CN111405705B

CN111405705B - Dimming LED controller and output short-circuit protection method

Info

Publication number: CN111405705B
Application number: CN202010220053.XA
Authority: CN
Inventors: 俞剑峰; 赵鹏远; 王科
Original assignee: Ningbo Self Electronics Co Ltd
Current assignee: Ningbo Self Electronics Co Ltd
Priority date: 2020-03-25
Filing date: 2020-03-25
Publication date: 2023-06-27
Anticipated expiration: 2040-03-25
Also published as: CN111405705A

Abstract

The invention discloses a dimming LED controller and an output short-circuit protection method, wherein the controller comprises a power supply positive electrode input end, a power supply negative electrode input end, a power supply module connected with the power supply positive electrode input end, a control module connected with the power supply module, a signal output end connected with the control module and a switch module used for driving an external load, the dimming LED controller also comprises a short-circuit protection module for collecting an electric signal of the negative electrode of the external load, the control module comprises a signal receiving end connected with the short-circuit protection module, and the control module controls the working state of the switch module according to the electric signal output to the switch module and the electric signal collected by the short-circuit protection module; the invention can accurately and effectively protect the controller when the load is short-circuited, and has simple structure, low cost and small energy loss.

Description

Dimming LED controller and output short-circuit protection method

Technical Field

The invention relates to power supply equipment, in particular to a dimming LED controller and an output short-circuit protection method.

Background

Under the background of energy conservation and environmental protection, the LED lamp is increasingly applied to the fields of household and commercial illumination due to high light emitting efficiency and good light condensing performance. The current dimming LED lamp controllers in the market mainly have two types, one type is provided with no short-circuit protection, and the high current caused by the condition of short circuit of a circuit can instantaneously burn out the power devices and the like at the later stage although the function is not affected; the other is to select a power device with larger rated current, so that the current flowing by the power supply when in short circuit is smaller than the rated current of the power device at the later stage, but the implementation cost is higher and the mode has certain locality.

Disclosure of Invention

In view of the above, the present invention provides a dimming LED controller to solve the above technical problems.

The utility model provides a LED controller adjusts luminance, includes the positive input of power, the negative pole input of power, connects the power module of the positive input of power, connect power module's control module and the signal output part of connection control module are used for driving external load's switch module, LED controller adjusts luminance still includes the collection the short-circuit protection module of the signal of external load negative pole, control module is including connecting the signal receiving terminal of short-circuit protection module, control module is according to the output for the signal of switch module and receive and come from the signal of telecommunication control that short-circuit protection module gathered switch module's operating condition.

Preferably, the short-circuit protection module comprises a first resistor R1, a second resistor R2 and a voltage stabilizing unit, wherein the positive electrode of the voltage stabilizing unit is connected with one end of the first resistor R1, the other end of the first resistor R1 is connected to the signal receiving end of the control module, one end of the second resistor R2 is connected to the signal receiving end of the control module, and the other end of the second resistor R2 is connected to the negative electrode input end of the power supply.

Preferably, the switch module adopts a MOS tube Q1 or a triode.

Preferably, a gate of the MOS transistor Q1 is connected to the signal output end of the control module, a drain is connected to the negative electrode of the load, and a source is connected to the negative input end of the power supply.

Preferably, the voltage stabilizing unit includes a voltage stabilizing tube D1.

Preferably, an anode of the voltage stabilizing tube D1 is connected with the first resistor R1, and a cathode is connected with the external load cathode.

Preferably, the voltage stabilizing unit includes a TL431Q2, a resistor R3 and a resistor R4, where an anode of the TL431Q2 is connected to the first resistor R1, a cathode is connected to the external load negative electrode, a reference end is simultaneously connected to one end of the resistor R3 and one end of the resistor R4, another end of the resistor R3 is connected to the anode of the TL431Q2, and another end of the resistor R4 is connected to the cathode of the TL431Q 2.

The invention provides a dimming LED controller output short-circuit protection method, which adopts the dimming LED controller and comprises the following steps:

001. after the dimming LED controller is connected with a power supply and a load, the dimming LED controller is powered on to work, and the switch module is initialized and closed;

002. the control module controls the switch module to be started and the external load to work normally, at the moment, the control module outputs high level to the switch module, and the signal receiving end of the control module is low level;

003. when the external load is short-circuited, the voltage of the signal receiving end of the control module instantaneously changes to a high level, and when the voltage of the signal receiving end of the control module is high level, the control module closes the switch module for a duration t;

004. the control module re-opens the switch module, if the external load is normal, the step 002 is performed, and if the external load is short-circuited, the step 003 is performed.

Preferably, t is more than or equal to 0.5s and less than or equal to 3s.

The invention has the technical effects that:

the dimming LED controller and the output short-circuit protection method thereof can accurately and effectively protect the controller when a load is short-circuited, and have the advantages of simple structure, low cost and small energy loss.

Drawings

Embodiments of the invention are described below with reference to the accompanying drawings, in which:

fig. 1 is a block diagram of a structure of a dimming LED controller of the present invention.

Fig. 2 is a circuit schematic diagram of a dimming LED controller of one embodiment.

Fig. 3 is a circuit schematic diagram of a dimming LED controller according to another embodiment.

Fig. 4 is a flow chart diagram of a method of output short-circuit protection of the dimming LED controller of fig. 1.

Detailed Description

Specific embodiments of the present invention will be described in further detail below based on the drawings. It should be understood that the description herein of the embodiments of the invention is not intended to limit the scope of the invention.

As shown in fig. 1 and 2, the dimming LED controller of the present embodiment includes a positive power input terminal 100, a negative power input terminal 200, a power supply module 300 connected to the positive power input terminal 100, a control module 400 connected to the power supply module 300, and a switch module 500 connected to a signal output terminal of the control module 400 and used for driving an external load 700.

The power supply positive electrode input terminal 100 and the power supply negative electrode input terminal 200 are used for connecting a power supply, the power supply module 300 and the control module 400 can adopt existing circuits, and the control module 400 generally adopts a micro control unit (Microcontroller Unit; MCU).

The switch module 500 is used for driving the external load 700, and the external load 700 of the present invention is mainly an LED lamp, in this embodiment, the switch module 500 adopts a MOS transistor Q1, a gate of the MOS transistor Q1 is connected to the signal output end of the control module 400, a drain is connected to a negative electrode of the load, and a source is connected to the negative input end 200 of the power supply. The on-voltage of the MOS transistor (field effect transistor) is reduced, the on-resistance is small, the gate driving does not need current, the loss is small, the driving circuit is simple, the self-protection diode is provided, the thermal resistance is good, and in another embodiment, the switching module 500 adopts a triode.

The dimming LED controller of this embodiment further includes a short-circuit protection module 600 that collects an electrical signal of the negative electrode of the external load 700, the control module 400 includes a signal receiving end connected to the short-circuit protection module 600, and the control module 400 controls the working state of the switch module 500 according to the electrical signal output to the switch module 500 and the electrical signal collected by the short-circuit protection module 600. When the external load 700 is shorted, the voltage signal at the signal receiving end of the control module 400 is changed, so that the control module 400 generates a signal for closing the switch module 500, thereby achieving the purpose of protecting the switch module 500, specifically, obtaining a control signal according to the comparison of the electrical signal output to the switch module 500 and the electrical signal collected by the short-circuit protection module 600.

The short-circuit protection module 600 of this embodiment includes a first resistor R1, a second resistor R2, and a voltage stabilizing unit 601, where an anode of the voltage stabilizing unit 601 is connected to one end of the first resistor R1, the other end of the first resistor R1 is connected to a signal receiving end of the control module 400, one end of the second resistor R2 is connected to the signal receiving end of the control module 400, and the other end is connected to the negative input end 200 of the power supply. The combined structure is simple, the stability is good, the data acquisition precision is high, and the switch module 500 can be effectively protected.

In this embodiment, the voltage stabilizing unit 601 includes a voltage stabilizing tube D1, where an anode of the voltage stabilizing tube D1 is connected to the first resistor R1, and a cathode of the voltage stabilizing tube D1 is connected to a cathode of the external load 700. The voltage stabilizing tube is convenient to purchase, has multiple types, can meet the requirements and is low in cost.

As shown in fig. 3, in another embodiment, the voltage stabilizing unit 601 includes a TL431Q2, a resistor R3, and a resistor R4, where an anode of the TL431Q2 is connected to the first resistor R1, a cathode is connected to a cathode of the external load 700, a reference terminal is simultaneously connected to one end of the resistor R3 and one end of the resistor R4, another end of the resistor R3 is connected to an anode of the TL431Q2, and another end of the resistor R4 is connected to a cathode of the TL431Q 2. TL431 is a controllable precision voltage stabilizing source, and the resistor R3 and the resistor R4 are used for adjusting the conduction parameter, which can replace a zener diode and has higher sampling precision.

As shown in fig. 4, the output short-circuit protection method of the dimming LED controller of the present embodiment, which adopts the dimming LED controller shown in fig. 1, includes the following steps:

001. after the dimming LED controller is connected to a power supply and a load, the dimming LED controller is powered on, initializes and closes the switch module 500, and sets a signal receiving end of the control module 400, and when the control module 400 adopts a micro control unit, an ascending and descending interrupt needs to be set for the signal receiving end.

002. The control module 400 controls the switch module 500 to be turned on, and the external load 700 works normally, at this time, the control module 400 outputs a high level to the switch module 500, and a signal receiving end of the control module 400 is a low level;

003. when the external load 700 is shorted, the voltage of the signal receiving end of the control module 400 instantaneously changes to a high level, and when the voltage of the signal receiving end and the voltage of the signal receiving end output by the control module 400 to the switch module 500 are both at the high level, the control module 400 turns off the switch module 500 for a duration t;

004. the control module 400 re-opens the switch module 500, the external load 700 goes to step 002 if it is normal, and goes to step 003 if the external load 700 is short-circuited.

In this embodiment, t is more than or equal to 0.5s and less than or equal to 3s, the time t can be set manually, and when the load is short-circuited due to too short time, the switch module 500 is damaged due to too frequent switching, and when the load is recovered due to too long time, a longer time is required for recovering the normal load.

The above is only a preferred embodiment of the present invention and is not intended to limit the scope of the present invention, and any modifications, equivalent substitutions or improvements within the spirit of the present invention are intended to be covered by the claims of the present invention.

Claims

1. The dimming LED controller comprises a power supply positive electrode input end (100), a power supply negative electrode input end (200), a power supply module (300) connected with the power supply positive electrode input end (100), a control module (400) connected with the power supply module (300) and a switch module (500) connected with a signal output end of the control module (400) and used for driving an external load (700), and is characterized by further comprising a short-circuit protection module (600) for collecting an electric signal of the negative electrode of the external load (700), wherein the control module (400) comprises a signal receiving end connected with the short-circuit protection module (600), and the control module (400) controls the working state of the switch module (500) according to the electric signal output to the switch module (500) and the electric signal collected by the short-circuit protection module (600);

the short-circuit protection module (600) comprises a first resistor R1, a second resistor R2 and a voltage stabilizing unit (601), wherein the positive electrode of the voltage stabilizing unit (601) is connected with one end of the first resistor R1, the other end of the first resistor R1 is connected to a signal receiving end of the control module (400), one end of the second resistor R2 is connected to the signal receiving end of the control module (400), and the other end of the second resistor R2 is connected to the negative input end (200) of the power supply;

the voltage stabilizing unit (601) comprises a voltage stabilizing tube D1; the anode of the voltage stabilizing tube D1 is connected with the first resistor R1, and the cathode of the voltage stabilizing tube D1 is connected with the cathode of the external load (700);

after the dimming LED controller is connected with a power supply and a load, the dimming LED controller is powered on to work, and the switch module (500) is initialized and closed; the control module (400) controls the switch module (500) to be turned on, the external load (700) works normally, at the moment, the control module (400) outputs high level to the switch module (500), and the signal receiving end of the control module (400) is low level; when the external load (700) is short-circuited, the voltage of the signal receiving end of the control module (400) instantaneously changes to a high level, and when the voltage output by the control module (400) to the switch module (500) and the signal receiving end are both high levels, the control module (400) closes the switch module (500).

2. The dimming LED controller of claim 1, wherein the switching module (500) employs a MOS transistor Q1 or a triode.

3. The dimming LED controller of claim 2, wherein the MOS transistor Q1 has a gate connected to the signal output of the control module (400), a drain connected to the negative pole of the load, and a source connected to the negative power input (200).

4. The dimming LED controller according to claim 1, wherein the voltage stabilizing unit (601) comprises a TL431Q2, a resistor R3 and a resistor R4, an anode of the TL431Q2 is connected to the first resistor R1, a cathode is connected to a cathode of the external load (700), a reference terminal is simultaneously connected to one end of the resistor R3 and one end of the resistor R4, the other end of the resistor R3 is connected to an anode of the TL431Q2, and the other end of the resistor R4 is connected to a cathode of the TL431Q 2.

5. A method for protecting output short circuit of a dimming LED controller, wherein the dimming LED controller as claimed in any one of claims 1 to 4 is adopted, comprising the steps of:

001. after the dimming LED controller is connected with a power supply and a load, the dimming LED controller is powered on to work, and the switch module (500) is initialized and closed;

002. the control module (400) controls the switch module (500) to be turned on, the external load (700) works normally, at the moment, the control module (400) outputs high level to the switch module (500), and the signal receiving end of the control module (400) is low level;

003. when the external load (700) is short-circuited, the voltage of the signal receiving end of the control module (400) instantaneously changes to a high level, and when the voltage output by the control module (400) to the switch module (500) and the signal receiving end are both high levels, the control module (400) closes the switch module (500) for a duration t;

004. the control module (400) re-opens the switch module (500), the external load (700) enters step 002 if normal, and enters step 003 if the external load (700) is short-circuited.

6. The method of claim 5, wherein t is greater than or equal to 0.5s and less than or equal to 3s.