Disclosure of Invention
The present invention aims to solve at least one of the technical problems existing in the prior art or related art.
To this end, an object of the present invention is to propose an LED driving circuit.
Therefore, another object of the present invention is to provide an LED lamp.
To achieve the above object, an embodiment of a first aspect of the present invention provides an LED driving circuit, including: the rectification filter module is used for rectifying the input alternating voltage into pulsating direct voltage; the power factor correction module is connected to the rectifying and filtering module in series and is used for improving the driving power factor; the linear constant current module is connected to the power factor correction module in series and used for limiting the peak value of the driving current; and one end of the first electrolytic capacitor is arranged between the power factor correction module and the linear constant current module, and the other end of the first electrolytic capacitor is grounded and is used for supplying power to the LED load module when the trough voltage is reached.
In the technical scheme, a first electrolytic capacitor is arranged between the power factor correction module and the linear constant current module, on one hand, the power factor of the driving circuit is improved through the power factor correction module, on the other hand, the maximum current flowing through the LED load in the driving circuit is limited through the linear constant current module, so that the LED load is prevented from being over-current, the display stability of the LED load is improved, and on the other hand, the first electrolytic capacitor is arranged, when the driving voltage is in a trough state, the LED load is discharged, and the continuous light emission of the LED load is maintained.
According to the LED driving circuit provided by the technical scheme, the use requirement of stable light emitting of the LED under the input voltage of low voltage 85V and high voltage 277V can be met.
For the stroboscopic problem, the root of the stroboscopic problem is that ripple voltage or ripple circuit on the LED is overlarge, when the voltage passing through the rectifying and filtering module is in a trough, the first electrolytic capacitor discharges to maintain normal light emission of the LED load, and the proper first electrolytic capacitor value is rotated according to the power of the LED load, so that the LED load is ensured not to have larger ripple voltage or ripple current, and no stroboscopic effect is realized.
In addition, the LED driving circuit in the above embodiment provided by the present invention may further have the following additional technical features:
in the above technical solution, preferably, the power factor correction module includes: the input end of the voltage transformation submodule is connected to the output end of the rectifying and filtering module and is used for performing voltage transformation operation on the pulsating direct current voltage; the buffer submodule is connected to the first output end of the transformation submodule; and the correction submodule is respectively connected to the first output end of the voltage transformation submodule, the second output end of the voltage transformation submodule and the first output end of the buffer submodule and is used for executing power factor correction.
In the technical scheme, the power factor correction module comprises a voltage-changing sub-module, a buffering sub-module and a correction sub-module, the direct-current voltage generated after passing through the rectification filter circuit is subjected to voltage-changing operation after passing through the voltage-changing sub-module and is directly input into the correction sub-module or is input into the correction sub-module after passing through the buffering sub-module, so that the power factor is improved.
In any of the foregoing solutions, preferably, the transformation submodule includes: the first input end of the transformer is connected to the output end of the rectifying and filtering module, the second input end of the transformer is grounded, the first output end of the transformer is connected to the buffer submodule, the second output end of the transformer is the first output end of the voltage-changing submodule and is connected to one end of the first parallel resistor, and the other end of the first parallel resistor is sequentially connected with the first capacitor and the voltage-stabilizing diode in series and then grounded; the input end of the first series resistor is connected to the output end of the rectifying and filtering module, and the output end of the second electrolytic capacitor is grounded; the anode of the first diode is arranged between the first capacitor and the voltage stabilizing diode, and the cathode of the first diode is arranged between the first series resistor and the second electrolytic capacitor to be used as the second output end of the voltage-changing sub-module.
In the technical scheme, the transformer is arranged to perform transformation operation on the direct-current voltage output by the rectification filter module so as to realize energy storage and transmission.
The first parallel resistor may include three resistors connected in parallel, and the first series resistor may include two resistors connected in series.
In any of the above embodiments, preferably, the correction submodule includes: the factor correction control chip comprises a first end, a second end, a third end, a fourth end, a fifth end and a sixth end, wherein the first end is connected with the first resistor and the second capacitor in series and then grounded, the second end is grounded, the third end is connected with the third capacitor in series and then grounded, the fourth end is connected to the grid electrode of the MOS tube through the second resistor and the third resistor, the fifth end is connected to the cathode of the first diode, the sixth end is connected to the first output end of the buffer submodule, the drain electrode of the MOS tube is connected to the first output end of the transformer, the source electrode of the MOS tube is grounded with one end of the second parallel resistor, the other end of the second parallel resistor is grounded, and a fourth resistor is further arranged between the other end of the second parallel resistor and the third end.
In the technical scheme, the power factor correction control chip is arranged to control and adjust the power factor through the power factor correction control chip, the MOS tube is arranged to serve as a switching tube, the MOS tube is controlled to be turned on and off through the output voltage value of the sixth pin, the first electrolytic capacitor is charged when the MOS tube is turned off, the fourth resistor is arranged to detect the current signal flowing through the third pin so as to detect whether an overcurrent signal appears, and the MOS tube is controlled to be turned off through the sixth pin when the overcurrent signal appears, so that overcurrent protection is realized.
The first pin (COMP) is a grounding pin, the third pin (CS/ZCP) is used for suppressing high-frequency noise, the fourth pin is an NV pin, the fifth pin (VCC) is used for providing working voltage of a controller and a control circuit, and the sixth pin is a GD pin.
In any of the foregoing solutions, preferably, the power factor correction module further includes: one end of the fourth capacitor is connected to the first end of the control chip, and the other end of the fourth capacitor is grounded; the anode of the second diode is connected to the grid electrode, and the cathode of the second diode is arranged between the second resistor and the third resistor; and one end of the fifth resistor is connected to the anode of the second diode, and the other end of the fifth resistor is connected to the source electrode.
In any of the foregoing solutions, preferably, the buffering submodule includes: the anode of the third diode is connected to the first output end of the transformer, and the cathode of the third diode is determined as the second output end of the buffer sub-module and is connected to the linear constant current module; one end of the second series resistor is connected to the cathode of the third diode, and the other end of the second series resistor is determined as a first output end of the buffer submodule; one end of the sixth resistor is connected to the other end of the second series resistor, and the other end of the sixth resistor is grounded; and a fifth capacitor connected in parallel with the sixth resistor.
In the technical scheme, when the buffer loop in the buffer submodule is used for buffering the MOS switch off, the high voltage released by the leakage inductance is used for blocking the output signal of the control chip when the overcurrent signal of the MOS tube is detected, so that overcurrent protection is realized.
In any of the above solutions, preferably, the linear constant current module includes: a third electrolytic capacitor; one end of the third electrolytic capacitor is connected to the cathode of the third diode, and the other end of the third electrolytic capacitor is grounded; the parallel two constant current control chips comprise an OUT pin, a GND pin and a REXT pin, wherein the REXT is connected with a divider resistor in series and then is grounded, and the GND pin is grounded; and one end of the LED load is connected to one end of the third electrolytic capacitor, and the other end of the LED load is connected to the OUT pin.
In the technical scheme, through setting the third electrolytic capacitor, the charging current of the third electrolytic capacitor in the charging process can be in a constant value, the two constant current control chips can be regarded as the two constant current control chips, the output control ends of the two constant current control chips are connected with LED loads so as to realize the control of the light emission of the LED loads, wherein when the voltage difference is not higher than the constant current threshold voltage of the chips, the current flowing through the chips is not constant, the current can be increased along with the increase of the voltage drop between the OUT pins and the GND pins, and when the voltage difference between the OUT pins and the GND pins is higher than the constant current threshold voltage of the chips, the chips are in a constant current working state, namely the current flowing through the chips is basically kept unchanged, so that the ripple current on the LED loads is further reduced, and the light efficiency of the LED loads and the service life of the LED loads are improved.
In any of the foregoing solutions, preferably, the rectifying and filtering module includes: a commutator module comprising: the first input end of the first common mode inductor is connected to the live wire end of the alternating current power supply through a fuse, and the second input end of the first common mode inductor is connected to the zero line end of the alternating current power supply; the first input end of the second common mode inductor is connected to the first output end of the first working mode inductor, and the second input end of the second common mode inductor is connected to the second output end of the first working mode inductor.
In the technical scheme, common mode inductance is arranged to eliminate common mode interference, the rectifier bridge stack is connected with the commercial power live wire L through the fuse, and peak voltage can be absorbed due to the fact that the fuse has a certain resistance value, and the surge prevention effect is achieved.
When the current passing through the fuse tube exceeds the rated current by 1.25-1.5 times, the fuse of the fuse tube is blown out quickly.
In any of the foregoing aspects, preferably, the rectifying sub-module further includes: the differential mode capacitor is connected in parallel between the first input end and the second input end of the first common mode inductor; the variable resistor is connected with the differential mode capacitor in parallel; the first input end of the rectifier bridge stack is connected to the first output end of the second common mode inductor, the second input end of the rectifier bridge stack is connected to the second output end of the second common mode inductor, and the first output end of the rectifier bridge stack is grounded.
In the technical scheme, the differential mode capacitor is arranged to filter out higher harmonic interference in the power supply, and the variable resistor is a negative temperature coefficient thermistor and is used for current limiting protection in the instant of power on.
In addition, the rectifier bridge stack is a full rectifier bridge stack, is connected and packaged into a whole by 4 rectifier diodes according to a bridge type full-wave rectifier circuit, and is respectively provided with two input ends and two output ends, wherein the two input ends are connected with mains supply through a common mode inductor, the two output ends are respectively a direct current output positive electrode and a grounding electrode, and the direct current output ends are connected to the filtering submodule.
In any of the foregoing solutions, preferably, the rectifying and filtering module includes: a filtering sub-module, comprising: one end of the filter inductor is connected to the second output end of the rectifier bridge stack, and the other end of the filter inductor is determined as the output end of the rectifier filter module; one end of the first filter capacitor is connected to one end of the filter inductor, and the other end of the first filter capacitor is grounded; one end of the second filter capacitor is connected to the other end of the filter inductor, and the other end of the second filter capacitor is grounded; and the seventh resistor is arranged in parallel with the filter inductor.
In the technical scheme, the ripple in the driving circuit is reduced by arranging the filter inductor and the filter capacitor.
According to the technical scheme of the invention, the LED load bulb can reduce the stroboscopic index to within 20% on the premise of ensuring the power factor to be more than 0.9, thereby achieving the purpose of protecting eyes.
An embodiment of a second aspect of the invention provides an LED luminaire comprising an LED driving circuit according to any of the embodiments of the first aspect of the invention.
Additional aspects and advantages of the invention will be set forth in part in the description which follows, or may be learned by practice of the invention.
Detailed Description
In order that the above-recited objects, features and advantages of the present invention will be more clearly understood, a more particular description of the invention will be rendered by reference to the appended drawings and appended detailed description. It should be noted that, in the case of no conflict, the embodiments of the present application and the features in the embodiments may be combined with each other.
In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention, however, the present invention may be practiced in other ways than those described herein, and the scope of the invention is therefore not limited to the specific embodiments disclosed below.
As shown in fig. 1, an LED driving circuit according to an embodiment of the present invention includes: an alternating current power supply for providing an alternating current voltage; a rectifying and filtering module 10 for rectifying an input ac voltage into a pulsating dc voltage; the power factor correction module 20 is connected to the rectifying and filtering module 10 in series, and the power factor correction module 20 is used for improving the driving power factor; a linear constant current module 30 connected in series to the power factor correction module 20 for limiting a peak value of the driving current; the first electrolytic capacitor 40, one end of the first electrolytic capacitor 40 is disposed between the power factor correction module 20 and the linear constant current module 30, and the other end of the first electrolytic capacitor 40 is grounded for supplying power to the LED load module at the valley voltage.
In this technical solution, a first electrolytic capacitor 40 is disposed between the pfc module 20 and the linear constant current module 30, on one hand, the pfc module 20 is disposed to increase the power factor of the driving circuit, on the other hand, the linear constant current module 30 limits the maximum current flowing through the LED load in the driving circuit to prevent the LED load from being overcurried, so as to improve the stability of the LED load display, and on the other hand, the first electrolytic capacitor 40 is disposed to discharge the LED load when the driving voltage is in the valley state, so as to maintain the continuous light emission of the LED load.
According to the LED driving circuit provided by the technical scheme, the use requirement of stable light emitting of the LED under the input voltage of low voltage 85V and high voltage 277V can be met.
For the stroboscopic problem, the root of the stroboscopic problem is that the ripple voltage or the ripple circuit on the LED is too large, when the voltage passing through the rectifying and filtering module 10 is in the trough, the first electrolytic capacitor 40 discharges to maintain the normal light emission of the LED load, and the first electrolytic capacitor 40 rotates according to the power of the LED load, so as to ensure that the LED load 312 does not have larger ripple voltage or ripple current, and realize stroboscopic free.
In addition, the LED driving circuit in the above embodiment provided by the present invention may further have the following additional technical features:
in the above technical solution, preferably, the power factor correction module includes: the input end of the voltage transformation submodule is connected to the output end of the rectifying and filtering module 10 and is used for performing voltage transformation operation on the pulsating direct current voltage; the buffer submodule is connected to the first output end of the transformation submodule; and the correction submodule is respectively connected to the first output end of the voltage transformation submodule, the second output end of the voltage transformation submodule and the first output end of the buffer submodule and is used for executing power factor correction.
In the technical scheme, the power factor correction module comprises a voltage-changing sub-module, a buffering sub-module and a correction sub-module, the direct-current voltage generated after passing through the rectification filter circuit is subjected to voltage-changing operation after passing through the voltage-changing sub-module and is directly input into the correction sub-module or is input into the correction sub-module after passing through the buffering sub-module, so that the power factor is improved.
As shown in fig. 2, in any one of the foregoing embodiments, preferably, the transformation submodule includes: the first input end of the transformer 202 is connected to the output end of the rectifying and filtering module 10, the second input end of the transformer 202 is grounded, the first output end of the transformer 202 is connected to the buffering submodule, the second output end of the transformer 202 is the first output end of the voltage transformation submodule, the second output end of the transformer 202 is connected to one end of the first parallel resistor 204, and the other end of the first parallel resistor 204 is sequentially connected with the first capacitor 206 and the voltage stabilizing diode 208 in series and then grounded; the first series resistor 210 and the second electrolytic capacitor 212 are connected in series, the input end of the first series resistor 210 is connected to the output end of the rectifying and filtering module 10, and the output end of the second electrolytic capacitor 212 is grounded; the anode of the first diode 214 is disposed between the first capacitor 206 and the zener diode 208, and the cathode of the first diode 214 is disposed between the first series resistor 210 and the second electrolytic capacitor 212 to serve as the second output terminal of the voltage-variable sub-module.
In this solution, the transformer 202 is provided to perform a transformation operation on the dc voltage output by the rectifying filter module 10, so as to store and transmit energy.
The first parallel resistor 204 may include three resistors connected in parallel, and the first series resistor 210 may include two resistors connected in series.
As shown in fig. 2, in any of the above embodiments, preferably, the correction submodule includes: the pfc control chip 216 includes a first end, a second end, a third end, a fourth end, a fifth end and a sixth end, where the first end is connected in series with the first resistor 218 and the second capacitor 220 and then grounded, the second end is connected in series with the third capacitor 222 and then grounded, the fourth end is connected to the gate of the MOS transistor 228 through the second resistor 224 and the third resistor 226, the fifth end is connected to the cathode of the first diode 214, the sixth end is connected to the first output end of the buffering submodule, the drain of the MOS transistor 228 is connected to the first output end of the transformer 202, the source of the MOS transistor 228 is grounded with one end of the second parallel resistor 230, the other end of the second parallel resistor 230 is grounded, and a fourth resistor 232 is further disposed between the other end of the second parallel resistor 230 and the third end.
In this technical solution, by setting the pfc control chip 216 to control and adjust the power factor through the pfc control chip 216, by setting the MOS transistor 228 as a switching transistor, by controlling the on and off of the MOS transistor 228 through the output voltage value of the sixth pin, to charge the first electrolytic capacitor 40 when it is turned off, by setting the fourth resistor 232 to detect the current signal flowing through the third pin, to detect whether an overcurrent signal occurs, and by controlling the off MOS transistor 228 through the sixth pin when it is detected that the overcurrent signal occurs, overcurrent protection is achieved.
The first pin (COMP) is a grounding pin, the third pin (CS/ZCP) is used for suppressing high-frequency noise, the fourth pin is an NV pin, the fifth pin (VCC) is used for providing working voltage of a controller and a control circuit, and the sixth pin is a GD pin.
As shown in fig. 2, in any of the foregoing solutions, preferably, the power factor correction module further includes: one end of the fourth capacitor 234 is connected to the first end of the control chip, and the other end of the fourth capacitor 234 is grounded; the second diode 236, the anode of the second diode 236 is connected to the gate, and the cathode of the second diode 236 is disposed between the second resistor 224 and the third resistor 226; and a fifth resistor 238, one end of the fifth resistor 238 being connected to the anode of the second diode 236, and the other end of the fifth resistor 238 being connected to the source.
As shown in fig. 2, in any one of the above embodiments, preferably, the buffering submodule includes: a third diode 240, an anode of the third diode 240 is connected to the first output terminal of the transformer 202, and a cathode of the third diode 240 is defined as the second output terminal of the buffer sub-module and is connected to the linear constant current module 30; a second series resistor 242, one end of the second series resistor 242 is connected to the cathode of the third diode 240, and the other end of the second series resistor 242 is defined as the first output end of the buffer sub-module; a sixth resistor 244, one end of the sixth resistor 244 is connected to the other end of the second series resistor 242, and the other end of the sixth resistor 244 is grounded; a fifth capacitor 246 is connected in parallel with the sixth resistor 244.
In this technical scheme, when the buffer loop in the buffer submodule is used for buffering the off state of the MOS switch, the high voltage released by the leakage inductance is used for blocking the output signal of the control chip when the overcurrent signal of the MOS transistor 228 is detected, so as to realize overcurrent protection.
As shown in fig. 2, in any of the above embodiments, it is preferable that the linear constant current module 30 includes: a third electrolytic capacitor 302; one end of the third electrolytic capacitor 302 is connected to the cathode of the third diode 240, and the other end of the third electrolytic capacitor 302 is grounded; the parallel-connection two constant-current control chips (304 and 306) comprise an OUT pin, a GND pin and a REXT pin, wherein the REXT is connected with a divider resistor (308 and 310) in series and then grounded, and the GND pin is grounded; and an LED load 312, one end of the LED load 312 is connected to one end of the third electrolytic capacitor 302, and the other end of the LED load 312 is connected to the OUT pin.
In this technical solution, by setting the third electrolytic capacitor 302, the charging current of the third electrolytic capacitor 302 in the charging process can be at a constant value, the two constant current control chips can be regarded as two constant current control chips, and the output control ends of the two constant current control chips are connected with the LED load 312 to realize the control of the light emission of the LED load 312, where a voltage difference exists between the OUT pin and the GND pin, when the voltage difference is not higher than the constant current threshold voltage of the chip, the current flowing through the chip is not constant, the current increases along with the increase of the voltage drop between the OUT pin and the GND pin, and when the voltage difference between the OUT pin and the GND pin is higher than the constant current threshold voltage of the chip, the chip presents a constant current working state, i.e. the current flowing through the chip remains unchanged basically, thereby further reducing the ripple current on the LED load 312, so as to improve the light efficiency of the LED load 312 and the life of the LED load 312.
As shown in fig. 2, in any of the above embodiments, preferably, the rectifying and filtering module 10 includes: a commutator module comprising: the first input end of the first common mode inductor 102 is connected to the live wire end of the alternating current power supply through the fuse 104, and the second input end of the first common mode inductor 102 is connected to the zero line end of the alternating current power supply; and a second common mode inductor 106, wherein a first input end of the second common mode inductor 106 is connected to a first output end of the first working mode inductor, and a second input end of the second common mode inductor 106 is connected to a second output end of the first working mode inductor.
In this technical scheme, the common mode inductance is set to eliminate common mode interference, and the rectifier bridge stack 112 is connected with the mains supply live wire L through the fuse 104, and the fuse 104 has a certain resistance value, so that peak voltage can be absorbed, and the surge prevention effect is achieved.
When the current passing through the fuse tube exceeds the rated current by 1.25-1.5 times, the fuse of the fuse tube is blown out quickly.
As shown in fig. 2, in any of the above embodiments, preferably, the rectifying sub-module further includes: a differential-mode capacitor 108 connected in parallel between the first input terminal and the second input terminal of the first common-mode inductor 102; a variable resistor 110 connected in parallel with the differential mode capacitor 108; the rectifier bridge stack 112, the first input terminal of the rectifier bridge stack 112 is connected to the first output terminal of the second common-mode inductor 106, the second input terminal of the rectifier bridge stack 112 is connected to the second output terminal of the second common-mode inductor 106, and the first output terminal of the rectifier bridge stack 112 is grounded.
In this technical solution, by setting the differential mode capacitor 108 to filter out the higher harmonic interference in the power supply, the variable resistor 110 is a negative temperature coefficient thermistor for current limiting protection during power-on.
In addition, the rectifier bridge stack 112 is a full rectifier bridge stack 112, and 4 rectifier diodes are connected and packaged into an integral rectifier bridge stack 112 in a bridge type full-wave rectifier circuit mode, and each rectifier bridge stack is provided with two input ends and two output ends, the two input ends are connected to the mains supply through a common mode inductor, the two output ends are respectively a direct current output positive electrode and a grounding electrode, and the direct current output ends are connected to the filtering submodule.
As shown in fig. 2, in any of the above embodiments, preferably, the rectifying and filtering module 10 includes: a filtering sub-module, comprising: the filter inductor 114, one end of the filter inductor 114 is connected to the second output end of the rectifier bridge stack 112, and the other end of the inductor is determined as the output end of the rectifier filter module 10; the first filter capacitor 116, one end of the first filter capacitor 116 is connected to one end of the filter inductor 114, and the other end of the first filter capacitor 116 is grounded; one end of the second filter capacitor 118 is connected to the other end of the filter inductor 114, and the other end of the second filter capacitor 118 is grounded; the seventh resistor 120 is disposed in parallel with the filter inductance 114.
In this embodiment, the filter inductor 114 and the filter capacitor are provided to reduce ripple in the driving circuit.
The technical scheme of the invention is described in detail with reference to the accompanying drawings, and the invention provides an LED driving circuit, wherein a first electrolytic capacitor is arranged between a power factor correction module and a linear constant current module.
The LED lamp provided by the embodiment of the invention comprises the LED driving circuit provided by any embodiment.
In the present invention, the terms "first," "second," "third," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance; the term "plurality" means two or more, unless expressly defined otherwise. The terms "mounted," "connected," "secured," and the like are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; "coupled" may be directly coupled or indirectly coupled through intermediaries. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art according to the specific circumstances.
In the description of the present invention, it should be understood that the directions or positional relationships indicated by the terms "upper", "lower", "left", "right", "front", "rear", etc. are based on the directions or positional relationships shown in the drawings, are merely for convenience of describing the present invention and simplifying the description, and do not indicate or imply that the devices or units referred to must have a specific direction, be constructed and operated in a specific direction, and thus should not be construed as limiting the present invention.
In the description of the present specification, the terms "one embodiment," "some embodiments," "particular embodiments," and the like, mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.
The above is only a preferred embodiment of the present invention, and is not intended to limit the present invention, but various modifications and variations can be made to the present invention by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.