LED controller

Abstract

The utility model relates to the technical field of LED control, in particular to an LED controller. The rectification filtering unit is electrically connected with the PFC flyback switching power supply, the PFC flyback switching power supply is electrically connected with primary sides of a main winding and an auxiliary winding of the transformer T2, the PFC flyback switching power supply and the high-efficiency descrambling unit are both connected with a high-voltage starting source, and the PFC flyback switching power supply is electrically connected with the high-efficiency descrambling unit. The high-efficiency descrambling unit is electrically connected with the primary side of a main winding of the transformer T2, the secondary side of the main winding of the transformer T2 is electrically connected with the load receiving unit, and the high-efficiency descrambling unit is electrically connected with the load receiving unit; the high-efficiency descrambling unit is used for absorbing leakage inductance energy of the transformer T2 when the PFC flyback switching power supply is switched off; the filter is also used for filtering common-mode interference of the primary side and the secondary side of the transformer T2; therefore, the common-mode interference is filtered while the leakage inductance energy is quickly absorbed, and the dimming fluency is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of LED control, in particular to an LED controller. Background Art

[0002] With the advancement of lighting technology and the increase in application needs, people's requirements for lighting effects are no longer limited to basic brightness requirements, but are more pursuing a comfortable and natural lighting experience. Dimming smoothness, as one of the key factors affecting lighting effects, is directly related to people's visual perception and user experience. Therefore, in order to meet the ever-increasing lighting needs, the requirements for the dimming smoothness of LED controllers are also getting higher and higher. For example, in some special application scenarios, such as museums, art galleries, and other places where precise control of lighting brightness and color temperature is required, dimming smoothness is particularly important. In these places, slight changes in brightness may have a greater impact on the exhibits, so the LED controller is required to achieve a more accurate and smooth dimming effect.

[0003] At present, LED controllers usually use PFC flyback switching power supplies as the core circuit. After the switching power supply is started at high voltage, the auxiliary winding is often used for continuous power supply and the main winding outputs the dimming current. When the switching power supply is turned off, the inductive components in the circuit (such as transformers, inductors, etc.) often generate leakage inductance energy. If this part of energy is not properly handled or handled in time, it will form high-voltage spikes or short-term high-voltage spike disturbances, impacting the switching power supply, causing the dimming current to be disturbed, resulting in problems such as uneven dimming of the LED controller and flickering of the LED. Utility Model Content

[0004] In view of the above-mentioned defects, the purpose of the utility model is to provide an LED controller that can quickly absorb leakage inductance energy while filtering out common-mode interference, thereby improving dimming smoothness.

[0005] To achieve this purpose, the utility model adopts the following technical solutions:

[0006] An LED controller includes a rectifier filter unit and a transformer T2; also includes a PFC flyback switching power supply, a high-efficiency interference removal unit and a load receiving unit; the output end of the rectifier filter unit is electrically connected to the input end of the PFC flyback switching power supply, the high-voltage startup end of the PFC flyback switching power supply and the first end of the high-efficiency interference removal unit are both connected to a high-voltage startup source, the leakage inductance energy absorption end of the PFC flyback switching power supply is electrically connected to the second end of the high-efficiency interference removal unit, the third end of the high-efficiency interference removal unit is electrically connected to the primary side opposite end of the main winding of the transformer T2, and the high-efficiency The fourth end of the interference elimination unit is electrically connected to the anti-interference end of the load receiving unit, the output end of the PFC flyback switching power supply is electrically connected to the same-name end of the primary side of the main winding of the transformer T2, the feedback end, the first power supply end and the second power supply end of the PFC flyback switching power supply are electrically connected to the same-name end of the primary side of the auxiliary winding of the transformer T2, the primary side opposite-name end of the auxiliary winding of the transformer T2 is grounded, the same-name end of the secondary side of the main winding of the transformer T2 is electrically connected to the input end of the load receiving unit, and the opposite-name end of the secondary side of the main winding of the transformer T2 is electrically connected to the ground end of the load receiving unit;

[0007] The high-efficiency interference elimination unit is used to absorb the leakage inductance energy of the transformer T2 when the PFC flyback switching power supply is turned off; and is also used to filter out the common-mode interference on the primary side and the secondary side of the transformer T2.

[0008] Further, the high-efficiency interference removal unit includes a capacitor C8, a resistor R9, a resistor R11, a resistor R10, a diode D8, a diode D3 and an anti-interference circuit; one end of the resistor R11 is used as a first end of the high-efficiency interference removal unit, an anode of the diode D3 is used as a second end of the high-efficiency interference removal unit, one end of the capacitor C8 is used as a third end of the high-efficiency interference removal unit, and one end of the anti-interference circuit is used as a fourth end of the high-efficiency interference removal unit;

[0009] One end of the resistor R11, one end of the resistor R10, and the other end of the anti-interference circuit 31 are all electrically connected to one end of the capacitor C8, the other end of the resistor R11, the other end of the resistor R10, one end of the resistor R9, and the cathode of the diode D8 are all electrically connected to the other end of the capacitor C8, and the other end of the resistor R9 and the anode of the diode D8 are all electrically connected to the cathode of the diode D3;

[0010] The anti-interference circuit is used to filter out common-mode interference on the primary side and the secondary side of the transformer T2.

[0011] Furthermore, the anti-interference circuit includes a capacitor CY1; one end of the capacitor CY1 is used as one end of the anti-interference circuit, and the other end of the capacitor CY1 is used as the other end of the anti-interference circuit.

[0012] Further, the PFC flyback switching power supply includes a PFC unit and a flyback unit integrated with a MOS tube; the input end of the PFC unit is used as the input end of the PFC flyback switching power supply, the high-voltage startup end of the PFC unit or the high-voltage startup end of the flyback unit is used as the high-voltage startup end of the PFC flyback switching power supply, the leakage inductance energy absorption end of the flyback unit is used as the leakage inductance energy absorption end of the PFC flyback switching power supply, the power supply end of the PFC unit is used as the first power supply end of the PFC flyback switching power supply, the power supply end of the flyback unit is used as the second power supply end of the PFC flyback switching power supply, the feedback end of the flyback unit is used as the feedback end of the PFC flyback switching power supply, and the output end of the flyback unit is used as the output end of the PFC flyback switching power supply;

[0013] The high voltage start-up terminal of the flyback unit is electrically connected to the high voltage start-up terminal of the PFC unit, and the ground terminal of the flyback unit is electrically connected to the ground terminal of the PFC unit.

[0014] Further, the PFC unit includes an inductor L2, a capacitor C1, a capacitor C2, a capacitor C2, a capacitor CB1, a capacitor EC1, a resistor R4, a resistor R5, a resistor R6, a resistor R7, a resistor RS1, a resistor RS2, a resistor RS3, a diode D1, a diode D2, a PFC chip U1 and a first voltage limiting circuit; one end and the other end of the capacitor CB1 are both used as input ends of the PFC unit, one end of the capacitor EC1 is used as a high-voltage starting end of the PFC unit, the other end of the capacitor EC1 is used as a ground end of the PFC unit, and the first end of the first voltage limiting circuit is used as a power supply end of the PFC unit;

[0015] One end of the capacitor C1, the anode of the diode D1, and one end of the inductor L2 are all electrically connected to one end of the capacitor CB1, the other end of the capacitor C1, the cathode of the diode D2, and one end of the resistor R7 are all electrically connected to the positive electrode of the capacitor EC1, the other end of the inductor L2 and the anode of the diode D2 are all electrically connected to the DRAIN end of the PFC chip U1, the other end of the resistor R7 is electrically connected to one end of the resistor R6, the other end of the resistor R6 is electrically connected to one end of the resistor R5, the other end of the resistor R5, one end of the resistor R4, and one end of the capacitor C2 ... The FB end of the PFC chip U1 is electrically connected, the second end of the first voltage limiting circuit and one end of the capacitor C3 are electrically connected to the VCC end of the PFC chip U1, one end of the resistor RS1, one end of the resistor RS2, and one end of the resistor RS3 are electrically connected to the CS end of the PFC chip U1, and the negative electrode of the capacitor EC1, the other end of the resistor RS1, the other end of the resistor RS2, the other end of the resistor RS3, the other end of the capacitor C3, the GND end of the PFC chip U1, the other end of the resistor R4, and the other end of the capacitor C2 are electrically connected to the other end of the capacitor CB1.

[0016] Further, the flyback unit includes an inductor LB1, a resistor R13, a resistor R17, a resistor R18, a resistor R19, a resistor RS4, a resistor RS5, a resistor RS6, a capacitor C4, a capacitor C5, a capacitor C6, a capacitor C7, a flyback chip U3 integrated with a MOS tube, and a second voltage limiting circuit; one end of the resistor R13 is used as a high-voltage start-up end of the flyback unit, a GND end of the flyback chip U3 is used as a ground end of the flyback unit, one end of the inductor LB1 is used as an output end of the flyback unit, one end of the resistor R17 is used as a feedback end of the flyback unit, a first end of the second voltage limiting circuit is used as a power supply end of the flyback unit, and one end of the capacitor C4 is used as a leakage inductance energy absorption end of the flyback unit;

[0017] The other end of the resistor R13 is electrically connected to the HV end of the flyback chip U3, the other end of the inductor LB1 is electrically connected to the DRAIN end of the flyback chip U3, the other end of the capacitor C4, one end of the resistor R19, one end of the resistor RS4, one end of the resistor RS5, and one end of the resistor RS6 are all electrically connected to the SRC end of the flyback chip U3, the other end of the resistor R19 is electrically connected to the CS end of the flyback chip U3, the other end of the resistor R17, one end of the resistor R18, and one end of the capacitor C5 are all electrically connected to the FB end of the flyback chip U3, one end of the capacitor C7 is electrically connected to the COMP end of the flyback chip U3, one end of the capacitor C6 and the second end of the second voltage limiting circuit are all electrically connected to the VCC end of the flyback chip U3, and the other end of the capacitor C5, the other end of the capacitor C6, the other end of the capacitor C7, and the other end of the resistor R18 are all electrically connected to the GND end of the flyback chip U3.

[0018] Further, the load receiving unit includes a resistor R22, a resistor R20, a capacitor C9, a capacitor EC2, a diode D6 and a diode D7; the anode of the diode D7 and the cathode of the capacitor EC2 are both used as input terminals of the load receiving unit, the cathode of the diode D7 is used as an anti-interference terminal of the load receiving unit, and one end and the other end of the resistor R20 are used as output terminals of the load receiving unit;

[0019] The anode of the diode D6 and one end of the resistor R22 are electrically connected to the anode of the diode D7, the other end of the resistor R22 is electrically connected to one end of the capacitor C9, the other end of the capacitor C9, the cathode of the diode D6, the positive electrode of the capacitor EC2, and one end of the resistor R20 are electrically connected to the cathode of the diode D7, and the negative electrode of the capacitor EC2 and the other end of the resistor R20 are grounded.

[0020] Furthermore, the first voltage limiting circuit and the second voltage limiting circuit have the same circuit structure;

[0021] The first voltage limiting circuit includes a resistor R15 and a diode D4; the anode of the diode D4 is used as the first end of the first voltage limiting circuit, and one end of the resistor R15 is used as the second end of the first voltage limiting circuit; the other end of the resistor R15 is electrically connected to the cathode of the diode D4.

[0022] The technical solution provided by the utility model may include the following beneficial effects: when the PFC flyback switching power supply is turned off, the transformer T2 will generate a back electromotive force, and this part of the reverse voltage will not be completely transmitted to the secondary side of the transformer T2, but will be superimposed on the power supply voltage to form a voltage spike, thereby causing voltage fluctuations, component damage and electromagnetic interference (EMI) on the secondary side of the transformer T2, etc., causing fluctuations or distortions in the dimming current, and further affecting the stability of the light. To this end, a high-efficiency interference removal unit is set between the PFC flyback switching power supply and the primary side of the transformer T2. The high-efficiency interference removal unit quickly absorbs the leakage inductance energy in the shortest time and filters out the common-mode interference generated by the coupling of the primary and secondary sides of the transformer T2, thereby maintaining the stability of the dimming current, making the dimming process smoother, and preventing the circuit components of the LED controller from being damaged by the spike voltage impact. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a circuit diagram of an LED controller according to one embodiment of the present utility model.

[0024] Wherein: rectifier filter unit 1, transformer T2, PFC flyback switching power supply 2, high efficiency interference elimination unit 3, load receiving unit 4, capacitor C8, resistor R9, resistor R11, resistor R10, diode D8, diode D3, anti-interference circuit 31, capacitor CY1, PFC unit 21, flyback unit 22, inductor L2, capacitor C1, capacitor C2, capacitor C2, capacitor CB1, capacitor EC1, resistor R4, resistor R5, resistor R6, resistor R7, resistor RS1, resistor R S2, resistor RS3, diode D1, diode D2, PFC chip U1, first voltage limiting circuit 211, inductor LB1, resistor R13, resistor R17, resistor R18, resistor R19, resistor RS4, resistor RS5, resistor RS6, capacitor C4, capacitor C5, capacitor C6, capacitor C7, flyback chip U3, second voltage limiting circuit 221, resistor R22, resistor R20, capacitor C9, capacitor EC2, diode D6, diode D7, resistor R15, diode D4. DETAILED DESCRIPTION

[0025] 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.

[0026] In the description of the embodiments of the present invention, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0027] In the description of the embodiments of the present invention, 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 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 embodiments of the present invention can be understood according to specific circumstances.

[0028] Combine the following Figure 1 , describing an LED controller according to an embodiment of the utility model.

[0029] An LED controller includes a rectifying and filtering unit 1 and a transformer T2; further includes a PFC flyback switching power supply 2, a high-efficiency interference removal unit 3 and a load receiving unit 4; the output end of the rectifying and filtering unit 1 is electrically connected to the input end of the PFC flyback switching power supply 2, the high-voltage starting end of the PFC flyback switching power supply 2 and the first end of the high-efficiency interference removal unit 3 are both connected to a high-voltage starting source, the leakage inductance energy absorption end of the PFC flyback switching power supply 2 is electrically connected to the second end of the high-efficiency interference removal unit 3, and the third end of the high-efficiency interference removal unit 3 is electrically connected to the primary side opposite end of the main winding of the transformer T2 , the fourth end of the high-efficiency interference elimination unit 3 is electrically connected to the anti-interference end of the load receiving unit 4, the output end of the PFC flyback switching power supply 2 is electrically connected to the same-name end of the primary side of the main winding of the transformer T2, the feedback end, the first power supply end and the second power supply end of the PFC flyback switching power supply 2 are electrically connected to the same-name end of the primary side of the auxiliary winding of the transformer T2, the opposite-name end of the primary side of the auxiliary winding of the transformer T2 is grounded, the same-name end of the secondary side of the main winding of the transformer T2 is electrically connected to the input end of the load receiving unit 4, and the opposite-name end of the secondary side of the main winding of the transformer T2 is electrically connected to the ground end of the load receiving unit 4;

[0030] The high-efficiency interference elimination unit 3 is used to absorb the leakage inductance energy of the transformer T2 when the PFC flyback switching power supply 2 is turned off; and is also used to filter out the common-mode interference on the primary side and the secondary side of the transformer T2.

[0031] The utility model proposes a preferred embodiment of an LED controller, such as Figure 1As shown, when the PFC flyback switching power supply 2 is turned off, the transformer T2 will generate a back electromotive force. This part of the reverse voltage will not be completely transmitted to the secondary side of the transformer T2, but will be superimposed on the power supply voltage to form a voltage spike, thereby causing voltage fluctuations, component damage and electromagnetic interference (EMI) on the secondary side of the transformer T2, causing fluctuations or distortions in the dimming current, and further affecting the stability of the light. For this reason, a high-efficiency interference removal unit 3 is set between the PFC flyback switching power supply 2 and the primary side of the transformer T2. The high-efficiency interference removal unit 3 quickly absorbs the leakage inductance energy and filters out the common-mode interference generated by the coupling of the primary and secondary sides of the transformer T2 in the shortest time, thereby maintaining the stability of the dimming current, making the dimming process smoother, and preventing the circuit components of the LED controller from being damaged by the spike voltage impact.

[0032] Further, the high-efficiency interference removal unit 3 includes a capacitor C8, a resistor R9, a resistor R11, a resistor R10, a diode D8, a diode D3 and an anti-interference circuit 31; one end of the resistor R11 is used as a first end of the high-efficiency interference removal unit 3, an anode of the diode D3 is used as a second end of the high-efficiency interference removal unit 3, one end of the capacitor C8 is used as a third end of the high-efficiency interference removal unit 3, and one end of the anti-interference circuit 31 is used as a fourth end of the high-efficiency interference removal unit 3;

[0033] One end of the resistor R11, one end of the resistor R10, and the other end of the anti-interference circuit 31 are all electrically connected to one end of the capacitor C8, the other end of the resistor R11, the other end of the resistor R10, one end of the resistor R9, and the cathode of the diode D8 are all electrically connected to the other end of the capacitor C8, and the other end of the resistor R9 and the anode of the diode D8 are all electrically connected to the cathode of the diode D3;

[0034] The anti-interference circuit 31 is used to filter out common-mode interference on the primary side and the secondary side of the transformer T2.

[0035] In this embodiment, the high-efficiency interference elimination unit 3 is composed of a capacitor C8, a resistor R9, a resistor R11, a resistor R10, a diode D8, and a diode D3 to form an RCD absorption circuit to achieve leakage inductance energy absorption; and uses an anti-interference circuit 313 to filter out common-mode interference, ultimately achieving the preset function.

[0036] It should be noted that the RCD circuit effectively absorbs and consumes the energy generated by the transformer leakage inductance through the charging and discharging process of the capacitor and the energy consumption of the resistor, thereby protecting the switch tube from damage by voltage spikes; more importantly, the RCD circuit also uses a diode D8 to replace the original resistor, so that the RCD circuit does not need to pass through the resistor R9 during the charging process, and can directly charge the capacitor C8 from the diode D8 (the charging process is the leakage inductance energy absorption process), which greatly improves the absorption efficiency of the leakage inductance energy of the RCD circuit, so that the high-efficiency interference elimination unit 3 can achieve the purpose of efficiently absorbing the leakage inductance energy.

[0037] Furthermore, the anti-interference circuit 31 includes a capacitor CY1 ; one end of the capacitor CY1 is used as one end of the anti-interference circuit 31 , and the other end of the capacitor CY1 is used as the other end of the anti-interference circuit 31 .

[0038] In this embodiment, since there is parasitic capacitance between each coil winding of the transformer T2, a voltage is formed during operation, which becomes a noise source. A capacitor is connected across the primary and secondary sides of the transformer T2, and the common-mode disturbance generated by the primary and secondary coupling can be filtered out by utilizing the characteristics of the capacitor. Therefore, the anti-interference circuit 31 uses the capacitor CY1 as a decoupling capacitor, because in addition to the mutual inductance flux coupling to transfer power between the primary and secondary sides of the high-frequency transformer (transformer T2), there is also distributed capacitance coupling between the coils. If the loop formed by the distributed capacitance coupling is not connected, there will be high-frequency interference on all windings on the secondary side. After the capacitor CY1 is connected, the high-frequency interference from the distributed capacitance on the secondary winding will be "short-circuited" back through CY1, so that the high-frequency interference is short-circuited.

[0039] Further, the PFC flyback switching power supply 2 includes a PFC unit 21 and a flyback unit 22 integrated with a MOS tube; the input end of the PFC unit 21 is used as the input end of the PFC flyback switching power supply 2, the high-voltage startup end of the PFC unit 21 or the high-voltage startup end of the flyback unit 22 is used as the high-voltage startup end of the PFC flyback switching power supply 2, the leakage inductance energy absorption end of the flyback unit 22 is used as the leakage inductance energy absorption end of the PFC flyback switching power supply 2, the power supply end of the PFC unit 21 is used as the first power supply end of the PFC flyback switching power supply 2, the power supply end of the flyback unit 22 is used as the second power supply end of the PFC flyback switching power supply 2, the feedback end of the flyback unit 22 is used as the feedback end of the PFC flyback switching power supply 2, and the output end of the flyback unit 22 is used as the output end of the PFC flyback switching power supply 2;

[0040] The high voltage start-up terminal of the flyback unit 22 is electrically connected to the high voltage start-up terminal of the PFC unit 21 , and the ground terminal of the flyback unit 22 is electrically connected to the ground terminal of the PFC unit 21 .

[0041] In this embodiment, the PFC flyback switching power supply 2 is composed of a PFC unit 21 and a flyback unit 22 integrated with a MOS tube. After the two are started simultaneously by high voltage, they are powered by the auxiliary winding of the transformer T2, providing a stable power supply voltage and electrically isolating the switch power supply side and the load side to ensure dimming stability; then, the PFC unit 21 first optimizes the waveform and phase of the rectified current input by the rectifier filter unit 1, improves the power factor (PF value) and stabilizes the output current, so that the final output current is closer to a sine wave; then the flyback unit 22 is combined with the transformer T2 to realize voltage conversion and isolation. When the built-in MOS tube of the flyback unit 22 is turned on, the current on the primary side of the transformer increases, and energy is stored in the transformer. When the switch tube is turned off, the secondary side of the transformer releases energy and outputs a dimming current. In this way, the PFC flyback switching power supply 2 can provide efficient, stable and smooth dimming current output.

[0042] Further, the PFC unit 21 includes an inductor L2, a capacitor C1, a capacitor C2, a capacitor C2, a capacitor CB1, a capacitor EC1, a resistor R4, a resistor R5, a resistor R6, a resistor R7, a resistor RS1, a resistor RS2, a resistor RS3, a diode D1, a diode D2, a PFC chip U1 and a first voltage limiting circuit 211; one end and the other end of the capacitor CB1 are both used as input ends of the PFC unit 21, one end of the capacitor EC1 is used as a high-voltage starting end of the PFC unit 21, the other end of the capacitor EC1 is used as a ground end of the PFC unit 21, and the first end of the first voltage limiting circuit 211 is used as a power supply end of the PFC unit 21;

[0043] One end of capacitor C1, the anode of diode D1, and one end of inductor L2 are all electrically connected to one end of capacitor CB1. The other end of capacitor C1, the cathode of diode D2, and one end of resistor R7 are all electrically connected to the positive electrode of capacitor EC1. The other end of inductor L2 and the anode of diode D2 are all electrically connected to the DRAIN end of PFC chip U1. The other end of resistor R7 is electrically connected to one end of resistor R6. The other end of resistor R6 is electrically connected to one end of resistor R5. The other end of resistor R5, one end of resistor R4, and one end of capacitor C2 are all electrically connected to PFC chip The FB end of PFC chip U1 is electrically connected, the second end of the first voltage limiting circuit 211 and one end of capacitor C3 are electrically connected to the VCC end of PFC chip U1, one end of resistor RS1, one end of resistor RS2, and one end of resistor RS3 are electrically connected to the CS end of PFC chip U1, the negative electrode of capacitor EC1, the other end of resistor RS1, the other end of resistor RS2, the other end of resistor RS3, the other end of capacitor C3, the GND end of PFC chip U1, the other end of resistor R4, and the other end of capacitor C2 are electrically connected to the other end of capacitor CB1.

[0044] In this embodiment, the PFC unit 21 is composed of the PFC chip U1 and its peripheral circuits, which has higher integration and stability and simple circuits, and can better optimize the waveform and phase of the rectified current, improve the power factor (PF value) and stabilize the output current, so that the final output current is closer to a sine wave. More importantly, a first voltage limiting circuit 211 is also provided to limit the power supply voltage from the auxiliary winding of the transformer T2, to avoid overvoltage of the PFC chip U1, and to ensure the working stability of the PFC chip U1.

[0045] Further, the flyback unit 22 includes an inductor LB1, a resistor R13, a resistor R17, a resistor R18, a resistor R19, a resistor RS4, a resistor RS5, a resistor RS6, a capacitor C4, a capacitor C5, a capacitor C6, a capacitor C7, a flyback chip U3 integrated with a MOS tube, and a second voltage limiting circuit 221; one end of the resistor R13 is used as a high-voltage starting end of the flyback unit 22, a GND end of the flyback chip U3 is used as a ground end of the flyback unit 22, one end of the inductor LB1 is used as an output end of the flyback unit 22, one end of the resistor R17 is used as a feedback end of the flyback unit 22, a first end of the second voltage limiting circuit 221 is used as a power supply end of the flyback unit 22, and one end of the capacitor C4 is used as a leakage inductance energy absorption end of the flyback unit 22;

[0046] The other end of the resistor R13 is electrically connected to the HV end of the flyback chip U3, the other end of the inductor LB1 is electrically connected to the DRAIN end of the flyback chip U3, the other end of the capacitor C4, one end of the resistor R19, one end of the resistor RS4, one end of the resistor RS5, and one end of the resistor RS6 are all electrically connected to the SRC end of the flyback chip U3, the other end of the resistor R19 is electrically connected to the CS end of the flyback chip U3, the other end of the resistor R17, one end of the resistor R18, and one end of the capacitor C5 are all electrically connected to the FB end of the flyback chip U3, one end of the capacitor C7 is electrically connected to the COMP end of the flyback chip U3, one end of the capacitor C6 and the second end of the second voltage limiting circuit 221 are all electrically connected to the VCC end of the flyback chip U3, and the other end of the capacitor C5, the other end of the capacitor C6, the other end of the capacitor C7, and the other end of the resistor R18 are all electrically connected to the GND end of the flyback chip U3.

[0047] In this embodiment, the flyback unit 22 is composed of a flyback chip U3 integrated with a MOS tube and its peripheral circuits, which has higher integration and stability and a simple circuit, and can better achieve voltage conversion and isolation. More importantly, a second voltage limiting circuit 221 is also provided to limit the power supply voltage from the auxiliary winding of the transformer T2, thereby avoiding overvoltage of the flyback chip U3 and ensuring the working stability of the flyback chip U3.

[0048] Further, the load receiving unit 5 includes a resistor R22, a resistor R20, a capacitor C9, a capacitor EC2, a diode D6 and a diode D7; the anode of the diode D7 and the cathode of the capacitor EC2 are both used as input terminals of the load receiving unit 5, the cathode of the diode D7 is used as an anti-interference terminal of the load receiving unit 5, and one end and the other end of the resistor R20 are used as output terminals of the load receiving unit 5;

[0049] The anode of diode D6 and one end of resistor R22 are electrically connected to the anode of diode D7, the other end of resistor R22 is electrically connected to one end of capacitor C9, the other end of capacitor C9, the cathode of diode D6, the positive electrode of capacitor EC2, and one end of resistor R20 are electrically connected to the cathode of diode D7, and the negative electrode of capacitor EC2 and the other end of resistor R20 are grounded.

[0050] In this embodiment, the load receiving unit 5 is composed of a resistor R22, a resistor R20, a capacitor C9, a capacitor EC2, a diode D6 and a diode D7 to form a rectifier filter circuit for receiving the dimming current transmitted from the secondary side of the transformer T1 to ensure the stability of the dimming current.

[0051] Furthermore, the circuit structures of the first voltage limiting circuit 211 and the second voltage limiting circuit 221 are the same;

[0052] The first voltage limiting circuit 211 includes a resistor R15 and a diode D4; the anode of the diode D4 is used as the first end of the first voltage limiting circuit 211, and one end of the resistor R15 is used as the second end of the first voltage limiting circuit 211; the other end of the resistor R15 is electrically connected to the cathode of the diode D4.

[0053] In this embodiment, the first voltage limiting circuit 211 and the second voltage limiting circuit 221 have the same function, so the circuit structure can also be set to be the same. Taking the first voltage limiting circuit 211 as an example, using the characteristics of the diode and the resistor, when the voltage transmitted from the auxiliary winding of the transformer T2 exceeds the set value, the diode D4 will be turned on, thereby shunting the excess voltage to the resistor R15, reducing the output voltage and realizing the voltage limiting function; and the resistor R15 plays the role of current limiting and voltage dividing in this circuit, ensuring the stability and safety of the circuit.

[0054] Other structures and operations of an LED controller according to an embodiment of the utility model are known to ordinary technicians in the field and will not be described in detail here.

[0055] In the description of this specification, the description with reference to the terms "embodiment", "example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the utility model. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0056] Although the embodiments of the present invention have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. An LED controller, comprising a rectifier and filter unit and a transformer T2; characterized in that: It also includes a PFC flyback switching power supply, a high-efficiency interference removal unit and a load receiving unit; the output end of the rectifier and filter unit is electrically connected to the input end of the PFC flyback switching power supply, the high-voltage startup end of the PFC flyback switching power supply and the first end of the high-efficiency interference removal unit are both connected to a high-voltage startup source, the leakage inductance energy absorption end of the PFC flyback switching power supply is electrically connected to the second end of the high-efficiency interference removal unit, the third end of the high-efficiency interference removal unit is electrically connected to the primary side opposite end of the main winding of the transformer T2, the fourth end of the high-efficiency interference removal unit is electrically connected to the load receiving unit, and the load receiving unit receives the load receiving unit from the load receiving unit. The anti-interference end of the load receiving unit is electrically connected, the output end of the PFC flyback switching power supply is electrically connected to the same-name end of the primary side of the main winding of the transformer T2, the feedback end, the first power supply end and the second power supply end of the PFC flyback switching power supply are electrically connected to the same-name end of the primary side of the auxiliary winding of the transformer T2, the primary side opposite-name end of the auxiliary winding of the transformer T2 is grounded, the same-name end of the secondary side of the main winding of the transformer T2 is electrically connected to the input end of the load receiving unit, and the opposite-name end of the secondary side of the main winding of the transformer T2 is electrically connected to the ground end of the load receiving unit; The high-efficiency interference elimination unit is used to absorb the leakage inductance energy of the transformer T2 when the PFC flyback switching power supply is turned off; and is also used to filter out the common-mode interference on the primary side and the secondary side of the transformer T2.

2. The LED controller according to claim 1, characterized in that: The high-efficiency interference removal unit includes a capacitor C8, a resistor R9, a resistor R11, a resistor R10, a diode D8, a diode D3 and an anti-interference circuit; one end of the resistor R11 is used as a first end of the high-efficiency interference removal unit, an anode of the diode D3 is used as a second end of the high-efficiency interference removal unit, one end of the capacitor C8 is used as a third end of the high-efficiency interference removal unit, and one end of the anti-interference circuit is used as a fourth end of the high-efficiency interference removal unit; One end of the resistor R11, one end of the resistor R10, and the other end of the anti-interference circuit are all electrically connected to one end of the capacitor C8, the other end of the resistor R11, the other end of the resistor R10, one end of the resistor R9, and the cathode of the diode D8 are all electrically connected to the other end of the capacitor C8, and the other end of the resistor R9 and the anode of the diode D8 are all electrically connected to the cathode of the diode D3; The anti-interference circuit is used to filter out common-mode interference on the primary side and the secondary side of the transformer T2.

3. The LED controller according to claim 2, characterized in that: The anti-interference circuit includes a capacitor CY1; one end of the capacitor CY1 is used as one end of the anti-interference circuit, and the other end of the capacitor CY1 is used as the other end of the anti-interference circuit.

4. The LED controller according to claim 1, characterized in that: The PFC flyback switching power supply comprises a PFC unit and a flyback unit integrated with a MOS tube; the input end of the PFC unit is used as the input end of the PFC flyback switching power supply, the high-voltage startup end of the PFC unit or the high-voltage startup end of the flyback unit is used as the high-voltage startup end of the PFC flyback switching power supply, the leakage inductance energy absorption end of the flyback unit is used as the leakage inductance energy absorption end of the PFC flyback switching power supply, the power supply end of the PFC unit is used as the first power supply end of the PFC flyback switching power supply, the power supply end of the flyback unit is used as the second power supply end of the PFC flyback switching power supply, the feedback end of the flyback unit is used as the feedback end of the PFC flyback switching power supply, and the output end of the flyback unit is used as the output end of the PFC flyback switching power supply; The high voltage start-up terminal of the flyback unit is electrically connected to the high voltage start-up terminal of the PFC unit, and the ground terminal of the flyback unit is electrically connected to the ground terminal of the PFC unit.

5. The LED controller according to claim 4, characterized in that: The PFC unit includes an inductor L2, a capacitor C1, a capacitor C2, a capacitor C3, a capacitor CB1, a capacitor EC1, a resistor R4, a resistor R5, a resistor R6, a resistor R7, a resistor RS1, a resistor RS2, a resistor RS3, a diode D1, a diode D2, a PFC chip U1 and a first voltage limiting circuit; one end and the other end of the capacitor CB1 are both used as input ends of the PFC unit, one end of the capacitor EC1 is used as a high-voltage starting end of the PFC unit, the other end of the capacitor EC1 is used as a ground end of the PFC unit, and the first end of the first voltage limiting circuit is used as a power supply end of the PFC unit; One end of the capacitor C1, the anode of the diode D1, and one end of the inductor L2 are all electrically connected to one end of the capacitor CB1, the other end of the capacitor C1, the cathode of the diode D2, and one end of the resistor R7 are all electrically connected to the positive electrode of the capacitor EC1, the other end of the inductor L2 and the anode of the diode D2 are all electrically connected to the DRAIN end of the PFC chip U1, the other end of the resistor R7 is electrically connected to one end of the resistor R6, the other end of the resistor R6 is electrically connected to one end of the resistor R5, the other end of the resistor R5, one end of the resistor R4, and one end of the capacitor C2 ... The FB end of the PFC chip U1 is electrically connected, the second end of the first voltage limiting circuit and one end of the capacitor C3 are electrically connected to the VCC end of the PFC chip U1, one end of the resistor RS1, one end of the resistor RS2, and one end of the resistor RS3 are electrically connected to the CS end of the PFC chip U1, and the negative electrode of the capacitor EC1, the other end of the resistor RS1, the other end of the resistor RS2, the other end of the resistor RS3, the other end of the capacitor C3, the GND end of the PFC chip U1, the other end of the resistor R4, and the other end of the capacitor C2 are electrically connected to the other end of the capacitor CB1.

6. The LED controller according to claim 5, characterized in that: The flyback unit includes an inductor LB1, a resistor R13, a resistor R17, a resistor R18, a resistor R19, a resistor RS4, a resistor RS5, a resistor RS6, a capacitor C4, a capacitor C5, a capacitor C6, a capacitor C7, a flyback chip U3 integrated with a MOS tube, and a second voltage limiting circuit; one end of the resistor R13 is used as a high-voltage start-up end of the flyback unit, a GND end of the flyback chip U3 is used as a ground end of the flyback unit, one end of the inductor LB1 is used as an output end of the flyback unit, one end of the resistor R17 is used as a feedback end of the flyback unit, a first end of the second voltage limiting circuit is used as a power supply end of the flyback unit, and one end of the capacitor C4 is used as a leakage inductance energy absorption end of the flyback unit; The other end of the resistor R13 is electrically connected to the HV end of the flyback chip U3, the other end of the inductor LB1 is electrically connected to the DRAIN end of the flyback chip U3, the other end of the capacitor C4, one end of the resistor R19, one end of the resistor RS4, one end of the resistor RS5, and one end of the resistor RS6 are all electrically connected to the SRC end of the flyback chip U3, the other end of the resistor R19 is electrically connected to the CS end of the flyback chip U3, the other end of the resistor R17, one end of the resistor R18, and one end of the capacitor C5 are all electrically connected to the FB end of the flyback chip U3, one end of the capacitor C7 is electrically connected to the COMP end of the flyback chip U3, one end of the capacitor C6 and the second end of the second voltage limiting circuit are all electrically connected to the VCC end of the flyback chip U3, and the other end of the capacitor C5, the other end of the capacitor C6, the other end of the capacitor C7, and the other end of the resistor R18 are all electrically connected to the GND end of the flyback chip U3.

7. The LED controller according to claim 1, characterized in that: The load receiving unit includes a resistor R22, a resistor R20, a capacitor C9, a capacitor EC2, a diode D6 and a diode D7; the anode of the diode D7 and the cathode of the capacitor EC2 are both used as input terminals of the load receiving unit, the cathode of the diode D7 is used as an anti-interference terminal of the load receiving unit, and one end and the other end of the resistor R20 are used as output terminals of the load receiving unit; The anode of the diode D6 and one end of the resistor R22 are electrically connected to the anode of the diode D7, the other end of the resistor R22 is electrically connected to one end of the capacitor C9, the other end of the capacitor C9, the cathode of the diode D6, the positive electrode of the capacitor EC2, and one end of the resistor R20 are electrically connected to the cathode of the diode D7, and the negative electrode of the capacitor EC2 and the other end of the resistor R20 are grounded.

8. The LED controller according to claim 6, characterized in that: The first voltage limiting circuit and the second voltage limiting circuit have the same circuit structure; The first voltage limiting circuit includes a resistor R15 and a diode D4; the anode of the diode D4 is used as the first end of the first voltage limiting circuit, and one end of the resistor R15 is used as the second end of the first voltage limiting circuit; the other end of the resistor R15 is electrically connected to the cathode of the diode D4.

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