Power supply circuit of light-emitting diode

Abstract

The invention discloses a power supply circuit of a light-emitting diode. A first positive output end and a first negative output end of a power source supply device are used for receiving input voltages and outputting drive voltages to a light-emitting diode component. The power supply circuit comprises a second positive output end, a second negative output end, a post-state power source conversion circuit and a control circuit, wherein the second positive output end and the second negative output end are connected with the light-emitting diode component, and the second negative output end is connected with the first negative output end; the post-stage power source conversion circuit is used for converting the input voltages into compensating voltages and is provided with a third positive output end connected with the second positive output end and a third negative output end connected with the first positive output end; and the control circuit is connected with the post-stage powersource conversion circuit and the light-emitting diode component and is used for detecting and controlling the current of the light-emitting diode component, wherein the drive voltage is obtained by adding the input voltage and the compensating voltage. The power supply circuit improves efficiency because of a little electric energy conversion loss, and because elements with low voltage-resistinglimit can be selected as the elements in the post-stage power source conversion circuit, the cost is reduced.

Description

technical field

[0001] The invention relates to a power supply circuit, in particular to a light-emitting diode power supply circuit capable of reducing power conversion loss. Background technique

[0002] In recent years, due to breakthroughs in light emitting diode (Light Emitting Diode, LED) manufacturing technology, the luminous brightness and luminous efficiency of light emitting diodes have been greatly improved, thus making light emitting diodes gradually replace known lamp tubes and become new lighting components, widely used in For example, lighting applications such as household lighting devices, automotive lighting devices, handheld lighting devices, LCD panel backlights, traffic sign lights, and signage boards.

[0003] In order to increase the brightness of the LEDs, usually a plurality of LEDs are connected in series to form an LED module. However, due to the relationship between the LED technology, the start-up voltage of each LED will not be exactly the same...

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