CN220629625U - LED driving power supply - Google Patents

Abstract

The utility model proposes an LED driving power supply, comprising: the device comprises a power module, an interface, a short circuit feedback circuit, a singlechip circuit and a switch circuit. When the output of the LED driving power supply is normal, the short circuit feedback circuit triggers the singlechip circuit to control the switch circuit to be conducted, and at the moment, the power supply voltage output by the power supply module is output to external equipment through an interface so as to drive the external equipment to normally operate; when the LED driving power supply outputs a short circuit, the short circuit feedback circuit outputs a short circuit feedback signal to the singlechip circuit so as to trigger the singlechip circuit to control the switch circuit to disconnect a connecting passage between the power supply module and external equipment, and the power supply voltage output by the power supply module cannot be output to the external equipment at the moment, so that the function of short circuit protection is realized, and meanwhile, the reduction of short circuit protection efficiency caused by the analog circuit is avoided.

Description

LED driving power supply

Technical Field

The utility model relates to the technical field of short-circuit protection, in particular to an output LED driving power supply.

Background

The prior art generally uses analog circuits to cope with, for example, over-current protection circuits when an interface short circuit occurs. Specifically, when the overcurrent protection circuit detects that the current of the interface exceeds the preset current, the main controller is triggered to cut off the switching tube so as to disconnect the passage between the driving power supply and the external equipment. However, such analog circuits are used to realize short-circuit protection, the internal detection circuit thereof causes efficiency loss, and the internal AD conversion circuit generates noise and noise, so as to reduce the accuracy of short-circuit detection and further reduce the efficiency of short-circuit protection.

Disclosure of Invention

The utility model mainly aims to provide an LED driving power supply, which aims to improve the efficiency of short-circuit protection.

Accordingly, the present utility model provides an LED driving power supply, comprising:

the power supply module is used for outputting the power supply voltage of the LED driving power supply;

the interface is connected with the output end of the power supply module and external equipment; the interface is used for accessing external equipment to output the power supply voltage of the power supply module to the external equipment;

the detection end of the short circuit feedback circuit is connected with the interface; the short circuit feedback circuit is used for outputting a short circuit feedback signal when the short circuit of the output interface is detected according to the power supply voltage of the power supply module;

the input end of the singlechip circuit is connected with the output end of the short-circuit feedback circuit; the singlechip circuit is used for outputting a turn-off signal when receiving the short circuit feedback signal;

the controlled end of the switch circuit is connected with the control end of the singlechip circuit, the first output end of the switch circuit is connected with the grounding end of external equipment through the interface, and the second output end of the switch circuit is grounded; the switching circuit is used for disconnecting the passage between the power supply module and the external equipment when receiving the turn-off signal.

Optionally, the switch circuit includes a first triode and a first MOS tube;

the base electrode of the first triode is connected with the control end of the singlechip circuit, the collector electrode of the first triode is connected with the controlled end of the first MOS tube, the emitter electrode of the first triode is connected with the output end of the first MOS tube, and the interconnection point is grounded; the input end of the first MOS tube is connected with the interface.

Optionally, the number of the interfaces is multiple, the number of the short-circuit feedback circuits is multiple, and each interface is connected with each short-circuit feedback circuit in a one-to-one correspondence.

Optionally, the LED driving power supply includes:

the power supply end is used for accessing alternating voltage;

the input end of the overvoltage protection circuit is connected with the power supply end; the overvoltage protection circuit is used for detecting the alternating voltage of the power supply end and disconnecting the passage between the overvoltage protection circuit and the power supply end when the alternating voltage reaches the preset voltage.

Optionally, the LED driving power supply includes:

the input end of the rectifying circuit is connected with the output end of the overvoltage protection circuit; the rectification circuit is used for rectifying the alternating voltage of the overvoltage protection circuit into direct voltage.

Optionally, the LED driving power supply includes:

the control circuit is connected with the output end of the rectifying circuit; the control circuit is used for starting to work when receiving the direct-current voltage so as to output a control signal;

the control end of the driving circuit is connected with the control end of the control circuit, the input end of the driving circuit is connected with the rectifying circuit, and the output end of the driving circuit is connected with external equipment; and the driving circuit is used for conducting a passage between the rectifying circuit and external equipment when receiving the control signal so as to enable the direct-current voltage output by the rectifying circuit to be output to the external equipment so as to drive the external equipment to operate.

Optionally, the LED driving power supply includes:

the input end of the transformation circuit is connected with the output end of the driving circuit, and the output end of the transformation circuit is connected with external equipment; the transformation circuit is used for transforming the direct-current voltage output by the rectification circuit and outputting the direct-current voltage to external equipment.

Optionally, the LED driving power supply includes:

the input end of the filter circuit is connected with the output end of the voltage transformation circuit, and the output end of the filter circuit is connected with the input end of the power supply module;

the filter circuit is used for filtering the direct-current voltage of the transformation circuit and outputting the direct-current voltage to the power supply module; and the power supply module is used for outputting the voltage of the filter circuit to external equipment through the interface.

Optionally, the LED driving power supply includes:

the input end of the voltage stabilizing circuit is connected with the output end of the filter circuit, and the output end of the voltage stabilizing circuit is connected with the power end of the singlechip circuit; the voltage stabilizing circuit is used for stabilizing the direct-current voltage output by the filter circuit and outputting the direct-current voltage to the singlechip circuit so as to provide working voltage for the singlechip circuit.

Optionally, the LED driving power supply includes:

the input end of the output feedback circuit is connected with the output end of the transformation circuit, and the output end of the output feedback circuit is connected with the input end of the control circuit; the output feedback circuit is used for outputting corresponding voltage feedback signals to the control circuit according to the direct-current voltage of the voltage transformation circuit;

and the control circuit is also used for controlling the reset of the voltage transformation circuit when detecting that the direct current output by the voltage transformation circuit is lower than the preset voltage according to the voltage feedback signal.

The utility model proposes an LED driving power supply, comprising: the device comprises a power module, an interface, a short circuit feedback circuit, a singlechip circuit and a switch circuit. When the output of the LED driving power supply is normal, the short circuit feedback circuit triggers the singlechip circuit to control the switch circuit to be conducted, and at the moment, the power supply voltage output by the power supply module is output to external equipment through an interface so as to drive the external equipment to normally operate; when the LED driving power supply outputs a short circuit, the short circuit feedback circuit outputs a short circuit feedback signal to the singlechip circuit so as to trigger the singlechip circuit to control the switch circuit to disconnect a connecting passage between the power supply module and external equipment, and the power supply voltage output by the power supply module cannot be output to the external equipment at the moment, so that the function of short circuit protection is realized, and meanwhile, the reduction of short circuit protection efficiency caused by the analog circuit is avoided.

Drawings

In order to more clearly illustrate the embodiments of the present utility model or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described, and it is obvious that the drawings in the following description are only some embodiments of the present utility model, and other drawings may be obtained according to the structures shown in these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a circuit flow diagram of an LED driving power supply according to the present utility model;

FIG. 2 is a circuit flow diagram of another embodiment of an LED driving power supply according to the present utility model;

fig. 3 is a circuit configuration diagram of an LED driving power supply according to the present utility model.

The achievement of the objects, functional features and advantages of the present utility model will be further described with reference to the accompanying drawings, in conjunction with the embodiments.

Detailed Description

The following description of the embodiments of the present utility model will be made clearly and fully with reference to the accompanying drawings, in which it is evident that the embodiments described are only some, but not all embodiments of the utility model. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to be within the scope of the utility model.

It should be noted that, if directional indications (such as up, down, left, right, front, and rear … …) are included in the embodiments of the present utility model, the directional indications are merely used to explain the relative positional relationship, movement conditions, etc. between the components in a specific posture (as shown in the drawings), and if the specific posture is changed, the directional indications are correspondingly changed.

In addition, if there is a description of "first", "second", etc. in the embodiments of the present utility model, the description of "first", "second", etc. is for descriptive purposes only and is not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include at least one such feature. In addition, if the meaning of "and/or" is presented throughout this document, it is intended to include three schemes in parallel, taking "a and/or B" as an example, including a scheme, or B scheme, or a scheme where a and B meet simultaneously. In addition, the technical solutions of the embodiments may be combined with each other, but it is necessary to base that the technical solutions can be realized by those skilled in the art, and when the technical solutions are contradictory or cannot be realized, the combination of the technical solutions should be considered to be absent and not within the scope of protection claimed in the present utility model.

It should be appreciated that the prior art typically employs analog circuitry to cope with, for example, over-current protection circuitry, when an interface short circuit occurs. Specifically, when the overcurrent protection circuit detects that the current of the interface exceeds the preset current, the main controller is triggered to cut off the switching tube so as to disconnect the passage between the driving power supply and the external equipment. However, such analog circuits are used to realize short-circuit protection, the internal detection circuit thereof causes efficiency loss, and the internal AD conversion circuit generates noise and noise, so as to reduce the accuracy of short-circuit detection and further reduce the efficiency of short-circuit protection.

The present utility model proposes an LED driving power supply, referring to fig. 1, comprising:

a power supply module 10 for outputting a power supply voltage of the LED driving power supply;

an interface 30, wherein the interface 30 is connected with an output end of the power module 10 and external equipment; the interface 30 is configured to access an external device, so as to output a power supply voltage of the power supply module 10 to the external device;

a short-circuit feedback circuit 40, wherein a detection end of the short-circuit feedback circuit 40 is connected with the interface 30; the short-circuit feedback circuit 40 is configured to output a short-circuit feedback signal when detecting that the output interface 30 is short-circuited according to the power supply voltage of the power supply module 10;

the input end of the singlechip circuit 50 is connected with the output end of the short-circuit feedback circuit 40; the singlechip circuit 50 is configured to output a shutdown signal when receiving the short-circuit feedback signal;

the controlled end of the switch circuit 20 is connected with the control end of the singlechip circuit 50, the first output end of the switch circuit 20 is connected with the grounding end of external equipment through the interface 30, and the second output end of the switch circuit 20 is grounded; the switch circuit 20 is configured to disconnect a path between the power module 10 and an external device when receiving the off signal.

It can be understood that in the existing LED driving power supply, when the positive electrode led+ of the interface 30 is connected with the negative electrode of the LED light strip and the negative electrode LED of the interface 30 is connected with the positive electrode of the LED light strip, that is, the positive electrode and the negative electrode of the interface 30 are reversely connected with the positive electrode and the negative electrode of the LED light strip, the current output to the interface 30 by the LED driving power supply will generate an overcurrent phenomenon. At this time, the overcurrent protection circuit detects that the interface 30 is shorted according to the current of the interface 30, and measures taken by the overcurrent protection circuit are to directly trigger the main controller to control the switching tube to be turned off so as to turn off the path between the LED driving power supply and the external device. Further, it is to be understood that analog circuits refer to circuits for performing operations such as transmitting, converting, processing, amplifying, measuring, and displaying analog signals, and that transmitted analog signals refer to continuously varying electrical signals. The process of short-circuit protection of the LED driving power supply by the overcurrent protection circuit is a process of processing an analog signal, however, short-circuit protection is realized by adopting the analog circuit, so that other working circuits in the LED driving power supply, such as a short-circuit detection circuit, an AD conversion circuit and the like, have efficiency loss, generate noise and clutter, further reduce the accuracy of short-circuit detection and reduce the efficiency of short-circuit protection. Therefore, in order to prevent the short-circuit protection by adopting the analog circuit from reducing the efficiency of the short-circuit protection, the singlechip circuit 50 triggers the switching tube to turn off the connecting passage between the LED driving power supply and the external equipment, so as to avoid the problem of efficiency reduction caused by the short-circuit protection by adopting the overcurrent protection circuit to directly trigger the switching tube to turn off.

In this embodiment, a single chip circuit 50 is taken as a logic chip U5, and an external device is taken as an LED strip for example, where the logic chip U5 has an input pin ST1, an anode led+ of the interface 30 is connected to the output end of the power module 10, and a cathode LED-of the interface 30 is connected to the short circuit feedback circuit 40. In practical application, under the condition that the output power of the LED driving power supply is normal, the positive electrode LED+ of the interface 30 is connected with the positive electrode of the LED lamp strip, and the negative electrode LED-of the interface 30 is connected with the negative electrode of the LED lamp strip. The short circuit feedback circuit 40 detects that the power supply voltage at the output interface 30 is normal, and outputs a low level signal to the input pin ST1 of the logic chip U5, and the logic chip U5 detects that the current output interface 30 is not shorted according to the low level signal, and does not trigger the switch circuit 20 to be turned off, but maintains the switch circuit 20 to be in a turned-on state. At this time, the power voltage output by the power module 10 sequentially passes through the switching circuit 20 and the interface 30, and is finally output to the external device, so as to drive the external device to operate normally. When the output of the LED driving power supply is in short circuit, the positive electrode LED+ of the interface 30 is connected with the negative electrode of the LED lamp strip, and the negative electrode LED of the interface 30 is connected with the positive electrode of the LED lamp strip, namely the positive electrode and the negative electrode of the interface 30 are reversely connected with the positive electrode and the negative electrode of the LED lamp strip. At this time, the short feedback circuit 40 detects that the output interface 30 is short-circuited and outputs a short feedback signal to the input pin ST1 of the logic chip U5 through the detection terminal, and it should be understood that the short feedback signal refers to a high level signal. The logic chip U5 detects that the current output interface 30 is shorted according to the high level signal, and triggers the switch circuit 20 to turn off so as to turn off the connection path between the interface 30 and the ground, at this time, a loop cannot be formed between the power module 10 and the interface 30, and the power voltage output by the power module 10 cannot be output to an external device, thereby realizing the function of short-circuit protection.

The utility model proposes an LED driving power supply, comprising: the power module 10, the interface 30, the short circuit feedback circuit 40, the singlechip circuit 50 and the switch circuit 20. The interface 30 is connected with an output end of the power module 10 and external equipment; the detection end of the short circuit feedback circuit 40 is connected with the interface 30; the input end of the singlechip circuit 50 is connected with the output end of the short-circuit feedback circuit 40; the controlled end of the switch circuit 20 is connected with the control end of the single chip microcomputer circuit 50, the first output end of the switch circuit 20 is connected with the grounding end of the external equipment through the interface 30, and the second output end of the switch circuit 20 is grounded. When the output of the LED driving power supply is normal, the short circuit feedback circuit 40 outputs a low-level signal to the singlechip circuit 50, the singlechip circuit 50 maintains the conduction of the switch circuit 20 according to the low-level signal, and at the moment, the power supply voltage output by the power supply module 10 is output to external equipment through the interface 30 so as to drive the external equipment to normally operate; when the output of the LED driving power is shorted, the short-circuit feedback circuit 40 outputs a high-level signal to the singlechip circuit 50, and the singlechip circuit 50 triggers the switch circuit 20 to disconnect the connection path between the interface 30 and the ground according to the high-level signal, so that a loop cannot be formed between the power module 10 and the interface 30, and the power voltage output by the power module 10 cannot be output to external equipment, thereby avoiding the problem of efficiency reduction caused by using an analog circuit to realize short-circuit protection.

In an embodiment, referring to fig. 3, the switch circuit 20 includes a first triode Q1 and a first MOS transistor Q2;

the base electrode of the first triode Q1 is connected with the control end of the singlechip circuit 50, the collector electrode of the first triode Q1 is connected with the controlled end of the first MOS tube Q2, the emitter electrode of the first triode Q1 is connected with the output end of the first MOS tube Q2, and the interconnection points are grounded; the input end of the first MOS transistor Q2 is connected to the interface 30.

It can be understood that, in the present embodiment, when the output of the LED driving power supply is normal, the short circuit feedback circuit 40 outputs a low level signal to the single chip microcomputer circuit 50, and the single chip microcomputer circuit 50 triggers the first triode Q1 to be in an off state according to the low level signal, and the first MOS tube Q2 to be in an on state, that is, the path between the power supply module 10 and the external device is turned on; when the LED driving power supply outputs a short circuit, the short circuit feedback circuit 40 outputs a high level signal to the singlechip circuit 50, the singlechip circuit 50 triggers the first triode Q1 to be in a conducting state according to the high level signal, the first MOS tube Q2 is in a cut-off state, a path between the interface 30 and the ground is cut off, and referring to fig. 3, the interface 30 is the interface CON1. At this time, the path between the power module 10 and the external device is blocked. At this time, the power supply voltage outputted from the power supply module 10 cannot be outputted to the external device, thereby realizing a short-circuit protection function.

In an embodiment, the number of the interfaces 30 is plural, the number of the short-circuit feedback circuits 40 is plural, and each interface 30 is connected to each short-circuit feedback circuit 40 in a one-to-one correspondence.

It can be understood that in the present embodiment, the number of interfaces 30 is plural, the number of short-circuit feedback circuits 40 is plural, and the number of interfaces 30 and the number of short-circuit feedback circuits 40 are the same, and are connected in one-to-one correspondence. The number of the interfaces 30 is increased, so that the output channels of the LED driving power supply are increased, the interfaces 30 are connected with a plurality of external devices, and working voltages can be simultaneously provided for the plurality of external devices to drive the plurality of external devices to be simultaneously started, so that the functions of single-channel input and multi-channel output are realized. In addition, in the process of multiplexing output, the plurality of short-circuit feedback circuits 40 can monitor the connection condition between each interface 30 and the external device, so as to output a corresponding short-circuit feedback signal to the singlechip circuit 50 when a certain interface 30 is shorted with the external device, so as to trigger the singlechip circuit 50 to control the switch circuit 20 to disconnect the channel of the interface 30.

In one embodiment, referring to fig. 2, the LED driving power supply includes:

the power supply end is used for accessing alternating voltage;

the overvoltage protection circuit 100, the input end of the overvoltage protection circuit 100 is connected with the power supply end; the overvoltage protection circuit 100 is configured to detect an ac voltage at the power supply terminal, and disconnect a path from the power supply terminal when the ac voltage is detected to reach a preset voltage.

It will be appreciated that in this embodiment, the overvoltage protection circuit 100 is implemented using a first fuse. In practical application, the power supply terminal is configured to input an ac voltage of the mains supply to the overvoltage protection circuit 100, and the ac voltage passes through the first fuse of the overvoltage protection circuit 100. The first fuse is disconnected when detecting that the alternating voltage reaches the preset voltage, so that a passage between the power end and the LED driving power supply is disconnected, the alternating voltage of the power end cannot be input to the LED driving power supply, and then the overvoltage protection function is achieved.

In one embodiment, referring to fig. 2, the LED driving power supply includes:

the input end of the rectifying circuit 200 is connected with the output end of the overvoltage protection circuit 100; the rectifying circuit 200 is configured to rectify an ac voltage of the overvoltage protection circuit 100 into a dc voltage.

It can be understood that in the present embodiment, the rectifying circuit 200 is composed of four diodes, and specifically, the first diode, the second diode, the third diode, and the fourth diode form the full-wave rectifying circuit 200. In practical application, when the ac voltage input to the overvoltage protection circuit 100 from the power supply terminal is within the preset voltage range, the overvoltage protection circuit 100 outputs the ac voltage from the power supply terminal to the rectifying circuit 200, and the four diodes in the rectifying circuit 200 convert the ac voltage into the dc voltage and then output the dc voltage.

In one embodiment, referring to fig. 2, the LED driving power supply includes:

a control circuit 600, wherein the control circuit 600 is connected with the output end of the rectifying circuit 200; the control circuit 600 is configured to start to operate when receiving the dc voltage, so as to output a control signal;

the control end of the driving circuit 300 is connected with the control end of the control circuit 600, the input end of the driving circuit 300 is connected with the rectifying circuit 200, and the output end of the driving circuit 300 is connected with external equipment; the driving circuit 300 is configured to, when receiving the control signal, turn on a path between the rectifying circuit 200 and an external device, so that the dc voltage output by the rectifying circuit 200 is output to the external device to drive the external device to operate.

Alternatively, the control circuit 600 may be implemented using a main control chip, such as an MCU, a DSP (Digital Signal Process, digital signal processing chip), an FPGA (Field Programmable Gate Array, programmable gate array chip), or the like. In this embodiment, the control circuit 600 is implemented by using a main control chip, and the driving circuit 300 is implemented by using a first coupler, a first triode Q1 and a second triode. Specifically, the main control chip has a control pin and an input pin ST1, and when the input pin ST1 of the main control chip receives the dc voltage output by the rectifying circuit 200, the main control chip starts to operate, and outputs a control signal to the driving circuit 300 through the control pin to trigger the driving circuit 300 to start to operate. At this time, the first coupler in the driving circuit 300 amplifies the driving signal corresponding to the dc voltage, and outputs the amplified driving signal to the first transistor Q1 and the second transistor, and the amplified driving signal drives the first transistor Q1 and the second transistor to be turned on, so as to turn on the path between the rectifying circuit 200 and the external device. At this time, the dc voltage output from the rectifying circuit 200 is output to the external device through the driving circuit 300 to drive the external device to operate.

In one embodiment, referring to fig. 2, the LED driving power supply includes:

the input end of the voltage transformation circuit 400 is connected with the output end of the driving circuit 300, and the output end of the voltage transformation circuit 400 is connected with external equipment; the transformer 400 is configured to transform the dc voltage output from the rectifier 200 and output the transformed dc voltage to an external device.

It is understood that in this embodiment, the transformer circuit 400 is implemented by using a second transformer. Wherein the second transformer has a primary side and a secondary side. In practical application, the primary side of the second transformer is used for receiving the dc voltage output by the driving circuit 300, and the second transformer converts the received dc voltage into a working voltage required by the external device, and outputs the working voltage to the external device through the secondary side, so as to drive the normal operation of the external device.

In one embodiment, referring to fig. 2, the LED driving power supply includes:

the input end of the filter circuit 500 is connected with the output end of the voltage transformation circuit 400, and the output end of the filter circuit 500 is connected with the input end of the power module 10;

the filter circuit 500 is configured to filter the dc voltage of the voltage transformation circuit 400 and output the filtered dc voltage to the power module 10; the power module 10 is configured to output the voltage of the filter circuit 500 to an external device via the interface 30.

It will be appreciated that in this embodiment, the filter circuit 500 is implemented using capacitance and inductance. In practical applications, the filter circuit 500 receives the dc voltage transformed by the transformer circuit 400, performs noise filtering on the dc voltage through the capacitor and the inductor, and outputs the dc voltage to the power module 10. The power module 10 outputs the dc voltage of the filter circuit 500 to an external device through the interface 30 to drive the external device to operate.

In one embodiment, referring to fig. 2, the LED driving power supply includes:

the input end of the voltage stabilizing circuit 800 is connected with the output end of the filter circuit 500, and the output end of the voltage stabilizing circuit 800 is connected with the power end of the singlechip circuit 50; the voltage stabilizing circuit 800 is configured to stabilize the dc voltage output from the filter circuit 500 and output the stabilized dc voltage to the single-chip microcomputer circuit 50, so as to provide a working voltage for the single-chip microcomputer circuit 50.

It should be understood that in this embodiment, the voltage stabilizing circuit 800 is implemented by using a voltage stabilizing chip and a capacitor. In practical application, the power module 10 has a first output terminal and a second output terminal, wherein the first output terminal is used for outputting the dc voltage of the filter circuit 500 to an external device; the second output terminal is configured to output the dc voltage of the filter circuit 500 to the voltage stabilizing chip, and the voltage stabilizing chip charges and discharges the capacitor by using the dc voltage, so as to output a stable 3.3V voltage to the singlechip circuit 50, so as to provide the working voltage for the singlechip circuit 50.

In one embodiment, referring to fig. 2, the LED driving power supply includes:

an output feedback circuit 700, wherein an input end of the output feedback circuit 700 is connected with an output end of the voltage transformation circuit 400, and an output end of the output feedback circuit 700 is connected with an input end of the control circuit 600; the output feedback circuit 700 is configured to output a corresponding voltage feedback signal to the control circuit 600 according to the dc voltage of the voltage transformation circuit 400;

the control circuit 600 is further configured to control the voltage transformation circuit 400 to reset when detecting that the dc voltage output by the voltage transformation circuit 400 is lower than a preset voltage according to the voltage feedback signal.

In this embodiment, the output feedback circuit 700 is implemented by an optocoupler, where the optocoupler is composed of a light emitting diode and a phototransistor. It should be understood that the photocoupler is used for assembling the light emitting diode and the photo transistor together, and the coupling is realized by light to form an electric-optical-electric conversion device. Specifically, when an electric signal is input to the input end of the photoelectric coupler, the light emitting diode emits light through the electric signal, and the phototriode generates current after being illuminated and is in a conducting state; when no electric signal is input to the input end of the photoelectric coupler or the voltage is lower than the voltage of the preset electric signal, the light emitting diode is not lightened, and the phototriode is in a cut-off state. For the change of the input level and the output level, when the input is low level 0, the phototriode is cut off, and the output is high level 1; when the input is high level 1, the phototriode is saturated and conducted, and the output is low level 0.

Therefore, in practical application, when the voltage output from the voltage transformation circuit 400 to the filter circuit 500 is zero or lower than the preset voltage, the light emitting diode in the optocoupler is not on, the phototransistor is in a cut-off state, and a high level is output to the control circuit 600 to trigger the control circuit 600 to reset the voltage transformation circuit 400, so that the voltage transformation circuit 400 performs voltage transformation conversion on the dc voltage again; when the voltage output from the voltage transformation circuit 400 to the filter circuit 500 is the normal voltage, the light emitting diode in the optocoupler emits light, the phototransistor is in a conducting state, and outputs a low level to the control circuit 600, and at this time, the control circuit 600 detects the normal voltage output from the power module 10 according to the low level, that is, does not trigger the reset.

The above embodiments are only preferred embodiments of the present utility model, and are not limited to the patent scope of the utility model, and all equivalent structures or equivalent processes using the descriptions of the present utility model and the accompanying drawings, or direct or indirect application in other related technical fields are included in the scope of the present utility model.

Claims (10)

1. An LED driving power supply, comprising:

the power supply module is used for outputting the power supply voltage of the LED driving power supply;

the interface is connected with the output end of the power supply module and external equipment; the interface is used for accessing external equipment to output the power supply voltage of the power supply module to the external equipment;

the detection end of the short circuit feedback circuit is connected with the interface; the short circuit feedback circuit is used for outputting a short circuit feedback signal when the interface short circuit is detected according to the power supply voltage of the power supply module;

the input end of the singlechip circuit is connected with the output end of the short-circuit feedback circuit; the singlechip circuit is used for outputting a turn-off signal when receiving the short circuit feedback signal;

the controlled end of the switch circuit is connected with the control end of the singlechip circuit, the first output end of the switch circuit is connected with the grounding end of external equipment through the interface, and the second output end of the switch circuit is grounded; the switching circuit is used for disconnecting the passage between the power supply module and the external equipment when receiving the turn-off signal.

2. The LED driving power supply of claim 1, wherein the switching circuit comprises a first triode and a first MOS tube;

the base electrode of the first triode is connected with the control end of the singlechip circuit, the collector electrode of the first triode is connected with the controlled end of the first MOS tube, the emitter electrode of the first triode is connected with the output end of the first MOS tube, and the interconnection point is grounded; the input end of the first MOS tube is connected with the interface.

3. The LED driving power supply of claim 1, wherein the number of the interfaces is plural, the number of the short-circuit feedback circuits is plural, and each of the interfaces is connected to each of the short-circuit feedback circuits in a one-to-one correspondence.

4. The LED driving power supply as set forth in claim 1, including:

the power supply end is used for accessing alternating voltage;

the input end of the overvoltage protection circuit is connected with the power supply end; the overvoltage protection circuit is used for detecting the alternating voltage of the power supply end and disconnecting the passage between the overvoltage protection circuit and the power supply end when the alternating voltage reaches the preset voltage.

5. The LED driving power supply as set forth in claim 4, including:

the input end of the rectifying circuit is connected with the output end of the overvoltage protection circuit; the rectification circuit is used for rectifying the alternating voltage of the overvoltage protection circuit into direct voltage.

6. The LED driving power supply as set forth in claim 5, including:

the control circuit is connected with the output end of the rectifying circuit; the control circuit is used for starting to work when receiving the direct-current voltage so as to output a control signal;

the control end of the driving circuit is connected with the control end of the control circuit, the input end of the driving circuit is connected with the rectifying circuit, and the output end of the driving circuit is connected with external equipment; and the driving circuit is used for conducting a passage between the rectifying circuit and external equipment when receiving the control signal so as to enable the direct-current voltage output by the rectifying circuit to be output to the external equipment so as to drive the external equipment to operate.

7. The LED driving power supply as set forth in claim 6, including:

the input end of the transformation circuit is connected with the output end of the driving circuit, and the output end of the transformation circuit is connected with external equipment; the transformation circuit is used for transforming the direct-current voltage output by the rectification circuit and outputting the direct-current voltage to external equipment.

8. The LED driving power supply as set forth in claim 7, including:

the input end of the filter circuit is connected with the output end of the voltage transformation circuit, and the output end of the filter circuit is connected with the input end of the power supply module;

the filter circuit is used for filtering the direct-current voltage of the transformation circuit and outputting the direct-current voltage to the power supply module; and the power supply module is used for outputting the voltage of the filter circuit to external equipment through the interface.

9. The LED driving power supply as set forth in claim 8, including:

the input end of the voltage stabilizing circuit is connected with the output end of the filter circuit, and the output end of the voltage stabilizing circuit is connected with the power end of the singlechip circuit; the voltage stabilizing circuit is used for stabilizing the direct-current voltage output by the filter circuit and outputting the direct-current voltage to the singlechip circuit so as to provide working voltage for the singlechip circuit.

10. The LED driving power supply as set forth in claim 7, including:

the input end of the output feedback circuit is connected with the output end of the transformation circuit, and the output end of the output feedback circuit is connected with the input end of the control circuit; the output feedback circuit is used for outputting corresponding voltage feedback signals to the control circuit according to the direct-current voltage of the voltage transformation circuit;

and the control circuit is also used for controlling the reset of the voltage transformation circuit when detecting that the direct current output by the voltage transformation circuit is lower than the preset voltage according to the voltage feedback signal.