A low frequency flicker AC led circuit

A LED light string and LED drive technology, applied in electric light sources, electrical components, electroluminescent light sources, etc., can solve problems such as adverse stimulation of the visual nerve center, eye fatigue and even headaches, and achieve reduced switching power and stroboscopic flicker , high efficiency effect

Active Publication Date: 2018-02-23
北京易美新创科技有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The frequency of the full-wave rectified input voltage is usually around 100Hz. Such a stroboscopic frequency will cause adverse stimulation to the human visual nerve center, which may easily cause symptoms such as eye fatigue and even headaches.

Method used

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  • A low frequency flicker AC led circuit
  • A low frequency flicker AC led circuit
  • A low frequency flicker AC led circuit

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0027] Embodiment 1: see figure 1 , a low-frequency flashing AC LED drive circuit, including: drive IC, LED light string D0, LED light string D1, LED light string D2, LED light string D3, LED light string D4, PMOS tube M0, PMOS tube M1, PMOS tube M2, PMOS tube M3, PMOS tube M4, current limiting resistor Rs;

[0028] The control IC is used to control the gate voltage of PMOS transistor M0, PMOS transistor M1, PMOS transistor M2, PMOS transistor M3, and PMOS transistor M4;

[0029] The positive pole of the LED light string D0 is connected to the source of the PMOS tube M0, and the negative pole of the LED light string D0 is connected to the drain of the PMOS tube M0;

[0030] LED light string D0, LED light string D1, LED light string D2, LED light string D3, LED light string D4 are connected in series, the conduction voltage of LED light string D0 is less than half of the conduction voltage of LED light string D4 ;The maximum power of LED light string D1, LED light string D2,...

Embodiment 2

[0043] Embodiment 2, on the basis of the low-flicker AC LED drive circuit in Embodiment 1, a valley-filling circuit is added at the DC power supply end, and the valley-filling circuit is used to improve the power factor of the DC power supply, thereby reducing stroboscopic flicker.

Embodiment 3

[0044] Example 3, see figure 2 , on the basis of a low-frequency flashing AC LED drive circuit in Embodiment 1, the energy storage capacitor control pin of the drive IC is added with an energy storage capacitor C1, and when the drive IC judges that the input DC power is zero, the LED light string D0, Light string D1, LED light string D2, LED light string D3, LED light string D4 power supply, eliminate the DC power supply when the LED light string D0, LED light string D1, LED light string D2, LED light string D3, LED light string D4 Strobe caused by extinguishing.

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PUM

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Abstract

The invention discloses a low-frequency flashing AC LED driving circuit, comprising: a driving IC, an LED light string D0, an LED light string D1, an LED light string D2, an LED light string D3, an LED light string D4, a PMOS tube M0, and a PMOS tube M1 , PMOS transistor M2, PMOS transistor M3, PMOS transistor M4, current limiting resistor Rs. The invention adopts the method of combining gate negative feedback and source feedback to control the conduction current of different LED segments, so that the total load power of LEDs with different voltages remains consistent, so that the LED luminous flux changes very little; The high-voltage and high-current structure keeps the LED load power stable in a wide range of input voltage ranges; the use of high-end PMOS control tubes and LED series circuits ensures that the system still has high efficiency at low voltages; fundamentally increases the drive efficiency, The power factor is improved, the switching power of the MOS tube is reduced, and the strobe is reduced.

Description

technical field [0001] The invention belongs to the technical field of semiconductor lighting applications, in particular to a low-frequency flicker AC LED circuit structure. Background technique [0002] At present, LED chips have been widely used in the field of new energy-saving light sources due to their high efficiency, high integration and long life. In LED light sources, power drive is a key technology. Due to the high integration and low cost requirements of LED applications, AC LED drive solutions without inductance and capacitors and other energy storage devices are taking an increasing share in the market. In this type of driving scheme, the control IC controls the number of LEDs that the actual conduction current passes through by adjusting the gate voltage of the LED pass switch MOS tube, so as to compensate for the excessive conduction current to the input voltage caused by the non-linearity of the LED. Sensitive, so as to achieve the purpose of current limit...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H05B33/08H05B44/00
CPCH05B45/37
Inventor 冯向光孙国喜范振灿
Owner 北京易美新创科技有限公司
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