Circuit for driving LED (light-emitting diode) by HID (high intensity discharge) electronic ballast

Abstract

A circuit for an HID electronic ballast to drive an LED comprises a transformer T, a full-bridge rectifier module, a valley filling module and a filtering module, the transformer T is provided with a primary winding and a secondary winding, the primary winding of the transformer T is connected with the output end of the electronic ballast, the full-bridge rectifier module is connected with the secondary winding of the transformer T, the valley filling module is connected with the filtering module in parallel, and the filtering module is connected with the full-bridge rectifier module. The full-bridge rectification module is respectively connected with the valley filling module, the filtering module and the load LED lamp, a primary winding of the transformer T is provided with a dotted terminal and a non-dotted terminal, the dotted terminal of the primary winding is connected with the electronic ballast through a capacitor CX1, and the non-dotted terminal of the primary winding is directly connected with the electronic ballast. According to the utility model, the input current follows the input voltage, the PF value of the product is improved, the utilization efficiency after alternating current is converted into direct current is improved, and the impact of the product on a power grid and a post-stage circuit is reduced.

Description

Technical Field

[0001] The utility model relates to the field of LED driving, in particular to a circuit used for a HID electronic ballast to drive an LED. Background Art

[0002] Traditional gas discharge lamps HID are driven by electronic ballasts, which have better characteristics, such as eliminating flicker and providing stable current. Some LEDs are driven directly by power supply, while others are driven by electronic ballasts. LED electronic ballasts also have the characteristics of good stability and long life. LED electronic ballasts use high-quality components and materials, have high working stability, and can work normally in harsh environments. The life of LED electronic ballasts can generally reach tens of thousands of hours, which is longer than traditional electronic ballasts.

[0003] The existing electronic ballast driving circuit usually adopts a full-bridge wave rectifier circuit. Since the electrolytic capacitor is directly connected in parallel behind the existing full-wave rectifier circuit, its disadvantage is that the input current cannot follow the change of the input voltage. This situation will have the following problems. First, due to the unidirectional conductivity of the diode, the diode will only be turned on when the voltage on the electrolytic capacitor is lower than the input voltage. It can be seen that the conduction angle of the diode in one cycle is very small, which means that the diode must obtain the power required by the subsequent circuit in a short time, which will inevitably lead to large conduction losses, and the temperature rise is self-evident; secondly, at the moment of the diode being turned on, its current spike pulse is very high, and the EMI generated during the circuit operation will interfere with the normal operation of the subsequent circuit. Finally, since the current does not follow the change of the input voltage, the conversion efficiency will become low and the loss will be too large. Utility Model Content

[0004] In order to solve the above technical problems, the utility model provides a circuit for driving LEDs with a HID electronic ballast.

[0005] In order to solve the above technical problems, the utility model adopts the following technical solutions:

[0006] A circuit for driving an LED with an HID electronic ballast comprises a transformer T, a full-bridge rectifier module and a filter module. The transformer T has a primary winding and a secondary winding. The primary winding of the transformer T has a same-name end and a non-same-name end. The same-name end of the primary winding is connected to the output end of the electronic ballast through a capacitor CX1, and the non-same-name end of the primary winding is directly connected to the output end of the electronic ballast. The full-bridge rectifier module is connected to the secondary winding of the transformer T, and the full-bridge rectifier module is connected to the filter module and a load LED lamp.

[0007] As a further improvement, a valley-filling module is provided between the filtering module and the secondary winding of the transformer T, the valley-filling module is connected in parallel to the full-bridge rectifier module, and the valley-filling module is connected in parallel to the filtering module.

[0008] As a further improvement, the full-bridge rectifier module includes a diode D1, a diode D2, a diode D3 and a diode D4, the cathode of the diode D1 is connected to the anode of the diode D3, the cathode of the diode D3 is connected to the cathode of the diode D4, the anode of the diode D4 is connected to the cathode of the diode D2, and the anode of the diode D2 is connected to the anode of the diode D1.

[0009] As a further improvement, the cathode of the diode D1 and the anode of the diode D3 are both connected to the non-same-name ends of the secondary winding of the transformer T, and the cathode of the diode D2 and the anode of the diode D4 are both connected to the same-name ends of the secondary winding of the transformer T.

[0010] As a further improvement, the valley filling module includes a diode D5, a diode D6, a diode D7, a capacitor EC1 and a capacitor EC2. The anode of the diode D5 is connected to one end of the capacitor EC1 and the cathode of the diode D6, respectively, the anode of the diode D6 is connected to one end of the capacitor EC2 and the cathode of the diode D7, the cathode of the diode D5 is connected to the other end of the capacitor EC2, and the anode of the diode D7 is connected to the other end of the capacitor EC1.

[0011] As a further improvement, the filtering module includes a resistor R1, a resistor R2 and a capacitor EC3, and the resistor R1 and the resistor R2 are connected in series and then connected in parallel with the capacitor EC3.

[0012] As a further improvement, the resistor R1 and the resistor R2 are chip resistors or plug-in resistors, and the capacitor EC3 is an electrolytic capacitor.

[0013] As a further improvement, the cathode of the diode D3 and the cathode of the diode D4 are connected to the cathode of the diode D5, the capacitor EC2, the resistor R1, the capacitor EC3 and the anode of the load LED lamp in sequence; the anode of the diode D1 and the anode of the diode D4 are connected to the cathode of the capacitor EC1, the anode of the diode D7, the resistor R2, the capacitor EC3 and the anode of the load LED in sequence.

[0014] As a further improvement, the transformer T is further provided with a second secondary winding Ns1, and the second secondary winding Ns1 is connected to a heat dissipation module.

[0015] As a further improvement, the heat dissipation module includes a diode D8, a resistor R3, a capacitor EC4, a capacitor C1, a capacitor C2, a capacitor EC5, a voltage regulator U1 and a cooling fan, the positive electrode of the diode D8 is connected to the same-name end of the second secondary winding Ns1, the resistor R3, the capacitor EC4, the capacitor C1, and the input pin of the voltage regulator U1 are connected in parallel, the capacitor C2 and the capacitor EC5 are connected in parallel and connected to the output pin of the voltage regulator U1, the negative electrode of the diode D8 is connected to the input pin of the voltage regulator U1, and the non-same-name end of the second secondary winding Ns1 is connected to the ground pin of the voltage regulator U1.

[0016] Compared with the prior art, the utility model has the following beneficial technical effects:

[0017] By adding the valley-filling module, the input current can follow the changes in the input voltage, thereby improving the PF value and increasing the efficiency of converting AC to DC, realizing power factor correction, improving the utilization efficiency after AC is converted to DC, and reducing the impact of the product on the power grid and subsequent circuits. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the principle of the utility model;

[0019] Figure 2 This is a schematic diagram of the principle of setting a heat dissipation module in the utility model;

[0020] Figure 3 It is a schematic diagram of another embodiment of the utility model. DETAILED DESCRIPTION

[0021] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0022] In the description of the present utility model, it should be understood that if the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like are involved, the orientation or position relationship indicated is based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present utility model and simplifying the description, and does 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 therefore cannot be understood as a limitation on the present utility model. In addition, the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the said features. In the description of the present utility model, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0023] In the description of the present utility model, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection. It can be a mechanical connection or an electrical connection. It can be directly connected or indirectly connected through an intermediate medium. It can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0024] Embodiment 1

[0025] refer to Figure 1 As shown, a circuit for driving LEDs with HID electronic ballasts includes a transformer T, a full-bridge rectifier module, a valley-filling module and a filter module. The transformer T has a primary winding and a secondary winding. The primary winding of the transformer T is connected to the output end of the electronic ballast, the full-bridge rectifier module is connected to the secondary winding of the transformer T, the valley-filling module is connected in parallel with the filter module, and the full-bridge rectifier module is respectively connected to the valley-filling module, the filter module and the load LED lamp. By adding a valley-filling module behind the transformer T, the input current is changed with the input voltage, the power factor PF value is improved, and the efficiency of converting AC to DC is increased. The filter module is used to stabilize the voltage and current and filter interference. By actually testing the circuit, it is found that the input current changes accordingly with the input voltage, and the power factor value is automatically corrected, which can reduce the temperature rise of each electronic component.

[0026] The primary winding of the transformer T has a like-name end and a non-like-name end. The like-name end of the primary winding is connected to the electronic ballast via capacitor CX1, and the non-like-name end of the primary winding is directly connected to the electronic ballast. The electronic ballast directly outputs voltage and current to the transformer T. Through the coupling effect of the transformer T, the secondary winding generates corresponding voltage and current.

[0027] refer to Figure 1 As shown, a circuit for driving an LED with an HID electronic ballast includes a transformer T, a full-bridge rectifier module, a valley-filling module and a filtering module. The transformer T has a primary winding and a secondary winding. The primary winding of the transformer T is connected to the output end of the electronic ballast. The full-bridge rectifier module is connected to the secondary winding of the transformer T. The valley-filling module is connected in parallel with the filtering module. The full-bridge rectifier module is respectively connected to the valley-filling module, the filtering module and a load LED lamp. The full-bridge rectifier module includes a diode D1, a diode D2, a diode D3 and a diode D4. The cathode of the diode D1 is connected to the anode of the diode D3, the cathode of the diode D2 is connected to the anode of the diode D4, the anode of the diode D1 is connected to the anode of the diode D2, and the cathode of the diode D3 is connected to the cathode of the diode D4. The cathode of the diode D1 and the anode of D3 are both connected to the non-same-name end of the secondary winding Ns of the transformer T, and the cathode of the diode D2 and the anode of the diode D4 are both connected to the same-name end of the secondary winding Ns of the transformer T. The diode D1, the diode D2, the diode D3 and the diode D4 are connected in sequence to form a full-bridge rectifier module. The capacitor EC1, the anode of the diode D7, the resistor R2 and the capacitor EC3 are also grounded.

[0028] The same-name end of the secondary winding of the transformer T is connected to the line between the diode D2 and the diode D4, so that the current output from the same-name end of the secondary winding Ns enters the diode D4, and then passes through the valley filling module, the filtering module, the diode D1, and finally returns to the non-same-name end of the secondary winding Ns to form a loop; the non-same-name end of the secondary winding Ns is connected to the line between the diode D1 and the diode D3, so the current output from the non-same-name end of the secondary winding enters the diode D3, and then passes through the valley filling module, the filtering module, the diode D2, and finally returns to the same-name end of the secondary winding Ns to form a loop.

[0029] The valley filling module includes a diode D5, a diode D6, a diode D7, a capacitor EC1 and a capacitor EC2. The positive electrode of the diode D5 is connected to one end of the capacitor EC1 and the negative electrode of the diode D6, respectively, the positive electrode of the diode D6 is connected to one end of the capacitor EC2 and the negative electrode of the diode D7, the negative electrode of the diode D5 is connected to the other end of the capacitor EC2, and the positive electrode of the diode D7 is connected to the other end of the capacitor EC1. The filtering module includes a resistor R1, a resistor R2 and a capacitor EC3, and the resistor R1 and the resistor R2 are connected in series and connected in parallel with the capacitor EC3. By using the additionally set valley filling module, the conduction angle of each diode can be increased, and the input current can be changed from a peak pulse to a waveform close to a sine wave by filling the valley point, thereby improving the power factor, correcting the power factor, improving the conversion efficiency, reducing the impact of the product on the power grid and the subsequent circuit, and reducing the loss.

[0030] The resistor R1 and the resistor R2 are both selected as chip resistors or plug-in resistors, and the capacitors EC1, EC2, and EC3 are selected as electrolytic capacitors.

[0031] The cathode of the diode D3 and the cathode of the diode D4 are connected to the cathode of the diode D5, the capacitor EC2, the resistor R1, the capacitor EC3 and the anode of the load LED lamp in sequence; the anode of the diode D1 and the anode of the diode D2 are connected to the anode of the capacitor EC1, the anode of the diode D7, the resistor R2, the capacitor EC3 and the cathode of the load LED in sequence, forming a flow loop of the circuit as a whole.

[0032] During specific operation, the electronic ballast outputs alternating current. In the positive half cycle, the current flows into the same-name end of the primary winding Np of the transformer T, flows out from the non-same-name end of the primary winding Np to form a loop. It can be seen that the voltage of the primary winding at this time is positive at the top and negative at the bottom. After the coupling of the transformer T, the current flows out from the same-name end of the secondary winding Ns of the transformer, passes through the diode D4, the valley-filling module, and the filtering module, enters the positive electrode of the load LED, comes out from the negative electrode of the load LED, and then passes through the diode D1 to return to the non-same-name end of the secondary winding Ns of the transformer; in the negative half cycle, the current flows into the non-same-name end of the primary winding Np, flows out from the same-name end of the primary winding Np to form a loop. It can be seen that the voltage of the primary winding at this time is negative at the top and positive at the bottom. After the coupling of the transformer T, the current flows out from the non-same-name end of the secondary winding Ns of the transformer T, passes through the diode D3, the valley-filling module, and the filtering module to enter the positive electrode of the load LED, then flows out from the negative electrode of the load LED, and then passes through the diode D2 to return to the same-name end of the secondary winding Ns of the transformer T.

[0033] By controlling the flow direction of the above current and utilizing the functions of each module, the current coming out of the full-bridge rectifier module can change with the voltage, thereby increasing the conduction angle of the diode without increasing the conduction angle loss of the diode, thereby preventing the diode from generating a large temperature rise. Since the current follows the voltage change through the valley filling module, the conversion efficiency can be improved and the loss can be reduced.

[0034] Embodiment 2

[0035] refer to Figure 2 As shown, on the basis of the first embodiment, the transformer T is further provided with a second secondary winding Ns1, and the second secondary winding Ns1 is connected to a heat dissipation module. The heat dissipation module includes a diode D8, a resistor R3, a capacitor EC4, a capacitor C1, a capacitor C2, a capacitor EC5, a voltage regulator U1 and a heat dissipation fan, the positive electrode of the diode D8 is connected to the same-name end of the second secondary winding Ns1, the resistor R3, the capacitor EC4, the capacitor C1, and the input pin of the voltage regulator U1 are connected in parallel, the capacitor C2 and the capacitor EC5 are connected in parallel and connected to the output pin of the voltage regulator U1, the negative electrode of the diode D8 is connected to the input pin of the voltage regulator U1, and the non-same-name end of the second secondary winding Ns1 is connected to the ground pin of the voltage regulator U1. A second secondary winding Ns1 is added to the transformer T to control the heat dissipation module. When applied to electronic equipment, the heat dissipation module can play a role in heat dissipation, and the output of an electronic ballast can be used to realize the control of the load and the heat dissipation module, improve the diversification of functions, and meet more usage requirements.

[0036] When working, the electronic ballast outputs AC power. In the positive half cycle, the current flows in from the same-name end of the primary winding of the transformer T, and flows out from the non-same-name end of the primary winding to form a loop. It can be seen that the voltage of the primary winding at this time is positive at the top and negative at the bottom. After the coupling of the transformer T, the current flows out from the same-name end of the second secondary winding Ns1 of the transformer, passes through the diode D8, the resistor R3, the capacitor EC4, and the capacitor C1, and enters the voltage regulator U1. The voltage regulator U1 stabilizes the voltage at a limited voltage and then enters the cooling fan through the capacitor C2 and the capacitor EC5, and finally comes out and returns to the non-same-name end of the second secondary winding Ns1. The number of turns of the second secondary winding and the value of the voltage regulator U1 can be changed to change the voltage for use by other equipment.

[0037] Embodiment 3

[0038] refer to Figure 3As shown, a circuit for driving an LED with an HID electronic ballast includes a transformer T, a full-bridge rectifier module and a filter module. The transformer T has a primary winding and a secondary winding. The primary winding of the transformer T has a same-name end and a non-same-name end. The same-name end of the primary winding is connected to the output end of the electronic ballast through a capacitor CX1, and the non-same-name end of the primary winding is directly connected to the output end of the electronic ballast. The full-bridge rectifier module is connected to the secondary winding of the transformer T, and the full-bridge rectifier module is connected to the filter module and a load LED lamp. The transformer T is also provided with a second secondary winding Ns1, and the second secondary winding Ns1 is connected to a heat dissipation module.

[0039] The full-bridge rectifier module includes a diode D1, a diode D2, a diode D3 and a diode D4, wherein the cathode of the diode D1 is connected to the anode of the diode D3, the cathode of the diode D2 is connected to the anode of the diode D4, the anode of the diode D1 is connected to the anode of the diode D2, and the cathode of the diode D3 is connected to the cathode of the diode D4. The cathode of the diode D1 and the anode of the diode D3 are both connected to the non-same-name end of the secondary winding Ns of the transformer T, and the cathode of the diode D2 and the anode of the diode D4 are both connected to the same-name end of the secondary winding Ns of the transformer T. The filter module includes a capacitor EC6 and a capacitor EC7, a resistor R4, a resistor R5 and a resistor R6, the capacitor EC6 and the capacitor EC7 are connected in series, the resistors R4, the resistor R5 and the resistor R6 are connected in series, and then connected in parallel with each other.

[0040] The heat dissipation module includes a diode D8, a resistor R3, a capacitor EC4, a capacitor C1, a capacitor C2, a capacitor EC5, a voltage regulator U1 and a heat dissipation fan, the positive electrode of the diode D8 is connected to the same-name end of the second secondary winding, the resistor R3, the capacitor EC4, the capacitor C1, are connected in parallel to the input pin of the voltage regulator U1, the capacitor C2 and the capacitor EC5 are connected in parallel and connected to the output pin of the voltage regulator U1, the negative electrode of the diode D8 is connected to the input pin of the voltage regulator U1, and the non-same-name ends of the second secondary winding Ns1 are all connected to the ground pin of the voltage regulator U1. A second secondary winding Ns1 is added through the transformer T to control the heat dissipation module. When applied to electronic equipment, the heat dissipation module can play a role in heat dissipation, and the output of an electronic ballast can be used to control the load and the heat dissipation module, improve the diversification of functions, and meet more usage requirements.

[0041] The second secondary winding is set in parallel on one side of the secondary winding. Through the primary input of the primary winding, two control outputs can be realized, one for directly controlling the load LED and the other for controlling the cooling fan, which play different roles respectively.

[0042] During specific operation, the electronic ballast outputs alternating current. In the positive half cycle, the current flows into the same-name end of the primary winding Np of the transformer T, flows out from the non-same-name end of the primary winding Np to form a loop. It can be seen that the voltage of the primary winding at this time is positive at the top and negative at the bottom. After the coupling of the transformer T, the current flows out from the same-name end of the secondary winding Ns of the transformer, passes through the diode D4, capacitors EC6 and EC7, resistors R4, resistors R5 and R6, and then passes through the diode D1 to return to the non-same-name end of the secondary winding Ns of the transformer; in the negative half cycle, the current flows into the non-same-name end of the primary winding Np, flows out from the same-name end of the primary winding Np to form a loop. It can be seen that the voltage of the primary winding at this time is negative at the top and positive at the bottom. After the coupling of the transformer T, the current flows out from the non-same-name end of the secondary winding Ns of the transformer T, passes through the diode D3, capacitors EC6 and EC7, resistors R4, resistors R5 and R6, and then passes through the diode D2 to return to the same-name end of the secondary winding Ns of the transformer T.

[0043] By adding a winding in the transformer for the heat sink. In the positive half cycle, the current flows in from the same-name end of the primary winding of the transformer T, and flows out from the non-same-name end of the primary winding to form a loop. It can be seen that the voltage of the primary winding at this time is positive at the top and negative at the bottom. After the coupling of the transformer T, the current flows out from the same-name end of the second secondary winding Ns1 of the transformer, passes through the diode D8, the resistor R3, the capacitor EC4, and the capacitor C1, and enters the voltage regulator U1. The voltage regulator U1 stabilizes the voltage at a limited voltage and then returns to the non-same-name end of the secondary winding Ns1 of the transformer to form a loop after passing through the capacitor C2 and the capacitor EC5. The number of turns of the second secondary winding Ns1 and the value of the voltage regulator U1 can be changed to change the voltage for use by other devices.

[0044] It should be noted that the above are only preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or make equivalent substitutions for some of the technical features therein. However, any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A circuit for driving LEDs with HID electronic ballasts, characterized in that: It includes a transformer T, a full-bridge rectifier module and a filter module. The transformer T has a primary winding and a secondary winding. The primary winding of the transformer T has a same-name end and a non-same-name end. The same-name end of the primary winding is connected to the output end of the electronic ballast through a capacitor CX1, and the non-same-name end of the primary winding is directly connected to the output end of the electronic ballast. The full-bridge rectifier module is connected to the secondary winding of the transformer T, and the full-bridge rectifier module is connected to the filter module and the load LED lamp.

2. The circuit for driving LED by HID electronic ballast according to claim 1, characterized in that: A valley-filling module is provided between the filtering module and the secondary winding of the transformer T. The valley-filling module is connected in parallel to the full-bridge rectifier module, and the valley-filling module is connected in parallel to the filtering module.

3. The circuit for driving LED by HID electronic ballast according to claim 2, characterized in that: The full-bridge rectifier module includes a diode D1, a diode D2, a diode D3 and a diode D4, the cathode of the diode D1 is connected to the anode of the diode D3, the cathode of the diode D3 is connected to the cathode of the diode D4, the anode of the diode D4 is connected to the cathode of the diode D2, and the anode of the diode D2 is connected to the anode of the diode D1.

4. The circuit for driving LED by HID electronic ballast according to claim 3, characterized in that: The cathode of the diode D1 and the anode of the diode D3 are both connected to the non-same-name ends of the secondary winding of the transformer T, and the cathode of the diode D2 and the anode of the diode D4 are both connected to the same-name ends of the secondary winding of the transformer T.

5. The circuit for driving LED by HID electronic ballast according to claim 3, characterized in that: The valley filling module includes a diode D5, a diode D6, a diode D7, a capacitor EC1 and a capacitor EC2, the anode of the diode D5 is respectively connected to one end of the capacitor EC1 and the cathode of the diode D6, the anode of the diode D6 is respectively connected to one end of the capacitor EC2 and the cathode of the diode D7, the cathode of the diode D5 is connected to the other end of the capacitor EC2, and the anode of the diode D7 is connected to the other end of the capacitor EC1.

6. The circuit for driving LED by HID electronic ballast according to claim 5, characterized in that: The filtering module includes a resistor R1, a resistor R2 and a capacitor EC3. The resistor R1 and the resistor R2 are connected in series and then connected in parallel with the capacitor EC3.

7. The circuit for driving LED by HID electronic ballast according to claim 6, characterized in that: The resistor R1 and the resistor R2 are chip resistors or plug-in resistors, and the capacitor EC3 is an electrolytic capacitor.

8. The circuit for driving LED by HID electronic ballast according to claim 5, characterized in that: The cathode of the diode D3 and the cathode of the diode D4 are connected to the cathode of the diode D5, the capacitor EC2, the resistor R1, the capacitor EC3 and the anode of the load LED lamp in sequence; the anode of the diode D1 and the anode of the diode D2 are connected to the cathode of the capacitor EC1, the anode of the diode D7, the resistor R2, the capacitor EC3 and the cathode of the load LED in sequence.

9. The circuit for driving LED by HID electronic ballast according to any one of claims 1 to 8, characterized in that: The transformer T is further provided with a second secondary winding Ns1 , and the second secondary winding Ns1 is connected to a heat dissipation module.

10. The circuit for driving LED by HID electronic ballast according to claim 9, characterized in that: The heat dissipation module includes a diode D8, a resistor R3, a capacitor EC4, a capacitor C1, a capacitor C2, a capacitor EC5, a voltage regulator U1 and a heat dissipation fan. The positive electrode of the diode D8 is connected to the same-name end of the second secondary winding Ns1, the resistor R3, the capacitor EC4, the capacitor C1, and the input pin of the voltage regulator U1 are connected in parallel, the capacitor C2 and the capacitor EC5 are connected in parallel and connected to the output pin of the voltage regulator U1, the negative electrode of the diode D8 is connected to the input pin of the voltage regulator U1, and the non-same-name end of the second secondary winding Ns1 is connected to the ground pin of the voltage regulator U1.

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