CN218868406U

CN218868406U - LED drive circuit without afterglow, light-emitting component and LED lamp

Info

Publication number: CN218868406U
Application number: CN202222990079.XU
Authority: CN
Inventors: 李旻; 黄剑伟; 张懿水; 杨夜开; 潘安宇
Original assignee: Xiamen Municipal Smart City Technology Co ltd; XIAMEN GUANGPU ELECTRONICS CO Ltd
Current assignee: Xiamen Municipal Smart City Technology Co ltd; XIAMEN GUANGPU ELECTRONICS CO Ltd
Priority date: 2022-11-07
Filing date: 2022-11-07
Publication date: 2023-04-14
Anticipated expiration: 2032-11-07

Abstract

The utility model provides a LED drive circuit of no afterglow, include: the EMI filter circuit, the rectifier circuit, the output filter circuit and the output ripple removing circuit; the EMI filter circuit is connected between the alternating current input ends of the commercial power and the rectifying circuit; the direct current output end of the rectification circuit is connected with the switching power supply and controls the on and off of a switching device in the switching power supply so as to connect or disconnect the LED load and the direct current output end of the rectification circuit; the output filter circuit comprises an electrolytic capacitor CE1 and a bleeder resistor R2 which are connected in parallel between the anode and the cathode of the LED load; the leakage resistor R2 is used for providing a leakage loop for the electrolytic capacitor CE1 when the switching device is turned off; the de-ripple circuit is used for reducing ripple voltage across the led load.

Description

LED drive circuit without afterglow, light-emitting component and LED lamp

Technical Field

The utility model relates to a LED illumination especially relates to LED drive circuit.

Background

LED lighting products become lighting equipment commonly used in life, various LED lamps have various shapes, but the non-isolated LED driving power supply in the market at present still has the phenomenon of weak luminescence (namely afterglow) after the lamp is turned off, and still consumes power and has the situation of lamp bead leakage, so that the energy efficiency, the service life of the LED and the product safety are influenced.

SUMMERY OF THE UTILITY MODEL

The utility model aims to solve the main technical problem that a LED drive circuit of no afterglow is provided, LED does not have weak luminous phenomenon after turning off the lamp.

In order to solve the technical problem, the utility model provides a LED drive circuit of no afterglow, include: the EMI filter circuit, the rectifier circuit, the output filter circuit and the output ripple removing circuit;

the EMI filter circuit is connected between the alternating current input ends of the commercial power and the rectifying circuit; the direct current output end of the rectification circuit is connected with the switching power supply and controls the on and off of a switching device in the switching power supply so as to connect or disconnect the LED load and the direct current output end of the rectification circuit;

the output filter circuit comprises an electrolytic capacitor CE1 and a bleeder resistor R2 which are connected in parallel between the anode and the cathode of the LED load; the leakage resistor R2 is used for providing a leakage loop for the electrolytic capacitor CE1 when the switching device is turned off;

the de-ripple circuit is used for reducing ripple voltage across the led load.

In a preferred embodiment: and the direct current output end of the rectifying circuit is also connected with a pi-type filter.

In a preferred embodiment: the pi-type filter comprises a filter inductor L2, a capacitor CB1 and a capacitor CB2; the inductor is connected to the direct current output positive electrode of the rectifying circuit; and the capacitor CB1 and the capacitor CB2 are respectively connected between the two ends of the inductor L2 and the DC output negative electrode of the rectifier bridge.

In a preferred embodiment: the ripple removing circuit consists of an electrolytic capacitor CE2, a switching tube MQ1, voltage stabilizing diodes D5, D6 and D7 and resistors R10 and R11;

the control electrode of the switching tube MQ1 is connected to the cathode of the LED load through a resistor R11 and an electrolytic capacitor CE2, and the switching tube MQ1 is connected between the direct current output anode of the rectifier bridge and the anode of the LED load; the control electrode of the switching tube MQ1 is also connected to the direct current output anode of the rectifier bridge through voltage stabilizing diodes D6 and D5, and the resistor R10 is connected with the voltage stabilizing diode D5 in parallel; the control electrode of the switching tube MQ1 is also connected to the anode of the LED load through a voltage stabilizing diode D7.

In a preferred embodiment: the anode of the voltage stabilizing diode D5 is connected with the direct current output anode of the rectifying circuit, the cathode of the voltage stabilizing diode D5 is connected with the cathode of the voltage stabilizing diode D6, and the anode of the voltage stabilizing diode D6 is connected with the cathode of the LED load through the electrolytic capacitor CE 2.

In a preferred embodiment: and the cathode of the voltage stabilizing diode D7 is connected with the control electrode of the switching tube MQ1, and the anode of the voltage stabilizing diode D7 is connected with the anode of the LED load.

In a preferred embodiment: the switch tube is an MOS tube, the source electrode of the switch tube is connected with the anode of the LED load, and the drain electrode of the switch tube is connected with the direct current output cathode of the rectifying circuit.

The utility model also provides a LED light-emitting component has used as above drive circuit.

The utility model also provides a LED lamps and lanterns have assembled as above light-emitting component.

In a preferred embodiment: the LED lamp is a straight-tube type LED lamp

Compared with the prior art, the technical scheme of the utility model possess following beneficial effect:

the utility model provides a LED drive circuit of no afterglow, when commercial power input, through EMI filter circuit, get rid of behind the electric wire netting noise signal again through rectifier circuit, become the direct current with the alternating current rectification, turn-off and open through the switching device among the switching power supply, with energy transfer to LED load end, electrolytic capacitor through the output filter circuit, play the current value of energy storage and stable LED load and the voltage at LED load both ends, and at the parallelly connected bleeder resistor in electrolytic capacitor's both ends, when lamps and lanterns turn-off, provide the return circuit of bleeding for the energy among the electrolytic capacitor, in the time of extremely short, get off the voltage drop at LED load both ends, increase at the load end simultaneously and remove the ripple circuit, reduce the ripple voltage at LED load both ends, when output voltage is less than LED operating voltage, LED can not appear the phenomenon afterglow.

Drawings

Fig. 1 is a circuit diagram of the preferred embodiment of the present invention.

Detailed Description

The technical solution in the embodiment of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiment of the present invention; obviously, the described embodiments are only a part of the embodiments of the present invention, and not all embodiments, and all other embodiments obtained by those skilled in the art without making creative efforts based on the embodiments of the present invention belong to the protection scope of the present invention.

In the description of the present invention, it should be noted that the terms "upper", "lower", "inner", "outer", "top/bottom", and the like indicate orientations or positional relationships based on orientations or positional relationships shown in the drawings, and are only for convenience of description of the present invention and simplification of description, but do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present invention, it should be noted that, unless explicitly stated or limited otherwise, the terms "mounted," "disposed," "sleeved/connected," "connected," and the like are used in a broad sense, and for example, "connected," may be a wall-mounted connection, a detachable connection, or an integrated connection, a mechanical connection, an electrical connection, a direct connection, an indirect connection through an intermediate medium, or a connection between two elements, and those skilled in the art will understand the specific meaning of the terms in the present invention in a specific case.

Referring to fig. 1, the present embodiment provides an afterglow-free LED driving circuit, including: the EMI filter circuit, the rectifier circuit, the output filter circuit and the output ripple removing circuit;

the EMI filter circuit is connected between the commercial power and the alternating current input end of the rectification circuit; the direct current output end of the rectification circuit is connected with the switching power supply and controls the on and off of a switching device in the switching power supply so as to connect or disconnect the LED load and the direct current output end of the rectification circuit; the output filter circuit comprises an electrolytic capacitor CE1 and a bleeder resistor R2 which are connected in parallel between the anode and the cathode of the LED load; the discharge resistor R2 is used for providing a discharge loop for the electrolytic capacitor CE1 when the switching device is turned off; the de-ripple circuit is used for reducing ripple voltage across the led load.

When the lamp is turned off, a discharge loop is provided for the energy in the electrolytic capacitor, the voltage at the two ends of the LED load is reduced in a very short time, meanwhile, a ripple removing circuit is added at the load end, the ripple voltage at the two ends of the LED load is reduced, and when the output voltage is lower than the LED working voltage, the LED does not have the phenomenon of afterglow.

The discharge time of the electrolytic capacitor is in direct proportion to the resistance value of the discharge resistor and the electrolytic capacitance value, and in order to shorten the discharge time, the capacitance value and the discharge resistor are as small as possible, so that on one hand, the stored energy of the electrolytic capacitor is reduced, and on the other hand, the discharge current is increased. In this embodiment, in the output filter circuit, when 220V is input, two ends of the electrolytic capacitor CE1 start to be charged, voltage V0 at two ends of the stabilized electrolytic capacitor CE1 is 67V, that is, voltage at two ends of the LED load, when the input is disconnected, the electrolytic capacitor CE1 discharges through the discharge resistor R2, when voltage Vt at two ends of the load is reduced to 60V, the LED lamp is turned off, the capacitance value of the electrolytic capacitor CE1 is 150uF, and the resistance value of the discharge resistor is 100K, so that the discharge time of CE1 can be calculated by the following formula:

t = RCLn [ V0/Vt ], where Ln () is the base e logarithm;

substituting the above parameters, t =100 e3 150uf e-6 ln [ 2/67/60 ] =1.4S can be obtained

From the above, it can be seen that at the moment of power failure, the LED goes out completely after 1.4s, and no afterglow occurs.

In this embodiment, the dc output end of the rectifying circuit is further connected to a pi-type filter. Specifically, the pi-type filter comprises a filter inductor L2, a capacitor CB1 and a capacitor CB2; the inductor is connected to the direct current output positive electrode of the rectifying circuit; and the capacitor CB1 and the capacitor CB2 are respectively connected between the two ends of the inductor L2 and the DC output negative electrode of the rectifier bridge.

Because electrolytic capacitor CE 1's electric capacity value is less, direct influence output filtering effect, great ripple voltage appears easily in the LED load, can absorb the voltage ripple through removing the ripple circuit, makes ripple voltage control within reasonable scope, solves the stroboscopic problem to guarantee the life of LED product. In this embodiment, the ripple removing circuit includes an electrolytic capacitor CE2, a switching tube MQ1, voltage stabilizing diodes D5, D6, and D7, and resistors R10 and R11; the grid electrode of the switching tube MQ1 is connected to the cathode of the LED load through a resistor R11 and an electrolytic capacitor CE2, and the drain electrode and the source electrode of the switching tube MQ1 are connected between the direct current output anode of the rectifier bridge and the anode of the LED load; the grid electrode of the switching tube MQ1 is also connected to the direct current output anode of the rectifier bridge through voltage stabilizing diodes D6 and D5, and the resistor R10 is connected with the voltage stabilizing diode D5 in parallel; the control electrode of the switching tube MQ1 is also connected to the anode of the LED load through a voltage stabilizing diode D7. The anode of the voltage stabilizing diode D5 is connected with the direct current output anode of the rectifying circuit, the cathode of the voltage stabilizing diode D5 is connected with the cathode of the voltage stabilizing diode D6, and the anode of the voltage stabilizing diode D6 is connected with the cathode of the LED load through the electrolytic capacitor CE 2. And the cathode of the voltage stabilizing diode D7 is connected with the control electrode of the switching tube MQ1, and the anode of the voltage stabilizing diode D7 is connected with the anode of the LED load.

In the ripple removing circuit, when the previous-stage voltage is higher than the average value, the electrolytic capacitor CE2 is charged through D5 and D6, and when the previous-stage voltage is lower than the average value, at this time, the electrolytic capacitor CE2 discharges through D6 and R10 to maintain Vds, and simultaneously maintains Vds through R11, so that the previous-stage valley interval of the Q1 is still kept in the constant current region, and D7 is a protection device to prevent the MOS transistor GS from being overvoltage, that is, the electrolytic capacitor CE2 is increased to charge in the input current peak interval, and discharges in the valley interval, and the supplementary maintenance MOS can work in the constant current region in the whole period, and under the same stroboscopic effect, the value of D6 can be reduced, so that the loss is reduced. Therefore, the value of the CE1 electrolytic capacitor can be smaller, the ripple voltage is reduced through the ripple elimination circuit, the problem of power-off afterglow of the LED lamp is solved, and the problem of large output ripple caused by the small value of the CE1 electrolytic capacitor is also solved.

The driving circuit can be used for driving various LED chips to be lightened, so that the driving circuit can be applied to various LED lamps, such as straight-tube LED lamps and the like.

The above, only be the preferred embodiment of the present invention, but the design concept of the present invention is not limited to this, and any skilled person familiar with the technical field is in the technical scope disclosed in the present invention, and it is right to utilize this concept to perform insubstantial changes to the present invention, all belong to the act of infringing the protection scope of the present invention.

Claims

1. An LED driving circuit without afterglow, comprising: the EMI filter circuit, the rectifier circuit, the output filter circuit and the output ripple removing circuit;

the EMI filter circuit is connected between the commercial power and the alternating current input end of the rectification circuit; the direct current output end of the rectification circuit is connected with the switching power supply and controls the on and off of a switching device in the switching power supply so as to connect or disconnect the LED load and the direct current output end of the rectification circuit;

the output filter circuit comprises an electrolytic capacitor CE1 and a bleeder resistor R2 which are connected in parallel between the anode and the cathode of the LED load; the discharge resistor R2 is used for providing a discharge loop for the electrolytic capacitor CE1 when the switching device is turned off;

the de-ripple circuit is used for reducing ripple voltage across the led load.

2. The non-afterglow LED driving circuit of claim 1, wherein: and the direct current output end of the rectifying circuit is also connected with a pi-type filter.

3. The non-afterglow LED driving circuit of claim 2, wherein: the pi-type filter comprises a filter inductor L2, a capacitor CB1 and a capacitor CB2; the inductor is connected to the direct current output positive electrode of the rectifying circuit; and the capacitor CB1 and the capacitor CB2 are respectively connected between the two ends of the inductor L2 and the DC output negative electrode of the rectifier bridge.

4. The LED driving circuit without afterglow of claim 1, wherein: the ripple removing circuit consists of an electrolytic capacitor CE2, a switching tube MQ1, voltage stabilizing diodes D5, D6 and D7 and resistors R10 and R11;

5. The non-afterglow LED driving circuit as defined in claim 4, wherein: the anode of the voltage stabilizing diode D5 is connected with the direct current output anode of the rectifying circuit, the cathode of the voltage stabilizing diode D5 is connected with the cathode of the voltage stabilizing diode D6, and the anode of the voltage stabilizing diode D6 is connected with the cathode of the LED load through the electrolytic capacitor CE 2.

6. The non-afterglow LED driving circuit as defined in claim 4, wherein: and the cathode of the voltage stabilizing diode D7 is connected with the control electrode of the switching tube MQ1, and the anode of the voltage stabilizing diode D7 is connected with the anode of the LED load.

7. The afterglow-free LED driving circuit as defined in claim 4, wherein: the switch tube is an MOS tube, the source electrode of the switch tube is connected with the anode of the LED load, and the drain electrode of the switch tube is connected with the direct current output cathode of the rectifying circuit.

8. An LED lighting assembly, characterized in that the driving circuit of any one of claims 1 to 7 is used.

9. An LED lamp equipped with the light emitting module according to claim 8.

10. The LED lamp of claim 9, wherein: the LED lamp is a straight tube type LED lamp.