LED circuit for removing AC component

Abstract

The utility model relates to an LED circuit for removing an alternating current component, which comprises an LED driving power supply and an LED lamp, a constant voltage filter circuit is arranged between the LED driving power supply and the LED lamp, the constant voltage filter circuit comprises three parallel branches, the first branch comprises R1, D1 and ZD1 are connected in series behind the R1, the second branch comprises R2, the third branch comprises R3, C1 is connected in series behind the R3, and the C1 is connected in series behind the R2. The three branches are connected in parallel and then connected with R4 in series to form a constant-voltage filter circuit; one end of the constant-voltage filter circuit is connected with the V + end of the LED driving power supply, and the V-end of the LED driving power supply is connected to the middle part of the R3 and the C1; source electrodes of a Q1 and a Q2 which are connected in parallel are connected to a V + end of an LED driving power supply, grid electrodes of the Q1 and the Q2 are connected with an R4, drain electrodes of the Q1 and the Q2 are connected with an R6, the R6 is connected to an LED + end, and an LED-end is connected with a V-end of the driving power supply. According to the novel circuit, an inductance element with a large size in a traditional filter circuit is omitted, a control chip element does not need to be used, and the whole circuit is simple in structure and low in manufacturing cost.

Description

Technical Field

[0001] The utility model relates to the field of LED lighting equipment, in particular to an LED circuit for removing alternating current components. Background Art

[0002] In the lighting circuit, a rectifier circuit and an LED drive circuit are needed between the AC mains and the LED load to convert the AC power into DC power and keep the current flowing through the LED load constant to ensure constant brightness of the LED lighting.

[0003] Convert AC voltage to DC voltage, that is, convert the sinusoidal voltage into a pulsating voltage in a single direction. Since the rectified voltage contains a certain AC component (ripple), it will affect the normal operation of the load circuit and cannot be used directly. In order to reduce the pulsation of the voltage, it is necessary to filter it through a filter circuit (capacitor) to make the output voltage smooth. Ideally, all AC components should be filtered out so that the output voltage of the filter circuit is only DC voltage. However, in practical applications, since the filter circuit is a passive circuit, its filtering effect will be affected after connecting to the load.

[0004] For example, during the LED driving process, there is often an AC component (ripple) in the input AC mains that is carried into the DC output, which will produce flicker on the LED that is perceptible to the human eye and cause damage to the human eye.

[0005] Chinese Patent Publication (Announcement) No.: CN208549046U, Patent Title: A Flicker Removal Circuit, where flicker removal means removing AC components (ripples). In the background technology, it is described that "a traditional high power factor flicker-free LED driver power supply will use a bipolar power factor calibration circuit, which will use a MOS tube, a boost inductor and a control chip. The use of a boost inductor will cause the LED driver power supply to be larger in size, so that the size of the LED driver power supply housing also needs to be increased accordingly, resulting in higher processing costs and reduced product aesthetics." It achieves the flicker removal function through "the beneficial effects of the utility model are: performing ripple removal processing at the rear stage of the traditional unipolar power factor calibration circuit to achieve flicker-free LED light sources; only a control chip, a first MOS tube and very few peripheral circuits are required", which can significantly reduce the size of the LED driver power supply, and correspondingly reduce the size of the LED driver power supply housing and reduce costs.

[0006] However, the addition of a control chip increases the cost of the LED driver power supply. Summary of the invention

[0007] The purpose of the utility model is to provide an LED circuit for removing AC components to solve the problems raised in the above background technology.

[0008] In order to solve the above technical problems, the utility model is implemented by the following technical measures: an LED circuit for removing AC components, including an LED driving power supply as a power supply, and an LED lamp as an electrical appliance, wherein a constant voltage filter circuit is arranged between the LED driving power supply and the LED lamp, and the constant voltage filter circuit includes three parallel branches, the first parallel branch includes a resistor R1, a unidirectional diode D1 and a voltage regulator diode ZD1 are connected in series after the resistor R1, the second parallel branch includes a resistor R2, and the third parallel branch includes a resistor R3, and a capacitor C1 is connected in series after the resistor R3 , the three branches are connected in parallel and then connected in series with a resistor R4 to form the constant voltage filter circuit; the end of the constant voltage filter circuit close to the resistor is connected to the V+ end of the LED driving power supply, and the V- end of the LED driving power supply is connected to the middle part of the resistor R3 and the capacitor C1; the source electrodes of two parallel MOS tubes Q1 and Q2 are connected to the V+ end of the LED driving power supply, the gate electrodes of the MOS tubes Q1 and Q2 are connected to the resistor R4, the drain electrodes of the MOS tubes Q1 and Q2 are connected to the resistor R6, and the resistor R6 is then connected to the LED+ end of the LED lamp, and the LED- end of the LED lamp is connected to the V- end of the LED driving power supply.

[0009] Compared with the prior art, the utility model has the advantages that: the constant voltage filter circuit composed of resistor R1, unidirectional diode D1, voltage regulator diode ZD1, resistor R2, resistor R3, and capacitor C1 eliminates the large inductor components in the traditional filter circuit, and does not need to use control chip components. The whole circuit structure is simple and the production cost is low.

[0010] As an improvement of the utility model, a resistor R5 and a voltage regulator diode ZD2 are connected in parallel between the gate and drain of the MOS tubes Q1 and Q2. The purpose of selecting this design is to control the gate voltage parameter size of the MOS tube and facilitate the on and off adjustment of the MOS tube. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation on the present invention.

[0012] In the attached picture:

[0013] Figure 1 This is a LED circuit diagram for removing AC components described in the utility model. DETAILED DESCRIPTION

[0014] The preferred embodiments of the present invention are described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0015] Example 1

[0016] Please refer to Figure 1 The present embodiment provides an LED circuit for removing AC components, including an LED driving power supply as a power supply, and an LED lamp as an electrical appliance, wherein a constant voltage filter circuit is provided between the LED driving power supply and the LED lamp, and the constant voltage filter circuit includes three parallel branches, the first parallel branch includes a resistor R1, a unidirectional diode D1 and a voltage regulator diode ZD1 are connected in series after the resistor R1, the second parallel branch includes a resistor R2, and the third parallel branch includes a resistor R3, a capacitor C1 is connected in series after the resistor R3, and the three branches are connected in parallel and then in series. A resistor R4 is provided to form the constant voltage filter circuit; one end of the constant voltage filter circuit close to the resistor is connected to the V+ end of the LED driving power supply, and the V- end of the LED driving power supply is connected to the middle part of the resistor R3 and the capacitor C1; the source electrodes of two parallel MOS tubes Q1 and Q2 are connected to the V+ end of the LED driving power supply, the gate electrodes of the MOS tubes Q1 and Q2 are connected to the resistor R4, the drain electrodes of the MOS tubes Q1 and Q2 are connected to the resistor R6, and the resistor R6 is connected to the LED+ end of the LED lamp, and the LED- end of the LED lamp is connected to the V- end of the LED driving power supply.

[0017] In the embodiment of the utility model application, a resistor R5 and a voltage regulator diode ZD2 are connected in parallel between the gate and drain of the MOS tubes Q1 and Q2. By controlling the gate voltage parameter of the MOS tube, the conduction and cutoff of the MOS tube can be conveniently adjusted.

[0018] In the embodiment of the utility model application, when working, a constant voltage filter circuit is formed by a resistor R1, a unidirectional diode D1, a voltage stabilizing diode ZD1, a resistor R2, a resistor R3, and a capacitor C1. On the one hand, the AC component in the output voltage of the LED driving circuit is filtered out through the filter circuit, and on the other hand, a constant gate-source voltage is provided for the MOS tube. When the MOS tubes Q1 and Q2 have a constant gate-source turn-on voltage as a constant, when they are in the constant current region, the current flowing through the drain-source electrodes of the MOS tubes Q1 and Q2 is constant, so the MOS tubes are controlled to work in the constant current region, and the gate-source voltage is constant, then the MOS tubes Q1 and Q2 have a constant current characteristic, so that the LED load current does not contain a DC power of the AC component to the LED load end.

[0019] The beneficial effects of the utility model are: eliminating the inductor element with a large volume in the traditional filter circuit, and not needing to use the control chip element, the whole circuit structure is simple, and the manufacturing cost is low.

[0020] In the description of the present invention, it should be noted that the terms "vertical", "up", "down", "horizontal", etc. indicate orientations or positional relationships 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.

[0021] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" 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 a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0022] Finally, it should be noted that the above description is only a preferred embodiment of the utility model and is not intended to limit the utility model. Although the utility model is described in detail with reference to the above embodiments, those skilled in the art can still modify the technical solutions recorded in the above embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the utility model shall be included in the protection scope of the utility model.

Claims

1. An LED circuit for removing AC components, including an LED driving power supply as a power supply, and an LED lamp as an electrical appliance, characterized in that: A constant voltage filter circuit is arranged between the LED driving power supply and the LED lamp, and the constant voltage filter circuit includes three parallel branches, the first parallel branch includes a resistor R1, a unidirectional diode D1 and a voltage stabilizing diode ZD1 are connected in series behind the resistor R1, the second parallel branch includes a resistor R2, and the third parallel branch includes a resistor R3, a capacitor C1 is connected in series behind the resistor R3, and the three branches are connected in parallel and then connected in series with a resistor R4 to form the constant voltage filter circuit; the end of the constant voltage filter circuit close to the resistor is connected to the V+ end of the LED driving power supply, and the V- end of the LED driving power supply is connected to the middle part of the resistor R3 and the capacitor C1; the source electrodes of two parallel MOS tubes Q1 and Q2 are connected to the V+ end of the LED driving power supply, the gate electrodes of the MOS tubes Q1 and Q2 are connected to the resistor R4, the drain electrodes of the MOS tubes Q1 and Q2 are connected to the resistor R6, and the resistor R6 is connected to the LED+ end of the LED lamp, and the LED- end of the LED lamp is connected to the V- end of the LED driving power supply.

2. The LED circuit for removing AC components according to claim 1, characterized in that: A resistor R5 and a voltage stabilizing diode ZD2 are connected in parallel between the gate and drain of the MOS tubes Q1 and Q2.

Images