CN103634991A - High-voltage integrated alternating-current LED multistage linear drive device - Google Patents

Abstract

The invention is a high-voltage integrated AC LED multi-segment linear driving device. It includes a rectifier circuit, a number of LED modules, a number of turn-on and turn-off circuits, a number of MOS tubes, a turn-on protection circuit, a turn-off protection circuit and a constant current source. The output end of the group, the on-off circuit, the on-off protection circuit and the off-protection circuit are connected. The invention has high integration, direct AC high-voltage drive, high power factor, long service life, low cost, stable and reliable high-voltage integrated AC LED multi-segment linear drive device.

Description

A high-voltage integrated AC LED multi-segment linear drive device

technical field

The invention is a high-voltage integrated AC LED multi-segment linear drive device, which belongs to the innovative technology of the high-voltage integrated AC LED multi-segment linear drive device.

Background technique

LED light-emitting diode is a semiconductor component that can convert electrical energy into light energy. It has the advantages of small size, low power consumption, long service life, environmental protection and durability, and is widely used in lighting fixtures, displays, traffic lights and other fields. Compared with traditional incandescent lamps, light-emitting diodes are unidirectional conduction elements, and light-emitting diodes need a suitable DC low voltage to drive light. In addition, light-emitting diodes have negative temperature characteristics and from the volt-ampere characteristics of LEDs, small voltage fluctuations will cause large current changes in LEDs, which will affect the life of LEDs and luminous efficiency. Therefore, if you want to apply light-emitting diodes to AC mains power, you need to add an AC-DC converter between the AC power and the LED load to achieve DC drive. The general design scheme is shown in Figure 1. This basic LED driver circuit consists of an AC-DC or DC-DC converter. However, inductance or large capacitors are used in these driving circuits, which undoubtedly increases the weight, volume and cost of the lamp. Moreover, the life of the electrolytic capacitor is greatly affected by temperature, which becomes the bottleneck of the life of the LED drive power supply, and the use of the inductor will also cause serious EMI problems. If the LED (AC-LED) is directly driven by alternating current, no AC-DC conversion is required, thus solving a series of problems caused by the AC-DC conversion circuit.

Traditional AC-LEDs are integrated with matrix-arranged microcrystals, and a bridge circuit is added to the design. As long as alternating current is applied to both ends of the AC-LED, the current can flow in both directions to make the LED emit light. However, the power factor of such LED is low, and it can be seen from the LED volt-ampere characteristic curve that a small voltage fluctuation can cause a large current change (10% change in current voltage, 60% change in current), which affects the life of the LED and Luminous efficiency has been affected.

Contents of the invention

The purpose of the present invention is to consider the above problems and provide a high-integrated high-voltage integrated AC LED multi-segment linear drive device with high power factor, long life, low cost, stable and reliable use, directly driven by AC high voltage. The invention is reasonable in design, convenient and practical.

The technical solution of the present invention is: the voltage integrated AC LED multi-segment linear drive device of the present invention includes a rectifier circuit, a plurality of LED modules, a plurality of on-off circuits, a plurality of MOS tubes, a turn-on protection circuit, a turn-off protection circuit and a constant current source, wherein the input terminal of the rectifier circuit is connected to the AC power supply, and the MOS tube is respectively connected to the output terminal of the LED module, the on-off circuit, the on-protection circuit and the off-protection circuit.

The above-mentioned several LED modules include the first LED module, the second LED module, the third LED module and the fourth LED module connected in sequence, and the several MOS tubes include the first MOS tube, the second MOS tube, the third MOS tube and the fourth MOS tube, several on-off circuits include a first on-off circuit, a second on-off circuit, a third on-off circuit and a fourth on-off circuit, wherein the first LED module, The second LED module, the third LED module, and the fourth LED module are connected in series in sequence, and one end of the first LED module is connected to the rectifier circuit, connected to the opening protection circuit, and connected to the first opening and closing circuit, the second opening The shutdown circuit, the third on-off circuit and the fourth on-off circuit are connected, one end of the second LED module is connected to the first MOS tube, the other end of the second LED module is connected to the second MOS tube, and the third One end of the LED module is connected to the second MOS tube, the other end of the third LED module is connected to the third MOS tube, one end of the fourth LED module is connected to the third MOS tube, and the other end of the fourth LED module is connected to the third MOS tube. The fourth MOS transistor is connected, and the first MOS transistor, the second MOS transistor, the third MOS transistor and the fourth MOS transistor are all connected to the turn-on protection circuit, the turn-off protection circuit and the constant current source.

The drains of the first MOS tube, the second MOS tube, the third MOS tube and the fourth MOS tube are connected to the output terminals of each group of LED modules, the sources are connected to the constant current source, and the gates are connected to the protection circuit.

10%，极低的电磁干扰辐射。本发明是由交流电源直接驱动，不需使用任何变压器、电容器与电感器等储能电子元件，故不会有功率因数低落的问题，而不须额外设置功率因数校正器，是大幅减少本发明所使用的电子元件及体积，满足交流LED驱动电路小型化的需求。本发明是一种设计巧妙，性能优良，方便实用的高压集成交流LED多段线性驱动装置。 The present invention adopts a loop structure formed by including an AC power input terminal, a rectifier circuit, a turn-on protection circuit, an LED module, a turn-on turn-off circuit, a MOS tube, a turn-off protection circuit and a constant current source. The present invention eliminates capacitors and inductance elements, greatly reducing the volume of LED lighting; compared with other LED lighting design schemes, the present invention uses AC power to directly drive, making the circuit simpler and more reliable, and facilitating large-scale integration of LED lighting ;The hierarchical drive scheme also makes the circuit power factor reach 0.99, the power drive efficiency reaches 0.9, and the total harmonic distortion

10%, extremely low electromagnetic interference radiation. The present invention is directly driven by an AC power source without using any energy storage electronic components such as transformers, capacitors, and inductors, so there is no problem of low power factor, and no additional power factor corrector is required, which greatly reduces the cost of the present invention. The used electronic components and volume meet the miniaturization requirements of the AC LED drive circuit. The invention is a convenient and practical high-voltage integrated AC LED multi-segment linear driving device with ingenious design and excellent performance.

Description of drawings

Figure 1 is a schematic diagram of a traditional LED high-frequency chopper drive design scheme.

Fig. 2 is a schematic diagram of the present invention.

Detailed ways

Example:

The structural diagram of the present invention is shown in Figure 2. The voltage-integrated AC LED multi-segment linear drive device of the present invention includes a rectifier circuit 102, a number of LED modules, a number of on-off circuits, a number of MOS tubes, a turn-on protection circuit 115, an off-circuit An off protection circuit 116 and a constant current source 117, wherein the input terminal of the rectifier circuit 102 is connected to the AC power supply 101, and the MOS tube is connected to the output terminal of the LED module, the on-off circuit, the on-off protection circuit 115 and the off-protection circuit 116 respectively .

The above-mentioned several LED modules include the first LED module 103, the second LED module 104, the third LED module 105, and the fourth LED module 106 connected in sequence, and the several MOS tubes include the first MOS tube 108, the second MOS tube 110, the third MOS tube 112 and the fourth MOS tube 114, several on-off circuits include a first on-off circuit 107, a second on-off circuit 109, a third on-off circuit 111 and a fourth on-off circuit Turn off the circuit 113, wherein the first LED module 103, the second LED module 104, the third LED module 105, and the fourth LED module 106 are connected in series in sequence, and one end of the first LED module 103 is connected to the rectifier circuit 102 , connected with the on-off protection circuit 115 and connected with the first on-off circuit 107, the second on-off circuit 109, the third on-off circuit 111 and the fourth on-off circuit 113, one end of the second LED module 104 Connected to the first MOS tube 108, the other end of the second LED module 104 is connected to the second MOS tube 110, one end of the third LED module 105 is connected to the second MOS tube 110, the other end of the third LED module 105 Connected to the third MOS tube 112, one end of the fourth LED module 106 is connected to the third MOS tube 112, the other end of the fourth LED module 106 is connected to the fourth MOS tube 114, the first MOS tube 108, the second MOS tube The transistor 110 , the third MOS transistor 112 and the fourth MOS transistor 114 are all connected to the turn-on protection circuit 115 , to the turn-off protection circuit 116 and to the constant current source 117 . The input end of the on-off protection circuit is connected with the input end of the on-off circuit. Ensure that at the moment the circuit is turned on, there will be no overvoltage or overcurrent in the circuit. The input end of the turn-off protection circuit is connected to the output end of the turn-on protection circuit, and the output end is connected to the MOS tube to ensure that when the LED module is switched, the reverse voltage generated will not damage the MOS tube. The on-off circuit of the present invention adopts the control mode of turning on the LED modules in sections. The rectifier circuit, on-on protection circuit, on-off circuit and off-protection circuit of the present invention completely use resistors and semiconductor devices. The turn-on protection circuit of the present invention is instantaneous overvoltage protection. The constant current value of the present invention can be realized by adjusting the resistance. The method of the present invention employs piecewise linear drives.

In this embodiment, the AC power supply 101 uses an AC220V power supply. The LED driving power supply of the present invention uses AC220V/110V power supply, directly uses alternating current, and the rectifier circuit 102 converts the alternating current energy of the alternating current power supply 101 into direct current electric energy. The input end of the rectifier circuit 102 is connected to an AC power source and converts the AC power source into a pulsating voltage, which is then output from its output end. The present invention is directly driven by 220V/110V AC power supply, and does not need a transformer to convert high-voltage electric energy into low-voltage electric energy.

The turn-on protection circuit 115 includes a Zener diode and a series resistor. Turning on the protection circuit 115 suppresses the impact of the peak voltage on the subsequent circuits, mainly including Zener diodes and series resistors

The first LED module 103 , the second LED module 104 , the third LED module 105 , and the fourth LED module 106 all include several LED light sources, and the several LED light sources are connected in series. The input terminal of the LED module is connected to the output terminal of the rectifier circuit, and the output terminal is connected to the drain of the MOS tube. It receives the pulsating voltage from the output terminal of the rectifier circuit and is controlled by the MOS tube to turn on and off the circuit where it is located, and controls the light emission.

The number of LED light sources contained in the first LED module 103, the second LED module 104, the third LED module 105, and the fourth LED module 106 are 7 and 6, respectively, according to the order of voltage starting from high to low. , 6 and 5, the first LED module 103, the second LED module 104, the third LED module 105, and the fourth LED module 106 are respectively connected to the MOS tube and the on-off circuit after outputting.

The first on-off circuit 107 , the second on-off circuit 109 , the third on-off circuit 111 and the fourth on-off circuit 113 are all composed of transistors and resistors. The input end of the on-off circuit is connected with the output end of the rectification circuit, and the output end is connected with the MOS tube. According to the voltage, the turn-on and turn-off of the MOS tube is controlled, so as to turn off other loops in a timely manner. The turn-on protection circuit ensures no overvoltage or overcurrent when turned on; the turn-off protection circuit ensures that the back pressure generated when the LED module is switched will not damage the MOS tube.

the

In this embodiment, the drains of the first MOS transistor 108, the second MOS transistor 110, the third MOS transistor 112 and the fourth MOS transistor 114 are connected to the output terminals of each group of LED modules, and the sources are connected to the constant current source 117 , the gate is connected to the opening protection circuit 115 . The MOS transistor controls the turn-on and turn-off of the circuit where it is located according to the gate voltage. When the MOS tube is turned on, the current forms a stepped constant current output. When the voltage is low, the working current is small, and when the voltage is high, the working current is large, thus obtaining a higher PF value. At the same time, the circuit changes the number of series-connected LED modules connected to the constant current source 117 according to the magnitude of the input voltage. The number of LED lamp beads connected to the constant current source 117 is small, and the number of connected LED lamp beads is connected to high voltage, thereby reducing the voltage loss on the constant current source 117 , improve drive efficiency.

The above-mentioned constant current source includes a triode and a resistor. The base of the triode is connected in series with the LED module, the emitter is grounded, and the collector is connected in parallel with the resistor. The other end of the resistor is grounded. The current flowing out of the LED module controls the turn-on and turn-off of the triode, thereby controlling the resistance in the circuit and ensuring the sinusoidal ladder wave in the circuit.

The working principle of the present invention is as follows: as shown in Figure 2, when the voltage gradually increases and reaches a certain size, the first LED module 103 starts, but the current only flows to the constant current source 117 through the first MOS tube 108, and the current The size is set by R1, R2, R3 and R4.

When the voltage continues to increase, the second LED module 104 starts, and the first MOS transistor 108 connected to the output of the first LED module 103 is turned off through the first on-off circuit 107, and the first LED module 103 and the second The LED modules 104 emit light in series, the second MOS transistor 110 is turned on, the current is set by R2, R3 and R4 at this time, the first MOS transistor 108 is cut off, and the current only flows to the constant current source 117 through the second MOS transistor 110;

When the voltage continues to increase, the third LED module 105 starts, and the second MOS transistor 110 connected to the output terminal of the second LED module 104 is turned off through the second on-off circuit 109, and the first LED module 103, the second The LED module 104 and the third LED module 105 are connected in series to emit light, and the third MOS transistor 112 is turned on. At this time, the current is set by R3 and R4. The first MOS transistor 108 and the second MOS transistor 110 are both cut off, and the current It flows to the constant current source 117 through the third MOS transistor 112 .

When the voltage continues to increase, the fourth LED module 106 starts, and the third MOS transistor 112 connected to the output terminal of the third LED module 105 is turned off through the third on-off circuit 111, and the first LED module 103, the second The LED module 104, the third LED module 105, and the fourth LED module 106 are connected in series to emit light, the fourth MOS transistor 114 is turned on, and the first MOS transistor 108, the second MOS transistor 110, and the third MOS transistor 112 are all cut off. , the magnitude of the current is set by R4, and the current flows to the constant current source 117 only through the fourth MOS transistor 114 . When the voltage drops, the fourth LED module 10 , the third LED module 105 , the second LED module 104 , and the first LED module 103 are turned off successively, and the current also drops successively.

The present invention is directly driven by the AC voltage, without the derivative problems of capacitors and inductors or other electronic components in the prior art.

The above are only preferred embodiments of the present invention, but the design concept of the present invention is not limited thereto, and any insubstantial modifications made to the present invention using this concept also fall within the scope of protection of the present invention.

Claims (8)

1. A high-voltage integrated AC LED multi-segment linear driver is characterized in that it includes a rectifier circuit, some LED modules, some opening and closing circuits, some MOS tubes, opening protection circuits, shutdown protection circuits and constant current sources, wherein The input end of the rectification circuit is connected with the AC power supply, and the MOS tube is respectively connected with the output end of the LED module, the turn-on and turn-off circuit, the turn-on protection circuit and the turn-off protection circuit. 2. The high-voltage integrated AC LED multi-segment linear drive device according to claim 1, characterized in that the above-mentioned LED modules include a first LED module, a second LED module, a third LED module, and a fourth LED module connected in sequence. In the LED module, several MOS tubes include a first MOS tube, a second MOS tube, a third MOS tube and a fourth MOS tube, and several on-off circuits include a first on-off circuit, a second on-off circuit, The third on-off circuit and the fourth on-off circuit, wherein the first LED module, the second LED module, the third LED module, and the fourth LED module are connected in series in sequence, and one end of the first LED module is connected to the The rectifier circuit is connected, connected with the on-off protection circuit and connected with the first on-off circuit, the second on-off circuit, the third on-off circuit and the fourth on-off circuit, and one end of the second LED module is connected to the first MOS tube connection, the other end of the second LED module is connected to the second MOS tube, one end of the third LED module is connected to the second MOS tube, the other end of the third LED module is connected to the third MOS tube, and the fourth One end of the LED module is connected to the third MOS tube, the other end of the fourth LED module is connected to the fourth MOS tube, the first MOS tube, the second MOS tube, the third MOS tube and the fourth MOS tube are all connected to the open protection The circuit is connected, connected with the shutdown protection circuit and connected with the constant current source. 3. The high-voltage integrated AC LED multi-segment linear drive device according to claim 1, characterized in that the AC power supply uses AC220V/110V power supply. 4. The high-voltage integrated AC LED multi-segment linear drive device according to claim 1, characterized in that said turn-on protection circuit comprises a Zener diode and a series resistor. 5. The high-voltage integrated AC LED multi-segment linear drive device according to claim 1, characterized in that the first LED module, the second LED module, the third LED module, and the fourth LED module all include several LED A light source, and several LED light sources are connected in series. 6. The high-voltage integrated AC LED multi-segment linear drive device according to claim 1, characterized in that the LED light sources included in the first LED module, the second LED module, the third LED module, and the fourth LED module The numbers are 7, 6, 6 and 5 according to the order of voltage start-up from high to low. The first LED module, the second LED module, the third LED module and the fourth LED module are respectively connected The MOS tube is connected with the on-off circuit. 7. The high-voltage integrated AC LED multi-segment linear drive device according to claim 1, characterized in that the first on-off circuit, the second on-off circuit, the third on-off circuit and the fourth on-off circuit are all It consists of a triode and a resistor. 8. The high-voltage integrated AC LED multi-segment linear drive device according to claim 1, characterized in that the drains of the first MOS tube, the second MOS tube, the third MOS tube and the fourth MOS tube are connected to each group of LED modules The output terminal of the group, the source is connected to the constant current source, and the gate is connected to the open protection circuit.

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