Hybrid LED light adjustment control circuit

Abstract

The invention relates to a hybrid LED light adjustment control circuit. The hybrid LED light adjustment control circuit comprises an LED lamp, a switching power supply voltage control loop, a switching power supply current control loop, a linear power supply control loop, a control loop selection circuit, a light adjustment control circuit, and a current detection resistor. The light adjustment control circuit is connected with the switching power supply voltage control loop through the switching power supply current control loop; one end of the LED lamp is connected with the switching power supply voltage control loop, while the other end of the LED lamp is connected with the linear power supply control loop; the current detection resistor is connected with the linear power supply control loop through the control loop selection circuit; and the current detection resistor is also connected with the switching power supply current control loop through the control loop selection circuit. With the hybrid LED light adjustment control circuit of the invention adopted, the whole LED driving circuit integrates the advantages of a switching power supply and a linear power supply, while prevents defects of low efficiency and high loss of a linear power supply circuit when current is heavy.

Description

【Technical field】 [0001] The invention relates to a control circuit, in particular to a hybrid LED dimming control circuit. 【Background technique】 [0002] There are two types of LED driving circuits in the prior art, which are: [0003] 1. Linear constant current control LED drive: This circuit uses an operational amplifier for current feedback to form a closed loop, thereby generating a stable current on the LED. The advantage of this circuit is that the circuit is simple, and the disadvantage lies in the MOSFET used to generate LED constant current. The step-down is usually relatively large, the efficiency is not high, and it can only be used for driving LEDs with very low currents; [0004] 2. Switching current constant current LED drive: This drive circuit is the most widely used LED drive circuit at present. The advantage is that the efficiency is as high as 80%, and it is used for high-power lighting drive. The disadvantage is that the stability and accuracy of high ...

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Problems solved by technology

[0003] 1. Linear constant current control LED drive: This circuit uses an operational amplifier for current feedback to form a closed loop, thereby generating a stable current on the LED. The advantage of this circuit is that the circuit is simple, and the disadvantage lies in the MOSFET used to generate LED constant current. The step-down is usually relatively large, the efficiency is not high, and it can only be used for driving LEDs with very low currents;

[0004] 2. Switching current constant current LED drive: This drive circuit is the most widely used LED drive circuit at present. The advantage is that the efficiency is as high as 80%, and it is used for high-power lighting drive. The disadvantage is that the stability and accuracy of high and low current output are difficult. Take into account, because most switching power supplies are easy to enter frequency hopping control under extremely light load conditions, which will cause loop instability or light flickering

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