Low-flashover circuit

Abstract

The utility model discloses a low flashover circuit, which comprises a dimming module, a switch tube module, an LC filter module and an RC filter module, the dimming module can output PWM dimming signals, the first end of the switch tube module is electrically connected with the output end of the dimming module, the second end of the switch tube module is electrically connected with one end of the LC filter module, and the other end of the LC filter module is electrically connected with the RC filter module. The third end of the switching tube module is grounded, the other end of the LC filtering module is electrically connected with one end of the RC filtering module, and the other end of the RC filtering module is electrically connected with an LED load.

Description

Technical Field

[0001] The utility model relates to the field of LED dimming technology, especially a low-stroke circuit. Background Art

[0002] At present, LED dimming mainly adopts PWM dimming technology. The specific method of implementing PWM dimming is to connect a switch tube in series in the LED load, and then add a PWM signal to the switch tube to quickly switch the LED load, thereby realizing dimming. There are also many dimming chips that have a PWM interface themselves, which can directly receive PWM signals and then output to control the switch tube. In the existing dimming circuit, the output of the chip is in chopping mode when dimming at low current and low brightness. The output ripple is too high, resulting in a high output flicker percentage. In order to solve this problem, most of the existing technologies use simple RC filter circuits to suppress ripples, but lack reactive compensation, and the low flicker effect is average. Utility Model Content

[0003] The purpose of the utility model is to solve at least one of the technical problems existing in the prior art and to provide a low strobe circuit that reduces the strobe percentage.

[0004] According to the low-frequency lightning circuit of the embodiment of the utility model, it includes a dimming module, a switch tube module, an LC filter module and an RC filter module. The dimming module can output a PWM dimming signal. The first end of the switch tube module is electrically connected to the output end of the dimming module, the second end of the switch tube module is electrically connected to one end of the LC filter module, the third end of the switch tube module is grounded, the other end of the LC filter module is electrically connected to one end of the RC filter module, and the other end of the RC filter module is electrically connected to the LED load.

[0005] According to the low-frequency lightning circuit of the embodiment of the utility model, the switch tube module includes a MOS tube Q1, the gate of the MOS tube Q1 is electrically connected to the output end of the dimming module, the source of the MOS tube Q1 is electrically connected to the LC filter circuit, and the drain of the MOS tube Q1 is grounded.

[0006] According to the low-frequency lightning circuit of the embodiment of the utility model, the LC filter module includes an inductor L1 and a capacitor CE1, one end of the inductor L1 is electrically connected to the source of the MOS tube Q1, and the other end of the inductor L1 is electrically connected to the capacitor CE1, and the capacitor CE1 is connected in parallel with the RC filter module.

[0007] According to the low-frequency lightning circuit of the embodiment of the utility model, the LC filter module also includes an inductor L2 and a capacitor CE2, one end of the inductor L2 is electrically connected to the other end of the inductor L1 and one end of the capacitor CE1 respectively, the other end of the inductor L2 is electrically connected to the capacitor CE2, and the capacitor CE2 is connected in parallel with the RC filter module.

[0008] According to the low-stroke circuit according to the embodiment of the present invention, further includes a capacitor C2, one end of the capacitor C2 is grounded, and the other end of the capacitor C2 is electrically connected to the other end of the inductor L1 and the capacitor CE1, respectively.

[0009] According to the low strobe circuit of the embodiment of the present invention, the RC filtering module includes a resistor R1 and a capacitor C1 connected in parallel to each other.

[0010] According to the low-frequency lightning circuit of the embodiment of the utility model, the switch tube module also includes a resistor R2, a resistor R3, a resistor R4 and a diode D1, one end of the resistor R2 is electrically connected to one end of the resistor R4 and the output end of the dimming module, the other end of the resistor R4 is electrically connected to the cathode of the diode D1, the other end of the resistor R2 is electrically connected to the anode of the diode D1, one end of the resistor R3 and the gate of the MOS tube Q1, and the other end of the resistor R3 is electrically connected to the drain of the MOS tube Q1.

[0011] According to the embodiment of the utility model, the low-frequency lightning circuit further includes a power inductor LF1, the input end of the power inductor LF1 is electrically connected to the output end of the LC filter circuit, and the output end of the power inductor LF1 is electrically connected to the input end of the RC filter module.

[0012] According to the low-stroke circuit according to the embodiment of the present invention, it further includes a diode D2, which is connected in parallel with the LC filter module.

[0013] The low-frequency lightning circuit according to the embodiment of the utility model has at least the following beneficial effects: the LC filter module can filter out one or more harmonics. In addition to filtering, it also takes into account the need for reactive power compensation, and can improve the power factor to reduce power loss and stabilize the voltage, thereby reducing the percentage of flicker; and the RC filter module has the function of selecting a specific frequency, retaining the frequency of a certain frequency band, and filtering out the frequencies outside the frequency band, with strong anti-interference performance and simple circuit composition; therefore, the combination of the LC filter module and the RC filter module further enhances the filtering effect, and also takes into account the need for reactive power compensation, thereby better reducing the percentage of flicker.

[0014] Additional aspects and advantages of the present invention will be given in part in the following description, and in part will become apparent from the following description, or will be learned through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The specific implementation of the utility model is further described below in conjunction with the accompanying drawings;

[0016] Figure 1 It is the schematic diagram of the low-frequency lightning circuit. DETAILED DESCRIPTION

[0017] This section will describe in detail the specific embodiments of the utility model. The preferred embodiments of the utility model are shown in the accompanying drawings. The purpose of the accompanying drawings is to supplement the description of the text part of the specification with graphics, so that people can intuitively and vividly understand each technical feature and the overall technical solution of the utility model, but it cannot be understood as a limitation on the protection scope of the utility model.

[0018] In the description of the present invention, it should be understood that descriptions involving orientation, such as up, down, front, back, left, right, etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and 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 therefore cannot be understood as a limitation on the present invention.

[0019] In the description of the present utility model, "several" means one or more, "more" means more than two, "greater than", "less than", "exceed" etc. are understood to exclude the number itself, and "above", "below", "within" etc. are understood to include the number itself. If there is a description of "first" or "second", it is only used for the purpose of distinguishing the technical features, and cannot be understood as indicating or implying the relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0020] Reference Figure 1 The utility model discloses a low-frequency lightning circuit, comprising a dimming module, a switch module 10, an LC filter module 20 and an RC filter module 30. The dimming module can output a PWM dimming signal. The first end of the switch module 10 is electrically connected to the output end of the dimming module, the second end of the switch module 10 is electrically connected to one end of the LC filter module 20, the third end of the switch module 10 is grounded, the other end of the LC filter module 20 is electrically connected to one end of the RC filter module 30, and the other end of the RC filter module 30 is electrically connected to the LED load. The LC filter module 20 can filter out one or more harmonics. In addition to filtering, it also takes into account the need for reactive power compensation, can improve the power factor to reduce power loss, stabilize the voltage, and thus reduce the percentage of flicker; and the RC filter module 30 has the function of selecting a specific frequency, retaining the frequency of a certain frequency band, filtering out the frequencies outside the frequency band, having strong anti-interference performance and simple circuit composition; therefore, the combination of the LC filter module 20 and the RC filter module 30 further enhances the filtering effect, and also takes into account the need for reactive power compensation, and better reduces the percentage of flicker.

[0021] like Figure 1The switch tube module 10 includes a MOS tube Q1, the gate of the MOS tube Q1 is electrically connected to the output end of the dimming module, the source of the MOS tube Q1 is electrically connected to the LC filter circuit, the drain of the MOS tube Q1 is grounded, and the dimming module adopts a dimming chip U1, and the dimming chip U1 outputs a PWM signal to control the switch of the MOS tube Q1. The LC filter module 20 includes an inductor L1 and a capacitor CE1, one end of the inductor L1 is electrically connected to the source of the MOS tube Q1, the other end of the inductor L1 is electrically connected to the capacitor CE1, and the capacitor CE1 is connected in parallel with the RC filter module 30. The LC filter module 20 also includes an inductor L2 and a capacitor CE2, one end of the inductor L2 is electrically connected to the other end of the inductor L1 and one end of the capacitor CE1 respectively, the other end of the inductor L2 is electrically connected to the capacitor CE2, and the capacitor CE2 is connected in parallel with the RC filter module 30 to further enhance the filtering effect. It also includes a capacitor C2, one end of the capacitor C2 is grounded, and the other end of the capacitor C2 is electrically connected to the other end of the inductor L1 and the capacitor CE1 respectively, and the capacitor C2 further filters. The RC filter module 30 includes a resistor R1 and a capacitor C1 connected in parallel, with a simple structure and good anti-interference effect. The switch tube module 10 also includes a resistor R2, a resistor R3, a resistor R4 and a diode D1, one end of the resistor R2 is electrically connected to one end of the resistor R4 and the output end of the dimming module, the other end of the resistor R4 is electrically connected to the cathode of the diode D1, the other end of the resistor R2 is electrically connected to the anode of the diode D1, one end of the resistor R3 and the gate of the MOS tube Q1, and the other end of the resistor R3 is electrically connected to the drain of the MOS tube Q1.

[0022] Furthermore, it also includes a power inductor LF1, the input end of the power inductor LF1 is electrically connected to the output end of the LC filter circuit, and the output end of the power inductor LF1 is electrically connected to the input end of the RC filter module 30, so as to further enhance the filtering effect and reduce the flicker percentage.

[0023] Furthermore, it also includes a diode D2, which is connected in parallel with the LC filter module 20, and the diode D2 has a reverse cut-off function to improve circuit safety and reliability.

[0024] It is easy for those skilled in the art to understand that the above preferred embodiments can be freely combined and superimposed without conflict.

[0025] The above are only preferred embodiments of the present invention, and are not intended to limit the patent scope of the present invention. All equivalent structural changes made using the contents of the present invention specification and drawings under the utility model concept, or directly or indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A low-frequency lightning circuit, characterized in that: include: A dimming module, a switch tube module (10), an LC filter module (20) and an RC filter module (30), wherein the dimming module is capable of outputting a PWM dimming signal, a first end of the switch tube module (10) is electrically connected to an output end of the dimming module, a second end of the switch tube module (10) is electrically connected to one end of the LC filter module (20), a third end of the switch tube module (10) is grounded, the other end of the LC filter module (20) is electrically connected to one end of the RC filter module (30), and the other end of the RC filter module (30) is electrically connected to an LED load.

2. The low-frequency lightning circuit according to claim 1, characterized in that: The switch tube module (10) comprises a MOS tube Q1, the gate of the MOS tube Q1 is electrically connected to the output end of the dimming module, the source of the MOS tube Q1 is electrically connected to the LC filter module, and the drain of the MOS tube Q1 is grounded.

3. The low-frequency lightning circuit according to claim 2, characterized in that: The LC filter module (20) comprises an inductor L1 and a capacitor CE1, one end of the inductor L1 is electrically connected to the source of the MOS tube Q1, the other end of the inductor L1 is electrically connected to the capacitor CE1, and the capacitor CE1 is connected in parallel to the RC filter module (30).

4. The low-frequency lightning circuit according to claim 3, characterized in that: The LC filter module (20) further comprises an inductor L2 and a capacitor CE2, one end of the inductor L2 is electrically connected to the other end of the inductor L1 and one end of the capacitor CE1 respectively, the other end of the inductor L2 is electrically connected to the capacitor CE2, and the capacitor CE2 is connected in parallel with the RC filter module (30).

5. The low-frequency lightning circuit according to claim 3, characterized in that: The device further includes a capacitor C2 , one end of which is grounded, and the other end of which is electrically connected to the other end of the inductor L1 and the capacitor CE1 .

6. The low-frequency lightning circuit according to claim 2, characterized in that: The RC filter module (30) comprises a resistor R1 and a capacitor C1 connected in parallel.

7. The low-frequency lightning circuit according to claim 2, characterized in that: The switch tube module (10) further comprises a resistor R2, a resistor R3, a resistor R4 and a diode D1, one end of the resistor R2 is electrically connected to one end of the resistor R4 and the output end of the dimming module respectively, the other end of the resistor R4 is electrically connected to the cathode of the diode D1, the other end of the resistor R2 is electrically connected to the anode of the diode D1, one end of the resistor R3 and the gate of the MOS tube Q1 respectively, and the other end of the resistor R3 is electrically connected to the drain of the MOS tube Q1.

8. The low-frequency lightning circuit according to claim 1, characterized in that: It also includes a power inductor LF1, the input end of the power inductor LF1 is electrically connected to the output end of the LC filter module, and the output end of the power inductor LF1 is electrically connected to the input end of the RC filter module (30).

9. The low-frequency lightning circuit according to claim 1, characterized in that: It also includes a diode D2, which is connected in parallel with the LC filter module (20).

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