A de-blooming circuit for a non-isolated LED driving power supply

Abstract

The utility model discloses a kind of dephosphorization circuits for non-isolated LED driving power, including the BOOST boost circuit being connected between commercial power and LED lamp panel;The BOOST boost circuit includes inductance L2, diode D1, MOS tube Q1 and capacitor CE1, also includes thyristor D7, MOS tube Q6 and control unit;The anode of thyristor D7 is connected to the high voltage output end of BOOST boost circuit, the cathode of thyristor D7 is connected to the anode of LED lamp panel;The source of MOS tube Q6 is connected to the low voltage output end of BOOST boost circuit and then grounded, the drain of MOS tube Q6 is connected to the cathode of LED lamp panel.The utility model can cut off leakage current path after non-isolated LED driving power is turned off, and then solve the problem of LED lamp pearl afterglow, and then improve the energy efficiency and service life of product, and the circuit structure is simple, low in cost, efficient and reliable, and strong practicality.

Description

Technical Field

[0001] This utility model relates to the field of LED lighting technology, and in particular to a de-afterglow circuit for non-isolated LED driver power supplies. Background Technology

[0002] Currently, non-isolated LED driver power supplies on the market generally suffer from a faint glow (afterglow) after the lights are turned off. This is due to the characteristics of non-isolated topologies; even after the main switching device stops operating, the LED chips may still emit a slight glow due to leakage current. On the one hand, this afterglow phenomenon causes unnecessary energy consumption, and long-term leakage may affect the lifespan of the LED chips and pose safety hazards. On the other hand, existing technologies often use high-resistance resistors connected in parallel across the LED to discharge leakage current, but this solution continues to consume power through the resistors when the LED is turned off, reducing energy efficiency. In addition, some solutions use mechanical components such as relays to physically disconnect the LED circuit when turned off to eliminate afterglow, but relays are expensive and bulky, affecting the reliability and economy of the circuit.

[0003] Therefore, there is an urgent need for a simple, low-cost, and effective technical solution to address the afterglow problem of non-isolated LED driver power supplies. Utility Model Content

[0004] The purpose of this invention is to provide a residual luminescence removal circuit for non-isolated LED driver power supplies. This circuit can cut off the leakage current path after the non-isolated LED driver power supply is turned off, thereby solving the problem of residual luminescence in LED beads, improving the energy efficiency and lifespan of the product. Moreover, the circuit has a simple structure, low cost, high efficiency and reliability, and strong practicality.

[0005] To achieve the above objectives, the following technical solution is adopted:

[0006] A residual luminescence elimination circuit for a non-isolated LED driver power supply includes a BOOST boost circuit connected between the mains power and the LED board. The BOOST boost circuit includes an inductor L2, a diode D1, a MOSFET Q1, and a capacitor CE1, as well as a thyristor D7, a MOSFET Q6, and a control unit. The anode of the thyristor D7 is connected to the high-voltage output terminal of the BOOST boost circuit, and the cathode of the thyristor D7 is connected to the positive terminal of the LED board. The source of the MOSFET Q6 is connected to the low-voltage output terminal of the BOOST boost circuit and then grounded, and the drain of the MOSFET Q6 is connected to the negative terminal of the LED board. The control unit outputs control signals HV_ON, LV_ON, and CTRL to the gates of the thyristor D7, MOSFET Q6, and MOSFET Q1, respectively. When all three control signals are low, the thyristor D7 and MOSFET Q6 are turned off.

[0007] Furthermore, the anode of the thyristor D7 is connected to the positive terminal of the capacitor CE1 and the cathode of the diode D1; the source of the MOSFET Q6 is connected to the negative terminal of the capacitor CE1 and then grounded.

[0008] Furthermore, it also includes a rectifier bridge connected between the mains power and the BOOST boost circuit; one end of the inductor L2 is connected to the positive output terminal of the rectifier bridge, and the other end of the inductor L2 is connected to the drain of the MOSFET Q1 and the anode of the diode D1; the source of the MOSFET Q1 is grounded.

[0009] By adopting the above solution, the beneficial effects of this utility model are:

[0010] This invention can cut off the leakage current path after the non-isolated LED driver power supply is turned off, thereby solving the problem of LED lamp bead afterglow, thus improving the energy efficiency and service life of the product. Moreover, the circuit structure is simple, low cost, highly efficient and reliable, and highly practical. Attached Figure Description

[0011] Figure 1 This is the circuit schematic diagram of this utility model. Detailed Implementation

[0012] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0013] Reference Figure 1 As shown, this utility model provides a residual luminescence removal circuit for a non-isolated LED driver power supply, including a BOOST boost circuit connected between the mains power and the LED lamp board. The BOOST boost circuit includes an inductor L2, a diode D1, a MOSFET Q1, and a capacitor CE1. In one embodiment, it also includes a thyristor D7, a MOSFET Q6, and a control unit. The anode of the thyristor D7 is connected to the high-voltage output terminal of the BOOST boost circuit, and the cathode of the thyristor D7 is connected to the positive terminal of the LED lamp board. The source of the MOSFET Q6 is connected to the low-voltage output terminal of the BOOST boost circuit and then grounded, and the drain of the MOSFET Q6 is connected to the negative terminal of the LED lamp board. The control unit is used to output control signals HV_ON, LV_ON, and CTRL to the gates of the thyristor D7, the MOSFET Q6, and the MOSFET Q1, respectively. When the control signals HV_ON, LV_ON, and CTRL are all low, the thyristor D7 and the MOSFET Q6 are turned off.

[0014] Furthermore, the anode of the thyristor D7 is connected to the positive terminal of capacitor CE1 and the cathode of diode D1; the source of the MOSFET Q6 is connected to the negative terminal of capacitor CE1 and then grounded; a rectifier bridge is also included, connected between the mains power and the BOOST boost circuit; one end of the inductor L2 is connected to the positive output terminal of the rectifier bridge, and the other end of the inductor L2 is connected to the drain of MOSFET Q1 and the anode of diode D1; the source of the MOSFET Q1 is grounded.

[0015] The non-isolated boost circuit, consisting of inductor L2, diode D1, MOSFET Q1, and capacitor CE1, has a very high output voltage and a large electrolytic capacitor, resulting in afterglow when directly connected to an LED board. This invention addresses this by adding a thyristor D7 to the high-voltage side and a MOSFET Q6 to the low-voltage side. When the light is off, if the three control signals HV_ON, LV_ON, and CRTL are simultaneously low, according to the thyristor's operating principle, once the gate current triggers conduction, it no longer affects the thyristor's state. It can only be turned off by reducing the anode voltage A or reducing the anode current below the holding current. Therefore, when HV_ON is a low-level control signal... At the same time, CRTL and LV_ON are also low-level control signals, and MOSFETs Q6 and Q1 are in the off state. After MOSFET Q1 is turned off, it no longer boosts the voltage (reduces the anode voltage A). The anode voltage A of the thyristor is lower than the cathode voltage K, and there is no forward bias. After MOSFET Q6 is turned off, its loop current is disconnected, that is, its anode current is disconnected. In this way, the anode current is reduced to the holding current, which satisfies the two conditions for the thyristor to turn off. When the thyristor D7 and MOSFET Q6 are completely disconnected, the AC current can no longer flow to the lamp board, so that the AC leakage current cannot form a loop with the ground through the distributed capacitances C2 and C3 of the lamp board, thereby eliminating the afterglow phenomenon.

[0016] Furthermore, it should be noted that the control unit of this utility model can be implemented by an existing LED driver control circuit or microcontroller, generating the above-mentioned logical combination of HV_ON, LV_ON and CTRL signals according to the light-off command; the above embodiment uses a boost-type driver circuit as an example for explanation, but the principle of this utility model is also applicable to other non-isolated LED driver power supplies. For example, for a non-isolated buck-type LED constant current circuit, it is only necessary to add a thyristor and a MOSFET switch at the high and low ends of the LED load respectively, and turn off both at the same time through the control circuit when turning off, so as to achieve the purpose of cutting off leakage current and preventing afterglow. These equivalent modifications are all within the protection scope of this utility model.

[0017] The above are merely preferred embodiments of the present utility model and are not intended to limit the present utility model. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A residual luminescence removal circuit for a non-isolated LED driver power supply, comprising a BOOST boost circuit connected between the mains power supply and the LED lamp board; the BOOST boost circuit comprising an inductor L2, a diode D1, a MOSFET Q1, and a capacitor CE1, characterized in that, It also includes a thyristor D7, a MOSFET Q6, and a control unit; the anode of the thyristor D7 is connected to the high-voltage output terminal of the BOOST boost circuit, and the cathode of the thyristor D7 is connected to the positive terminal of the LED light board; the source of the MOSFET Q6 is connected to the low-voltage output terminal of the BOOST boost circuit and then grounded, and the drain of the MOSFET Q6 is connected to the negative terminal of the LED light board; the control unit is used to output control signals HV_ON, LV_ON, and CTRL to the gates of the thyristor D7, the MOSFET Q6, and the MOSFET Q1, respectively, and when the control signals HV_ON, LV_ON, and CTRL are all low, the thyristor D7 and the MOSFET Q6 are turned off.

2. The afterglow reduction circuit for non-isolated LED driver power supplies according to claim 1, characterized in that, The anode of the thyristor D7 is connected to the positive terminal of capacitor CE1 and the cathode of diode D1; the source of the MOSFET Q6 is connected to the negative terminal of capacitor CE1 and then grounded.

3. The afterglow elimination circuit for non-isolated LED driver power supplies according to claim 2, characterized in that, It also includes a rectifier bridge connected between the mains power and the BOOST boost circuit; one end of the inductor L2 is connected to the positive output terminal of the rectifier bridge, and the other end of the inductor L2 is connected to the drain of the MOSFET Q1 and the anode of the diode D1; the source of the MOSFET Q1 is grounded.

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