LED drive circuit and LED lamp
阅读说明：本技术 一种led驱动电路及led灯具 (LED drive circuit and LED lamp ) 是由 尹尚平 于 2020-07-28 设计创作，主要内容包括：本发明涉及一种LED驱动电路,属于照明领域,其包括包括整流模块、有源功率因数校正及恒压模块和线性恒流模块；所述整流模块将电源输出的电信号整流成直流信号；所述有源功率因数校正及恒压模块接于所述整流模块和线性恒流模块之间,将接收到的所述直流信号进行功率因数的提高处理,输出恒压；所述线性恒流模块包括恒流控制芯片,所述恒流控制芯片的输出电流值设置端口上连接有限流电阻,所述限流电阻背向恒流控制芯片一端接地,所述恒流控制芯片上设有PWM调光调色端口或连接有调光调色电路。本发明具有解决了线性恒流电源在市电浮动时出现的功率不恒定的问题的效果。一种LED灯具,属于照明领域。(The invention relates to an LED drive circuit, which belongs to the field of illumination and comprises a rectifying module, an active power factor correction and constant voltage module and a linear constant current module; the rectification module rectifies an electric signal output by the power supply into a direct current signal; the active power factor correction and constant voltage module is connected between the rectification module and the linear constant current module, and is used for improving the power factor of the received direct current signal and outputting a constant voltage; the linear constant current module comprises a constant current control chip, a current limiting resistor is connected to an output current value setting port of the constant current control chip, one end of the current limiting resistor, which is opposite to the constant current control chip, is grounded, and a PWM dimming and color mixing port or a dimming and color mixing circuit is arranged on the constant current control chip. The invention has the effect of solving the problem that the power of the linear constant current power supply is not constant when the commercial power floats. An LED lamp belongs to the field of illumination.)
1. An LED drive circuit, characterized by: the power factor correction circuit comprises a rectification module (2), an active power factor correction and constant voltage module (3) and a linear constant current module (4);
the rectification module (2) rectifies the electric signal output by the power supply into a direct current signal;
the active power factor correction and constant voltage module (3) is connected between the rectifier module (2) and the linear constant current module (4), and is used for improving the power factor of the received direct current signal and outputting a constant voltage;
the linear constant current module (4) comprises a constant current control chip, a current limiting resistor is connected to an output current value setting port of the constant current control chip, one end of the current limiting resistor, which is opposite to the constant current control chip, is grounded, and a PWM dimming and color mixing port or a dimming and color mixing circuit is arranged on the constant current control chip.
2. The LED driving circuit according to claim 1, wherein: the active power factor correction and constant voltage module (3) comprises a boost PFC active power factor correction control chip.
3. The LED driving circuit according to claim 1, wherein: the boost PFC active power factor correction control chip is KP1511 XSP.
4. The LED driving circuit according to claim 3, wherein: the active power factor correction and constant voltage module (3) comprises an active power factor correction and constant voltage unit comprising a boost PFC active power factor correction control chip, wherein the DRAIN end of the boost PFC active power factor correction control chip is connected with one end of a third inductor and the positive electrode of a fifth diode, one end of the third inductor, which faces away from the fifth diode, is connected with a second capacitor, and one end of the second capacitor, which faces away from the third inductor, is grounded.
5. The LED driving circuit according to claim 4, wherein: the end of the boost PFC active power factor correction control chip COMP is sequentially connected with a third capacitor and a first resistor, one end of the first resistor, which is back to the third capacitor, is grounded, and a fourth capacitor is connected in parallel with the third capacitor and the first resistor;
the VDD end of the boost PFC active power factor correction control chip is sequentially connected with a fifth capacitor and the ground;
the CS end of the boost PFC active power factor correction control chip is sequentially connected with a second resistor and the ground;
the GND end of the boost PFC active power factor correction control chip is directly grounded;
the FB end of the boost PFC active power factor correction control chip is connected with a third resistor and a fourth resistor, the third resistor and the fourth resistor are connected in series, the FB end of the boost PFC active power factor correction control chip is connected between the third resistor and the fourth resistor, one end of the fourth resistor, back to the third resistor, is grounded, and one end of the third resistor, back to the fourth resistor, is connected with a cathode of a fifth diode.
6. The LED driving circuit according to claim 1, wherein: the front end of the rectifier module (2) is provided with an EMC circuit (1).
7. The LED driving circuit according to claim 1, wherein: the constant current control chip is SM2082 EAS.
8. The LED driving circuit according to claim 1, wherein: the rectifying module (2) and the active power factor correction and constant voltage module (3) are provided with an EMC circuit (1).
9. The LED driving circuit according to claim 6 or 8, wherein: the EMC circuit (1) comprises two groups of common mode inductors, and a first capacitor is connected between the two groups of common mode inductors.
10. An LED lamp comprising the LED driving circuit according to any one of claims 1 to 9.
Technical Field
The invention relates to the technical field of electric lighting, in particular to an LED driving circuit and an LED lamp.
Background
The LED (light emitting diode) is used as a novel light source, has the characteristics of energy conservation, environmental protection and high efficiency, is mature in technology and is applied to various fields. LEDs are widely used as illumination light sources, and various LED driving circuits have been developed.
Existing circuit existence patterns applied to this field can be roughly classified into 3 types. The power supply is an isolated constant current power supply, a non-isolated constant current power supply and a linear constant current power supply. The isolated constant-current power supply has the characteristics of low efficiency and high cost. The non-isolated constant current power supply has high efficiency, the upper limit of load voltage generally cannot exceed about 180V, and the same relative cost of larger power is high. Although the linear constant-current power supply has relative advantages in cost, the floating of the power of the whole lamp is obvious when the commercial power floats.
Disclosure of Invention
In view of the defects in the prior art, an object of the present invention is to provide an LED driving circuit that solves the problem of non-constant power of a linear constant current power supply when the mains supply is floating.
The above object of the present invention is achieved by the following technical solutions:
an LED drive circuit comprises a rectifying module, an active power factor correction and constant voltage module and a linear constant current module;
the rectification module rectifies an electric signal output by the power supply into a direct current signal;
the active power factor correction and constant voltage module is connected between the rectification module and the linear constant current module, and is used for improving the power factor of the received direct current signal and outputting a constant voltage;
the linear constant current module comprises a constant current control chip, a current limiting resistor is connected to an output current value setting port of the constant current control chip, one end of the current limiting resistor, which is opposite to the constant current control chip, is grounded, and a PWM dimming and color mixing port or a dimming and color mixing circuit is arranged on the constant current control chip.
By adopting the technical scheme, when the current input into the constant current control chip is increased, the current-limiting resistance detection current is changed along with the change of the current, so that the internal resistance of the constant current control chip is increased (or reduced) to ensure that the current input into the constant current control chip at the input end is kept relatively constant, meanwhile, the constant voltage is input through the active power factor correction and constant voltage module, the combined linear constant current power supply is not influenced by the floating of the mains supply voltage any more to greatly increase or decrease the power of the whole lamp, the output power of 90-265VAC can be constant in principle, the problem that the power of the linear constant current power supply is not constant when the mains supply floats is solved, meanwhile, the cost is low, the power factor is.
The present invention in a preferred example may be further configured to: the active power factor correction and constant voltage module comprises a boost PFC active power factor correction control chip.
The present invention in a preferred example may be further configured to: the boost PFC active power factor correction control chip is KP1511 XSP.
By adopting the technical scheme, the KP1511X is a highly integrated boost PFC power switch, and the chip adopts a quasi-resonance working mode and an active power factor correction control technology, so that the requirements of high power factor, low harmonic distortion and high efficiency can be met.
The present invention in a preferred example may be further configured to: the active power factor correction and constant voltage module comprises an active power factor correction and constant voltage unit comprising a boost PFC active power factor correction control chip, wherein the DRAIN end of the boost PFC active power factor correction control chip is connected with one end of a third inductor and the anode of a fifth diode, one end of the third inductor, which faces away from the fifth diode, is connected with a second capacitor, and one end of the second capacitor, which faces away from the third inductor, is grounded.
The present invention in a preferred example may be further configured to: the end of the boost PFC active power factor correction control chip COMP is sequentially connected with a third capacitor and a first resistor, one end of the first resistor, which is back to the third capacitor, is grounded, and a fourth capacitor is connected in parallel with the third capacitor and the first resistor;
the VDD end of the boost PFC active power factor correction control chip is sequentially connected with a fifth capacitor and the ground;
the CS end of the boost PFC active power factor correction control chip is sequentially connected with a second resistor and the ground;
the GND end of the boost PFC active power factor correction control chip is directly grounded;
the FB end of the boost PFC active power factor correction control chip is connected with a third resistor and a fourth resistor, the third resistor and the fourth resistor are connected in series, the FB end of the boost PFC active power factor correction control chip is connected between the third resistor and the fourth resistor, one end of the fourth resistor, back to the third resistor, is grounded, and one end of the third resistor, back to the fourth resistor, is connected with a cathode of a fifth diode.
The present invention in a preferred example may be further configured to: and an EMC circuit is arranged at the front end of the rectifying module.
By adopting the technical scheme, internal and external interference is eliminated.
The present invention in a preferred example may be further configured to: the constant current control chip is SM2082 EAS.
By adopting the technical scheme, the SM2082EAS is a single-channel LED linear constant current control chip, the chip uses the constant current setting and control technology of the chip, the output current is set by an external Rext resistor, the maximum current can reach 40mA, the output current does not change along with the voltage of an OUT port of the chip, and the constant current control chip has better constant current performance. The system has simple structure, few peripheral elements and low scheme cost. The chip has an over-temperature regulation function, when the temperature of the chip reaches an over-temperature regulation point, the output current is gradually reduced, the function of protecting the IC is achieved, and the application reliability is improved.
The present invention in a preferred example may be further configured to: the rectifying module and the active power factor correction and constant voltage module are provided with an EMC circuit.
The present invention in a preferred example may be further configured to: the EMC circuit comprises two groups of common mode inductors, and a first capacitor is connected between the two groups of common mode inductors.
The second aim of the invention is realized by the following technical scheme:
an LED lamp is characterized by comprising the LED driving circuit.
In summary, the invention includes at least one of the following beneficial technical effects:
1. the combined linear constant-current power supply is not influenced by the floating of the mains supply voltage any more, so that the power of the whole lamp is greatly increased and reduced, and the output power of 90-265VAC can be constant in principle;
2. the high power factor and the low harmonic content can reduce the neutral current pressure to the commercial power grid, thereby achieving the functions of environmental protection and consumption reduction;
3. the front-end EMC circuit is simpler;
4. the output direct current has low ripple content and no stroboflash;
5. the cost is low, the national CCC requirement is easily met, and technical force is contributed to the resource-saving society;
6. the number of the components is small, and the volume is small, so that the output voltage is high, and the loaded power is high.
Drawings
FIG. 1 is a schematic diagram of an LED driver circuit according to one embodiment.
The attached drawings are as follows: 1. an EMC circuit; 2. a rectification module; 3. an active power factor correction and constant voltage module; 4. and the linear constant current module.
Detailed Description
The present invention will be described in further detail with reference to the accompanying drawings.
Referring to fig. 1, the LED driving circuit disclosed by the present invention includes an EMC circuit 1, a rectifying
The EMC circuit eliminates internal and external interference, and the
The constant current control chip U2 is SM2082EAS, SM2082EAS is a single-channel or multichannel LED linear constant current control chip, the output current is set by the freewheel resistor R5, the basic principle is that when the current of the input OUT is increased (or decreased), the detection current of the freewheel resistor R5 is changed, so that the internal resistance of the U2 is increased (or decreased) to ensure that the current of the input OUT is kept relatively constant.
The EMC circuit 1 includes two sets of common mode inductances L1, L2, and a first capacitance C1 is connected between the two sets of common mode inductances L1, L2. The EMC circuit 1 may be replaced with an anti-surge circuit, and the EMC circuit 1 may be provided in the
In addition, in order to ensure the safety of the resistor, a fuse FU and a piezoresistor RV can be arranged at the port of the commercial power entering the driving circuit.
The active PFC and
The active power factor correction and
A COMP end of the boost PFC active power factor correction control chip U1 is sequentially connected with a third capacitor L3 and a first resistor R1, one end of the first resistor R1, back to the third capacitor C3, is grounded, and a fourth capacitor C4 is connected in parallel with the third capacitor C3 and the first resistor R1; the VDD end of the boost PFC active power factor correction control chip U1 is sequentially connected with a fifth capacitor C5 and the ground; the CS end of the boost PFC active power factor correction control chip U1 is sequentially connected with a second resistor R2 and the ground; the GND end of the boost PFC active power factor correction control chip U1 is directly grounded; the FB end of the boost PFC active power factor correction control chip U1 is connected to a third resistor R3 and a fourth resistor R4, the third resistor R3 is connected in series with the fourth resistor R4, the FB end of the boost PFC active power factor correction control chip U1 is connected between the third resistor R3 and the fourth resistor R4, one end of the fourth resistor R4, which faces away from the third resistor R3, is grounded, and one end of the third resistor R3, which faces away from the fourth resistor R4, is connected to the cathode of a fifth diode D5.
The implementation principle of the embodiment is as follows: when the current input into the constant current control chip U2 is increased, the current limiting resistor R5 detects that the current changes along with the current, so that the internal resistance of the constant current control chip U2 is increased (or reduced) to ensure that the current input into the input end constant current control chip U2 is kept relatively constant, meanwhile, constant voltage is input through the active power factor correction and constant voltage module 3d, the combined linear constant current power supply is not influenced by the floating of the mains supply voltage any more to greatly increase and decrease the power of the whole lamp, the 90-265VAC output power can be constant in principle, the problem that the power of the linear constant current power supply is not constant when the mains supply floats is solved, and meanwhile, the cost is low, the power factor is high, and the ripple content.
An LED lamp comprises the LED drive circuit.
The embodiments of the present invention are preferred embodiments of the present invention, and the scope of the present invention is not limited by these embodiments, so: all equivalent changes made according to the structure, shape and principle of the invention are covered by the protection scope of the invention.
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