CN212162790U - Under-voltage protection circuit, vehicle-mounted charger and protection system - Google Patents
Under-voltage protection circuit, vehicle-mounted charger and protection system Download PDFInfo
- Publication number
- CN212162790U CN212162790U CN202020963597.0U CN202020963597U CN212162790U CN 212162790 U CN212162790 U CN 212162790U CN 202020963597 U CN202020963597 U CN 202020963597U CN 212162790 U CN212162790 U CN 212162790U
- Authority
- CN
- China
- Prior art keywords
- unit
- resistor
- electrically connected
- voltage
- output
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
- Y02T10/00—Road transport of goods or passengers
- Y02T10/60—Other road transportation technologies with climate change mitigation effect
- Y02T10/70—Energy storage systems for electromobility, e.g. batteries
Landscapes
- Charge And Discharge Circuits For Batteries Or The Like (AREA)
Abstract
The utility model discloses an under-voltage protection circuit, a vehicle-mounted charger and a protection system, wherein the under-voltage protection circuit comprises a first comparison unit, a switch unit, a second comparison unit and a judgment unit; the input end of the first comparing unit is electrically connected with the output end of the external power supply, and the first output end of the first comparing unit is electrically connected with the first input end of the judging unit; the input end of the switch unit is electrically connected with the second output end of the first comparison unit, the control end of the switch unit is electrically connected with an external control circuit, and the output end of the switch unit is electrically connected with the grounding end; the input end of the second comparison unit is electrically connected with an external power supply and an external sampling circuit, and the output end of the second comparison unit is electrically connected with the second input end of the judgment unit; the output end of the judging unit is electrically connected with the rear-stage output circuit. The utility model discloses can carry out the undervoltage detection at the machine equipment that charges start-up in-process, promote the convenience.
Description
Technical Field
The utility model relates to an on-vehicle machine field that charges especially relates to an under-voltage protection circuit, on-vehicle machine and the protection system that charges.
Background
The electric automobile is a necessary trend of future development, so the development of the electric automobile is generally established by main producing countries in the world as an important way for improving the automobile industry competitiveness, guaranteeing the energy safety and transforming low-carbon economy. The vehicle-mounted charger is an important component of the electric automobile, converts alternating current into direct current required by a battery of the electric automobile when the electric automobile is charged, and monitors key data such as output voltage, output current, charger temperature and the like in the charging process.
In order to ensure the reliability and stable operation of the vehicle-mounted charger product, a detection circuit for bus voltage and output voltage is generally arranged to monitor the voltage, and when the voltage is abnormally reduced in the starting process or normal operation, the fault is considered to occur and the vehicle-mounted charger is shut down for protection.
The protection threshold of the conventional undervoltage protection circuit is generally a fixed value, that is, undervoltage protection is triggered if the values of the detected bus voltage and the output voltage are lower than the protection threshold, but because the detected voltage gradually rises from zero to the starting voltage in the starting process of the vehicle-mounted charger device, if the undervoltage protection circuit is started, the undervoltage protection is triggered because the detected voltage is lower than the threshold voltage, so that the normal starting cannot be performed. Therefore, at present, it is common practice that the under-voltage protection detection is not performed when the vehicle-mounted charger device is started until the vehicle-mounted charger device is started, and the under-voltage detection is performed after the voltage is stabilized. However, in the starting process of the vehicle-mounted charger device, the bus voltage and the output voltage cannot be detected, so that the problem cannot be found in advance.
SUMMERY OF THE UTILITY MODEL
The utility model provides an under-voltage protection circuit, switching power supply and protection system, its simple structure can detect busbar voltage and output voltage in the machine starting process that charges and after the completion of starting, has improved the security of circuit and the convenience of use.
In a first aspect, the utility model provides an under-voltage protection circuit, under-voltage protection circuit is applied to the on-vehicle machine that charges, under-voltage protection circuit includes first comparing element, switch element, second comparing element and judgement unit;
the input end of the first comparing unit is electrically connected with the output end of an external power supply, and the first output end of the first comparing unit is electrically connected with the first input end of the judging unit; the input end of the switch unit is electrically connected with the second output end of the first comparison unit, the control end of the switch unit is electrically connected with an external control circuit, and the output end of the switch unit is electrically connected with the grounding end; the input end of the second comparing unit is electrically connected with the external power supply and the external sampling circuit, and the output end of the second comparing unit is electrically connected with the second input end of the judging unit; the output end of the judging unit is electrically connected with the rear-stage output circuit; when the vehicle-mounted charger is not started, the switch unit receives a control signal sent by the external control circuit and is conducted, and the voltage of the external power supply flows into a grounding end through the first comparison unit and the switch unit; when the vehicle-mounted charger is started, the switch unit receives a control signal sent by the external control circuit and is switched off, so that the voltage of the external power supply provides voltage for the judgment unit through the first comparison unit, and meanwhile, the second comparison unit also provides voltage for the judgment unit, so that the judgment unit outputs a corresponding signal to the rear-stage output circuit according to the voltage of the first comparison unit and the voltage of the second comparison unit.
Further, the first comparing unit comprises a first resistor, a second resistor, a third resistor and a capacitor; one end of the first resistor is used as an input end of the first comparison unit and is electrically connected with the external power supply; the other end of the first resistor is electrically connected with one end of the third resistor, and the other end of the third resistor is used as a first output end of the first comparing unit and is electrically connected with a first input end of the judging unit; the second resistor is connected with the capacitor in parallel, one end of the second resistor is electrically connected between the first resistor and the third resistor after the second resistor and the capacitor are connected in parallel, and the other end of the second resistor is grounded; the other end of the first resistor is also used as a second output end of the first comparison unit and is electrically connected with the input end of the switch unit.
Further, the switch unit comprises a fourth resistor and a switch tube; one end of the fourth resistor is used as the input end of the switch unit and is electrically connected with the second output end of the first comparison unit, the other end of the fourth resistor is electrically connected with the source S of the switch tube, the drain D of the switch tube is electrically connected with the grounding end, and the grid G of the switch tube is used as the control end of the switch unit and is electrically connected with the output end of the external control circuit.
Further, the switch unit further comprises a fifth resistor and a sixth resistor; and the grid G of the switch tube is electrically connected with the output end of the external control circuit through the fifth resistor, and the sixth resistor is electrically connected between the grid G and the drain D of the switch tube.
Further, the model of the switch tube is NMOS.
Further, the second comparing unit includes a seventh resistor and an eighth resistor; one end of the seventh resistor is used as one of the input ends of the second comparison unit and is electrically connected with the external sampling circuit; the other end of the seventh resistor is used as one of the output ends of the second comparison unit and is electrically connected with the second input end of the judgment unit; one end of the eighth resistor is used as one of the input ends of the second comparing unit and is electrically connected with the external power supply, and the other end of the eighth resistor is used as one of the output ends of the second comparing unit and is electrically connected with the second input end of the judging unit.
Further, the judging unit comprises a comparator and a first power supply; the positive electrode of the comparator is used as the first input end of the judging unit and is electrically connected with the first output end of the first comparing unit, the negative electrode of the comparator is used as the second input end of the judging unit and is connected with the output end of the second comparing unit, and the output end of the comparator is used as the output end of the judging unit and is electrically connected with the rear-stage output circuit; the first power supply is used for supplying power to the comparator.
Furthermore, the judging unit further comprises a ninth resistor, an input end of the ninth resistor is electrically connected with the positive electrode of the comparator, and an output end of the ninth resistor is electrically connected with an output end of the comparator.
The second aspect, the utility model also provides an on-vehicle machine that charges, on-vehicle machine that charges includes as above under-voltage protection circuit.
In a third aspect, the utility model also provides a protection system of the vehicle-mounted charger, the protection system includes an external power supply, the vehicle-mounted charger and a rear-stage output circuit, the vehicle-mounted charger includes any one of the undervoltage protection circuit; the output end of the external power supply is electrically connected with the input end of the vehicle-mounted charger, the input end of the rear-stage output circuit is electrically connected with the output end of the vehicle-mounted charger, and the under-voltage protection circuit is used for detecting the voltage of the vehicle-mounted charger.
The utility model has the advantages of simple structure, can be at the on-vehicle in-process that charges the machine and start, first comparing unit and second comparing unit can provide voltage to the judgement unit along with the lifting of voltage continuously, then the judgement unit exports corresponding signal to back level output unit according to the voltage of first comparing unit and the instant size of the voltage of second comparing unit in real time, make under-voltage protection's voltage threshold value be dynamic change, thereby can carry out under-voltage detection at the on-vehicle in-process that charges the machine and start, and then discover the trouble in advance, convenience and security have been improved.
Drawings
In order to more clearly illustrate the technical solution of the present invention, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without creative efforts.
Fig. 1 is a block diagram of an under-voltage protection circuit provided by the present invention;
fig. 2 is a circuit diagram of an under-voltage protection circuit provided by the present invention;
fig. 3 is a structural block diagram of a protection system of the vehicle-mounted charger.
Detailed Description
The technical solution of the present invention will be described clearly and completely with reference to the accompanying drawings, and obviously, the described embodiments are some, but not all embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.
It will be understood that the terms "comprises" and/or "comprising," when used in this specification and the appended claims, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.
It is also to be understood that the terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used in the specification 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. It should be further understood that the term "and/or" as used in the specification and the appended claims refers to any and all possible combinations of one or more of the associated listed items, and includes such combinations.
Referring to fig. 1 and fig. 2, the utility model provides an under-voltage protection circuit is often used in on-vehicle machine that charges, and this under-voltage protection circuit can carry out undervoltage detection to busbar voltage and output voltage at the start-up process of on-vehicle machine that charges to whether check out test set exists the trouble in advance, consequently improved the convenience of use and user's use experience degree.
The utility model provides an under-voltage protection circuit 10 includes a first comparing unit 11, a switch unit 12, a second comparing unit 13 and a judging unit 14; the input end of the first comparing unit 11 is electrically connected to the output end of the external power supply 30, and the first output end of the first comparing unit 11 is electrically connected to the first input end of the determining unit 14; the input end of the switch unit 12 is electrically connected to the second output end of the first comparing unit 11, the control end thereof is electrically connected to the external control circuit 50, and the output end thereof is electrically connected to the ground end; the input end of the second comparing unit 13 is used for electrically connecting with the external power supply 30 and the external sampling circuit 60, and the output end of the second comparing unit 13 is electrically connected with the second input end of the judging unit 14; the output end of the judging unit 14 is electrically connected with the post-stage output circuit 40; when the vehicle-mounted charger is not started, the switch unit 12 receives a control signal sent by the external control circuit 50 to be turned on, and the voltage of the external power supply 30 flows into a ground terminal through the first comparison unit 11 and the switch unit 12; when the vehicle-mounted charger is started, the switch unit 12 receives a control signal sent by the external control circuit 50 and is turned off, so that the voltage of the external power supply 30 provides the voltage for the determination unit 14 through the first comparison unit 11, and the second comparison unit 13 also provides the voltage for the determination unit 14, so that the determination unit 14 outputs a corresponding signal to the rear-stage output circuit 40 according to the voltage of the first comparison unit 11 and the voltage of the second comparison unit 13.
Specifically, when the charger device is not started, the external control circuit 50 outputs a high level signal to the switch unit 12 to keep the switch unit 12 and the first comparing unit 11 conducting, so that the voltage of the external power supply 30 is transmitted to the switch unit 12 through the first comparing unit 11, at this time, the voltage output by the first comparing unit 11 to the determining unit 14 is close to 0, the external sampling circuit 60 is used for sampling a voltage signal of the voltage to be measured, i.e., a voltage signal of the bus voltage of the vehicle-mounted charger 20, since the charger device is not started at this time, the bus voltage of the vehicle-mounted charger 20 is 0, but the second comparing unit 13 is also electrically connected to the external power supply 30, the voltage of the external power supply 30 is transmitted to the determining unit 14 through the second comparing unit 13, and the voltage of the second comparing unit 13 is greater than the voltage of the first comparing unit 11, so that the determining unit 14 outputs a low level signal to the rear-stage output circuit 40, no undervoltage protection is enabled.
When the charger device is started, the external control circuit 50 outputs a low level signal to the control end of the switch unit 12 to disconnect the switch unit 12 from the first comparing unit 11, so that the voltage of the external power supply 30 is transmitted to the judging unit 14 through the first comparing unit 11; and because of the start of the device, the external sampling circuit 60 transmits the sampled voltage signal of the bus voltage of the vehicle-mounted charger 20 to the judging unit 14 through the second comparing unit 13, and simultaneously, the external power supply 30 also transmits the voltage to the judging unit 14 through the second comparing unit 13, if the circuit is normal, the voltage of the second comparing unit 13 is greater than the voltage of the first comparing unit 11, the judging unit 14 outputs a low level to the rear-stage output circuit 40, no undervoltage protection occurs, and if the voltage of the second comparing unit 13 is less than the voltage of the first comparing unit 11 due to the circuit or device failure, the judging unit 14 outputs a high level, and undervoltage protection occurs.
In the process of starting the vehicle-mounted charger 20, the voltage of the first comparing unit 11 and the voltage of the second comparing unit 13 are both gradually increased, and in this process, the determining unit 14 compares the voltage of the first comparing unit 11 and the voltage of the second comparing unit 13 in real time, and outputs the result to the rear-stage output circuit 40, so that the protection threshold value for triggering the under-voltage protection is dynamically changed according to the voltage of the first comparing unit 11 and the voltage of the second comparing unit 13, when the vehicle-mounted charger 20 is completely started, the voltage of the first comparing unit 11 and the voltage of the second comparing unit 13 do not change, and the protection threshold value for triggering the under-voltage protection is also fixed correspondingly, and the determining unit 14 can compare the voltages according to a conventional method, thereby determining whether to start the under-voltage protection.
As a further example, the first comparing unit 11 includes a first resistor R1, a second resistor, R2, a third resistor R3, and a capacitor C; one end of the first resistor R1 is used as an input end of the first comparing unit 11, and is electrically connected to the external power supply 30; the other end of the first resistor R1 is electrically connected to one end of the third resistor R3, and the other end of the third resistor R3 is used as a first output end of the first comparing unit 11 and is electrically connected to a first input end of the determining unit 14; the second resistor R2 is connected in parallel with the capacitor C, one end of the second resistor R2 is electrically connected between the first resistor R1 and the third resistor R3 after the second resistor R2 is connected in parallel, and the other end of the second resistor R3 is grounded; the other end of the first resistor R1 is also used as a second output end of the first comparing unit 11 and electrically connected to the input end of the switching unit 12.
The first resistors R1 and R3 are used for dividing the voltage from the external power supply 30, and at the same time, the magnitude of the first resistor R1 and the magnitude of the third resistor R3 are adjusted to change the rising speed of the voltage output from the first comparing unit to the determining unit 14, so as to change the protection threshold value for triggering the under-voltage protection, the capacitor C is used for storing energy, so as to reduce the rising speed of the voltage output from the first comparing unit 11 to the determining unit 14, and the third resistor R3 is connected in parallel with the capacitor C, so as to absorb the electric energy of the capacitor and prevent the current of the capacitor from being too large, so as to function as a protection circuit. Through such an arrangement, the speed of increasing the voltage output from the first comparing unit 11 to the determining unit 14 can be reduced, and if the voltage output from the second comparing unit 13 to the determining unit 14 is still lower than the voltage output from the first comparing unit 11 to the determining unit 14, the under-voltage protection is triggered, so as to reduce the possibility of causing the erroneous determination.
As a further example, the switching unit 12 includes a fourth resistor R4 and a switching tube Q; one end of the fourth resistor R4 is electrically connected to the second output terminal of the first comparing unit 11 as the input terminal of the switch unit 12, the other end of the fourth resistor R4 is electrically connected to the source S of the switch tube Q, the drain D of the switch tube is electrically connected to the ground terminal, and the gate G of the switch tube is used as the control terminal of the switch unit and is electrically connected to the output terminal of the external control circuit 50.
The fourth resistor R4 is used to reduce the voltage and current in the circuit and avoid the switch Q from being burned by the too high voltage and current, the switch Q is used to receive the control signal from the external control circuit 50, specifically, if the external control circuit 50 outputs a high level to the switch Q, the switch Q is kept in a conducting state, at this time, the switch unit 12 is communicated with the first comparing unit 11, the voltage of the external power supply 30 flows into the ground terminal through the switch Q, and the voltage output by the first comparing unit 11 to the determining unit 14 is close to 0; if the external control circuit 50 outputs a low level to the switch tube Q, the switch tube Q is turned off, and at this time, the switch unit 12 is turned off from the first comparison unit 11, so that the external power supply 30 outputs a voltage to the determination unit 14, wherein the type of the switch tube may be specifically an NMOS, or may be a triode, and the specific type thereof is not limited in this category.
As a further example, the switch unit 12 further includes a fifth resistor R5 and a sixth resistor R6; the gate G of the switching tube Q is electrically connected to the output terminal of the external control circuit 50 through the fifth resistor R5, and the sixth resistor R6 is electrically connected between the gate G and the drain D of the switching tube Q.
The sixth resistor R6 is used to reduce the voltage of the switching tube Q, so as to ensure that the control signal output by the external control circuit 50 can be stably transmitted to the switching tube Q, the fifth resistor R5 is used to limit the circuit current, and in this embodiment, the input terminal of the fourth resistor R4 is electrically connected to the output terminal of the first resistor R1.
As a further example, the second comparing unit 13 includes a seventh resistor R7 and an eighth resistor R8; one end of the seventh resistor R7 is used as one of the input ends of the second comparing unit 13, and is electrically connected to the external sampling circuit 60; the other end of the seventh resistor R7 is used as one of the output ends of the second comparing unit 13, and is electrically connected to the second input end of the judging unit 14; one end of the eighth resistor R8 is used as one of the input ends of the second comparing unit 13 for electrically connecting with the external power supply 30, and the other end of the eighth resistor R8 is used as one of the output ends of the second comparing unit 13 for electrically connecting with the second input end of the judging unit 14.
The voltage output from the second comparing unit 13 to the determining unit 14 is determined by the voltage of the external power supply 30 electrically connected to the second comparing unit 13 and the voltage signal of the external sampling circuit 60, the seventh resistor R7 is a resistor with a large resistance value, and is used for dividing the voltage of the external power supply 30 to reduce the voltage output from the external power supply 30 to the determining unit 14, and in addition, the magnitude of the voltage signal from the external sampling circuit 60 can be adjusted by changing the magnitude of the eighth resistor R8, in an embodiment, if the external sampling circuit 60 includes a resistor for adjusting the magnitude of the voltage signal, the eighth resistor R8 may not be provided in the second comparing unit 13, and in this embodiment, the seventh resistor R7 and the eighth resistor R8 are both electrically connected to the determining unit 14.
As a further example, the determination unit 14 includes a comparator X and a first power supply V; the positive electrode of the comparator X is used as the first input end of the judging unit 14 and is electrically connected to the first output end of the first comparing unit 11, the negative electrode of the comparator X is used as the second input end of the judging unit 14 and is connected to the output end of the second comparing unit 13, and the output end of the comparator X is used as the output end of the judging unit 14 and is electrically connected to the rear-stage output circuit 40; the first power supply V is used for supplying power to the comparator X.
The principle of the comparator X is that if the voltage from the positive electrode is greater than the voltage from the negative electrode, a high level is output, and at this time, the post-stage output circuit 40 starts the under-voltage protection according to the high level; if the voltage from the positive pole is less than the voltage from the negative pole, a low level is output, and the circuit and the equipment are started and operated normally. The first power source V is used for providing power to the comparator, and may be a single power source, such as a storage battery, or an external power source 30 for providing voltage to the first comparing unit 11 and the second comparing unit 13, in this embodiment, the output terminal of the third resistor R3 is electrically connected to the positive electrode of the comparator X, the seventh resistor R7 and the eighth resistor R8 are electrically connected to the negative electrode of the comparator X, and the comparator outputs a high level or a low level according to the voltage magnitude of the third resistor R3 and the voltage magnitudes of the seventh resistor R7 and the eighth resistor R8.
In a further embodiment, the determining unit X further includes a ninth resistor R9, an input terminal of the ninth resistor R9 is electrically connected to the positive electrode of the comparator X, and an output terminal of the ninth resistor R9 is electrically connected to the output terminal of the comparator X.
The ninth resistor R9 may cooperate with the comparator X to realize a hysteresis comparison function, that is, if the comparator X outputs a high level, it indicates that the voltage of the first comparison unit 11 is greater than the voltage of the second comparison unit 13, and the voltage of the first comparison unit 11 may be further increased by the ninth resistor R9, so as to increase the difference between the voltage of the first comparison unit 11 and the voltage of the second comparison unit 13, thereby ensuring that the output of the comparator X is a high level; if the comparator X outputs a low level, which means that the voltage of the first comparing unit 11 is lower than the voltage of the second comparing unit 13, the ninth resistor R9 may further lower the voltage of the first comparing unit 11, thereby increasing the difference between the voltage of the first comparing unit 11 and the voltage of the second comparing unit 13, and further ensuring that the comparator X outputs a low level. Therefore, when the voltage difference between the first comparing unit 11 and the second comparing unit 13 is very small, the comparator does not repeatedly output a high level and a low level in a short time, and the possibility of false alarm is reduced.
The following description is made for the principle of the present embodiment, the signal output by the external control circuit 50 is usually a CNT signal, which is the start control of the under-voltage protection circuit, when the CNT signal is at a low level, the under-voltage detection circuit starts to operate, that is, the switching tube Q is disconnected from the first resistor R1, while the signal transmitted by the external sampling circuit 60 is usually a VSEN signal, which is a sampling signal of the monitored voltage, usually the bus voltage of the vehicle-mounted charger 20, the signal output by the comparator X is an under-voltage protection output signal, if the low level is output, it represents that the vehicle-mounted charger 20 normally operates, and if the high level is output, the external controller or the related control unit is notified, so that under-voltage protection occurs.
When the vehicle-mounted charger 20 is not started, the CNT signal is at a low level, the switching tube Q is turned on, so that the level of the output end of the first resistor R1 is pulled down to a low level, at this time, the voltage of the capacitor C is 0, the voltage of the positive electrode of the comparator X is also 0, if the comparator X still outputs a high level at this time, because the resistance value of the ninth resistor R9 is far greater than that of the third resistor R3, after the voltage division of the ninth resistor R9 and the third resistor R3, the voltage of the positive electrode of the comparator X still approaches 0, and thus the comparator X is prevented from outputting a high level when the vehicle-mounted charger 20 is not started. In addition, the voltage of the negative pole of the comparator X is determined by the voltage division of the VSEN signal transmitted from the external sampling circuit 60 and the external power 30 through the seventh resistor R7 and the eighth resistor R8, the specific relationship is that the negative voltage of the comparator X is equal to the voltage of the external power supply 30 multiplied by the resistance value of the seventh resistor R7 divided by the sum of the resistance value of the seventh resistor R7 and the resistance value of the eighth resistor R8 plus the voltage value of the VSEN signal multiplied by the sum of the eighth resistor R8 divided by the sum of the seventh resistor R7 and the eighth resistor R8, and since the vehicle-mounted charger is not activated, the VSEN signal is 0, the negative electrode voltage of the comparator X is the voltage of the external power supply 30 multiplied by the resistance value of the seventh resistor R7 divided by the sum of the resistance value of the seventh resistor R7 and the resistance value of the eighth resistor R8, therefore, the voltage of the negative electrode of the comparator X is higher than the voltage of the positive electrode of the comparator X, so that the comparator X outputs a low level.
When the vehicle-mounted charger 20 is started, the CNT signal is a low level signal, the switching tube Q is turned off, the external power supply 30 starts to charge the capacitor C through the first resistor R1, the voltage of the positive electrode of the comparator X starts to gradually rise, at this time, the external sampling circuit 60 outputs a VSEN signal to the second comparing unit 13, and along with the rise of the voltage of the vehicle-mounted charger, the voltage of the VSEN signal also gradually rises, so that the voltage of the negative electrode of the comparator X also rises, when the voltage rising speed of the VSEN signal is larger than the voltage rising speed of the positive electrode of the comparator X, the voltage of the negative electrode of the comparator X is greater than the voltage of the positive electrode of the comparator X, the comparator X outputs low level, at the moment, the vehicle-mounted charger is normal, when the vehicle-mounted charger breaks down, and the voltage rising speed of the VSEN signal is lower than the voltage rising speed of the positive electrode of the comparator X, the comparator X outputs high level, and under-voltage protection occurs.
The utility model also discloses a vehicle-mounted machine 20 that charges, vehicle-mounted machine 20 that charges is equipped with in any embodiment of the above-mentioned embodiment undervoltage protection circuit 10.
Referring to fig. 3, the utility model also discloses a protection system 1 of the vehicle-mounted charger, the protection system 1 of the vehicle-mounted charger includes an external power supply 30, a vehicle-mounted charger 20 and a rear-stage output circuit 40, the vehicle-mounted charger 20 includes any one of the undervoltage protection circuit 10; specifically, in this embodiment, the input end of the rear-stage output circuit 40 is electrically connected to the output end of the determination unit 14 of the vehicle-mounted charger 20, and the under-voltage protection circuit 10 is configured to detect the voltage of the vehicle-mounted charger 20.
Meanwhile, the undervoltage protection circuit 10 may also be the undervoltage protection circuit 10 described in any embodiment of the foregoing embodiments, and specific electrical elements, connection modes of devices, and specific working principles of the undervoltage protection circuit 10 have been described in detail in the foregoing embodiments, and are not described herein again.
In a word, the utility model discloses a dynamic comparison first comparing element 11's voltage and second comparing element 13's voltage to make at the in-process that equipment started, can carry out the undervoltage detection to the bus voltage of on-vehicle machine that charges, thereby can find circuit or equipment in advance and have the trouble, and then protection circuit and equipment have promoted the convenience greatly.
The above description is only for the specific embodiments of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily think of various equivalent modifications or replacements within the technical scope of the present invention, and these modifications or replacements should be covered within the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.
Claims (10)
1. The undervoltage protection circuit is characterized by being applied to a vehicle-mounted charger and comprising a first comparison unit, a switch unit, a second comparison unit and a judgment unit;
the input end of the first comparing unit is electrically connected with the output end of an external power supply, and the first output end of the first comparing unit is electrically connected with the first input end of the judging unit;
the input end of the switch unit is electrically connected with the second output end of the first comparison unit, the control end of the switch unit is electrically connected with an external control circuit, and the output end of the switch unit is electrically connected with the grounding end;
the input end of the second comparing unit is electrically connected with the external power supply and the external sampling circuit, and the output end of the second comparing unit is electrically connected with the second input end of the judging unit;
the output end of the judging unit is electrically connected with the rear-stage output circuit;
when the vehicle-mounted charger is not started, the switch unit receives a control signal sent by the external control circuit and is conducted, and the voltage of the external power supply flows into a grounding end through the first comparison unit and the switch unit; when the vehicle-mounted charger is started, the switch unit receives a control signal sent by the external control circuit and is switched off, so that the voltage of the external power supply provides voltage for the judgment unit through the first comparison unit, and meanwhile, the second comparison unit also provides voltage for the judgment unit, so that the judgment unit outputs a corresponding signal to the rear-stage output circuit according to the voltage of the first comparison unit and the voltage of the second comparison unit.
2. The undervoltage protection circuit of claim 1, wherein the first comparison unit comprises a first resistor, a second resistor, a third resistor, and a capacitor;
one end of the first resistor is used as an input end of the first comparison unit and is electrically connected with the external power supply; the other end of the first resistor is electrically connected with one end of the third resistor, and the other end of the third resistor is used as a first output end of the first comparing unit and is electrically connected with a first input end of the judging unit;
the second resistor is connected with the capacitor in parallel, one end of the second resistor is electrically connected between the first resistor and the third resistor after the second resistor and the capacitor are connected in parallel, and the other end of the second resistor is grounded;
the other end of the first resistor is also used as a second output end of the first comparison unit and is electrically connected with the input end of the switch unit.
3. The undervoltage protection circuit of claim 1, wherein the switching unit comprises a fourth resistor and a switching tube;
one end of the fourth resistor is used as the input end of the switch unit and is electrically connected with the second output end of the first comparison unit, the other end of the fourth resistor is electrically connected with the source S of the switch tube, the drain D of the switch tube is electrically connected with the grounding end, and the grid G of the switch tube is used as the control end of the switch unit and is electrically connected with the output end of the external control circuit.
4. The undervoltage protection circuit of claim 3, wherein the switching unit further comprises a fifth resistor and a sixth resistor;
and the grid G of the switching tube is electrically connected with the output end of the external control circuit through the fifth resistor, and the sixth resistor is electrically connected between the grid G and the drain D of the switching tube.
5. The undervoltage protection circuit of claim 4, wherein the switching tube is NMOS type.
6. The undervoltage protection circuit of claim 1, wherein the second comparison unit comprises a seventh resistor and an eighth resistor;
one end of the seventh resistor is used as one of the input ends of the second comparison unit and is electrically connected with the external sampling circuit; the other end of the seventh resistor is used as one of the output ends of the second comparison unit and is electrically connected with the second input end of the judgment unit;
one end of the eighth resistor is used as one of the input ends of the second comparing unit and is electrically connected with the external power supply, and the other end of the eighth resistor is used as one of the output ends of the second comparing unit and is electrically connected with the second input end of the judging unit.
7. The undervoltage protection circuit of claim 1, wherein the determining unit comprises a comparator and a first power supply;
the positive electrode of the comparator is used as the first input end of the judging unit and is electrically connected with the first output end of the first comparing unit, the negative electrode of the comparator is used as the second input end of the judging unit and is connected with the output end of the second comparing unit, and the output end of the comparator is used as the output end of the judging unit and is electrically connected with the rear-stage output circuit; the first power supply is used for supplying power to the comparator.
8. The under-voltage protection circuit of claim 7, wherein the determining unit further comprises a ninth resistor, an input terminal of the ninth resistor is electrically connected to the positive terminal of the comparator, and an output terminal of the ninth resistor is electrically connected to the output terminal of the comparator.
9. A vehicle-mounted charger, characterized in that, the vehicle-mounted charger comprises the undervoltage protection circuit according to any one of claims 1 to 8.
10. A protection system is characterized by comprising an external power supply, a vehicle-mounted charger and a rear-stage output circuit, wherein the vehicle-mounted charger comprises the undervoltage protection circuit as claimed in any one of claims 1 to 8;
the output end of the external power supply is electrically connected with the input end of the vehicle-mounted charger, the input end of the rear-stage output circuit is electrically connected with the output end of the vehicle-mounted charger, and the under-voltage protection circuit is used for detecting the voltage of the vehicle-mounted charger.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202020963597.0U CN212162790U (en) | 2020-05-29 | 2020-05-29 | Under-voltage protection circuit, vehicle-mounted charger and protection system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202020963597.0U CN212162790U (en) | 2020-05-29 | 2020-05-29 | Under-voltage protection circuit, vehicle-mounted charger and protection system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN212162790U true CN212162790U (en) | 2020-12-15 |
Family
ID=73703254
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202020963597.0U Active CN212162790U (en) | 2020-05-29 | 2020-05-29 | Under-voltage protection circuit, vehicle-mounted charger and protection system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN212162790U (en) |
-
2020
- 2020-05-29 CN CN202020963597.0U patent/CN212162790U/en active Active
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN108279373B (en) | Method and device for detecting charging switch of electric automobile | |
| CN107894567B (en) | Battery pack and detection system and detection method for interface state of battery pack | |
| US9829529B2 (en) | Power supply apparatus | |
| JP5369833B2 (en) | Electric vehicle charger and ground fault detection method | |
| CN107634571B (en) | Solar photovoltaic power generation device | |
| CN108832686B (en) | Charging circuit and charging circuit detection method | |
| US20220242264A1 (en) | Charging cable, charging system including the same, and method of charging vehicle | |
| CN106299180B (en) | The combination of electric tool and battery pack | |
| CN107465237A (en) | Battery control device and system | |
| CN109038762B (en) | Charging device and charging system | |
| CN100362354C (en) | Cell on-position detecting method for terminal device | |
| CN212162790U (en) | Under-voltage protection circuit, vehicle-mounted charger and protection system | |
| CN110912219A (en) | Charging protection circuit, charging device, electronic device, and charging protection method | |
| CN113759277B (en) | Battery cell short circuit detection device, method and storage medium | |
| KR20190013651A (en) | Battery cell management system | |
| EP3958428B1 (en) | Control device, energy converting system, energy converting method, and storage medium | |
| CN115091955A (en) | Charging and discharging system of electric automobile and control method thereof | |
| CN111856331B (en) | Method and device for detecting open-circuit fault of charging circuit of vehicle and vehicle | |
| KR20230052763A (en) | Battery diagnosis apparatus, battery pack, electric vehicle, and battery diagnosis method | |
| CN207588476U (en) | Battery control device and system | |
| CN111469667A (en) | External discharge method and device and automobile | |
| CN112305448A (en) | Power supply access state detection circuit, electronic device and electronic device protection method | |
| JP7357127B2 (en) | Smart battery device and its quick charging method | |
| CN213754059U (en) | Fill automatic adaptation of electric pile plug and charging safety protection circuit | |
| KR102687095B1 (en) | Smart battery device and fast charging method thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| TR01 | Transfer of patent right | ||
| TR01 | Transfer of patent right |
Effective date of registration: 20211216 Address after: 518000 Room 301, building 2, yingweiteng Guangming Technology Building, shutianpu community, Matian street, Guangming District, Shenzhen, Guangdong Patentee after: Invt Electric Vehicle Drive Technology (Shenzhen) Co.,Ltd. Address before: 518000 3rd floor, building 2, Longjing Gaofa Science Park, Taoyuan Street, Nanshan District, Shenzhen City, Guangdong Province Patentee before: SHENZHEN INVT ELECTRIC AUTOMOBILE CHARGING TECHNOLOGY CO.,LTD. |