CN215990185U - Overvoltage protection circuit and electrical equipment - Google Patents
Overvoltage protection circuit and electrical equipment Download PDFInfo
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- CN215990185U CN215990185U CN202121876275.3U CN202121876275U CN215990185U CN 215990185 U CN215990185 U CN 215990185U CN 202121876275 U CN202121876275 U CN 202121876275U CN 215990185 U CN215990185 U CN 215990185U
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Abstract
The application discloses an overvoltage protection circuit and electrical equipment, wherein the circuit comprises a power supply module, an isolation detection module and a protection module which are electrically connected in sequence; the power supply module is used for providing alternating voltage, converting the alternating voltage into direct voltage and outputting the direct voltage to the isolation detection module; the isolation detection module is used for comparing the direct-current voltage with a preset voltage threshold value to obtain a comparison result and outputting a first level to the protection module; the protection module is used for determining a working state according to the first level, so that the power supply module provides alternating voltage when the protection module is in a closed state, and the alternating voltage provided by the power supply module is cut off when the protection module is in an open state. When detecting overvoltage in the circuit in this application, protection module can switch over immediately to the off-state, cuts off the alternating voltage that power module provided to play the guard action to the electronic components in the circuit, prolong electronic components's life, improve circuit reliability.
Description
Technical Field
The application relates to the technical field of electronic circuits, in particular to an overvoltage protection circuit and electrical equipment.
Background
The electric equipment is a general name of appliances which can work only by being electrified, generally, the household electric equipment supplies power through an urban power distribution network, in China, the urban power distribution network directly faces to vast power consumers, the power supply mode can be summarized into a high-voltage receiving-transformer step-down-low-voltage distribution mode, and generally, high-voltage electricity of a power plant is converted into 220V commercial power to be supplied to the power consumers after being subjected to step-down conversion by a transformer substation.
However, since the voltage is transmitted from the power plant to the power consumer through the transformation of the transmission and distribution lines and the transformers at different levels, and when the load is different due to the line impedance or the internal impedance of the transformers, the voltage drops of the transmission and distribution lines and the transformers at different levels are different, so that the voltage of the utility power transmitted to the end for the power consumer is unstable, high voltage may fluctuate, and electronic components in the electrical equipment are easily damaged by the high voltage, which results in the failure of the electrical equipment.
At present, in order to avoid the damage of electronic components by high voltage, a scheme for realizing mains voltage detection through a voltage stabilizing source and an isolation optocoupler is provided, however, in the existing technical scheme, overvoltage detection in a circuit can be only carried out, when overvoltage is detected, artificial power off is needed, and if power off is not timely, electronic components, especially a main control chip, can be broken down and damaged.
SUMMERY OF THE UTILITY MODEL
The application provides an overvoltage protection circuit and electrical equipment, when aiming at solving among the prior art when detecting overvoltage in the circuit, need artificial outage, if the outage is untimely, just can lead to electronic components especially main control chip to be punctured the problem of destroying.
In a first aspect, the application provides an overvoltage protection circuit, which comprises a power supply module, an isolation detection module and a protection module, wherein the power supply module, the isolation detection module and the protection module are electrically connected in sequence;
the power supply module is used for providing alternating voltage and converting the alternating voltage into direct voltage to be output to the isolation detection module;
the isolation detection module is used for comparing the direct-current voltage with a preset voltage threshold value to obtain a comparison result and outputting a first level to the protection module according to the comparison result;
and the protection module is used for determining the working state according to the first level so that the power supply module provides alternating voltage when the protection module is in a closed state and cuts off the alternating voltage provided by the power supply module when the protection module is in an open state.
In one possible implementation manner of the present application, the overvoltage protection circuit further includes a microcontroller, and the microcontroller is electrically connected to the isolation detection module and the protection module, respectively;
the microcontroller is used for receiving the first level and obtaining a control level according to the first level and outputting the control level to the protection module, so that the protection module determines the working state according to the control level.
In one possible implementation manner of the present application, the protection module includes a relay configured with a normally closed contact, the normally closed contact is electrically connected to the power supply module, and the relay is configured to control a connection relationship between the normally closed contact and the power supply module according to a control level to determine a working state.
In one possible implementation manner of the application, the control level comprises a control high level and a control low level, and the relay controls the normally closed contact to be disconnected with the power supply module according to the control high level so that the protection module works in a disconnected state; the relay controls the normally closed contact to be connected with the power supply module according to the control low level so that the protection module works in a closed state.
In one possible implementation manner of the present application, the isolation detection module includes a detection module electrically connected to the power supply module, and the detection module includes a voltage regulator and a voltage dividing module;
the voltage division module is used for obtaining comparison voltage according to the direct-current voltage and outputting the comparison voltage to a voltage stabilizing source;
the voltage stabilizing source is used for comparing a preset voltage threshold value with a comparison voltage, the voltage stabilizing source is conducted when the comparison voltage is larger than or equal to the preset voltage threshold value, and the voltage stabilizing source is cut off when the comparison voltage is smaller than the preset voltage threshold value.
In one possible implementation manner of the present application, the first level includes a first high level and a first low level, the isolation detection module further includes an isolation optocoupler and a detection module electrically connected to each other, the isolation optocoupler is electrically connected to the detection module, and the detection module is electrically connected to the microcontroller;
the isolation optocoupler is used for conducting when the voltage stabilizing source is conducted and cutting off when the voltage stabilizing source is cut off;
the detection module is used for outputting a first low level to the microcontroller when the isolation optocoupler is switched on, and outputting a first high level to the microcontroller when the isolation optocoupler is switched off.
In this application, detection module includes first triode, and the isolation opto-coupler includes light emitting device and photosensitive device, and light emitting device is connected with detection module electricity, and photosensitive device's collecting electrode is connected with the base of first triode, and photosensitive device's projecting pole and the projecting pole of first triode are connected and ground connection, and microcontroller is connected to the collecting electrode of first triode.
In one possible implementation manner of the present application, the overvoltage protection circuit further includes a power module electrically connected to the microcontroller, and the power module is configured to supply power to the microcontroller when the protection module is in the off state, so that the microcontroller continuously outputs a control high level to ensure that the protection module is in the off state.
In one possible implementation manner of the present application, the overvoltage protection circuit further includes an audible and visual alarm module electrically connected to the microcontroller, and the audible and visual alarm module is configured to send an audible and visual alarm signal to indicate that the circuit is in an overvoltage state when the microcontroller receives the first low level.
In a second aspect, the present application further provides an electrical apparatus, in which the overvoltage protection circuit of the first aspect is integrated.
In one possible implementation manner of the present application, the electrical device is an air conditioner.
From the above, the present application has the following advantageous effects:
1. in this application, detect DC voltage through keeping apart detection module, compare DC voltage with predetermine voltage threshold, and obtain first level according to the comparison result and export protection module, protection module determines its self operating condition to be closed state or off-state according to first level, when protection module is in the off-state, it can cut off the alternating voltage that power module provided, avoid alternating voltage to transmit to the back stage circuit and cause the damage to the electronic components and parts in the circuit, when overvoltage in detecting the circuit promptly, protection module can switch over immediately to off-state, thereby play the guard action to the electronic components and parts in the circuit, the life of extension electronic components and parts, improve the circuit reliability.
2. In this application, being in the off-state at the protection module, under the unable condition that provides alternating voltage for the circuit of power module promptly, being the microcontroller power supply through power module, can ensure that microcontroller continuously outputs the high level to make the protection module be in the off-state all the time, further improved the circuit reliability.
Drawings
In order to more clearly illustrate the technical solutions in the present application, the drawings that are needed to be used in the description of the present application 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 it is obvious for those skilled in the art that other drawings can be obtained based on these drawings without inventive effort.
Fig. 1 is a schematic diagram of an overvoltage protection circuit provided in an embodiment of the present application;
FIG. 2 is a schematic circuit diagram of an over-voltage protection circuit provided in an embodiment of the present application;
fig. 3 is a schematic structural diagram of an electrical apparatus provided in an embodiment of the present application.
Detailed Description
The technical solutions in the present application will be described clearly and completely with reference to the accompanying drawings in the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and 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 application.
In the description of the present application, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like indicate orientations or positional relationships based on those shown in the drawings, and are used merely for convenience of description and for simplicity of description, and do not indicate or imply that the referenced device or element must have a particular orientation, be constructed in a particular orientation, and be operated, and thus should not be considered as limiting the present application. Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more features. In the description of the present application, "a plurality" means two or more unless specifically limited otherwise.
In this application, the word "exemplary" is used to mean "serving as an example, instance, or illustration. Any embodiment described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments. The following description is presented to enable any person skilled in the art to make and use the application. In the following description, details are set forth for the purpose of explanation. It will be apparent to one of ordinary skill in the art that the present application may be practiced without these specific details. In other instances, well-known structures and processes are not set forth in detail in order to avoid obscuring the description of the present application with unnecessary detail. Thus, the present application is not intended to be limited to the embodiments shown, but is to be accorded the widest scope consistent with the principles and features disclosed herein.
Referring to fig. 1, fig. 1 is a schematic structural diagram of an overvoltage protection circuit provided in an embodiment of the present application. The overvoltage protection circuit may include a power supply module 100, an isolation detection module 200, and a protection module 400 electrically connected in sequence, wherein the protection module 400 is configured with two operating states, a closed state and an open state. The power supply module 100 may be configured to provide an ac voltage, convert the ac voltage into a dc voltage, and output the dc voltage to the isolation detection module 200; the isolation detection module 200 may be configured to compare the dc voltage with a preset voltage threshold to obtain a comparison result, and output a first level to the protection module 400 according to the comparison result; the protection module 400 may be configured to determine an operating state according to the first level, so that the power supply module 100 provides the ac voltage in a closed state, and the power supply module 100 cuts off the ac voltage in an open state.
In this embodiment, the ac voltage provided by the power supply module 100 may be 220V ac power provided by a utility power grid, and since the operating voltage of the electronic components in the electrical equipment is mostly dc voltage, the power supply module 100 may be configured to convert the ac voltage into dc voltage, so as to provide the voltage for detection and supply power to the electronic components in the circuit through the dc voltage for the isolation detection module 200 in the subsequent circuit.
As shown in fig. 1, in some embodiments, the power supply module 100 may include a rectifying module 101, the rectifying module 101 may rectify 220V ac power provided by a utility grid into dc voltage, and provide the voltage for detection to the isolation detection module 200 at the subsequent stage, and the rectifying module 101 may be a conventional rectifier, a rectifying bridge, or the like. In addition, because there may be noise or sawtooth waves in the rectified dc voltage, in some embodiments of the present application, the power supply module 100 may further include a smoothing module 102 electrically connected to the rectification module 101, where the smoothing module 102 may be configured to filter the rectified dc voltage containing noise or sawtooth waves, so that the finally obtained dc voltage has a smooth dc waveform, so as to improve the detection accuracy of the subsequent isolation detection module 200 for detecting the dc voltage.
In this embodiment, the isolation detection module 200 compares the dc voltage with the preset voltage threshold, which may be by a voltage comparator, or by an electronic component with a comparison function, where the comparison result of the dc voltage with the preset voltage threshold may be that the dc voltage is greater than the preset voltage threshold, the dc voltage is equal to the preset voltage threshold, or the dc voltage is less than the preset voltage threshold, and when the dc voltage is equal to the preset voltage threshold or the dc voltage is less than the preset voltage threshold, it may be considered that the voltage of the circuit is within a tolerable range of the electronic component, that is, there is no high voltage in the circuit that may damage the electronic component, so that, in the two cases, the first level may be a level signal that does not affect normal operation of the circuit; in this case, the first level output by the isolation detection module 200 may be a level signal for changing the current operating state of the circuit.
In this embodiment, the protection module 400 is configured with two working states, i.e., a closed state and an open state, and the isolation detection module 200 outputs a first level to the protection module 400 according to a comparison result between the dc voltage and the preset voltage threshold, so that the protection module 400 determines the working state according to the first level. When the circuit normally operates, because the power supply module 100 needs to provide an alternating voltage for a subsequent circuit, at this time, the protection module 400 may be in a closed state, so that the power supply module 100 provides the alternating voltage, and when the direct voltage is equal to the preset voltage threshold or the direct voltage is less than the preset voltage threshold, the first level output by the isolation detection module 200 is a level signal that does not affect the normal operation of the circuit, that is, when the direct voltage is equal to the preset voltage threshold or the direct voltage is less than the preset voltage threshold, the protection module 400 determines that the working state is the closed state according to the first level; when the dc voltage is greater than the preset voltage threshold, because the first level output by the isolation detection module 200 is a level signal for changing the current operating state of the circuit, that is, under the condition that the dc voltage is greater than the preset voltage threshold, the protection module 400 determines that the operating state is the off state according to the first level, at this time, the protection module 400 may be used to cut off the ac voltage provided by the power supply module 100, so that the power supply module 100 cannot provide the ac voltage for the subsequent circuit, and the impact of the high voltage on the electronic components in the circuit is avoided.
In the embodiment of the present application, the dc voltage is detected by the isolation detection module 200, the dc voltage is compared with a preset voltage threshold, and a first level is obtained according to the comparison result and is output to the protection module 400, the protection module 400 determines whether its own working state is a closed state or an open state according to the first level, when the protection module 400 is in the open state, it can cut off the ac voltage provided by the power supply module 100, it is avoided that the ac voltage is transmitted to the rear-stage circuit to damage the electronic components in the circuit, that is, when an overvoltage is detected in the circuit, the protection module 400 can be immediately switched to the open state, thereby playing a protection role on the electronic components in the circuit, prolonging the service life of the electronic components, and improving the reliability of the circuit.
Referring to fig. 1, in some embodiments of the present application, the overvoltage protection circuit may further include a microcontroller 300, the microcontroller 300 may be electrically connected to the isolation detection module 200 and the protection module 400, respectively, and the microcontroller 300 may be configured to receive the first level and obtain a control level according to the first level to output the control level to the protection module 400, so that the protection module 400 determines the operating state according to the control level. In this embodiment, the microcontroller 300 may obtain a control level for controlling the working state of the protection module 400 according to the first level output by the isolation detection module 200, so that the protection module 400 determines that the working state thereof is a closed state or an open state according to the control level.
As shown in fig. 2, which is a schematic circuit diagram of the overvoltage protection circuit provided in the embodiment of the present application, in some embodiments of the present application, the protection module 400 may include a relay K1 configured with a normally closed contact, the normally closed contact of the relay K1 is electrically connected to the power supply module 100, and the relay K1 is configured to control a connection relationship between the normally closed contact and the power supply module 100 according to a control level to determine an operating state. Referring to fig. 2, in the present embodiment, the rectifier module 101 is a rectifier bridge DB1 connected to the commercial power, wherein the live line L of the commercial power is connected to pin 2 of the rectifier bridge DB1, the neutral line N of the commercial power is connected to pin 3 of the rectifier bridge DB1, the smoothing module 102 is a first electrolytic capacitor E1, the normally closed contact of the relay K1 is electrically connected to the neutral line N of the commercial power, specifically, the normally closed contact of the relay K1 is connected between the neutral line N of the commercial power and pin 3 of the rectifier bridge DB1, and the first output end OUT1 of the Microcontroller (MCU) is connected to the relay K1 through a second triode Q2 to output a control level to the relay K1. In this embodiment, the control level may include a control high level and a control low level, and the relay K1 may control the normally closed contact to disconnect from the power supply module 100 according to the control high level, so that the protection module 400 operates in an off state; the relay K1 may control the normally closed contact to connect with the power supply module 100 according to the control low level, so that the protection module 400 operates in the closed state.
Specifically, the first output end OUT1 of the MCU is connected to the base of the second transistor Q2, the emitter of the second transistor Q2 is grounded, and the collector is connected to the relay K1, where the second transistor Q2 is equivalent to a switch, when the control level output by the MCU is controlled to be high, the second transistor Q2 is turned on, since the relay K1 is provided with a normally closed contact, which is in a closed state when the circuit normally works, i.e., the commercial power normally provides an ac voltage to the rectifier bridge DB1, when the second transistor Q2 is turned on, the relay K1 is powered, and at this time, the normally closed contact is disconnected from the neutral line N, i.e., at this time, the normally closed contact cuts off the connection between the commercial power and the rectifier bridge DB1, and the power supply module 100 cannot provide an ac voltage to the subsequent circuit; when the control level of the control level output by the MCU is low, the second transistor Q2 is turned off, and the relay K1 is still in a closed state, i.e. the commercial power normally provides ac voltage to the rectifier bridge DB 1.
As shown in fig. 1, in some embodiments of the present application, the isolation detection module 200 may include a detection module 203 electrically connected to the power supply module 100, where the detection module 203 may include a voltage regulator 2031 and a voltage dividing module 2032, where the voltage dividing module 2032 may be configured to obtain a comparison voltage according to the dc voltage and output the comparison voltage to the voltage regulator 2031; the voltage regulator 2031 may be configured to compare a preset voltage threshold with a comparison voltage, turn on the voltage regulator 2031 when the comparison voltage is greater than or equal to the preset voltage threshold, and turn off the voltage regulator 2031 when the comparison voltage is less than the preset voltage threshold, specifically, the voltage regulator 2031 may be a controllable precision voltage regulator.
Referring to fig. 2, in the embodiment of the present application, the voltage regulator 2031 is a controllable precision voltage regulator of TL431K (BP), and the voltage dividing module 2032 includes a first resistor R1 and a second resistor R2, where the first resistor R1 and the second resistor R2 are connected in series between pin 1 of the rectifier bridge DB1 and ground, a connection point of the first resistor R1 and the second resistor R2 is connected to a reference electrode of the controllable precision voltage regulator TL431K (BP), an anode of the controllable precision voltage regulator TL431K (BP) is grounded, and a cathode is connected to pin 1 of the rectifier bridge DB1 sequentially through a fourth resistor R4 and a third resistor R3. The controllable precision voltage-stabilizing source TL431K (BP) can be turned on by adjusting the resistance values of the first resistor R1 and the second resistor R2, in this embodiment, the turn-on voltage of the controllable precision voltage-stabilizing source TL431K (BP) is a preset voltage threshold, so that when the comparison voltage of the connection point of the first resistor R1 and the second resistor R2 is greater than or equal to the preset voltage threshold, the controllable precision voltage-stabilizing source TL431K (BP) is turned on, and when the comparison voltage is less than the preset voltage threshold, the controllable precision voltage-stabilizing source TL431K (BP) is turned off.
As shown in fig. 1, in some embodiments of the present application, the isolation detection module 200 may further include an isolation optocoupler 204 and a detection module 205 electrically connected to each other, the isolation optocoupler 204 is electrically connected to the detection module 203, the detection module 205 is electrically connected to the microcontroller 300, the first level includes a first high level and a first low level, and the isolation optocoupler 204 may be configured to be turned on when the regulator 2031 is turned on and turned off when the regulator 2031 is turned off; the detection module 205 may be configured to output a first low level to the microcontroller 300 when the isolation optocoupler 204 is turned on, and output a first high level to the microcontroller 300 when the isolation optocoupler 204 is turned off. In the embodiment of the present application, through the characteristic of the isolation optocoupler 204, the isolation between strong current and weak current can be realized, voltage protection is performed on the microcontroller 300, and the detection module 205 can filter the lightning surge, so as to avoid the lightning surge in the circuit from affecting the control level output by the microcontroller 300.
As shown in fig. 2, the detection module 205 includes a first transistor Q1, the isolation optocoupler 204 is an optocoupler IC3 including a light emitting device and a photo sensor, the light emitting device is electrically connected to a controllable precision voltage regulator TL431K (BP) of the detection module, a collector of the photo sensor, i.e. 4 pin, is connected to a base of the first transistor Q1, an emitter of the photo sensor, i.e. 3 pin, is connected to an emitter of the first transistor Q1 and is grounded, a collector of the first transistor Q1 is connected to the MCU, specifically, an anode of the light emitting device, i.e. 1 pin, is connected to a connection point of a third resistor R3 and a fourth resistor R4, a cathode of the light emitting device, i.e. 2 pin, is connected to a cathode of the controllable precision voltage regulator TL431K (BP), a collector of the photo sensor, i.e. 4 pin, is connected to a base of the first transistor Q1 through a sixth resistor R6, and a collector of the photo sensor is further connected to a power supply VCC through a fifth resistor R5, a base of the first transistor Q1 is grounded through a first capacitor C1, the collector of the first triode Q1 is connected with a power supply VCC through a seventh resistor R7, and is connected with a first input end IN1 of the MCU through an eighth resistor R8, and the first input end IN1 of the MCU is further connected with a second capacitor C2 connected to ground, IN this embodiment of the present application, when the dc voltage is less than or equal to the preset voltage threshold, the controllable precision voltage regulator TL431K (BP) is turned off, the optical coupler IC3 is also turned off, at this time, the first triode Q1 is turned off, the first level received by the first input end IN1 of the MCU is a first high level, the control level output by the first output end OUT1 of the MCU is a control low level, and at this time, the relay K1 may control the contact to be closed according to the control low level, so that the commercial power is normally supplied; when the direct-current voltage is greater than the preset voltage threshold, the controllable precise voltage-stabilizing source TL431K (BP) is conducted, the optical coupler IC3 is also conducted, the first triode Q1 is conducted at the moment, the first level received by the first input end IN1 of the MCU is the first low level, the control level output by the first output end OUT1 of the MCU is the control high level, and at the moment, the relay K1 can control the normally closed contact to be disconnected according to the control high level, so that the high voltage can be prevented from impacting electronic components IN the circuit, and the electronic components are prevented from being damaged.
As shown in fig. 1, in some embodiments of the present application, the overvoltage protection circuit may further include a power module 600 electrically connected to the microcontroller 300, where the power module 600 may be configured to supply power to the microcontroller 300 when the protection module 400 is in an off state, so that the microcontroller 300 continuously outputs a control high level to ensure that the protection module 400 is in the off state, in this embodiment, the power module 600 may be a storage battery BA with a power storage function, and in addition, a switching power module 500 may be connected between the power module 100 and the power module 600, as shown in fig. 2, in this embodiment, the switching power module 500 is a chip IC1, which may output a voltage with the same magnitude as an operating voltage of the microcontroller 300 to supply power thereto, for example, a power VCC with a voltage value of 5V or 3.3V, and may also output different other circuit voltages to supply power to other devices in the circuit or to supply power, for example, the voltage value is 12V, and in addition, the switching power supply module 500 may also supply power to the load, so that the number of paths and the amplitude of the voltage output by the switching power supply module 500 may be adjusted and planned according to an actual application scenario, and in addition, in order to cause interference to the storage battery BA by the internal ac voltage, a second electrolytic capacitor is connected in parallel between the chip IC1 and the storage battery BA for filtering the ac voltage.
As shown IN fig. 1, IN some embodiments of the present application, the overvoltage protection circuit may further include an audible and visual alarm module 700 electrically connected to the microcontroller 300, where the audible and visual alarm module 700 is configured to send an audible and visual alarm signal to indicate that the circuit is IN an overvoltage state when the microcontroller 300 receives a first low level, specifically, as shown IN fig. 2, the audible and visual alarm module 700 is a chip IC2, a warning lamp and a buzzer may be welded on the chip IC2, for simplicity and clarity of the drawing, the warning lamp and the buzzer are not shown IN fig. 2, the chip IC2 is connected to a second output terminal OUT2 of the MCU, and when the first input terminal IN1 of the MCU receives the first low level, the second output terminal OUT2 of the MCU may output a driving signal to light the warning lamp IN the chip IC2 and make a sound to provide a user mains voltage fluctuation, so as to be IN an overvoltage state and power off IN time.
Fig. 3 is a schematic structural diagram of an electrical apparatus provided in the embodiment of the present application. On the basis of the foregoing embodiments, the present application further provides an electrical device 800, where any one of the overvoltage protection circuits in the foregoing embodiments is integrated in the electrical device 800, and specifically, in some embodiments, the electrical device may be an air conditioner or other household appliance. Specifically, the load in the above embodiment may be a motor, and if the air conditioner or other household appliance starts to operate, and the microcontroller 300 receives the first low level, the microcontroller 300 outputs a control high level to open the normally closed contact of the relay K1, so as to perform overvoltage protection on the electrical appliance.
In the above embodiments, the descriptions of the respective embodiments have respective emphasis, and parts that are not described in detail in a certain embodiment may refer to the above detailed descriptions of other embodiments, and are not described herein again.
In a specific implementation, each unit or structure may be implemented as an independent entity, or may be combined arbitrarily to be implemented as one or several entities, and the specific implementation of each unit or structure may refer to the foregoing embodiments, which are not described herein again.
The overvoltage protection circuit and the electrical equipment provided by the application are introduced in detail, specific examples are applied in the description to explain the principle and the implementation mode of the application, and the description is only used for helping to understand the circuit and the core idea of the application; meanwhile, for those skilled in the art, according to the idea of the present application, there may be variations in the specific embodiments and the application scope, and in summary, the content of the present specification should not be construed as a limitation to the present application.
Claims (10)
1. The overvoltage protection circuit is characterized by comprising a power supply module, an isolation detection module and a protection module which are electrically connected in sequence, wherein the protection module is configured with two working states of a closed state and an open state;
the power supply module is used for providing alternating-current voltage, converting the alternating-current voltage into direct-current voltage and outputting the direct-current voltage to the isolation detection module;
the isolation detection module is used for comparing the direct-current voltage with a preset voltage threshold value to obtain a comparison result, and outputting a first level to the protection module according to the comparison result;
the protection module is configured to determine the working state according to the first level, so that the power supply module provides the ac voltage in the closed state, and the power supply module cuts off the ac voltage provided by the power supply module in the open state.
2. The overvoltage protection circuit of claim 1, further comprising a microcontroller electrically connected to the isolation detection module and the protection module, respectively;
the microcontroller is used for receiving the first level, obtaining a control level according to the first level and outputting the control level to the protection module, so that the protection module determines the working state according to the control level.
3. The overvoltage protection circuit of claim 2, wherein the protection module includes a relay configured with a normally closed contact electrically connected to the power supply module, the relay being configured to control a connection relationship of the normally closed contact to the power supply module according to the control level to determine the operating state.
4. The overvoltage protection circuit of claim 3, wherein the control level comprises a control high level and a control low level, and the relay controls the normally closed contact to be disconnected from the power supply module according to the control high level so that the protection module operates in the disconnected state; and the relay controls the normally closed contact to be connected with the power supply module according to the control low level so as to enable the protection module to work in the closed state.
5. The overvoltage protection circuit of claim 2, wherein the isolation detection module comprises a detection module electrically connected to the power supply module, the detection module comprising a regulated power supply and a voltage divider module;
the voltage division module is used for obtaining comparison voltage according to the direct-current voltage and outputting the comparison voltage to the voltage stabilizing source;
the voltage stabilizing source is used for comparing the preset voltage threshold value with the comparison voltage, when the comparison voltage is larger than or equal to the preset voltage threshold value, the voltage stabilizing source is conducted, and when the comparison voltage is smaller than the preset voltage threshold value, the voltage stabilizing source is cut off.
6. The overvoltage protection circuit of claim 5, wherein the first level comprises a first high level and a first low level, wherein the isolation detection module further comprises an isolation optocoupler and a detection module electrically connected to each other, wherein the isolation optocoupler is electrically connected to the detection module, and wherein the detection module is electrically connected to the microcontroller;
the isolation optocoupler is used for conducting when the voltage stabilizing source is conducted and cutting off when the voltage stabilizing source is cut off;
the detection module is used for outputting the first low level to the microcontroller when the isolation optocoupler is switched on, and outputting the first high level to the microcontroller when the isolation optocoupler is switched off.
7. The overvoltage protection circuit of claim 6, wherein the detection module comprises a first transistor, the isolation optocoupler comprises a light emitting device and a light sensing device, the light emitting device is electrically connected to the detection module, a collector of the light sensing device is connected to a base of the first transistor, an emitter of the light sensing device is connected to an emitter of the first transistor and grounded, and a collector of the first transistor is connected to the microcontroller.
8. The overvoltage protection circuit of claim 4, further comprising a power module electrically connected to the microcontroller, the power module being configured to power the microcontroller when the protection module is in the off state such that the microcontroller continuously outputs the control high level.
9. The overvoltage protection circuit of claim 6, further comprising an audible and visual alarm module electrically connected to the microcontroller, the audible and visual alarm module being configured to emit an audible and visual alarm signal to indicate that the circuit is in the overvoltage condition when the microcontroller receives the first low level.
10. An electrical apparatus, characterized in that an overvoltage protection circuit according to any one of claims 1-9 is integrated in the electrical apparatus.
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| CN202121876275.3U CN215990185U (en) | 2021-08-11 | 2021-08-11 | Overvoltage protection circuit and electrical equipment |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN118100619A (en) * | 2024-04-23 | 2024-05-28 | 深圳市华浩德电子有限公司 | BUCK topology output overvoltage protection circuit with high-voltage input |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN118100619A (en) * | 2024-04-23 | 2024-05-28 | 深圳市华浩德电子有限公司 | BUCK topology output overvoltage protection circuit with high-voltage input |
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