stage to transfer electrical power from the input of the power converter to the output of the power converter, during a first time period when the input voltage is greater than the pre-determined voltage threshold; and
operate the second switcher stage to transfer electrical power from the reservoir capacitor to the output of the power converter, during a second time period when the input voltage is smaller than the pre-determined voltage threshold.
1 Assignment
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Accused Products
Abstract
Driver circuits to reduce or remove flicker of SSL devices are presented. A controller for a power converter which converts electrical power at an input voltage into electrical power at an output voltage is described. The controller is configured to determine whether the input voltage is greater or smaller than a pre-determined voltage threshold ; to operate a first switcher stage to transfer electrical power from the input of the power converter to the output of the power converter, during a first time period when the input voltage is greater than the pre-determined voltage threshold; and to operate a second switcher stage to transfer electrical power from the reservoir capacitor to the output of the power converter, during a second time period when the input voltage is smaller than the pre-determined voltage threshold.
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Citations
18 Claims
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1. A controller for controlling a power converter to convert electrical power at an input voltage into electrical power at an output voltage;
- wherein
the power converter comprises a first switcher stage comprising a primary winding of a transformer which is arranged in series with a first power switch;
wherein the first switcher stage is arranged in parallel to the input voltage at an input of the power converter;a second switcher stage comprising an auxiliary winding of the transformer which is arranged in series with a second power switch;
wherein the second switcher stage is arranged in parallel to a reservoir capacitor; anda secondary winding of the transformer which is arranged in parallel to the output voltage at an output of the power converter; the controller is configured to determine whether the input voltage is greater or smaller than a pre-determined voltage threshold; operate the first switcher stage to transfer electrical power from the input of the power converter to the output of the power converter, during a first time period when the input voltage is greater than the pre-determined voltage threshold; and operate the second switcher stage to transfer electrical power from the reservoir capacitor to the output of the power converter, during a second time period when the input voltage is smaller than the pre-determined voltage threshold. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
- wherein
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14. A method controlling a power converter to convert electrical power at an input voltage into electrical power at an output voltage;
- wherein the power converter comprises a first switcher stage comprising a primary winding of a transformer which is arranged in series with a first power switch;
wherein the first switcher stage is in parallel to the input voltage at an input of the power converter;
a second switcher stage comprising an auxiliary winding of the transformer which is in series with a second power switch;
wherein the second switcher stage is in parallel to a reservoir capacitor; and
a secondary winding of the transformer which is in parallel to the output voltage at an output of the power converter;wherein the method comprises determining whether the input voltage is greater or smaller than a pre-determined voltage threshold; operating the first switcher stage to transfer electrical power from the input of the power converter to the output of the power converter, during a first time period when the input voltage is greater than the pre-determined voltage threshold; and operating the second switcher stage to transfer electrical power from the reservoir capacitor to the output of the power converter, during a second time period when the input voltage is smaller than the pre-determined voltage threshold. - View Dependent Claims (15, 16, 17, 18)
- wherein the power converter comprises a first switcher stage comprising a primary winding of a transformer which is arranged in series with a first power switch;
Specification