CN219305085U

CN219305085U - Power supply protection circuit and electronic ballast

Info

Publication number: CN219305085U
Application number: CN202222129392.4U
Authority: CN
Inventors: 都金龙; 王迎丰; 吴永斌; 张广能
Original assignee: Megaphoton Inc
Current assignee: Megaphoton Inc
Priority date: 2022-08-11
Filing date: 2022-08-11
Publication date: 2023-07-04
Anticipated expiration: 2032-08-11

Abstract

The utility model relates to a power supply protection circuit and an electronic ballast. The circuit comprises: the charging and discharging circuit is used for connecting the second power supply circuit; the charge-discharge circuit is used for outputting a level signal; the integrated circuit is connected with the charge-discharge circuit and is used for being connected with the first power supply circuit; the integrated circuit is used for receiving the power supply voltage of the first power supply circuit under the condition that the electronic ballast is electrified; the integrated circuit is also used for receiving the level signal and outputting a control signal according to the level signal; the switch circuit is respectively connected with the integrated circuit and the charge-discharge circuit and is used for respectively connecting the first power supply circuit and the second power supply circuit; the switch circuit is used for receiving and responding to the control signal to enter a conducting state so that the power supply supplies power to the electronic ballast through the second power supply circuit and charges the charging and discharging circuit. Through the structure, the electronic ballast can be prevented from being frequently electrified and powered off in the process of frequent switching on and off, so that the protection of the electronic ballast can be improved.

Description

Power supply protection circuit and electronic ballast

Technical Field

The utility model relates to the technical field of ballasts, in particular to a power supply protection circuit and an electronic ballast.

Background

In the design of a switching power supply, a ballast is often needed, and the electronic ballast is currently an important measure for green lighting engineering to replace the traditional inductive ballast. Compared with an inductive ballast, the electronic ballast has the advantages of high power factor, high luminous efficiency, no stroboflash, no noise, quick and reliable starting, small volume, light weight, obvious electricity-saving effect and the like.

However, current electronic ballasts lack protection for the electronic ballast during frequent switching on and off.

Disclosure of Invention

Based on this, it is necessary to provide a power supply protection circuit and an electronic ballast that can protect the electronic ballast during frequent switching on and off of the electronic ballast.

In a first aspect, the present application provides a power supply protection circuit applied to an electronic ballast, the electronic ballast including a power supply, a first power supply circuit, and a second power supply circuit, the first power supply circuit being connected to the power supply; the power supply protection circuit includes:

the charging and discharging circuit is used for connecting the second power supply circuit; the charge-discharge circuit is used for outputting a level signal;

the integrated circuit is connected with the charge-discharge circuit and is used for being connected with the first power supply circuit; the integrated circuit is used for receiving the power supply voltage of the first power supply circuit under the condition that the electronic ballast is electrified; the integrated circuit is also used for receiving the level signal and outputting a control signal according to the level signal;

the switch circuit is respectively connected with the integrated circuit and the charge-discharge circuit and is used for respectively connecting the first power supply circuit and the second power supply circuit; the switch circuit is used for receiving and responding to the control signal to enter a conducting state so that the power supply supplies power to the electronic ballast through the second power supply circuit and charges the charging and discharging circuit.

In one embodiment, the switching circuit includes a transistor and a relay;

the control end of the transistor is connected with the output end of the integrated circuit, the first end of the transistor is connected with the output end of the relay, and the second end of the transistor is used for grounding; the transistor is used for responding to the control signal to enter a conducting state;

the input end of the relay is used for connecting with the first power supply circuit and connecting with the power end of the integrated circuit; one end of a contact of the relay is connected with the charge-discharge circuit and is also used for being connected with a second power supply circuit; the other end of the contact of the relay is used for being connected with a first power supply circuit and is respectively connected with the input end of the relay and the power supply end of the integrated circuit.

In one embodiment, the transistor is a triode; the control end of the transistor is the base electrode of the triode, the first end of the transistor is the collector electrode of the triode, and the second end of the transistor is the emitter electrode of the triode.

In one embodiment, the charge-discharge circuit includes a first capacitor, a first resistor, and a second resistor;

the first end of the first capacitor is connected with one end of the first resistor and is used for being grounded; the second end of the first capacitor is connected with the other ends of the switch circuit and the second resistor respectively and is used for being connected with a second power supply circuit;

one end of the first resistor is used for grounding, and the other end of the first resistor is connected with one end of the integrated circuit and one end of the second resistor respectively;

one end of the second resistor is also connected with the integrated circuit; the other end of the second resistor is also connected with a switch circuit and is also used for being connected with a second power supply circuit.

In one embodiment, the first capacitor is an electrolytic capacitor;

the first end of the first capacitor is the negative electrode of the electrolytic capacitor; the second end of the first capacitor is the positive electrode of the electrolytic capacitor.

In one embodiment, the power protection circuit further includes a third resistor;

one end of the third resistor is respectively connected with the anode of the electrolytic capacitor and the other end of the second resistor;

the other end of the third resistor is connected with the switch circuit and is also used for being connected with a second power supply circuit.

In one embodiment, the power protection circuit further comprises an integrating circuit;

the integrating circuit is respectively connected with the integrated circuit and the switching circuit.

In one embodiment, the integrating circuit includes a fourth resistor, a fifth resistor, and a second capacitor;

one end of the fourth resistor is connected with the integrated circuit, and the other end of the fourth resistor is respectively connected with one end of the fifth resistor, one end of the second capacitor and the switch circuit;

one end of the fifth resistor is also connected with one end of the second capacitor and the switch circuit respectively, the other end of the fifth resistor is connected with the other end of the second capacitor and the switch circuit respectively, and the other end of the fifth resistor is used for grounding;

one end of the second capacitor is connected with the switch circuit, the other end of the second capacitor is connected with the switch circuit, and the other end of the second capacitor is grounded.

In one embodiment, the integrating circuit further comprises a diode;

the positive pole of diode is connected with the other end of fourth resistance, and the negative pole of diode is connected with one end of fifth resistance, one end of second electric capacity and switch circuit respectively.

In a second aspect, the present application further provides an electronic ballast, including a power supply, a first power supply circuit, a second power supply circuit, and the power supply protection circuit described above;

the power supply is connected with the first power supply circuit; the first power supply circuit is connected with the power supply protection circuit; the power supply protection circuit is connected with the second power supply circuit.

The power supply protection circuit and the electronic ballast comprise a charging and discharging circuit, an integrated circuit and a switch circuit; the charge-discharge circuit is used for being connected with the second power supply circuit and outputting a level signal; the integrated circuit is connected with the charge-discharge circuit and is used for being connected with the first power supply circuit, the integrated circuit is used for receiving the power supply voltage of the first power supply circuit under the condition that the electronic ballast is electrified, and the integrated circuit is also used for receiving a level signal and outputting a control signal according to the level signal; and the switch circuit is respectively connected with the integrated circuit and the charge-discharge circuit and is used for respectively connecting the first power supply circuit and the second power supply circuit, and the switch circuit is used for receiving and responding to the control signal to enter a conducting state so that the power supply supplies power to the electronic ballast through the second power supply circuit and charges the charge-discharge circuit. Through the structure, the integrated circuit can output the control signal according to the level signal output by the charge-discharge circuit so as to control the on-off of the switch circuit, the charge-discharge circuit needs a certain time in the discharge process, and the integrated circuit stably outputs a control signal in the certain time, so that the frequent power-on and power-off of the electronic ballast in the frequent power-on and power-off process can be avoided, and the protection of the electronic ballast can be improved.

Drawings

In order to more clearly illustrate the technical solutions of embodiments or conventional techniques of the present application, the drawings required for the descriptions of the embodiments or conventional techniques will be briefly described below, and it is apparent that the drawings in the following description are only some embodiments of the present application, and other drawings may be obtained according to these drawings without inventive effort for a person of ordinary skill in the art.

FIG. 1 is a schematic diagram of a power protection circuit in one embodiment;

FIG. 2 is a schematic diagram of a power protection circuit according to another embodiment;

FIG. 3 is a schematic diagram of a power protection circuit according to another embodiment;

FIG. 4 is a schematic diagram of a power protection circuit according to another embodiment;

fig. 5 is a schematic diagram of a power supply protection circuit in a specific embodiment.

Detailed Description

In order to facilitate an understanding of the present application, a more complete description of the present application will now be provided with reference to the relevant figures. Examples of the present application are given in the accompanying drawings. This application may, however, be embodied in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the description of the application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

It will be understood that the terms "first," "second," and the like, as used herein, may be used to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish one element from another element. For example, a first resistance may be referred to as a second resistance, and similarly, a second resistance may be referred to as a first resistance, without departing from the scope of the present application. Both the first resistor and the second resistor are resistors, but they are not the same resistor.

It is to be understood that in the following embodiments, "connected" is understood to mean "electrically connected", "communicatively connected", etc., if the connected circuits, modules, units, etc., have electrical or data transfer between them.

As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or "comprising," and/or the like, specify the presence of stated features, integers, steps, operations, elements, components, or groups thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or groups thereof.

In the field of switching power supply design, the selection of ballasts, replacing the traditional inductive ballasts with electronic ballasts, is an important measure of green lighting engineering. Compared with an inductive ballast, the electronic ballast has the advantages of high power factor, high luminous efficiency, no stroboscopic effect, no noise, quick and reliable starting, small volume, light weight, obvious electricity-saving effect and the like.

However, in some application occasions, the electronic ballast is frequently started and shut down due to abnormal electrical switch or improper manual operation, the operation can impact an output power MOS tube of the electronic ballast, damage to the electronic ballast is easy to cause, and the probability of damaging the electronic ballast is higher when the electronic ballast is particularly applied to the use environment of an ocean fishing vessel.

Based on solving the problem that the electronic ballast is damaged due to frequent startup and shutdown of the electronic ballast caused by abnormal switching of an electric appliance or improper manual operation, the application provides a power supply protection circuit capable of protecting the electronic ballast in the frequent startup and shutdown process and the electronic ballast.

In one embodiment, as shown in fig. 1, the present application provides a power supply protection circuit applied to an electronic ballast, wherein the electronic ballast comprises a power supply, a first power supply circuit and a second power supply circuit, and the first power supply circuit is connected with the power supply; the power supply protection circuit includes:

a charge-discharge circuit 100 for connecting to a second power supply circuit; the charge-discharge circuit 100 is used for outputting a level signal;

an integrated circuit 200 connected to the charge-discharge circuit 100 for connecting to the first power supply circuit; the integrated circuit 200 is configured to receive a supply voltage of the first power supply circuit when the electronic ballast is powered on; the integrated circuit 200 is further configured to receive a level signal and output a control signal according to the level signal;

a switching circuit 300 connected to the integrated circuit 200 and the charge-discharge circuit 100, respectively, for connecting the first power supply circuit and the second power supply circuit, respectively; the switch circuit 300 is configured to receive and respond to the control signal to enter a conductive state, so that the power supply supplies power to the electronic ballast through the second power supply circuit, and charges the charge/discharge circuit 100.

The charging and discharging circuit can realize charging and discharging functions, and can output voltage to form a level signal; for example, if the output voltage of the charge/discharge circuit reaches a preset value, the charge/discharge circuit may be considered to output a high level. The integrated circuit may be any circuit having an output control signal, for example, a single chip microcomputer. The control signal may be a level signal. The connection relation between the first power supply circuit and the second power supply circuit can be changed by switching on and switching off the switching circuit; for example, the switching circuit is turned on in an on state and turned off in an off state.

Specifically, the integrated circuit is connected with the charge-discharge circuit and is used for being connected with the first power supply circuit; the switch circuit is connected with the integrated circuit and is used for being respectively connected with the first power supply circuit and the second power supply circuit; the charging and discharging circuit is connected with the switching circuit and is used for being connected with the second power supply circuit.

Specifically, when the electronic ballast starts to be electrified, the power supply can supply power to the integrated circuit through the first power supply circuit, the integrated circuit is in a working state, the integrated circuit judges the voltage output by the charging and discharging circuit, at the moment, the electronic ballast just starts to be electrified, the voltage output by the charging and discharging circuit is zero, the integrated circuit detects an input low-level signal, and the integrated circuit outputs a first control signal to control the switch circuit to enter a conducting state. When the switch circuit is in a conducting state, the first power supply circuit is connected with the second power supply circuit, and the power supply of the electronic ballast can supply power to the electronic ballast through the first power supply circuit and the second power supply circuit; meanwhile, the power supply can charge the charge-discharge circuit. After the electronic ballast is powered off, the charging and discharging circuit discharges to output a high level, the electronic ballast is powered on again in a short time, the integrated circuit can detect the high level output by the charging and discharging circuit (namely, the high level input to the integrated circuit), the integrated circuit outputs a second control signal to control the switching circuit to keep the switching circuit in an off state, the first power supply circuit and the second power supply circuit are kept to be disconnected, the power supply cannot supply power to the electronic ballast through the second power supply circuit, and the charging and discharging circuit cannot be charged until the charging and discharging circuit is completely discharged, the integrated circuit detects the input low level signal, and the integrated circuit outputs a first control signal to control the switching circuit to enter the on state. By arranging the switching circuit and the charging and discharging circuit, the state of the switching circuit is kept unchanged under the condition that the charging and discharging circuit discharges, so that repeated power-on of the electronic ballast can be avoided. The full discharge time of the charge-discharge circuit can be set according to practical situations.

In this embodiment, the integrated circuit can output a control signal according to the level signal output by the charge-discharge circuit to control the on-off of the switch circuit, and the charge-discharge circuit needs a certain time in the discharge process, and the integrated circuit stably outputs a control signal in the certain time, so that frequent power-on and power-off of the electronic ballast in the frequent power-on and power-off process can be avoided, and the protection of the electronic ballast can be improved.

In one embodiment, as shown in fig. 2, the switching circuit 300 includes a transistor 310 and a relay 320;

the control terminal 311 of the transistor 310 is connected to the output terminal 210 of the integrated circuit 200, the first terminal 312 of the transistor 310 is connected to the output terminal 322 of the relay 320, and the second terminal 313 of the transistor 310 is connected to ground; transistor 310 is configured to enter a conductive state in response to a control signal;

an input 321 of the relay 320 is used for connecting to the first power supply circuit and connecting to the power supply 220 of the integrated circuit 200; one end 323 of the contact of the relay 320 is connected with the charge-discharge circuit 100 and is also used for being connected with a second power supply circuit; the other ends 324 of the contacts of the relay 320 are for connection to a first power supply circuit and are connected to the input 321 of the relay 320 and to the power supply 220 of the integrated circuit 200, respectively.

The transistor can be any transistor which can be controlled to be switched on or off, and the on-off state of the contact of the relay can be changed based on the on-off of the transistor. The contacts of the relay may be normally open contacts.

Specifically, a control end of the transistor is connected with an output end of the integrated circuit, a first end of the transistor is connected with an output end of the relay, and a second end of the transistor is used for grounding; the input end of the relay is used for connecting with the first power supply circuit and connecting with the power end of the integrated circuit; one end of a contact of the relay is connected with the charge-discharge circuit and is used for being connected with a second power supply circuit; the other end of the contact of the relay is used for being connected with the first power supply circuit and is respectively connected with the power end of the integrated circuit and the input end of the relay.

Specifically, the transistor receives and responds to a control signal output by the integrated circuit to enter an on state or an off state. Under the condition that the transistor enters a conducting state, the output end of the relay is used for being grounded, the relay coil forms a closed loop, the contact of the relay is closed, so that the first power supply circuit is connected with the second power supply circuit, and the power supply can supply power to the electronic ballast through the first power supply circuit and the second power supply circuit and charge the charging and discharging circuit. Under the condition that the transistor enters an off state, the relay coil cannot form a loop, the contact of the relay is in a normally-open state, the first power supply circuit and the second power supply circuit are disconnected, and the power supply cannot supply power to the electronic ballast through the second power supply circuit.

In this embodiment, the on/off of the contacts of the relay is controlled by controlling the on/off of the transistor, so as to control the on/off of the first power supply circuit and the second power supply circuit, and the integrated circuit can stably output a control signal to control the transistor in the time of the discharging process of the charging and discharging circuit, so that frequent power-on and power-off of the electronic ballast in the frequent power-on and power-off process can be avoided, and the protection of the electronic ballast can be improved.

Specifically, the base of triode connects the output of integrated circuit, and the output of relay is connected to the collecting electrode of triode, and the projecting pole of triode is used for ground connection.

Specifically, a control signal output by the integrated circuit is transmitted to the base electrode of the triode, and the on and off between the collector electrode and the emitter electrode of the triode are controlled by the control signal; for example, the control signal may be a level signal, when the electronic ballast starts to power up, the voltage output by the charging and discharging circuit is zero, the first power supply circuit supplies power to the integrated circuit, the integrated circuit is in a working state, the integrated circuit detects that the voltage output by the charging and discharging circuit is low level, the integrated circuit may output high level, so that the collector and the emitter of the triode are conducted, the contact of the relay is closed, and the power supply supplies power to the electronic ballast through the second power supply circuit and charges the charging and discharging circuit. After the electronic ballast is powered off, the charge-discharge circuit discharges to output a high level, the electronic ballast is powered on again in a short time, the integrated circuit outputs a low level, the collector electrode and the emitter electrode of the triode are kept disconnected, the contact of the relay is kept in a normally open state until the charge-discharge circuit is completely discharged, and the integrated circuit outputs a high level to enable the collector electrode and the emitter electrode of the triode to be conducted. Therefore, the state of the switch circuit can be kept unchanged under the condition that the charge-discharge circuit discharges, so that repeated power-on of the electronic ballast can be avoided.

In this embodiment, the on-off of the contacts of the relay is controlled by the on-off of the tertiary tube, so as to control the on-off of the first power supply circuit and the second power supply circuit, thereby avoiding frequent power-on and power-off of the electronic ballast in the frequent power-on and power-off process, and further improving the protection of the electronic ballast.

In one embodiment, as shown in fig. 3, the charge-discharge circuit 100 includes a first capacitor 110, a first resistor 120, and a second resistor 130;

the first end of the first capacitor 110 is connected to one end of the first resistor 120 and is used for grounding; the second end of the first capacitor 110 is connected to the switch circuit and the other end of the second resistor 130, respectively, and is used for connecting to a second power supply circuit;

one end of the first resistor 120 is used for grounding, and the other end of the first resistor 120 is connected with one end of the integrated circuit and one end of the second resistor 130 respectively;

one end of the second resistor 130 is also connected with an integrated circuit; the other end of the second resistor 130 is further connected to a switching circuit and is further connected to a second power supply circuit.

Specifically, with the above configuration, the first capacitor, the first resistor, and the second resistor can form a charge-discharge circuit, and the power supply can charge the first capacitor through the first power supply circuit when the switching circuit is on, and can discharge the first capacitor and output a voltage to the integrated circuit when the switching circuit is off. The time of complete discharge can be set by adjusting the first capacitor, the power supply of the electronic ballast is electrified again in the time of the first capacitor being discharged, the integrated circuit detects that the charge-discharge circuit outputs a high level, and the integrated circuit outputs a second control signal, so that the switch circuit is kept to be turned off, and frequent electrifying of the electronic ballast in a short time by the power supply is avoided.

In this embodiment, by the above structure, the charge and discharge function of the charge and discharge circuit can be realized, and the time of complete discharge can be preset by setting the first capacitor. The charge/discharge circuit having the above-described simple structure can reduce the cost of the power supply protection circuit.

In one embodiment, the first capacitor is an electrolytic capacitor;

Specifically, the first capacitor may be an electrolytic capacitor, and the full discharge time of the charge/discharge circuit may be adjusted by providing different electrolytic capacitors. The electrolytic capacitor is utilized to charge and discharge, so that the electronic ballast is prevented from being frequently electrified and powered off in the process of frequent startup and shutdown, and the protection of the electronic ballast is further improved.

In one embodiment, the power protection circuit further comprises a third resistor;

Specifically, the third resistor is arranged between the charging and discharging circuit and the switching circuit, when the switching circuit is conducted, the power supply charges the electrolytic capacitor in the charging and discharging circuit through the third resistor, and the third resistor can limit the current in the process that the power supply charges the electrolytic capacitor so as to protect the charging and discharging circuit.

In one embodiment, as shown in fig. 4, the power protection circuit further includes an integrating circuit 400;

the integrating circuit 400 is connected to the integrated circuit 200 and the switching circuit 300, respectively.

The integrating circuit may be any circuit that can provide a linear voltage to the transistor.

Specifically, the control signal output by the integrated circuit is processed by the integrating circuit to obtain a linear voltage so as to provide the linear voltage for the transistor, so that the transistor is slowly conducted, and the protection of the electronic ballast is improved.

Specifically, through the structure, the fourth resistor, the fifth resistor and the second capacitor can form an integrating circuit, when the integrated circuit outputs a high level, the high level can be processed by the integrating circuit to obtain linear voltage, so that the transistor is slowly conducted, and the protection of the electronic ballast can be improved.

In one embodiment, the integrating circuit further comprises a diode;

Specifically, a diode is arranged in the integrating circuit, and the diode has unidirectional conductivity, so that the circuit current can be prevented from flowing backwards into the integrated circuit under the condition that the integrated circuit outputs a high level, and the integrated circuit can be protected from being damaged.

In a specific embodiment, as shown in fig. 5, the present application provides a power supply protection circuit applied to an electronic ballast, where the electronic ballast includes a power supply, a first power supply circuit and a second power supply circuit, and the first power supply circuit is connected with the power supply; the power supply protection circuit includes: the integrated circuit, the integrating circuit, the switching circuit, the resistor R5 and the charge-discharge circuit; the integrating circuit comprises a resistor R1, a diode D1, a resistor R2 and a capacitor C1; the switching circuit comprises a triode Q1 and a relay K1; the charge-discharge circuit includes a resistor R3, a resistor R4, and an electrolytic capacitor C2.

One end of the resistor R1 is connected with the output end 210 of the integrated circuit 200; the anode of the diode D1 is connected with the other end of the resistor R1; one end of the resistor R2 is connected with the cathode of the diode D1, and the other end of the resistor R2 is grounded; one end of the capacitor C1 is respectively connected with the cathode of the diode D1 and one end of the resistor R2, and the other end of the capacitor C1 is grounded and is connected with the other end of the resistor R2.

The base electrode of the triode Q1 is respectively connected with the output end 210 of the integrated circuit 200, the cathode of the diode D1, one end of the resistor R2 and one end of the capacitor C1; the emitter of the triode is grounded and is respectively connected with the other end of the resistor R2 and the other end of the capacitor C1; the output end of the relay K1 is connected with the collector electrode of the triode Q1; the input end of the relay K1 is used for being connected with the first power supply circuit and is connected with the power end 220 of the integrated circuit 200; one end of a contact of the relay K1 is used for being connected with a second power supply circuit; the other end of the contact of the relay K1 is used for being connected to the first power supply circuit, and is connected to the power supply terminal 220 of the integrated circuit 200 and the input terminal of the relay K1, respectively.

One end of the resistor R3 is used for grounding, and the other end of the resistor R3 is respectively connected with one end of the resistor R4 and the input end 230 of the integrated circuit 200; the negative electrode of the electrolytic capacitor C2 is connected with one end of the resistor R3 and is used for grounding; the positive electrode of the electrolytic capacitor C2 is respectively connected with one end of the resistor R5 and the other end of the resistor R4; one end of the resistor R4 is connected with the input end 230 of the integrated circuit 200, and the other end of the resistor R4 is connected with one end of the resistor R5; the other end of the resistor R5 is connected with one end of a contact of the relay K1 and is used for being connected with a second power supply circuit.

In this embodiment, through the above structure, if the electronic ballast is repeatedly powered on within a certain period of time when the electrolytic capacitor discharges, the integrated circuit controls the switching circuit to be disconnected, that is, the connection between the first power supply circuit and the second power supply circuit is disconnected, and the power supply cannot supply power to the electronic ballast, so that the electronic ballast can be protected.

In one embodiment, the present application provides an electronic ballast, including a power supply, a first power supply circuit, a second power supply circuit, and the power supply protection circuit described above;

In the description of the present specification, reference to the terms "one embodiment," "a particular embodiment," and the like, means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the utility model. In this specification, schematic descriptions of the above terms do not necessarily refer to the same embodiment or example.

The technical features of the above-described embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above-described embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.

The above examples illustrate only a few embodiments of the utility model, which are described in detail and are not to be construed as limiting the scope of the utility model. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the utility model, which are all within the scope of the utility model. Accordingly, the scope of protection of the present utility model is to be determined by the appended claims.

Claims

1. The power supply protection circuit is characterized by being applied to an electronic ballast, wherein the electronic ballast comprises a power supply source, a first power supply circuit and a second power supply circuit, and the first power supply circuit is connected with the power supply source; the power supply protection circuit includes:

2. The power supply protection circuit of claim 1, wherein the switching circuit comprises a transistor and a relay;

the input end of the relay is used for being connected with the first power supply circuit and the power supply end of the integrated circuit; one end of a contact of the relay is connected with the charge-discharge circuit and is also used for being connected with the second power supply circuit; the other end of the contact of the relay is used for being connected with the first power supply circuit and is respectively connected with the input end of the relay and the power end of the integrated circuit.

3. The power supply protection circuit of claim 2, wherein the transistor is a triode; the control end of the transistor is the base electrode of the triode, the first end of the transistor is the collector electrode of the triode, and the second end of the transistor is the emitter electrode of the triode.

4. The power supply protection circuit of claim 1, wherein the charge-discharge circuit comprises a first capacitor, a first resistor, and a second resistor;

the first end of the first capacitor is connected with one end of the first resistor and is used for being grounded; the second end of the first capacitor is connected with the switch circuit and the other end of the second resistor respectively and is used for being connected with the second power supply circuit;

one end of the second resistor is also connected with the integrated circuit; the other end of the second resistor is also connected with the switch circuit and is also used for being connected with the second power supply circuit.

5. The power supply protection circuit of claim 4, wherein the first capacitor is an electrolytic capacitor;

6. The power supply protection circuit of claim 5, further comprising a third resistor;

the other end of the third resistor is connected with the switch circuit and is also used for being connected with the second power supply circuit.

7. The power supply protection circuit of claim 6, further comprising an integrating circuit;

8. The power protection circuit of claim 7, wherein the integrating circuit comprises a fourth resistor, a fifth resistor, and a second capacitor;

9. The power protection circuit of claim 8, wherein the integrating circuit further comprises a diode;

the positive pole of the diode is connected with the other end of the fourth resistor, and the negative pole of the diode is respectively connected with one end of the fifth resistor, one end of the second capacitor and the switching circuit.

10. An electronic ballast comprising a power supply, a first power supply circuit, a second power supply circuit, and the power supply protection circuit of any one of claims 1 to 9;