CN112491256A

CN112491256A - Overcurrent protection circuit and electrical equipment

Info

Publication number: CN112491256A
Application number: CN202011242707.5A
Authority: CN
Inventors: 张珊; 黄猛; 王京; 俞贤桥; 安宏迪; 杨博
Original assignee: Gree Electric Appliances Inc of Zhuhai
Current assignee: Gree Electric Appliances Inc of Zhuhai
Priority date: 2020-11-09
Filing date: 2020-11-09
Publication date: 2021-03-12

Abstract

The invention discloses an overcurrent protection circuit and electrical equipment. Wherein, this circuit includes: the first end of the detection module is connected between the second end of the first resistor and the anode of the first unidirectional element, and the second end of the detection module is grounded and used for detecting whether the power switching device has an overcurrent fault or not and outputting a control voltage after the power switching device has the overcurrent fault; the first end of the first resistor is connected with a desaturation detection pin of the driving chip, and the cathode of the first unidirectional element is connected with the drain of the power switch device; and the first end of the protection module is connected with the third end of the detection module, the second end of the protection module is connected between the grid of the power switch device and the first resistor, and the third end of the protection module is grounded and is used for conducting under the control of the control voltage so as to reduce the current passing through the power switch device. According to the invention, the damage of the power switch device caused by overcurrent faults can be avoided, and the reliability of the power switch device is improved.

Description

Overcurrent protection circuit and electrical equipment

Technical Field

The invention relates to the technical field of electronic circuits, in particular to an overcurrent protection circuit and electrical equipment.

Background

Power switching devices (e.g., composite IGBT switching tubes composed of a bipolar transistor and an insulated gate field effect transistor) are increasingly used in the fields of motor drives, inverters, and the like because of their low driving power and reduced saturation voltage.

Along with the increase of the use frequency of the power switch device, the problem that the power switch device is damaged frequently is solved, the driving and the protection of the power switch device are more and more emphasized, and manufacturers such as England flying Ling and Toshiba develop the power switch device driving optocoupler to drive and protect the power switch device. However, since the drive optocoupler protection circuit needs a certain time to control the turn-off of the power switch device, before the power switch device is completely turned off, the current flowing through the power switch device is still large, that is, the protection circuit in the existing drive optocoupler can not timely protect the power switch device, and the problem of damage of the power switch device is occasionally caused.

Aiming at the problem that a protection circuit in the prior art cannot timely protect a power switch device, an effective solution is not provided at present.

Disclosure of Invention

The embodiment of the invention provides an overcurrent protection circuit and electrical equipment, and aims to solve the problem that a protection circuit in the prior art cannot timely protect a power switch device.

In order to solve the above technical problem, the present invention provides an overcurrent protection circuit, which is applied to a power switch device, wherein the power switch device is connected to a driving chip, and the circuit includes:

the first end of the detection module is connected between the second end of the first resistor and the anode of the first unidirectional element, the second end of the detection module is grounded, and the detection module is used for detecting whether the power switching device has an overcurrent fault or not and outputting a control voltage after the power switching device has the overcurrent fault; the first end of the first resistor is connected with a desaturation detection pin of the driving chip, and the cathode of the first unidirectional element is connected with the drain of the power switch device;

and the first end of the protection module is connected with the third end of the detection module, and the second end of the protection module is connected between the grid of the power switch device and the first resistor and is used for conducting under the control of the control voltage so as to reduce the current passing through the power switch device.

Further, the detection module includes:

the first end of a series branch formed by connecting the second resistor and the third resistor in series is connected between the second end of the first resistor and the anode of the first unidirectional element, and the second end of the series branch is grounded;

and a line between the second resistor and the third resistor is connected with the first end of the protection module.

Further, the protection module includes:

the base electrode of the first switch is connected with the third end of the detection module, and the emitter electrode of the first switch is grounded and is used for being switched on when the power switching device has overcurrent faults and being switched off when the power switching device is normally switched on;

and the first end of the voltage stabilizing unit is connected with the collector of the first switch, the second end of the voltage stabilizing unit is connected between the grid of the power switch device and the driving resistor, and the voltage stabilizing unit is used for being switched off when the first switch is switched off and being switched on when the first switch is switched on so as to reduce the current passing through the power switch device.

Further, the protection module further comprises:

and the anode of the second unidirectional element is connected between the grid of the power switch device and the driving resistor, and the cathode of the second unidirectional element is connected with the first end of the voltage stabilizing unit.

Further, the protection module further comprises:

and a fourth resistor, a first end of which is connected between the anode of the second unidirectional element and the driving resistor, and a second end of which is grounded, for reducing the driving resistance value when the power switch device is turned off.

Further, the protection circuit further includes:

and a first end of the first capacitor is connected between the anode of the second unidirectional element and the grid of the power switch device and used for reducing the conduction speed of the power switch device.

Further, the circuit further comprises:

and a first end of the second capacitor is connected between the desaturation detection pin and the first resistor, and a second end of the second capacitor is grounded and used for controlling the voltage of the desaturation detection pin so as to control whether the desaturation detection pin triggers overcurrent protection.

Further, the circuit further comprises:

a first end of the third capacitor is connected with the grounding pin of the driving chip, a second end of the third capacitor is connected between the positive voltage pin of the driving chip and the positive voltage power supply, and the third capacitor is used for filtering the voltage provided by the positive voltage power supply;

a fourth capacitor, a first end of which is connected between the positive voltage pin of the driving chip and the positive voltage power supply, and a second end of which is connected between the negative voltage pin of the driving chip and the negative voltage power supply, wherein the fourth capacitor is used for filtering the voltage provided by the positive voltage power supply and the voltage provided by the negative voltage power supply;

and a first end of the fifth capacitor is grounded, a second end of the fifth capacitor is connected between the negative voltage pin of the driving chip and the negative voltage power supply, and the fifth capacitor is used for filtering the voltage provided by the negative voltage power supply.

The invention also provides electrical equipment which comprises a power switch device and a driving chip and is characterized by also comprising the overcurrent protection circuit.

Further, the electrical device comprises at least one of:

air conditioner, washing machine, refrigerator, water heater, fan, drying-machine, air purifier, water purification machine.

By applying the technical scheme of the invention, whether the power switching device has overcurrent fault or not is detected through the detection module, and control voltage is output after the power switching device has overcurrent fault; and the protection module is conducted under the control of the control voltage so as to reduce the current passing through the power switch device. After the saturation-removing detection pin triggers the overcurrent protection, the current of the power switch device is reduced before the power switch device is completely turned off, the power switch device is prevented from being damaged due to overcurrent faults, and the reliability of the power switch device is improved.

Drawings

Fig. 1 is a block diagram of an overcurrent protection circuit according to an embodiment of the present invention;

fig. 2 is a block diagram of an overcurrent protection circuit according to another embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention clearer, the present invention will be described in further detail with reference to the accompanying drawings, and it is apparent that the described embodiments are only a part of the embodiments of the present invention, not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The terminology used in the embodiments of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used in the examples of the present invention and the appended claims, the singular forms "a", "an", and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise, and "a plurality" typically includes at least two.

It should be understood that the term "and/or" as used herein is merely one type of association that describes an associated object, meaning that three relationships may exist, e.g., a and/or B may mean: a exists alone, A and B exist simultaneously, and B exists alone. In addition, the character "/" herein generally indicates that the former and latter related objects are in an "or" relationship.

It should be understood that although the terms first, second, third, etc. may be used to describe the resistors in the embodiments of the present invention, the resistors should not be limited to these terms. These terms are only used to distinguish between resistors disposed at different locations. For example, a first resistance may also be referred to as a second resistance, and similarly, a second resistance may also be referred to as a first resistance, without departing from the scope of embodiments of the present invention.

The words "if", as used herein, may be interpreted as "at … …" or "at … …" or "in response to a determination" or "in response to a detection", depending on the context. Similarly, the phrases "if determined" or "if detected (a stated condition or event)" may be interpreted as "when determined" or "in response to a determination" or "when detected (a stated condition or event)" or "in response to a detection (a stated condition or event)", depending on the context.

It is also noted that the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that an article or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such article or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other like elements in the article or device in which the element is included.

Alternative embodiments of the present invention are described in detail below with reference to the accompanying drawings.

Example 1

The embodiment provides an overcurrent protection circuit, which is applied to a power switch device, the power switch device is connected with a driving chip, fig. 1 is a structural diagram of the overcurrent protection circuit according to the embodiment of the present invention, as shown in fig. 1, a driving chip U of a power switch device (in the embodiment, an IGBT is taken as an example) includes a ground pin VE, a positive voltage pin VCC, a negative voltage pin VEE, and an output pin VOUT, where the ground pin VE is grounded, the positive voltage pin VCC is connected with a positive voltage power supply VCC1, the negative voltage pin VEE is connected with a negative voltage power supply VCC2, the output pin VOUT is connected with a gate G of the IGBT through a driving resistor Rg, the driving chip U further includes a desaturation detection pin DESAT, the saturation pin DESAT is connected with a drain D of the IGBT through a first resistor R1 and a first unidirectional element D1, where the first unidirectional element D1 may be.

In order to realize that after the desaturation detection pin triggers the overcurrent protection, before the power switching device thoroughly turns off, reduce the electric current of power switching device, this overcurrent protection circuit includes:

and a first end of the detection module 1 is connected between a second end of the first resistor R1 and the anode of the first unidirectional element D1, and a second end of the detection module 1 is grounded. When the IGBT has an overcurrent fault, a high voltage is generated between the second end of the first resistor R1 and the anode of the first unidirectional element D1, when the DESAT detection pin DESAT detects the high voltage, the pulse output of the driver chip U is turned off, and the IGBT is turned off, however, a certain time is required for the IGBT to be turned off completely, and before the IGBT is turned off completely, the current in the IGBT is still large, and therefore, the detection module 1 detects whether the IGBT has an overcurrent fault by detecting the voltage between the first resistor R1 and the first unidirectional element D1, and outputs a control voltage to the protection module 2 after the IGBT has an overcurrent fault.

And a first end of the protection module 2 is connected with a third end of the detection module 1, a second end of the protection module 2 is connected between the grid G of the IGBT and the first resistor R1, and the third end of the protection module is grounded and is used for reducing the current passing through the IGBT under the control of the control voltage.

The overcurrent protection circuit of the embodiment detects whether the power switch device has an overcurrent fault through the detection module, and outputs a control voltage after the power switch device has the overcurrent fault; and the protection module is conducted under the control of the control voltage so as to reduce the current passing through the power switch device. After the saturation-removing detection pin triggers the overcurrent protection, the current of the power switch device is reduced before the power switch device is completely turned off, the power switch device is prevented from being damaged due to overcurrent faults, and the reliability of the power switch device is improved.

Example 2

In this embodiment, another over-current protection circuit is provided, and fig. 2 is a structural diagram of the over-current protection circuit according to another embodiment of the present invention, in order to convert a voltage between the second end of the first resistor R1 and the anode of the first unidirectional element D1 into a control voltage for controlling the protection module 2 to be turned on, as shown in fig. 2, the detection module 1 includes:

a second resistor R2 and a third resistor R3 which are arranged in series, wherein one end of a series branch formed by the series connection of the second resistor R2 and the third resistor R3 is connected between the second end of the first resistor R1 and the anode of the first unidirectional element D1, and the other end of the series branch is grounded; specifically, a first end of the second resistor R2 is connected between the second end of the first resistor R1 and the anode of the first unidirectional element D1, and a second end of the second resistor R2 is connected to a first end of the third resistor R3; the second end of the third resistor R3 is grounded; the line between the second resistor R2 and the third resistor R3 is connected to the first end of the protection module, the voltage between the second end of the first resistor R1 and the anode of the first unidirectional element D1 is divided by the second resistor R2 and the third resistor R3, and the line leading-out end between the second resistor R2 and the third resistor R3 is used as the third end of the detection module 1 to output the divided voltage.

In order to realize conduction when the control voltage is input, as shown in fig. 2, the protection module 2 includes:

and the base electrode of the first switch Q is connected with the third end of the detection module 1, the emitter electrode of the first switch Q is grounded, and the first switch Q is switched on when the IGBT has overcurrent faults and is switched off when the IGBT is normally switched on. When the IGBT has an overcurrent fault, the DESAT detection pin DESAT detects a higher voltage, the pulse output of the driving chip U is turned off, and the IGBT is further turned off, but the current in the IGBT is still larger before the IGBT is completely turned off; at this time, the voltage U2 at the detection point a between the second end of the first resistor R1 and the anode of the first unidirectional element D1 is higher, and the voltage U3 output at the detection point b between the second resistor R2 and the third resistor R3 is also higher, so as to drive the first switch Q to be turned on, and further turn on the protection module 2; wherein, U3 ═ (Vds + VD1) ×

The resistance of the third resistor R3/(the resistance of the second resistor R2 + the resistance of the third resistor R3), Vds is the voltage between the drain D and the source S of the IGBT, and VD1 is the voltage across the first unidirectional element D1; when the IGBT is normally turned on, the voltage detected by the desaturation detection pin DESAT is low, assuming that the desaturation detection pin DESAT outputs a current I1, the voltage detected by the desaturation detection pin DESAT is U1 ═ Vds + VD1+ I1 × the resistance of the first resistor R1, Vds is the voltage between the drain D and the source S of the IGBT, the voltage U2 at the detection point a between the second end of the first resistor R1 and the anode of the first unidirectional element D1 is low, the voltage U3 output at the detection point b between the second resistor R2 and the third resistor R3 is also low, and the voltage U3 is insufficient to drive the first switch Q to be turned on, so that the first switch Q is turned off, and the protection module 2 is turned off. In this embodiment, the first switch Q is an NPN transistor.

The protection module 2 further comprises a voltage stabilizing unit Z1, a first end of the voltage stabilizing unit Z1 is connected to a collector of the first switch Q, a second end of the voltage stabilizing unit Z1 is connected between the gate G of the IGBT and the driving resistor Rg, the voltage stabilizing unit Z1 is turned off when the first switch Q is turned off, and is turned on when the first switch Q is turned on, that is, the voltage stabilizing unit Z1 is turned on after the IGBT has an overcurrent fault, so as to clamp the voltage of the gate G of the IGBT to a lower voltage, thereby reducing the current passing through the IGBT.

In order to avoid the reverse current passing through the voltage regulation unit Z1 and the first switch Q, the protection module further comprises: and an anode of the second unidirectional element D2 is connected between the gate G of the IGBT and the driving resistor Rg, and a cathode of the second unidirectional element D2 is connected to the first end of the voltage regulator unit Z1. Through the second unidirectional element D2, the control current can flow only from the gate G of the IGBT to the regulator unit Z1 and the collector and emitter of the first switch Q. In this embodiment, the second unidirectional element D2 is a diode, and the zener cell Z1 is a zener diode.

When controlling the turn-off of the IGBT, ideally, once a turn-off signal is sent, the IGBT is turned off immediately, but in practical application, there is always a certain delay in turn-off of the IGBT, and in order to increase the turn-off response speed of the IGBT, as shown in fig. 2, the protection module 2 further includes:

the first end of the fourth resistor R4 is connected between the anode of the second unidirectional element D2 and the driving resistor Rg, the second end of the fourth resistor R4 is grounded, when the IGBT inputs a turn-off signal, the fourth resistor R4 and the driving resistor Rg are in parallel connection, and after the fourth resistor R4 and the driving resistor Rg are in parallel connection, the total driving resistance value is reduced, and the turn-off response speed of the IGBT is improved.

In the above embodiment, since it is desired that the IGBT turns off quickly when the turn-off signal is input, the turn-off response is improved by the fourth resistor R4, but when the IGBT inputs the turn-on signal, if the response is too fast, the instantaneous impact on the IGBT is too large, and therefore, in order to reduce the turn-on speed of the IGBT, as shown in fig. 2, the protection circuit further includes:

and a first end of a first capacitor C1, wherein a first end of the first capacitor C1 is connected between the anode of the second unidirectional element D2 and the gate G of the IGBT, and is used for reducing the turn-on speed of the IGBT so as to avoid overlarge instantaneous impact on the IGBT.

When the IGBT is normally turned on, without triggering the overcurrent protection, the voltage detected by the DESAT pin needs to maintain a low value, and when the IGBT has an overcurrent fault, the voltage detected by the DESAT pin should be raised, and in order to control the voltage detected by the DESAT pin, as shown in fig. 2, the circuit further includes:

the first end of the second capacitor C2 and the first end of the second capacitor C2 are connected between the desaturation detection pin DESAT and the first resistor R1, the second end of the second capacitor C2 is grounded, and the second capacitor C2 is used for enabling the two ends of the second capacitor C2 not to be charged after being charged to a certain value when the IGBT is normally turned on, so that the desaturation detection pin DESAT always detects a low voltage, and when the IGBT has an overcurrent fault, the second capacitor C2 continues to be charged, so that the desaturation detection pin DESAT detects a high voltage, and overcurrent protection is triggered.

According to the above, the ground pin VE of the driver chip U is grounded, the positive voltage pin VCC is connected to the positive voltage power supply VCC1, the negative voltage pin VEE is connected to the negative voltage power supply VCC2, and since the positive voltage power supply VCC1 and the negative voltage power supply VCC2 contain interference signals, in order to remove these interference signals, the above overcurrent protection circuit further includes:

third electric capacity C3, the ground pin VE of driver chip U is connected to the first end of third electric capacity C3, and the second end is connected to between driver chip U's the malleation pin VCC and the malleation power VCC1, and third electric capacity C3 is used for right the voltage that malleation power VCC1 provided filters, gets rid of interfering signal.

The overcurrent protection circuit further comprises a fourth capacitor C4, a first end of the fourth capacitor C4 is connected between a positive voltage pin VCC of the driving chip U and a positive voltage power supply VCC1, a second end of the fourth capacitor C4 is connected between a negative voltage pin VEE of the driving chip U and a negative voltage power supply VCC2, and the fourth capacitor C4 is used for filtering a voltage provided by the positive voltage power supply VCC1 and a voltage provided by the negative voltage power supply VCC2 to remove an interference signal.

The overcurrent protection circuit further comprises a fifth capacitor C5, the first end of the fifth capacitor C5 is grounded, the second end of the fifth capacitor C5 is connected between the negative voltage pin VEE of the driving chip U and the negative voltage power supply VCC2, and the fifth capacitor C5 is used for filtering the voltage provided by the negative voltage power supply VCC2 and removing interference signals.

Example 3

The embodiment provides another overcurrent protection circuit, and the overcurrent protection circuit of the embodiment is shown in fig. 2 mentioned above, where the driving chip U is specifically a driving optocoupler, the driving optocoupler is connected to the positive voltage power supply VCC1 and the negative voltage power supply VCC2, and the voltages output by the positive voltage power supply VCC1 and the negative voltage power supply VCC2 are filtered by the third capacitor C3, the fourth capacitor C4, and the fifth capacitor C5 to supply power to the driving optocoupler.

The driving optocoupler is provided with a desaturation detection pin DESAT, when the IGBT has overcurrent faults, the desaturation detection pin DESAT can output a high voltage, and the driving optocoupler can control pulse output to be turned off, so that the IGBT is turned off.

The IGBT-driven over-current protection circuit comprises a desaturation detection circuit, an over-current protection circuit and a pulse output circuit.

The desaturation detection circuit comprises a second capacitor C2, a first resistor R1 and a first one-way element D1, when the IGBT is normally conducted, the desaturation detection pin DESAT outputs weak current, a lower voltage is detected, the voltage is lower than a trigger voltage of the desaturation detection pin DESAT, and the driving optical coupler does not report overcurrent faults. Assuming that the DESAT detection pin DESAT outputs a current I1, the voltage value is U1 — Vds + VD1+ I1 × R1. When overcurrent faults occur, the voltage Vds between the drain electrode D and the source electrode S of the IGBT rises, the second capacitor C2 starts to be charged, the voltage detected by the desaturation detection pin DESAT rises, when the voltage rises to be higher than the trigger voltage of the desaturation detection pin DESAT, the drive optical coupler reports the overcurrent faults, the output pin VOUT IGBT is turned off, and the IGBT is controlled to be turned off.

The overcurrent protection circuit comprises a detection module and a protection module: the detection module comprises a second resistor R2 and a third resistor R3, the protection module comprises a second unidirectional element D2, a voltage stabilizing element Z1 and a first switch Q1, and when overcurrent faults occur, the protection module can clamp the grid level of the IGBT to a low level.

The protection module comprises a second unidirectional element D2, a voltage stabilizing element Z1 and a first switch Q1, when the IGBT is normally turned on, a point a detects a voltage U2, a point b detects a voltage U3, at this time, U3 is smaller than a first switch Q1 conduction voltage, the first switch Q1 is turned off, and U3 ═ U3 ═ (Vds + VD1) × the resistance of a third resistor R3/(the resistance of a second resistor R2 + the resistance of a third resistor R3). When overcurrent fault occurs, Vds rises, U2 and U3 rise, when the voltage at the point 2 is higher than the conducting voltage of the first switch Q1, the first switch Q1 is conducted, before the second capacitor C2 is charged to the trigger voltage of the desaturation detection pin DESAT, the voltage stabilizing element Z1 clamps the voltage of the IGBT grid G to a low level, the amplitude of fault current is reduced, the IGBT power loss is reduced, the short-circuit endurance time of the device is prolonged, and therefore the IGBT can be prevented from being damaged due to overcurrent before being turned off.

In addition, when the IGBT is subjected to a short-time noise and interference spike, the DESAT pin detects the spike voltage, the second capacitor C2 starts to charge, the spike voltage is detected at the point a, the spike voltage is divided by the second resistor R3 and the third resistor R3, and a voltage value is output through the point b, the voltage value exceeds the conduction threshold of the first switch Q1, the first switch Q1 is turned on, the voltage stabilizing element Z1 operates to pull down the gate voltage of the IGBT, so that the interference spike is reduced, therefore, the second capacitor C2 does not charge the DESAT threshold voltage, the driving optocoupler does not report overcurrent protection, and the circuit can normally operate.

Example 4

This embodiment provides an electrical equipment, including power switch device and driver chip, this electrical equipment still includes above-mentioned overcurrent protection circuit for realize power switch device's overcurrent protection, after moving back saturation detection pin and triggering overcurrent protection, before power switch device thoroughly shuts off, reduce power switch device's electric current, avoid causing power switch device to damage, improve power switch device's reliability, and then improve whole electrical equipment's reliability, in this embodiment, this electrical equipment includes one of them below at least: air conditioner, washing machine, refrigerator, water heater, fan, drying-machine, air purifier, water purification machine.

The above-described embodiments of the apparatus are merely illustrative, wherein the modules described as separate parts may or may not be physically separate, and the parts displayed as units may or may not be physical modules, may be located in one place, or may be distributed on a plurality of network modules. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of the present embodiment.

Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.

Claims

1. The utility model provides an overcurrent protection circuit, is applied to power switching device, power switching device connects driver chip, its characterized in that, the circuit includes:

and the first end of the protection module is connected with the third end of the detection module, the second end of the protection module is connected between the grid of the power switch device and the first resistor, and the third end of the protection module is grounded and is used for being conducted under the control of the control voltage so as to reduce the current passing through the power switch device.

2. The circuit of claim 1, wherein the detection module comprises:

3. The circuit of claim 1, wherein the protection module comprises:

4. The circuit of claim 3, wherein the protection module further comprises:

5. The circuit of claim 4, wherein the protection module further comprises:

6. The circuit of claim 4, wherein the protection circuit further comprises:

7. The circuit of claim 1, further comprising:

8. The circuit of claim 1, further comprising:

and the first end of the fifth capacitor is grounded, the second end of the fifth capacitor is connected between the negative voltage pin of the driving chip and the negative voltage power supply, and the fifth capacitor is used for filtering the voltage provided by the negative voltage power supply.

9. An electrical apparatus comprising a power switch device and a driving chip, wherein the electrical apparatus further comprises the overcurrent protection circuit according to any one of claims 1 to 8.

10. The electrical device of claim 9, wherein the electrical device comprises at least one of: