CN218767094U - Overvoltage protection circuit, undervoltage protection circuit, overvoltage undervoltage protection circuit, electric appliance power supply and electronic equipment - Google Patents
Overvoltage protection circuit, undervoltage protection circuit, overvoltage undervoltage protection circuit, electric appliance power supply and electronic equipment Download PDFInfo
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- CN218767094U CN218767094U CN202222747790.2U CN202222747790U CN218767094U CN 218767094 U CN218767094 U CN 218767094U CN 202222747790 U CN202222747790 U CN 202222747790U CN 218767094 U CN218767094 U CN 218767094U
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Abstract
The application discloses overvoltage protection circuit, undervoltage protection circuit, overvoltage undervoltage protection circuit, electrical apparatus power, electronic equipment of clothing. The overvoltage protection circuit includes: the reference electrode of the first reference voltage source is connected with the current power supply, and the anode of the first reference voltage source is grounded; the anode of the light emitting diode of the first photoelectric coupler is connected with the cathode of a first reference voltage source, and the cathode of the light emitting diode of the first photoelectric coupler is connected with a current power supply; the collector of the phototriode of the first photoelectric coupler is connected with a voltage power supply, and the emitter of the phototriode of the first photoelectric coupler is connected with an overvoltage alarm control module; the first end of the first divider resistor circuit is connected with a current power supply, and the second end of the first divider resistor circuit is grounded.
Description
Technical Field
The application relates to the technical field of circuits, in particular to an overvoltage protection circuit, an undervoltage protection circuit, an overvoltage undervoltage protection circuit, an electric appliance power supply and electronic equipment.
Background
Various electric appliances in life are damaged in different degrees due to the abnormity of the use environment in practical application, and input over-voltage and under-voltage are one of the common damage factors. The input over-voltage and under-voltage can cause the abnormal conditions of unstable control loop, overheating power devices, saturation magnetic devices and the like in the electric appliance, and the electric appliance is easily damaged.
Disclosure of Invention
In order to solve the technical problem, embodiments of the present application provide an overvoltage protection circuit, an undervoltage protection circuit, an overvoltage undervoltage protection circuit, an electrical appliance power supply, and an electronic device, which can improve overvoltage alarm accuracy.
Other features and advantages of the present application will be apparent from the following detailed description, or may be learned by practice of the application.
According to an aspect of an embodiment of the present application, there is provided an overvoltage protection circuit including: a reference electrode of the first reference voltage source is connected with a current power supply, and an anode of the first reference voltage source is grounded; the anode of a light emitting diode of the first photoelectric coupler is connected with the cathode of the first reference voltage source, and the cathode of the light emitting diode of the first photoelectric coupler is connected with the current power supply; the collector of the phototriode of the first photoelectric coupler is connected with a voltage power supply, and the emitter of the phototriode of the first photoelectric coupler is connected with an overvoltage alarm control module; a first voltage-dividing resistor circuit, a first end of the first voltage-dividing resistor circuit being connected to the current power supply, a second end of the first voltage-dividing resistor circuit being grounded; when the voltage value of the reference electrode of the first reference voltage source is greater than the first reference voltage provided by the first reference voltage source, the light emitting diode emits light to conduct the phototriode of the first photoelectric coupler, so that the emitter of the phototriode outputs a high-level signal to the overvoltage alarm control module to alarm for overvoltage.
In one exemplary embodiment, the circuit further comprises: a first resistor connected between a reference electrode of the first reference voltage source and the current source.
In one exemplary embodiment, the first reference voltage source includes: the negative input end of the comparator is connected with a reference voltage source, and the positive input end of the comparator is connected with the current power supply; and the base electrode of the triode is connected with the output end of the comparator, the collector electrode of the triode is connected with the anode of the light emitting diode of the first photoelectric coupler, and the emitter electrode of the triode is connected with the ground.
In one exemplary embodiment, the first reference voltage source further includes: and the input end of the diode is connected between the emitter of the triode and the collector of the triode.
In one exemplary embodiment, the circuit further comprises: and a first end of the first capacitor is connected with the reference electrode of the first reference voltage source, and a second end of the first capacitor is grounded.
In an exemplary embodiment, the circuit further includes a second capacitor and a second resistor, wherein a first terminal of the second resistor is connected to a first terminal of the second capacitor, a second terminal of the second resistor is connected to the current source, and a second terminal of the second capacitor is connected to a cathode of the first reference voltage source.
According to an aspect of an embodiment of the present application, there is provided an under-voltage protection circuit, including: a reference electrode of the second reference voltage source is connected with a current power supply, and an anode of the second reference voltage source is grounded; the anode of a light emitting diode of the second photoelectric coupler is connected with the cathode of the second reference voltage source, and the cathode of the light emitting diode of the second photoelectric coupler is connected with the current power supply; the collector of the phototriode of the second photoelectric coupler is connected with a voltage power supply, and the emitter of the phototriode of the second photoelectric coupler is connected with an undervoltage alarm control module; a second voltage-dividing resistor circuit, a first end of the second voltage-dividing resistor circuit being connected to the current power supply, and a second end of the second voltage-dividing resistor circuit being grounded; when the voltage value of the reference electrode of the second reference voltage source is smaller than the second reference voltage provided by the second reference voltage source, the light-emitting diode emits light to further conduct the phototriode of the second photoelectric coupler, so that the emitting electrode of the phototriode outputs a low-level signal to the undervoltage alarm control module to perform undervoltage alarm.
According to an aspect of the embodiments of the present application, there is provided an overvoltage and undervoltage protection circuit, including the overvoltage protection circuit described in any one of the above items, and the undervoltage protection circuit described above.
According to an aspect of an embodiment of the present application, there is provided an electrical appliance power supply including an overvoltage protection circuit or an undervoltage protection circuit as described in any one of the above.
According to an aspect of an embodiment of the present application, there is provided an electronic device including the electric appliance power supply provided above.
Compared with the scheme adopting the mutual inductor, the overvoltage protection circuit provided by the embodiment of the application carries out overvoltage alarm based on the reference voltage source and the photoelectric coupler, and has the advantages of high detection precision, high reliability, light weight, low price and the like. Compared with the scheme adopting the comparator, the overvoltage protection circuit provided by the embodiment has the advantages of being isolated from the detected voltage, simple in application, good in electromagnetic compatibility and the like.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the application.
Drawings
The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and together with the description, serve to explain the principles of the application. It is obvious that the drawings in the following description are only some embodiments of the application, and that for a person skilled in the art, other drawings can be derived from them without inventive effort. In the drawings:
FIG. 1 is a circuit diagram of an overvoltage protection circuit shown in an exemplary embodiment of the present application;
fig. 2 is a graph of current flowing through the first reference voltage source N702 as a function of input voltage;
FIG. 3 is a partial circuit diagram of a first reference voltage source shown in an exemplary embodiment;
FIG. 4 is a circuit diagram of an under-voltage protection circuit shown in an exemplary embodiment of the present application;
Detailed Description
Reference will now be made in detail to the exemplary embodiments, examples of which are illustrated in the accompanying drawings. When the following description refers to the accompanying drawings, like numbers in different drawings represent the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present application. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the present application, as detailed in the appended claims.
The block diagrams shown in the figures are functional entities only and do not necessarily correspond to physically separate entities. I.e. these functional entities may be implemented in the form of software, or in one or more hardware modules or integrated circuits, or in different networks and/or processor means and/or microcontroller means.
The flow charts shown in the drawings are merely illustrative and do not necessarily include all of the contents and operations/steps, nor do they necessarily have to be performed in the order described. For example, some operations/steps may be decomposed, and some operations/steps may be combined or partially combined, so that the actual execution sequence may be changed according to the actual situation.
It should also be noted that: reference to "a plurality" in this application means two or more. "and/or" describe the association relationship of the associated objects, meaning that there may be three relationships, e.g., A and/or B may mean: a exists alone, A and B exist simultaneously, and B exists alone. The character "/" generally indicates that the former and latter associated objects are in an "or" relationship.
In the prior art, a voltage transformer is adopted for general over-voltage and under-voltage protection to sample voltage. To the scheme that adopts the mutual-inductor mode to detect voltage, the mutual-inductor of itself has certain weight, and it is great to be applied to the product risk that the shock impact requires highly. The device is influenced by the precision of the mutual inductor, the integral detection precision is not high, the reliability is low, and particularly, when high-voltage alarming is carried out, the overvoltage is not caused under the specified voltage due to the precision problem, so that the system is damaged due to overvoltage. For a circuit which adopts a scheme of sampling resistance and a comparator to detect voltage, because strong current and weak current are not isolated, the electromagnetic compatibility of the system is seriously influenced.
In view of the above, the present application provides an overvoltage protection circuit, an undervoltage protection circuit, an overvoltage undervoltage protection circuit, an electrical power supply, and an electronic device, which will be described in detail through the following embodiments.
Referring to fig. 1, fig. 1 is a circuit diagram of an overvoltage protection circuit according to an exemplary embodiment of the present application, and as shown in fig. 1, the overvoltage protection circuit provided in this embodiment includes a first reference voltage source N702, a first photocoupler N701, and a first voltage-dividing resistor circuit, wherein a reference electrode of the first reference voltage source N702 is connected to a current power source DC _ input, an anode of the first reference voltage source N702 is grounded, a first end of the second voltage-dividing resistor circuit is connected to the current power source, and a second end of the second voltage-dividing resistor circuit is grounded.
Illustratively, as shown in fig. 1, the first voltage-dividing resistor circuit includes a third resistor R707, a fourth resistor R708, and a fifth resistor R709, wherein a first end of the third resistor R707 is connected to the reference electrode R of the first reference voltage source N702, a second end of the third resistor R707 is connected to a first end of the fourth resistor R708, a second end of the fourth resistor R708 is connected to a first end of the fifth resistor R709, and a second end of the fifth resistor R709 is grounded.
Illustratively, in the present embodiment, the resistances of the third resistor R707, the fourth resistor R708, and the fifth resistor R709 are 11K, 2.4K, and 0 Ω, respectively.
The anode of the light emitting diode of the first photoelectric coupler N701 is connected with the cathode K of the first reference voltage source N702, and the cathode of the light emitting diode of the first photoelectric coupler N701 is connected with the current power supply DC _ input; a collector C of the phototransistor of the first photocoupler N701 is connected to a voltage power supply, and an emitter E of the phototransistor of the first photocoupler N701 is connected to a PA1_ V _ HIGH terminal of an overvoltage alarm control module (not shown in the figure).
When the voltage value of the reference electrode R of the first reference voltage source N702 is greater than the first reference voltage provided by the first reference voltage source N702, the light emitting diode emits light to turn on the phototriode of the first photoelectric coupler N701, so that the emitter E of the phototriode outputs a high level signal to the overvoltage alarm control module to perform overvoltage alarm.
Specifically, the working principle of the overvoltage protection circuit provided by this embodiment is as follows:
after the circuit is powered on, if the input detected voltage is lower than a first reference voltage serving as an overvoltage alarm voltage, the current flowing through the light emitting diode of the first photoelectric coupler N701 and the current (i.e., ikao) from the cathode K to the anode a of the first reference voltage source N702 are both extremely small, so that the current of the emitter E of the phototriode of the first photoelectric coupler N701 is approximately zero, and at this time, the overvoltage alarm signal read by the overvoltage alarm control module is a logic low level, which indicates that no overvoltage alarm occurs in the system. When the external input voltage exceeds the first reference voltage, the current flowing from the cathode K to the anode A of the first reference voltage source N702 is rapidly increased, the first photoelectric coupler N701 is rapidly saturated and conducted, and at the moment, the overvoltage alarm signal read by the overvoltage alarm control module is in a logic high level, so that the overvoltage phenomenon of the overvoltage alarm control module circuit is prompted to occur.
Compared with the scheme of adopting the mutual inductor, the overvoltage protection circuit provided by the embodiment carries out overvoltage alarm based on the reference voltage source and the photoelectric coupler, and has the advantages of high detection precision, high reliability, light weight, low price and the like. Compared with the scheme adopting the comparator, the overvoltage protection circuit provided by the embodiment has the advantages of being isolated from the detected voltage, simple in application, good in electromagnetic compatibility and the like.
Referring to fig. 2, fig. 2 is a graph of a current flowing through a first reference voltage source N702 as a function of an input voltage, as shown in fig. 2, an abscissa indicates the input voltage, and an ordinate indicates a current flowing through a cathode K to an anode a of the first reference voltage source N701, and as can be seen from the graph, when the input voltage is less than a first voltage (the first voltage indicates a minimum voltage that causes the current flowing through the cathode K to the anode a of the first reference voltage source N702 to be zero, and is not identified), the current flowing through the cathode K to the anode a of the first reference voltage source N702 is less than zero, the current flowing through the cathode K to the anode a of the first reference voltage source N702 is not conducted to the anode a, when the input voltage is greater than the first voltage and less than a second voltage (the second voltage indicates a maximum voltage that causes the current flowing through the cathode K to the anode a of the first reference voltage source N702 to be zero, and is not identified), the current flowing through the cathode K to the anode a of the first reference voltage source N702 is equal to zero, and when the input voltage is greater than the second voltage, the cathode K to the anode a is rapidly conducted to the anode a, and the cathode K to the anode a is connected to the cathode K, and the cathode K of the anode a, and the alarm signal indicates that the overvoltage alarm module is rapidly connected to the first reference voltage source N701, and the alarm module. It can be seen that, in this embodiment, the preset first reference voltage is the second voltage, when the input voltage is less than the second voltage, the overvoltage warning signal is not sent out, and when the input voltage is greater than or equal to the second voltage, the overvoltage warning signal is sent out.
Illustratively, considering that there is a small output fluctuation theoretically when the voltage input to the first reference voltage source is close to the internal reference voltage, when the overvoltage alarm signal is read by the overvoltage alarm control module, the small section can be filtered by a proper filtering algorithm to achieve the purpose of further improving the detection accuracy. For example, a predetermined time period may be used for filtering, and only during this time period is the stable overvoltage alarm signal read, the corresponding action is executed.
Illustratively, the circuit further includes a first resistor R706, the first resistor R706 is connected between the reference electrode R of the first reference voltage source N702 and the current source DC _ input, and is configured to divide the input voltage, input the voltage obtained after dividing the input voltage into the reference electrode R, compare the voltage with the first reference voltage, and turn on the first reference voltage source R701 based on the comparison result.
In this embodiment, the first resistor R706 divides the input voltage and detects the divided voltage, thereby preventing the electric components from being damaged when the input voltage is too large. Illustratively, an ultra-precision resistance of 0.1% is employed as the first resistance R706. Illustratively, the first resistor R706 has a resistance of 1206-2M Ω.
For example, in order to further improve the accuracy of voltage detection, all components used in the overvoltage protection circuit need to be subjected to aging screening, so that the technical indexes of the components enter a stable state, and the attenuation of the detection accuracy of the product in the later use stage is reduced.
Illustratively, referring to fig. 1 and 3 together, fig. 3 is a partial circuit diagram of a first reference voltage source according to an exemplary embodiment, and as shown in fig. 3, the first reference voltage source N702 includes a comparator and a transistor, wherein a negative input terminal of the comparator is connected to a reference voltage source V REF The positive input terminal REF (i.e. the reference electrode R of the first reference voltage source N702) is connectedA current power supply DC _ input; the base electrode of the triode is connected with the output end of the comparator, the collector electrode of the triode (namely, the cathode K of the first reference voltage source N702) is connected with the anode of the light emitting diode of the first photoelectric coupler N701, and the emitter electrode of the triode (namely, the anode of the first reference voltage source N702) is connected with the ground.
When the switching power supply normally works, the output voltage is divided and sampled by the first resistor R706 and then is provided to the reference electrode of the first reference voltage source R702; the comparator of the first reference voltage source R702 compares the voltage of the reference electrode R with the first reference voltage, and at this time, the voltage of the reference electrode R is lower than the first reference voltage, the first reference voltage source R702 is not turned on, the first photocoupler N702 outputs a low level signal, and the switching power supply continues to operate normally. When the output voltage of the switching power supply rises, the potential of the reference electrode R of the first reference voltage source R702 rises along with the rise of the potential of the reference electrode R of the first reference voltage source R702, and when the output voltage continues to rise, which causes the potential of the reference electrode R of the first reference voltage source R702 to rise above the potential of the first reference voltage, the comparator of the first reference voltage source R702 outputs a high level to turn on the triode of the first reference voltage source R702, the light emitting diode of the first photoelectric coupler R701 is turned on to emit light, the phototriode in the first photoelectric coupler R701 receives a signal of the light emitting diode and feeds the signal back to the overvoltage alarm control module, and the overvoltage alarm control module can perform a corresponding overvoltage alarm operation based on the received high level signal. Illustratively, the overvoltage alarm control module controls the switching power supply to stop outputting, so that the function of outputting overvoltage protection is realized.
Illustratively, as shown in fig. 3, the first reference voltage source N702 further includes a diode, an input terminal of the diode is connected between an emitter of the transistor and a collector of the transistor, and this arrangement can function as a protection circuit, that is, when the load of the transistor is inductive, when the transistor is turned off, because the current flowing through the inductive load cannot change suddenly, a transient high voltage will be generated across the inductive load, and under this high voltage, the diode is turned on, and the transient energy is absorbed in time, so as to prevent the transistor from being broken down by the transient high voltage.
Illustratively, the overvoltage protection circuit provided by the present embodiment further includes: a first end of the first capacitor C702 is connected to the reference electrode R of the first reference voltage source N702, and a second end of the first capacitor C702 is connected to the GND2. For example, in this embodiment, the DC power supply DC _ input may be directly sampled, or the ac power supply may be sampled after being subjected to rectification filtering processing, so that high-precision voltage alarm detection can be provided. Specifically, if the ac power supply is connected to the circuit, the ac power supply is filtered by the first capacitor C702 before the voltage of the ac power supply is input to the reference electrode R of the first reference voltage source N702, so as to improve the accuracy of voltage alarm detection. Illustratively, the capacitance value of the first capacitor C702 is 1210-10uF.
Illustratively, the overvoltage protection circuit further includes a second capacitor C701 and a second resistor R710, wherein a first end of the second resistor R710 is connected to a first end of the second capacitor C701, a second end of the second resistor R710 is connected to the current power supply DC _ input, and a second end of the second capacitor C710 is connected to the cathode C of the first reference voltage source N702. In this embodiment, the second resistor R710 and the second capacitor C701 are disposed at corresponding positions, so that the steady-state response of the circuit can be improved, and the oscillation of the overvoltage protection circuit can be suppressed. Illustratively, the second capacitance C701 has a capacitance value of 10805-33nF. The resistance of the second resistor R710 is 10K omega-1%.
Illustratively, the overvoltage protection circuit provided by this embodiment further includes a sixth resistor R701, a seventh resistor R702, an eighth resistor R703, and a ninth resistor R704, where the sixth resistor R701, the seventh resistor R702, and the eighth resistor R703 are connected in parallel between the current power supply DC _ input and the negative electrode of the light emitting diode of the first photocoupler N701, a first end of the ninth resistor R704 is connected to a second end of the eighth resistor R703, and a second end of the ninth resistor R704 is grounded. Illustratively, the resistances of the sixth resistor R701, the seventh resistor R702 and the eighth resistor R703 are 1206-1M Ω, and the resistance of the ninth resistor R704 is 0603-18K Ω -1%.
Illustratively, the overvoltage protection circuit provided by this embodiment further includes a tenth resistor R705, a first end of the tenth resistor R705 is connected to the emitter E of the phototransistor of the first photocoupler N701, and a second end of the tenth resistor R705 is grounded. Illustratively, the tenth resistor R705 has a resistance of 10k.
Referring to fig. 4, fig. 4 is a circuit diagram of an under-voltage protection circuit according to an exemplary embodiment of the present application, and as shown in fig. 4, the under-voltage protection circuit provided in the present embodiment includes a second reference voltage source N722, a second voltage-dividing resistor circuit and a second photocoupler N721, wherein a reference electrode R of the second reference voltage source N722 is connected to a current power source DC _ input, and an anode a of the second reference voltage source N722 is grounded.
The anode of the light emitting diode of the second photoelectric coupler N721 is connected to the cathode K of the second reference voltage source N722, and the cathode of the light emitting diode of the second photoelectric coupler N721 is connected to the current power supply DC _ input; and a collector C of the phototriode of the second photoelectric coupler N721 is connected with a voltage power supply, and an emitter E of the phototriode of the second photoelectric coupler N721 is connected with the undervoltage alarm control module. The first end of the second voltage-dividing resistor circuit is connected with a current power supply, and the second end of the second voltage-dividing resistor circuit is grounded.
When the voltage value of the reference electrode of the second reference voltage source is smaller than the second reference voltage provided by the second reference voltage source, the light emitting diode emits light to conduct the phototriode of the second photoelectric coupler, so that the emitter of the phototriode outputs a LOW level signal to the PC12_ V _ LOW end of the undervoltage alarm control module to perform undervoltage alarm.
Exemplarily, the second voltage-dividing resistor circuit provided in this embodiment includes a thirteenth resistor R727, a fourteenth resistor R728, and a fifteenth resistor R729, wherein a first end of the thirteenth resistor R727 is connected to the reference electrode R of the second reference voltage source N722, a second end of the thirteenth resistor R727 is connected to a first end of the fourteenth resistor R728, a second end of the fourteenth resistor R728 is connected to a first end of the fifteenth resistor R729, and a second end of the fifteenth resistor R729 is grounded. Illustratively, in the present embodiment, the resistances of the thirteenth resistor R727, the fourteenth resistor R728 and the fifteenth resistor R729 are 0603-20K Ω -0.1%, 330 and 0 Ω, respectively.
Specifically, the operating principle of the under-voltage protection circuit provided by this embodiment is as follows:
after the system is powered up, if the input detected voltage is 0V, the second reference voltage source N722 in the under-voltage protection circuit is in an off state, the current flowing from the cathode K to the anode a of the second reference voltage source N722 is 0, and the light emitting diode of the second photoelectric coupler N721 does not emit light, so that the current of the collector C of the second photoelectric coupler N721 is zero, and at this time, the under-voltage alarm signal received by the under-voltage alarm control module is a logic low level, which indicates that an under-voltage phenomenon occurs in the system. The undervoltage alarm signal read by the undervoltage alarm control module is always in a logic low level before the external input voltage reaches the undervoltage alarm voltage (i.e. the second reference voltage). When the input voltage exceeds the under-voltage alarm voltage, the current flowing through the cathode K to the anode a of the second reference voltage source N722 increases rapidly, the second photoelectric coupler N721 is turned on in a saturated state rapidly, and at this time, the under-voltage alarm signal read by the under-voltage alarm control module is a logic high level, and the under-voltage alarm signal is removed.
Illustratively, the circuit further includes an eleventh resistor R726, the eleventh resistor R726 is connected between the reference electrode R of the second reference voltage source N722 and the current power source DC _ input, and is configured to divide the input voltage, input the voltage after dividing the input voltage into the reference electrode R, compare the voltage with the first reference voltage, and turn on the first reference voltage source R701 based on the comparison result. Illustratively, the eleventh resistor R726 is a chip resistor having a resistance of 1206-2M-B0.1% Ω.
In this embodiment, the eleventh resistor R726 divides the input voltage and detects the divided voltage, thereby preventing the electric components from being damaged when the input voltage is too high. Illustratively, an ultra-precision resistance of 0.1% is employed as the eleventh resistance R726.
For example, in order to further improve the accuracy of voltage detection, components used in all the undervoltage protection circuits need to be subjected to aging screening, so that the technical indexes of the components enter a stable state, and the attenuation of the detection accuracy of the product in the later use stage is reduced.
Illustratively, as shown in fig. 4, the second reference voltage source N722 further includes a diode, an input terminal of the diode is connected between an emitter of the transistor and a collector of the transistor, and this arrangement can function as a protection circuit, that is, when the load of the transistor is inductive, because the current flowing through the inductive load cannot change suddenly when the transistor is turned off, a transient high voltage will be generated across the inductive load, under this high voltage, the diode is turned on, and transient energy is absorbed in time, so as to prevent the transistor from being broken down by the transient high voltage.
Illustratively, the undervoltage protection circuit provided by this embodiment further includes: a first terminal of the eleventh capacitor C704 is connected to the reference electrode R of the second reference voltage source N722, and a second terminal of the eleventh capacitor C704 is connected to the ground GND2. For example, in this embodiment, the DC power supply DC _ input may be directly sampled, or the ac power supply may be sampled after being subjected to rectification filtering processing, so that high-precision voltage alarm detection can be provided. Specifically, if the ac power supply is connected to the circuit, the eleventh capacitor C704 is used to filter the ac power supply before the voltage of the ac power supply is input to the reference electrode R of the second reference voltage source N722, thereby improving the accuracy of the voltage alarm detection. Illustratively, the capacitance value of the eleventh capacitor C704 is 1210-10uF.
Illustratively, the under-voltage protection circuit further includes a twelfth capacitor C721 and a twelfth resistor R730, wherein a first end of the twelfth resistor R730 is connected to a first end of the twelfth capacitor C721, a second end of the twelfth resistor R730 is connected to the current source DC _ input, and a second end of the twelfth capacitor C721 is connected to the cathode C of the second reference voltage source N702. In this embodiment, the second resistor R710 and the twelfth capacitor C721 are disposed at corresponding positions, so that the steady-state response of the circuit can be improved, and the oscillation of the under-voltage protection circuit can be suppressed. Illustratively, the capacitance of the twelfth capacitor C721 is 0805-33Nf, and the resistance of the second resistor R710 is 10K Ω -1%.
Illustratively, the under-voltage protection circuit provided by this embodiment further includes a sixteenth resistor R721, a seventeenth resistor R722, an eighteenth resistor R723 and a nineteenth resistor R724, wherein the sixteenth resistor R721, the seventeenth resistor R722 and the eighteenth resistor R723 are connected in parallel between the current power supply DC _ input and the negative electrode of the light emitting diode of the second photocoupler N721, a first end of the nineteenth resistor R724 is connected to a second end of the eighteenth resistor R723, and a second end of the nineteenth resistor R724 is grounded. Illustratively, the resistance values of the sixteenth resistor R721, the seventeenth resistor R722 and the eighteenth resistor R723 are 1206-1M Ω, and the resistance value of the nineteenth resistor R724 is 0603-18K Ω -1%.
Illustratively, the undervoltage protection circuit provided by this embodiment further includes a twentieth resistor R725, a first end of the twentieth resistor R725 is connected to the emitter E of the phototransistor of the second photocoupler N721, and a second end of the twentieth resistor R725 is grounded. Illustratively, the twentieth resistor R725 has a resistance of 10k.
In another exemplary embodiment, the present application provides an under-voltage protection circuit, which includes any one of the over-voltage protection circuits provided in the above embodiments, and any one of the under-voltage protection circuits provided in the above embodiments.
In another exemplary embodiment, the present application provides an electrical appliance power supply comprising any one of the over-voltage protection circuits or the under-voltage protection circuits provided in the above embodiments.
In another exemplary embodiment, the present application provides an electronic device including the appliance power supply provided in the above-described embodiment. Exemplary embodiments provide electronic devices including, but not limited to, air conditioners and electrical products that require protection of the system under over-voltage or under-voltage conditions.
It should be noted that the circuit provided in the foregoing embodiment and the device provided in the foregoing embodiment belong to the same concept, and the specific manner in which each module and unit execute operations has been described in detail in the method embodiment, and is not described again here.
The units described in the embodiments of the present application may be implemented by software, or may be implemented by hardware, and the described units may also be disposed in a processor. Wherein the names of the elements do not in some way constitute a limitation on the elements themselves.
The above description is only a preferred exemplary embodiment of the present application, and is not intended to limit the embodiments of the present application, and those skilled in the art can easily make various changes and modifications according to the main concept and spirit of the present application, so that the protection scope of the present application shall be subject to the protection scope of the claims.
Claims (10)
1. An overvoltage protection circuit, comprising:
a reference electrode of the first reference voltage source is connected with a current power supply, and an anode of the first reference voltage source is grounded;
the anode of a light emitting diode of the first photoelectric coupler is connected with the cathode of the first reference voltage source, and the cathode of the light emitting diode of the first photoelectric coupler is connected with the current power supply; the collector of the phototriode of the first photoelectric coupler is connected with a voltage power supply, and the emitter of the phototriode of the first photoelectric coupler is connected with an overvoltage alarm control module;
a first voltage-dividing resistor circuit, a first end of the first voltage-dividing resistor circuit being connected to the current power supply, a second end of the first voltage-dividing resistor circuit being grounded;
when the voltage value of the reference electrode of the first reference voltage source is greater than the first reference voltage provided by the first reference voltage source, the light-emitting diode emits light to further conduct the phototriode of the first photoelectric coupler, so that the emitter of the phototriode outputs a high-level signal to the overvoltage alarm control module to perform overvoltage alarm.
2. The circuit of claim 1, further comprising:
a first resistor connected between a reference electrode of the first reference voltage source and the current source.
3. The circuit of claim 1, wherein the first reference voltage source comprises:
the negative input end of the comparator is connected with a reference voltage source, and the positive input end of the comparator is connected with the current power supply;
and the base electrode of the triode is connected with the output end of the comparator, the collector electrode of the triode is connected with the anode of the light emitting diode of the first photoelectric coupler, and the emitter electrode of the triode is connected with the ground.
4. The circuit of claim 3, wherein the first reference voltage source further comprises:
and the input end of the diode is connected between the emitter of the triode and the collector of the triode.
5. The circuit of claim 1, further comprising:
and a first end of the first capacitor is connected with the reference electrode of the first reference voltage source, and a second end of the first capacitor is grounded.
6. The circuit of claim 1, further comprising a second capacitor and a second resistor, wherein a first terminal of the second resistor is connected to a first terminal of the second capacitor, a second terminal of the second resistor is connected to the current source, and a second terminal of the second capacitor is connected to a cathode of the first reference voltage source.
7. An undervoltage protection circuit, comprising:
a reference electrode of the second reference voltage source is connected with a current power supply, and an anode of the second reference voltage source is grounded;
the anode of a light emitting diode of the second photoelectric coupler is connected with the cathode of the second reference voltage source, and the cathode of the light emitting diode of the second photoelectric coupler is connected with the current power supply; the collector of the phototriode of the second photoelectric coupler is connected with a voltage power supply, and the emitter of the phototriode of the second photoelectric coupler is connected with an undervoltage alarm control module;
a second voltage-dividing resistor circuit, a first end of the second voltage-dividing resistor circuit being connected to the current power supply, and a second end of the second voltage-dividing resistor circuit being grounded;
when the voltage value of the reference electrode of the second reference voltage source is smaller than the second reference voltage provided by the second reference voltage source, the light-emitting diode emits light to further conduct the phototriode of the second photoelectric coupler, so that the emitting electrode of the phototriode outputs a low-level signal to the undervoltage alarm control module to perform undervoltage alarm.
8. An overvoltage and undervoltage protection circuit, comprising an overvoltage protection circuit according to any one of claims 1 to 6 and an undervoltage protection circuit according to claim 7.
9. An electrical appliance power supply comprising an overvoltage protection circuit or an undervoltage protection circuit as claimed in any one of claims 1 to 7.
10. An electronic device characterized by comprising an appliance power supply as claimed in claim 9.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202222747790.2U CN218767094U (en) | 2022-10-18 | 2022-10-18 | Overvoltage protection circuit, undervoltage protection circuit, overvoltage undervoltage protection circuit, electric appliance power supply and electronic equipment |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202222747790.2U CN218767094U (en) | 2022-10-18 | 2022-10-18 | Overvoltage protection circuit, undervoltage protection circuit, overvoltage undervoltage protection circuit, electric appliance power supply and electronic equipment |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN218767094U true CN218767094U (en) | 2023-03-28 |
Family
ID=85699956
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202222747790.2U Active CN218767094U (en) | 2022-10-18 | 2022-10-18 | Overvoltage protection circuit, undervoltage protection circuit, overvoltage undervoltage protection circuit, electric appliance power supply and electronic equipment |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN218767094U (en) |
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2022
- 2022-10-18 CN CN202222747790.2U patent/CN218767094U/en active Active
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