CN117607749A - Direct current load fault detection circuit and household electrical appliance with same - Google Patents
Direct current load fault detection circuit and household electrical appliance with same Download PDFInfo
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- CN117607749A CN117607749A CN202311874268.3A CN202311874268A CN117607749A CN 117607749 A CN117607749 A CN 117607749A CN 202311874268 A CN202311874268 A CN 202311874268A CN 117607749 A CN117607749 A CN 117607749A
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- 238000001514 detection method Methods 0.000 title claims abstract description 136
- 239000003990 capacitor Substances 0.000 claims description 51
- 230000002159 abnormal effect Effects 0.000 abstract description 10
- 238000012423 maintenance Methods 0.000 abstract description 10
- 238000000034 method Methods 0.000 description 13
- 238000007599 discharging Methods 0.000 description 9
- 238000010586 diagram Methods 0.000 description 7
- 238000012986 modification Methods 0.000 description 4
- 230000004048 modification Effects 0.000 description 4
- 230000000630 rising effect Effects 0.000 description 3
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Classifications
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/50—Testing of electric apparatus, lines, cables or components for short-circuits, continuity, leakage current or incorrect line connections
- G01R31/56—Testing of electric apparatus
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R1/00—Details of instruments or arrangements of the types included in groups G01R5/00 - G01R13/00 and G01R31/00
- G01R1/36—Overload-protection arrangements or circuits for electric measuring instruments
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H3/00—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection
- H02H3/08—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to excess current
- H02H3/087—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to excess current for dc applications
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H3/00—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection
- H02H3/08—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to excess current
- H02H3/10—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to excess current additionally responsive to some other abnormal electrical conditions
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H3/00—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection
- H02H3/20—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to excess voltage
- H02H3/207—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to excess voltage also responsive to under-voltage
Abstract
The invention discloses a direct current load fault detection circuit and a household appliance with the same, wherein the direct current load fault detection circuit comprises: the switch part is arranged in the direct-current load power supply loop; the overvoltage detection part is used for detecting that the output voltage of the direct current power supply part is overvoltage and outputting an overvoltage protection signal to the switch part; the undervoltage detection part is used for detecting that the output voltage of the direct current power supply part is undervoltage and outputting an undervoltage protection signal to the switch part; the overcurrent detection part is used for detecting the overcurrent of the load current and outputting an overcurrent protection signal to the switch part; the switch part is used for controlling the disconnection of the direct current load power supply loop according to at least one of the overvoltage protection signal, the undervoltage protection signal and the overcurrent protection signal, and can perform corresponding protection control in time when the load has abnormal faults, so that the load and an external controller are not damaged, the equipment fault rate is greatly reduced, the maintenance cost is reduced, and the user experience is improved.
Description
The present application is a divisional application of an invention patent application with a filing date of 2021, 05-25, a filing number of 202110573376.1, and an invention creation name of "direct current load fault detection circuit and home appliance having the same".
Technical Field
The invention relates to the technical field of electrical equipment, in particular to a direct current load fault detection circuit and household electrical equipment with the same.
Background
In household appliances such as air conditioners, fans, there are usually some open loop controlled dc loads, such as PTC (Positive Temperature Coefficient ) heaters, synchronous motors, stepper motors, etc., which only need to provide a dc power supply to operate. Because these direct current loads do not have feedback end, can't provide the fault signal, in case the inside abnormal failure that appears of load, external controller can't in time discern to can't in time carry out corresponding protection control, lead to equipment fault rate to improve greatly, not only increase cost of maintenance, still influence user experience.
Disclosure of Invention
According to the direct current load fault detection circuit and the household appliance with the same, the technical problem that corresponding protection cannot be carried out due to the fact that the fault condition of the direct current load cannot be identified in time in the prior art is solved, the load condition can be automatically identified by detecting the voltage and the current of the power supply for supplying the direct current load, corresponding protection control can be carried out in time when the load has abnormal faults, the load and an external controller cannot be damaged, the equipment fault rate is greatly reduced, the maintenance cost is reduced, and the user experience degree is improved.
The embodiment of the application provides a direct current load fault detection circuit, which comprises: the switch part is arranged on the direct-current load power supply loop; the overvoltage detection part is used for detecting the overvoltage of the output voltage of the direct current power supply part and outputting an overvoltage protection signal to the switch part; the undervoltage detection part is used for detecting the output voltage of the direct current power supply part and outputting an undervoltage protection signal to the switch part when the undervoltage occurs; the overcurrent detection part is used for detecting the overcurrent of the load current and outputting an overcurrent protection signal to the switch part; the switch part is used for controlling the disconnection of the direct-current load power supply loop according to at least one of the overvoltage protection signal, the undervoltage protection signal and the overcurrent protection signal.
According to the direct-current load fault detection circuit provided by the embodiment of the application, the switch part is arranged in the power supply loop, and the voltage and the load current of the direct-current power supply part are detected and judged, once overvoltage, undervoltage and overcurrent conditions occur, the switch part is directly triggered to disconnect the power supply loop, so that corresponding protection control can be timely carried out when the load has abnormal faults, the load and an external controller can not be damaged, the equipment fault rate is greatly reduced, the maintenance cost is reduced, and the user experience degree is improved.
Optionally, according to an embodiment of the present application, the overvoltage detection portion includes: the first comparison voltage supply unit is connected with the output end of the direct current power supply part and is used for charging and discharging according to the output voltage of the direct current power supply part so as to supply a first comparison voltage; the second comparison voltage supply unit is connected with the output end of the direct current power supply part and is used for dividing the output voltage of the direct current power supply part to supply a second comparison voltage; and the first comparison unit is used for outputting the overvoltage protection signal by comparing the first comparison voltage with the second comparison voltage when the output voltage of the direct current power supply part instantaneously rises from a preset stable voltage.
Optionally, according to an embodiment of the present application, the undervoltage detection portion includes: the third comparison voltage supply unit is connected with the output end of the direct current power supply part and is used for charging and discharging according to the output voltage of the direct current power supply part so as to supply a third comparison voltage; the fourth comparison voltage supply unit is connected with the output end of the direct current power supply part and is used for dividing the output voltage of the direct current power supply part to supply a fourth comparison voltage; and the second comparison unit is used for outputting the undervoltage protection signal by comparing the third comparison voltage with the fourth comparison voltage when the output voltage of the direct current power supply part instantaneously drops from a preset stable voltage.
Optionally, according to an embodiment of the present application, the undervoltage detection portion includes: the third comparison voltage supply unit is connected with the output end of the direct current power supply part and is used for charging and discharging according to the output voltage of the direct current power supply part so as to supply a third comparison voltage; and the second comparison unit is used for outputting the undervoltage protection signal by comparing the third comparison voltage with the second comparison voltage when the output voltage of the direct current power supply part instantaneously drops from a preset stable voltage.
Optionally, according to an embodiment of the present application, the overvoltage detection portion includes: a first comparison voltage supply unit for performing charge and discharge according to the output voltage of the DC power supply unit to supply a first comparison voltage; and the first comparison unit is used for outputting an overvoltage protection signal by comparing the first comparison voltage with the fourth comparison voltage when the output voltage of the direct current power supply part instantaneously rises from a preset stable voltage.
Optionally, according to an embodiment of the present application, the first comparison voltage providing unit includes: one end of the first resistor is connected with the output end of the direct current power supply part; one end of the second resistor is connected with the other end of the first resistor and is provided with a first node, and the other end of the second resistor is grounded; and the first capacitor is connected with the second resistor in parallel.
Optionally, according to an embodiment of the present application, the second comparison voltage providing unit includes: one end of the third resistor is connected with the output end of the direct current power supply part; and one end of the fourth resistor is connected with the other end of the third resistor and is provided with a second node, and the other end of the fourth resistor is grounded.
Optionally, according to an embodiment of the present application, the first comparing unit includes: the positive input end of the first comparator is connected with the first node, the negative input end of the first comparator is connected with the second node, and the output end of the first comparator is connected to the control end of the switch part; and one end of the fifth resistor is connected with the output end of the first comparator, and the other end of the fifth resistor is connected with the output end of the direct current power supply part.
Optionally, according to an embodiment of the present application, the third comparison voltage providing unit includes: one end of the sixth resistor is connected with the output end of the direct current power supply part; one end of the seventh resistor is connected with the other end of the sixth resistor and is provided with a third node, and the other end of the seventh resistor is grounded; and the second capacitor is connected with the seventh resistor in parallel.
Optionally, according to an embodiment of the present application, the fourth comparison voltage providing unit includes: one end of the eighth resistor is connected with the output end of the direct current power supply part; and one end of the ninth resistor is connected with the other end of the eighth resistor and is provided with a fourth node, and the other end of the ninth resistor is grounded.
Optionally, according to an embodiment of the present application, the second comparing unit comprises: and the positive input end of the second comparator is connected with the fourth node, the negative input end of the second comparator is connected with the third node, and the output end of the second comparator is connected to the control end of the switch part.
Optionally, according to an embodiment of the present application, the third comparison voltage providing unit includes: one end of the sixth resistor is connected with the output end of the direct current power supply part; one end of the seventh resistor is connected with the other end of the sixth resistor and is provided with a third node, and the other end of the seventh resistor is grounded; and the second capacitor is connected with the seventh resistor in parallel.
Optionally, according to an embodiment of the present application, the second comparing unit comprises: and the positive input end of the second comparator is connected with the output end of the second comparison voltage supply unit, the negative input end of the second comparator is connected with the third node, and the output end of the second comparator is connected to the control end of the switch part.
Optionally, according to an embodiment of the present application, the overcurrent detecting section includes: the current detection resistor is arranged in the direct-current load power supply loop; a tenth resistor, one end of which is connected with the reference voltage supply end of the direct current power supply part; an eleventh resistor, wherein one end of the eleventh resistor is connected with the other end of the tenth resistor and is provided with a fifth node, and the other end of the eleventh resistor is connected with one end of the current detection resistor and then grounded; and the positive input end of the third comparator is connected with the fifth node, the negative input end of the third comparator is connected with the other end of the current detection resistor, and the output end of the third comparator is connected to the control end of the switch part.
Optionally, according to an embodiment of the present application, the switch portion includes: a twelfth resistor, one end of which is used as a control end of the switch part; a thirteenth resistor, one end of which is connected with the other end of the twelfth resistor, and the other end of which is connected with the other end of the current detection resistor; the drain electrode of the first MOS tube is respectively connected with the other end of the thirteenth resistor and the other end of the current detection resistor, the source electrode of the first MOS tube is connected to a direct current load, and the grid electrode of the first MOS tube is connected with the other end of the twelfth resistor.
The embodiment of the application also provides the household electrical appliance, which comprises the direct-current load fault detection circuit.
According to the household electrical appliance provided by the embodiment of the application, through the direct current load fault detection circuit, corresponding protection control can be timely carried out when a load breaks down, so that the load and an external controller cannot be damaged, the equipment fault rate is greatly reduced, the maintenance cost is reduced, and the user experience degree is improved.
Drawings
FIG. 1 is a block schematic diagram of a DC load fault detection circuit according to one embodiment of the present application;
FIG. 2 is a circuit diagram of a DC load fault detection circuit according to one embodiment of the present application;
FIG. 3 is a circuit diagram of a DC load fault detection circuit according to another embodiment of the present application;
fig. 4 is a circuit diagram of a dc load fault detection circuit according to yet another embodiment of the present application;
FIG. 5 is a schematic diagram of protection logic waveforms of an overvoltage detection circuit according to one embodiment of the present application;
FIG. 6 is a schematic diagram of protection logic waveforms for a brown-out detection circuit according to one embodiment of the present application;
fig. 7 is a block schematic diagram of an electrical home appliance according to one embodiment of the present application.
Detailed Description
The direct current load fault detection circuit and the household electrical appliance with the same provided by the embodiment of the application detect the voltage and the current of the power supply for supplying the direct current load so as to automatically identify the load condition, and in case of overvoltage, undervoltage, overcurrent and the like, the direct trigger switch part is used for disconnecting the power supply loop, so that corresponding protection control can be timely carried out when the load has abnormal faults, the load and an external controller are prevented from being damaged, the equipment fault rate is greatly reduced, the maintenance cost is reduced, and the user experience is improved.
In order that the above-described aspects may be better understood, exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be embodied in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.
In order to better understand the above technical solutions, the following detailed description will refer to the accompanying drawings and specific embodiments.
The following describes a dc load fault detection circuit and a home appliance having the same according to an embodiment of the present application with reference to the accompanying drawings.
Embodiment one:
as shown in fig. 1, a circuit for detecting a fault of a dc load according to an embodiment of the present application includes a switch section 10, an overvoltage detection section 20, an undervoltage detection section 30, and an overcurrent detection section 40.
In the embodiment of the present application, the switch section 10 may be configured by a controllable switch, specifically, as shown in fig. 2 or fig. 3, may be a controllable switch circuit 101; the overvoltage detection section 20 may be composed of electronic components such as a resistor, a capacitor, and a comparator, and is an overvoltage detection circuit 201 for detecting and comparing whether or not an overvoltage occurs in the power supply voltage, specifically, as shown in fig. 2 or 3; similarly, the undervoltage detection unit 30 may be composed of electronic components such as a resistor, a capacitor, and a comparator, and the undervoltage detection circuit 301 may detect and compare whether the supply voltage is undervoltage, as shown in fig. 2 or 3; the overcurrent detecting section 40 may be an overcurrent detecting circuit 401 which is constituted by electronic components such as a resistor and a comparator and detects and compares whether or not an overcurrent occurs in the load current, and specifically, as shown in fig. 2 or 3.
As shown in fig. 1, the switch part 10 may be disposed in a power supply loop of a dc load to control on/off of the power supply loop; the overvoltage detection part 20 is connected with a positive output end of the direct current power supply part 50, such as a power module, and is used for detecting and comparing whether the power supply voltage output by the direct current power supply part 50 is greater than a voltage set value, determining that the power supply voltage is overvoltage when the power supply voltage output by the direct current power supply part 50 is greater than the voltage set value, outputting an overvoltage protection signal which can be a high-low level signal, outputting the signal to the switch part 10, controlling the switch part 10 to be disconnected, and thus disconnecting a power supply loop to realize corresponding protection control; the undervoltage detection part 30 is connected with a positive output end of the direct current power supply part 50, such as a power module, and is used for detecting and comparing whether the power supply voltage output by the direct current power supply part 50 is smaller than another voltage set value, determining that the power supply voltage is undervoltage when the power supply voltage output by the direct current power supply part 50 is smaller than another voltage set value, outputting an undervoltage protection signal, which can be a high-low level signal as well, and outputting the signal to the switch part 10, controlling the switch part 10 to be disconnected, thus disconnecting a power supply loop and realizing corresponding protection control; the overcurrent detecting section 40 is connected to the negative output end of the dc power supply section 50, and is configured to detect and compare whether the load current is greater than a current set value, and determine that the load current is overcurrent when the load current is greater than a current set value, and output an overcurrent protection signal to the switching section 10 to control the switching section 10 to be disconnected, so as to disconnect the power supply loop and implement corresponding protection control.
Therefore, in the embodiment of the present application, the switching section 10 can control the power supply circuit of the dc load to be disconnected according to the overvoltage protection signal, the undervoltage protection signal, or the overcurrent protection signal, so that protection control can be performed when an abnormal failure occurs in the load. It can be understood that the switching unit 10 can also control the power supply circuit of the dc load to be turned off when two or three of the overvoltage protection signal, the undervoltage protection signal, and the overcurrent protection signal are received, thereby realizing the abnormal protection control.
To sum up, the circuit for fault detection on the direct current load provided by the embodiment of the application sets the switch part in the power supply loop, and detects and compares the voltage and the current of the power supply for supplying the direct current load to automatically identify the load condition, and once overvoltage, undervoltage and overcurrent conditions occur, the switch part is directly triggered to disconnect the power supply loop, so that corresponding protection control can be timely performed when the load breaks down, the load and an external controller are not damaged, the equipment fault rate is greatly reduced, the maintenance cost is reduced, and the user experience degree is improved.
Embodiment two:
in one embodiment of the present application, as shown in fig. 2, the overvoltage detection section is an overvoltage detection circuit 201, which includes a first comparison voltage providing unit 2011, a second comparison voltage providing unit 2012, and a first comparison unit 2013.
The supply unit 2011 for supplying the first comparison voltage is connected to the dc power supply unit 50, for example, a positive output terminal of the power module, and performs charging and discharging according to the voltage of the positive output terminal of the power module, so as to supply the first comparison voltage; the providing unit 2012 for providing a second comparison voltage is connected to the dc power supply portion 50, for example, a positive output terminal of the power module, and provides the second comparison voltage by dividing the voltage of the positive output terminal of the power module; the first comparing unit 2013 is respectively connected to the providing unit 2011 that provides the first comparing voltage and the providing unit 2012 that provides the second comparing voltage, where the first comparing unit 2013 is configured to, when the output voltage of the dc power supply unit 50, for example, the power module, instantaneously rises from a preset stable voltage, for example, rise to be greater than a voltage set value, compare the first comparing voltage provided by the providing unit 2011 with the second comparing voltage provided by the providing unit 2012, and since the first comparing voltage is obtained by charging and discharging according to the positive output terminal voltage of the power module, and the second comparing voltage is obtained by directly dividing the positive output terminal voltage of the power module, the voltage change rate of the second comparing voltage is greater than the voltage change rate of the first comparing voltage, that is, the second comparing voltage will be greater than the first comparing voltage at this time, the first comparing unit 2013 will output an overvoltage protection signal, and the switching unit 10 is turned off under the triggering of the level signal corresponding to the overvoltage protection signal, so as to realize corresponding protection control.
Also, as shown in fig. 2, the brown-out detection section is a brown-out detection circuit 301, which may employ a circuit topology substantially identical to that of the brown-out detection circuit, and includes a third comparison voltage providing unit 3011, a fourth comparison voltage providing unit 3012, and a second comparison unit 3013.
Wherein the providing unit 3011 for providing the third comparison voltage is connected to the dc power supply section 50, for example, a positive output terminal of the power module, and performs charge and discharge according to the voltage of the positive output terminal of the power module, thereby providing the third comparison voltage; the supply unit 3012 for supplying the fourth comparison voltage is connected to the dc power supply section 50, for example, the positive output terminal of the power supply module, and supplies the fourth comparison voltage by dividing the voltage of the positive output terminal of the power supply module; the second comparing unit 3013 is respectively connected to the providing unit 3011 that provides the third comparing voltage and the providing unit 3012 that provides the fourth comparing voltage, where the second comparing unit 3013 is configured to, when the output voltage of the dc power supply unit 50, for example, the power module, drops instantaneously from a preset stable voltage, for example, drops to be smaller than another voltage set value, and the third comparing voltage provided by the providing unit 3011 is compared with the fourth comparing voltage provided by the providing unit 3012, and since the third comparing voltage is obtained by charging and discharging according to the positive output terminal voltage of the power module, and the fourth comparing voltage is obtained by directly dividing the positive output terminal voltage of the power module, the voltage change rate of the fourth comparing voltage is greater than the voltage change rate of the third comparing voltage, that is, the fourth comparing voltage will be smaller than the third comparing voltage at this time, the second comparing unit 3013 will output an under-voltage protection signal, and the switching unit 10 will be turned off under the triggering of the level signal corresponding to the under-voltage protection signal, to disconnect the power supply circuit, so as to realize corresponding protection control.
In another embodiment of the present application, as shown in fig. 3, the overvoltage detection section is an overvoltage detection circuit 201, which includes a first comparison voltage providing unit 2011, a second comparison voltage providing unit 2012, and a first comparison unit 2013.
The supply unit 2011 for supplying the first comparison voltage is connected to the dc power supply unit 50, for example, a positive output terminal of the power module, and performs charging and discharging according to the voltage of the positive output terminal of the power module, so as to supply the first comparison voltage; the providing unit 2012 for providing a second comparison voltage is connected to the dc power supply portion 50, for example, a positive output terminal of the power module, and provides the second comparison voltage by dividing the voltage of the positive output terminal of the power module; the first comparing unit 2013 is respectively connected to the providing unit 2011 that provides the first comparing voltage and the providing unit 2012 that provides the second comparing voltage, where the first comparing unit 2013 is configured to, when the output voltage of the dc power supply unit 50, for example, the power module, instantaneously rises from a preset stable voltage, for example, rise to be greater than a voltage set value, compare the first comparing voltage provided by the providing unit 2011 with the second comparing voltage provided by the providing unit 2012, and since the first comparing voltage is obtained by charging and discharging according to the positive output terminal voltage of the power module, and the second comparing voltage is obtained by directly dividing the positive output terminal voltage of the power module, the voltage change rate of the second comparing voltage is greater than the voltage change rate of the first comparing voltage, that is, the second comparing voltage will be greater than the first comparing voltage at this time, the first comparing unit 2013 will output an overvoltage protection signal, and the switching unit 10 is turned off under the triggering of the level signal corresponding to the overvoltage protection signal, so as to realize corresponding protection control.
Also, as shown in fig. 3, the brown-out detection section is a brown-out detection circuit 301 that shares the second comparison voltage supply unit 2012 with the brown-out detection circuit, and thus, the brown-out detection circuit 301 may include a third comparison voltage supply unit 3011 and a second comparison unit 3013.
Wherein the providing unit 3011 for providing the third comparison voltage is connected to the dc power supply section 50, for example, a positive output terminal of the power module, and performs charge and discharge according to the voltage of the positive output terminal of the power module, thereby providing the third comparison voltage; the second comparing unit 3013 is respectively connected to the providing unit 3011 that provides the third comparing voltage and the providing unit 2012 that provides the second comparing voltage, where the second comparing unit 3013 is configured to, when the output voltage of the dc power supply unit 50, for example, the power module, drops instantaneously from a preset stable voltage, for example, drops to be smaller than another voltage set value, and the switching unit 10 is turned off under the triggering of the level signal corresponding to the under-voltage protection signal to disconnect the power supply circuit by comparing the third comparing voltage provided by the providing unit 3011 with the second comparing voltage provided by the providing unit 2012, where the third comparing voltage is obtained by charging and discharging according to the positive output voltage of the power module, and the second comparing voltage is obtained by directly dividing the positive output voltage of the power module, so that the voltage change rate of the second comparing voltage is greater than the voltage change rate of the third comparing voltage, that is, where the second comparing voltage will be smaller than the third comparing voltage, and the second comparing unit 3013 will output the under-voltage protection signal.
Therefore, the direct current load fault detection circuit provided by the embodiment of the application can realize the rapid protection of the instantaneous overvoltage and the instantaneous undervoltage of the direct current load under the condition that feedback is not needed, so that the direct current load works in a certain voltage range, and the power supply loop is disconnected by directly triggering the switch part once abnormal conditions such as overvoltage and undervoltage occur, so that corresponding protection control can be timely performed when the load has abnormal faults, the load and an external controller can not be damaged, the equipment fault rate is greatly reduced, the maintenance cost is reduced, and the user experience degree is improved.
Embodiment III:
specifically, as shown in fig. 2, in one embodiment of the present application, the first comparison voltage providing unit 2011 includes a first resistor R1, a second resistor R2, and a first capacitor C1. One end of the first resistor R1 is connected to the positive output end of the dc power supply unit 50, for example, a power module, one end of the second resistor R2 is connected to the other end of the first resistor R1 and has a first node J1, the other end of the second resistor R2 is grounded, and the first capacitor C1 is connected in parallel with the second resistor R2.
As shown in fig. 2, the second comparison voltage supply unit 2012 includes a third resistor R3 and a fourth resistor R4, one end of the third resistor R3 is connected to the positive output terminal of the dc power supply unit 50, for example, a power module, one end of the fourth resistor R4 is connected to the other end of the third resistor R3 and has a second junction J2, and the other end of the fourth resistor R4 is grounded.
As shown in fig. 2, the first comparing unit 2013 includes a first comparator Vo1 and a fifth resistor R5, a positive input terminal of the first comparator Vo1 is connected to the first node J1, a negative input terminal of the first comparator Vo1 is connected to the second node J2, an output terminal of the first comparator Vo1 is connected to the control terminal of the switching part 10, one end of the fifth resistor R5 is connected to an output terminal of the first comparator Vo1, and the other end of the fifth resistor R5 is connected to a positive output terminal of the dc power supply part 50, for example, a power module.
That is, the overvoltage detection circuit 201 is composed of resistors R1, R2, R3, R4, R5, a capacitor C1, and a comparator Vo1, the positive output voltage Vdc of the power module is divided into a second comparison voltage V2 by the third resistor R3 and the fourth resistor R4 and connected to the negative input terminal of the first comparator Vo1, the positive output voltage Vdc of the power module is divided by the first resistor R1 and the second resistor R2 and charged and discharged by the first capacitor C1, the output first comparison voltage V1 is connected to the positive input terminal of the first comparator Vo1, the output terminal of the first comparator Vo1 is pulled up to Vdc by the fifth resistor R5, the first comparison voltage V1 is set to be greater than the second comparison voltage V2, for example, when vdc=112v, the first comparison voltage v1=112v and the second comparison voltage v2=10v can be set. As shown in fig. 2 and 5, the overvoltage detection circuit 201 performs the following detection and comparison process on the output voltage of the power module:
(1) When Vdc starts to rise from 0V to 12V, the second comparison voltage V2 reaches 10V quickly, but the first comparison voltage V1 will rise to 11V slowly due to the charging of the first capacitor C1; before the first comparison voltage V1 slowly rises to 10V, V1 is smaller than V2, the first comparator Vo1 outputs low level L, at the moment, the MOS tube Q1 in the controllable switch circuit 101 is not conducted, the power supply loop is not conducted, and the direct current load stops working; after the first comparison voltage V1 slowly rises to exceed 10V, V1 is greater than V2, and the first comparator Vo1 outputs a high level H, so that the MOS transistor Q1 in the controllable switch circuit 101 can be driven to be turned on.
(2) When Vdc is stabilized at 12V, the second comparison voltage V2 is stabilized at 10V, the first comparison voltage V1 is stabilized at 11V, V1 is larger than V2, and the first comparator Vo1 stably outputs high level H; if the voltage at the output end of the power module instantaneously rises and fluctuates at this time, the first capacitor C1 charges the capacitor, the voltage change rate of the second comparison voltage V2 is greater than the voltage change rate of the first comparison voltage V1, the second comparison voltage V2 instantaneously exceeds the first comparison voltage V1, the first comparator Vo1 timely outputs a low level L, and at this time, the MOS transistor Q1 in the controllable switch circuit 101 is driven to be turned off, the power supply loop is disconnected, and the dc load stops working.
(3) When Vdc starts to drop from 12V to 0V, the second comparison voltage V2 quickly reaches 0V, but the first comparison voltage V1 slowly drops to 0V due to the discharge of the C1 capacitor; in the falling process, the first comparison voltage V1 is always higher than the second comparison voltage V2, the first comparator Vo1 always outputs the high level H, at this time, Q1 is driven to the high level, no overvoltage detection protection is performed, and protection control is performed by the undervoltage detection circuit.
From this, the overvoltage detection circuit 201 is constructed by simple components such as resistors, capacitors, comparators, etc., and controls the MOS transistor Q1 in the controllable switch circuit 101, and adopts a pure hardware circuit design, without adding an MCU chip and control software, so that the implementation is simple, the cost is low, and the control is reliable.
Further, as shown in fig. 2, the third comparison voltage providing unit 3011 includes a sixth resistor R6, a seventh resistor R7, and a second capacitor C2. One end of the sixth resistor R6 is connected to the dc power supply unit 50, for example, the positive output end of the power module, one end of the seventh resistor R7 is connected to the other end of the sixth resistor R6 and has a third junction J3, the other end of the seventh resistor R7 is grounded, and the second capacitor C2 is connected in parallel to the seventh resistor R7.
As shown in fig. 2, the fourth comparison voltage supply unit 3012 includes an eighth resistor R8 and a ninth resistor R9, one end of the eighth resistor R8 is connected to the positive output terminal of the dc power supply unit 50, for example, a power supply module, one end of the ninth resistor R9 is connected to the other end of the eighth resistor R8 and has a fourth junction J4, and the other end of the ninth resistor R9 is grounded.
As shown in fig. 2, the second comparing unit 3013 includes a second comparator Vo2, a positive input terminal of the second comparator Vo2 is connected to the fourth node J4, a negative input terminal of the second comparator Vo2 is connected to the third node J3, and an output terminal of the second comparator Vo2 is connected to a control terminal of the switching section.
That is, the under-voltage detection circuit 301 is composed of resistors R6, R7, R8, R9, a capacitor C2, and a comparator Vo2, the positive output voltage Vdc of the power module is divided into a fourth comparison voltage V4 by the third resistor R8 and the fourth resistor R9 and connected to the positive input terminal of the second comparator Vo2, the positive output voltage Vdc of the power module is divided by the sixth resistor R6 and the seventh resistor R7 and is charged and discharged by the second capacitor C2, the output terminal of the second comparator Vo2 is pulled up to Vdc by the fifth resistor R5, the third comparison voltage V3 is set to be smaller than the fourth comparison voltage V4, for example, when vdc=12v, the third comparison voltage v3=10v and the fourth comparison voltage v4=11v can be set. As shown in fig. 2 and 6, the undervoltage detection circuit 301 performs a detection comparison process on the output voltage of the power supply module as follows:
(1) When Vdc starts to rise from 0V to 12V, the fourth comparison voltage V4 quickly reaches 11V, but the third comparison voltage V3 slowly rises to 10V due to the charging of the second capacitor C2; in the rising process, the fourth comparison voltage V4 is always greater than the third comparison voltage V3, and the second comparator Vo2 always outputs the high level H, at this time, Q1 is driven to the high level;
(2) When Vdc is stabilized at 12V, the fourth comparison voltage V4 is stabilized at 11V, the third comparison voltage V3 is stabilized at 10V, V4 is greater than V3, and the second comparator Vo2 stably outputs high level H; if the voltage at the output end of the power module instantaneously drops and fluctuates at this time, the second capacitor C2 charges the capacitor, the voltage change rate of the fourth comparison voltage V4 is greater than the voltage change rate of the third comparison voltage V3, the fourth comparison voltage V4 is instantaneously lower than the third comparison voltage V3, the second comparator Vo2 timely outputs a low level L, and at this time, the MOS transistor Q1 in the controllable switch circuit 101 is driven to be turned off, the power supply loop is disconnected, and the dc load stops working.
(3) When Vdc starts to drop from 12V to 0V, the fourth comparison voltage V4 quickly reaches 0V, but the third comparison voltage V3 slowly drops to 0V due to the discharge of the C2 capacitor; before the fourth comparison voltage V4 drops to 10V, the second comparator Vo2 outputs a high level H, and after the fourth comparison voltage V4 drops to less than 10V, the second comparator Vo2 outputs a low level L, at this time, the MOS transistor Q1 in the controllable switch circuit 101 is driven to be turned off, the power supply loop is disconnected, and the dc load stops working.
Therefore, the undervoltage detection circuit 301 is also constructed by simple components such as resistors, capacitors, comparators, etc., controls the MOS transistor Q1 in the controllable switch circuit 101, adopts a pure hardware circuit design, does not need to add an MCU chip and control software, is simple to realize, has low cost, and is reliable to control.
Specifically, in another embodiment of the present application, as shown in fig. 3, the circuit topology of the overvoltage detection circuit 201 is the same as that of the embodiment shown in fig. 2, and will not be described again here. The undervoltage detection circuit 301 may share the second comparison voltage supply unit 2012 with the overvoltage detection circuit 201, so that the voltage of the fourth comparison voltage V4 may be set to the voltage of the second comparison voltage V2, at this time, a voltage dividing circuit formed by the resistors R8 and R9 may be omitted, the negative input terminal of the first comparator Vo1 and the positive input terminal of the second comparator Vo2 may be connected together, the first comparison voltage V1 is set to be greater than the second comparison voltage V2, the second comparison voltage V2 is set to be greater than the third comparison voltage V3, and the level variation waveforms outputted by the comparators may be as described in the above embodiments, wherein the control logic may be as shown in fig. 5 and 6.
Here, when vdc=12v, the first comparison voltage v1=11v, the second comparison voltage v2=10v may be set. As shown in fig. 3 and 5, the overvoltage detection circuit 201 performs the following detection and comparison process on the output voltage of the power module:
(1) When Vdc starts to rise from 0V to 12V, the second comparison voltage V2 reaches 10V quickly, but the first comparison voltage V1 will rise to 11V slowly due to the charging of the first capacitor C1; before the first comparison voltage V1 slowly rises to 10V, V1 is smaller than V2, the first comparator Vo1 outputs low level L, at the moment, the MOS tube Q1 in the controllable switch circuit 101 is not conducted, the power supply loop is not conducted, and the direct current load stops working; after the first comparison voltage V1 slowly rises to exceed 10V, V1 is greater than V2, and the first comparator Vo1 outputs a high level H, so that the MOS transistor Q1 in the controllable switch circuit 101 can be driven to be turned on.
(2) When Vdc is stabilized at 12V, the second comparison voltage V2 is stabilized at 10V, the first comparison voltage V1 is stabilized at 11V, V1 is larger than V2, and the first comparator Vo1 stably outputs high level H; if the voltage at the output end of the power module instantaneously rises and fluctuates at this time, the first capacitor C1 charges the capacitor, the voltage change rate of the second comparison voltage V2 is greater than the voltage change rate of the first comparison voltage V1, the second comparison voltage V2 instantaneously exceeds the first comparison voltage V1, the first comparator Vo1 timely outputs a low level L, and at this time, the MOS transistor Q1 in the controllable switch circuit 101 is driven to be turned off, the power supply loop is disconnected, and the dc load stops working.
(3) When Vdc starts to drop from 12V to 0V, the second comparison voltage V2 quickly reaches 0V, but the first comparison voltage V1 slowly drops to 0V due to the discharge of the C1 capacitor; in the falling process, the first comparison voltage V1 is always higher than the second comparison voltage V2, the first comparator Vo1 always outputs the high level H, at this time, Q1 is driven to the high level, no overvoltage detection protection is performed, and protection control is performed by the undervoltage detection circuit.
Alternatively, referring to fig. 3, the third comparison voltage providing unit 3011 includes a sixth resistor R6, a seventh resistor R7, and a second capacitor C2. One end of the sixth resistor R6 is connected to the dc power supply unit 50, for example, the positive output end of the power module, one end of the seventh resistor R7 is connected to the other end of the sixth resistor R6 and has a third junction J3, the other end of the seventh resistor R7 is grounded, and the second capacitor C2 is connected in parallel to the seventh resistor R7.
And, the second comparing unit 3013 includes a second comparator Vo2, a positive input terminal of the second comparator Vo2 is connected to a negative input terminal of the first comparator Vo1, that is, an output terminal of the second comparison voltage providing unit, a negative input terminal of the second comparator Vo2 is connected to the third junction J3, and an output terminal of the second comparator Vo2 is connected to a control terminal of the switching section.
Specifically, when vdc=12v, the second comparison voltage v2=11v, the third comparison voltage v3=10v may be set. As shown in fig. 3 and 6, the undervoltage detection circuit 301 performs a detection comparison process on the output voltage of the power supply module as follows:
(1) When Vdc starts to rise from 0V to 12V, the second comparison voltage V2 reaches 11V soon, but the third comparison voltage V3 slowly rises to 10V due to the charging of the second capacitor C2; in the rising process, the second comparison voltage V2 is always greater than the third comparison voltage V3, and the second comparator Vo2 always outputs a high level H, at this time, Q1 is driven to be high level;
(2) When Vdc is stabilized at 12V, the second comparison voltage V2 is stabilized at 11V, the third comparison voltage V3 is stabilized at 10V, V2 is greater than V3, and the second comparator Vo2 stably outputs high level H; if the voltage at the output end of the power module instantaneously drops and fluctuates at this time, the voltage change rate of the second comparison voltage V2 is greater than the voltage change rate of the third comparison voltage V3 because the second capacitor C2 charges the capacitor, the second comparison voltage V2 instantaneously is lower than the third comparison voltage V3, the second comparator Vo2 timely outputs a low level L, and at this time, the MOS transistor Q1 in the controllable switch circuit 101 is driven to be turned off, the power supply loop is disconnected, and the dc load stops working.
(3) When Vdc starts to drop from 12V to 0V, the second comparison voltage V2 quickly reaches 0V, but the third comparison voltage V3 slowly drops to 0V due to the discharge of the C2 capacitor; before the second comparison voltage V2 drops to 10V, the second comparator Vo2 outputs a high level H, and after the second comparison voltage V2 drops to less than 10V, the second comparator Vo2 outputs a low level L, at this time, the MOS transistor Q1 in the controllable switch circuit 101 is driven to be turned off, the power supply loop is disconnected, and the dc load stops working.
Similarly, the undervoltage detection circuit 301 is also constructed by simple components such as resistors, capacitors, comparators and the like, controls the MOS transistor Q1 in the controllable switch circuit 101, adopts a pure hardware circuit design, does not need to add an MCU chip and control software, is simple to realize, has low cost, and is reliable to control.
Embodiment four:
in addition, in still another embodiment of the present application, as shown in fig. 4, the first comparing unit 2013 in the overvoltage detecting circuit 201 outputs the circuit signal by comparing the values of the first comparing voltage V1 and the fourth comparing voltage V4. The circuit topology of the brown-out detection circuit 301 is the same as that of the embodiment shown in fig. 2, and will not be described again here. The overvoltage detection circuit 201 may share the fourth comparison voltage supply unit 3012 with the undervoltage detection circuit 301, so that the voltage of the second comparison voltage V2 may be set to the voltage of the fourth comparison voltage V4, at this time, a voltage dividing circuit formed by resistors R3 and R4 may be omitted, the negative input terminal of the first comparator Vo1 and the positive input terminal of the second comparator Vo2 may be connected together, the first comparison voltage V1 is set to be greater than the fourth comparison voltage V4, and the fourth comparison voltage V4 is set to be greater than the third comparison voltage V3, where the control logic is the same as that described in the above embodiment, and the level variation waveforms outputted by the comparators may be shown with reference to fig. 5 and 6.
Here, when vdc=12v, the first comparison voltage v1=11v, the fourth comparison voltage v4=10v may be set. As shown in fig. 4 and 5, the overvoltage detection circuit 201 performs the following detection and comparison process on the output voltage of the power module:
(1) When Vdc rises from 0V to 12V, the fourth comparison voltage V4 reaches 10V quickly, but the first comparison voltage V1 slowly rises to 11V due to the charging of the first capacitor C1; before the first comparison voltage V1 slowly rises to 10V, V1 is smaller than V4, the first comparator Vo1 outputs low level L, at the moment, the MOS tube Q1 in the controllable switch circuit 101 is not conducted, the power supply loop is not conducted, and the direct current load stops working; after the first comparison voltage V1 slowly rises to exceed 10V, V1 is greater than V4, and the first comparator Vo1 outputs a high level H, so that the MOS transistor Q1 in the controllable switch circuit 101 can be driven to be turned on.
(2) When Vdc is stabilized at 12V, the fourth comparison voltage V4 is stabilized at 10V, the first comparison voltage V1 is stabilized at 11V, V1 is greater than V4, and the first comparator Vo1 stably outputs high level H; if the voltage at the output end of the power module instantaneously rises and fluctuates at this time, since the first capacitor C1 performs capacitor charging, the voltage change rate of the fourth comparison voltage V4 is greater than the voltage change rate of the first comparison voltage V1, the fourth comparison voltage V4 instantaneously is higher than the first comparison voltage V1, the first comparator Vo1 timely outputs the low level L, and at this time, the MOS transistor Q1 in the controllable switch circuit 101 is driven to be turned off, the power supply loop is disconnected, and the dc load stops working.
(3) When Vdc starts to drop from 12V to 0V, the fourth comparison voltage V4 quickly reaches 0V, but the first comparison voltage V1 slowly drops to 0V due to the discharge of the C1 capacitor; in the falling process, the first comparison voltage V1 is always higher than the fourth comparison voltage V4, the first comparator Vo1 always outputs the high level H, at this time, Q1 is driven to the high level, no overvoltage detection protection is performed, and protection control is performed by the undervoltage detection circuit.
Alternatively, referring to fig. 4, the third comparison voltage providing unit 3011 includes a sixth resistor R6, a seventh resistor R7, and a second capacitor C2. One end of the sixth resistor R6 is connected to the dc power supply unit 50, for example, the positive output end of the power module, one end of the seventh resistor R7 is connected to the other end of the sixth resistor R6 and has a third junction J3, the other end of the seventh resistor R7 is grounded, and the second capacitor C2 is connected in parallel to the seventh resistor R7.
The fourth comparison voltage providing unit 3012 includes an eighth resistor R8 and a ninth resistor R9, one end of the eighth resistor R8 is connected to the positive output terminal of the dc power supply section 50, for example, a power module, one end of the ninth resistor R9 is connected to the other end of the eighth resistor R8 and has a fourth junction J4, and the other end of the ninth resistor R9 is grounded.
Specifically, when vdc=12v, the fourth comparison voltage v4=11v, the third comparison voltage v3=10v may be set. As shown in fig. 3 and 6, the undervoltage detection circuit 301 performs a detection comparison process on the output voltage of the power supply module as follows:
(1) When Vdc starts to rise from 0V to 12V, the fourth comparison voltage V4 quickly reaches 11V, but the third comparison voltage V3 slowly rises to 10V due to the charging of the second capacitor C2; in the rising process, the fourth comparison voltage V4 is always greater than the third comparison voltage V3, and the second comparator Vo2 always outputs the high level H, at this time, Q1 is driven to the high level;
(2) When Vdc is stabilized at 12V, the fourth comparison voltage V4 is stabilized at 11V, the third comparison voltage V3 is stabilized at 10V, V4 is greater than V3, and the second comparator Vo2 stably outputs high level H; if the voltage at the output end of the power module instantaneously drops and fluctuates at this time, the second capacitor C2 charges the capacitor, the voltage change rate of the fourth comparison voltage V4 is greater than the voltage change rate of the third comparison voltage V3, the fourth comparison voltage V4 is instantaneously lower than the third comparison voltage V3, the second comparator Vo2 timely outputs a low level L, and at this time, the MOS transistor Q1 in the controllable switch circuit 101 is driven to be turned off, the power supply loop is disconnected, and the dc load stops working.
(3) When Vdc starts to drop from 12V to 0V, the fourth comparison voltage V4 quickly reaches 0V, but the third comparison voltage V3 slowly drops to 0V due to the discharge of the C2 capacitor; before the fourth comparison voltage V4 drops to 10V, the second comparator Vo2 outputs a high level H, and after the fourth comparison voltage V4 drops to less than 10V, the second comparator Vo2 outputs a low level L, at this time, the MOS transistor Q1 in the controllable switch circuit 101 is driven to be turned off, the power supply loop is disconnected, and the dc load stops working.
Similarly, the undervoltage detection circuit 301 is also constructed by simple components such as resistors, capacitors, comparators and the like, controls the MOS transistor Q1 in the controllable switch circuit 101, adopts a pure hardware circuit design, does not need to add an MCU chip and control software, is simple to realize, has low cost, and is reliable to control.
Alternatively, in one embodiment of the present application, as shown in fig. 2, 3 or 4, the over-current detection section is an over-current detection circuit 401 including a current detection resistor Rsh, a tenth resistor R10, an eleventh resistor R11 and a third comparator Vo3.
The current detection resistor Rsh is disposed in the power supply loop of the dc load, that is, one end of the current detection resistor Rsh is connected to the dc power supply 50, for example, the negative end of the power module, and then grounded, and the other end of the current detection resistor Rsh is connected to the controllable switch circuit 101. One end of the tenth resistor R10 is connected to the reference voltage supply end Vcc of the dc power supply section 50, for example, a power supply module, one end of the eleventh resistor R11 is connected to the other end of the tenth resistor R10 and has a fifth node J5, the other end of the eleventh resistor R11 is connected to one end of the current detection resistor Rsh and then grounded, the positive input end of the third comparator Vo3 is connected to the fifth node J5, the negative input end of the third comparator Vo3 is connected to the other end of the current detection resistor Rsh, and the output end of the third comparator Vo3 is connected to the control end of the switching section, that is, the controllable switching circuit 101.
As shown in fig. 2, 3 or 4, the over-current detection circuit 401 is composed of resistors R10, R11, rsh and a comparator Vo3, a reference power supply Vcc provided by the power supply module is divided into a reference voltage Vref by a tenth resistor R10 and an eleventh resistor R11, the reference voltage Vref is connected to an positive input terminal of the third comparator Vo3, a sampling voltage Vin formed by a load current I flowing through the current detection resistor Rsh is connected to a negative input terminal of the third comparator Vo3, and an output terminal of the third comparator Vo3 is connected to a fifth resistor R5 and pulled up to Vdc, so that when the load current I exceeds an over-current protection set value, vin is greater than Vref, the comparator Vo3 outputs a low level L, and at this time, a MOS transistor Q1 in the controllable switch circuit 101 is driven to be turned off, a power supply loop is disconnected, and the dc load stops working.
Therefore, the overcurrent detection circuit 401 is constructed by simple components such as resistors and comparators, can control the MOS transistor Q1 in the controllable switch circuit 101, adopts a pure hardware circuit design, does not need to add an MCU chip and control software, is simple to realize, has low cost, and is reliable to control.
In one embodiment of the present application, as shown in fig. 2, 3 or 4, the switching portion is a controllable switching circuit 101, which includes a twelfth resistor R12, a thirteenth resistor R13 and a first MOS transistor Q1. One end of a twelfth resistor R12 is used as a control end of the switch part, one end of a thirteenth resistor R13 is connected with the other end of the twelfth resistor R12, the other end of the thirteenth resistor R13 is connected with the other end of the current detection resistor Rsh, the drain electrode of the first MOS tube Q1 is respectively connected with the other end of the thirteenth resistor R13 and the other end of the current detection resistor Rsh, the source electrode of the first MOS tube Q1 is connected to a direct current load, and the grid electrode of the first MOS tube Q1 is connected with the other end of the twelfth resistor R12.
As can be seen, the controllable switch circuit 101 is composed of resistors R12, R13 and a MOS transistor Q1, when the outputs of the first comparator Vo1, the second comparator Vo2 and the third comparator Vo3 are all at the high level H, the first MOS transistor Q1 is turned on, the power supply loop of the dc load is turned on, and the dc load works normally; when any one of the outputs of the first comparator Vo1, the second comparator Vo2 and the third comparator Vo3 is the low level L, the first MOS transistor Q1 is turned off, and the power supply loop of the dc load is disconnected, so that the dc load stops working, and protection control is implemented.
It is to be understood that, in the embodiment of the present application, the first MOS transistor Q1 functioning as a switching device in the controllable switching circuit 101 is not limited to the MOS transistor, but may be another power transistor, for example, an IGBT or the like.
Specifically, the switching relationship between the outputs of the overvoltage detecting section 20, the undervoltage detecting section 30, and the overcurrent detecting section 40 and the switching section 10, that is, the driving relationship between the outputs of the first comparator Vo1, the second comparator Vo2, and the third comparator Vo3 and the first MOS transistor Q1 is as shown in the following table 1:
TABLE 1
As can be seen from table 1 above, as long as any one of the overvoltage detection unit 20, the undervoltage detection unit 30, and the overcurrent detection unit 40 outputs a protection signal, the switching unit 10 is turned off, and the power supply circuit of the dc load is disconnected, thereby realizing corresponding protection control. Therefore, the switch 10 controls the power supply circuit of the dc load to be disconnected according to at least one of the overvoltage protection signal (e.g., low level), the undervoltage protection signal (e.g., low level) and the overcurrent protection signal (e.g., low level), that is, by using a combination circuit of instantaneous overvoltage protection, instantaneous undervoltage protection and instantaneous overcurrent protection, any circuit trigger protection can disconnect the power supply circuit of the dc load, and the power supply is cut off, thereby realizing timely and effective protection.
It can be understood that in the embodiment of the application, the instantaneous overvoltage protection and the instantaneous undervoltage protection can be set to different protection values and protection times through the combination setting of the resistor and the capacitor, and the calibration can be specifically performed according to actual situations.
In summary, the direct current load fault detection circuit of the embodiment of the application can realize overvoltage detection, undervoltage detection and overcurrent detection through the pure hardware circuit when the direct current load is not fed back, achieves the rapid protection of instantaneous overvoltage, instantaneous undervoltage and instantaneous overcurrent of the direct current load, can enable the direct current load to work in a certain power supply voltage range, greatly reduces the fault rate of equipment, adopts the pure hardware circuit design, does not need to increase an MCU chip and control software, and is simple to realize and low in cost.
It should be noted that the dc load fault detection circuit provided in the embodiment of the present application may be applied to home appliances having dc loads such as an air conditioner and a fan, and the dc loads may be PTC heaters, motors, and the like, which are not limited herein.
According to the direct-current load fault detection circuit provided by the embodiment of the application, the switch part can be a controllable switch circuit for example through setting up the switch part in the power supply loop, and through detecting and judging the voltage and the load current of the direct-current power supply part, once overvoltage, undervoltage and overcurrent conditions occur, the switch part is directly triggered to disconnect the power supply loop of the direct-current load, so that corresponding protection control can be timely carried out when the direct-current load has abnormal faults, the load and an external controller can not be damaged, the equipment fault rate is greatly reduced, the maintenance cost is reduced, and the user experience degree is improved. And the whole fault detection circuit is built by simple components such as a resistor, a capacitor, a comparator and the like, adopts a pure hardware circuit design, does not need to add an MCU chip and control software, is simple to realize, and has low cost and reliable control.
As shown in fig. 7, the embodiment of the present application further provides a home appliance 1, where the home appliance 1 includes the dc load fault detection circuit 2 described in the foregoing embodiment.
In the embodiment of the present application, the home appliance may be a home appliance such as an air conditioner, a fan, or the like.
According to the household electrical appliance provided by the embodiment of the application, through the direct current load fault detection circuit, corresponding protection control can be timely carried out when a load breaks down, so that the load and an external controller cannot be damaged, the equipment fault rate is greatly reduced, the maintenance cost is reduced, and the user experience degree is improved.
It will be appreciated by those skilled in the art that embodiments of the present invention may be provided as a method. Accordingly, the present invention may take the form of an entirely hardware embodiment.
It should be noted that in the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. The word "comprising" does not exclude the presence of elements or steps not listed in a claim. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. The invention may be implemented by means of hardware comprising several distinct elements, and by means of a suitably programmed computer. In the unit claims enumerating several means, several of these means may be embodied by one and the same item of hardware. The use of the words first, second, third, etc. do not denote any order. These words may be interpreted as names.
While preferred embodiments of the present invention have been described, additional variations and modifications in those embodiments may occur to those skilled in the art once they learn of the basic inventive concepts. It is therefore intended that the following claims be interpreted as including the preferred embodiments and all such alterations and modifications as fall within the scope of the invention.
It will be apparent to those skilled in the art that various modifications and variations can be made to the present invention without departing from the invention
Clear spirit and scope. Thus, it is intended that the present invention also include such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof.
Claims (10)
1. A direct current load fault detection circuit, comprising:
the switch part is arranged in the direct-current load power supply loop;
the overvoltage detection part comprises a first resistor, a second resistor and a first capacitor, one end of the first resistor is connected to the output end of the direct current power supply part, one end of the second resistor is connected with the other end of the first resistor and is provided with a first node, the other end of the second resistor is grounded, the first capacitor is connected with the second resistor in parallel, and the overvoltage detection part is used for detecting the output voltage of the direct current power supply part and outputting an overvoltage protection signal to the switch part when the output voltage of the direct current power supply part is detected to be overvoltage;
The undervoltage detection part comprises a sixth resistor, a seventh resistor and a second capacitor, one end of the sixth resistor is connected with the output end of the direct current power supply part, one end of the seventh resistor is connected with the other end of the sixth resistor and is provided with a third node, the other end of the seventh resistor is grounded, the second capacitor is connected with the seventh resistor in parallel, and the undervoltage detection part is used for detecting the output voltage of the direct current power supply part and outputting an undervoltage protection signal to the switch part when the undervoltage of the output voltage of the direct current power supply part is detected;
the overcurrent detection part is used for detecting the overcurrent of the load current and outputting an overcurrent protection signal to the switch part;
the switch part is used for controlling the disconnection of the direct-current load power supply loop according to at least one of the overvoltage protection signal, the undervoltage protection signal and the overcurrent protection signal.
2. The direct current load fault detection circuit of claim 1, wherein the overvoltage detection section is further configured to compare the output voltage of the direct current power supply section based on a second comparison voltage to determine whether an overvoltage has occurred in the output voltage of the direct current power supply section.
3. The direct current load fault detection circuit of claim 2, wherein the overvoltage detection section further comprises:
the positive input end of the first comparator is connected with the first node, the negative input end of the first comparator receives the second comparison voltage, and the output end of the first comparator is connected to the control end of the switch part;
and one end of the fifth resistor is connected with the output end of the first comparator, and the other end of the fifth resistor is connected with the output end of the direct current power supply part.
4. The direct current load fault detection circuit of claim 2, wherein the brown-out detection section is further configured to compare the output voltage of the direct current power supply section based on a fourth comparison voltage to determine whether the output voltage of the direct current power supply section has a brown-out.
5. The direct current load fault detection circuit of claim 4, wherein the brown-out detection section further comprises:
and the positive input end of the second comparator receives the fourth comparison voltage, the negative input end of the second comparator is connected with the third node, and the output end of the second comparator is connected to the control end of the switch part.
6. The dc load fault detection circuit as claimed in claim 4, wherein the second comparison voltage and the fourth comparison voltage are divided according to an output voltage of the dc power supply unit, respectively.
7. The direct current load fault detection circuit of claim 6, wherein the second comparison voltage and the fourth comparison voltage are the same.
8. The direct current load fault detection circuit according to any one of claims 1 to 7, wherein the overcurrent detection section includes:
the current detection resistor is arranged in the direct-current load power supply loop;
a tenth resistor, one end of which is connected with the reference voltage supply end of the direct current power supply part;
an eleventh resistor, wherein one end of the eleventh resistor is connected with the other end of the tenth resistor and is provided with a fifth node, and the other end of the eleventh resistor is connected with one end of the current detection resistor and then grounded;
and the positive input end of the third comparator is connected with the fifth node, the negative input end of the third comparator is connected with the other end of the current detection resistor, and the output end of the third comparator is connected to the control end of the switch part.
9. The direct current load fault detection circuit of claim 8, wherein the switching section comprises:
a twelfth resistor, one end of which is used as a control end of the switch part;
a thirteenth resistor, one end of which is connected with the other end of the twelfth resistor, and the other end of which is connected with the other end of the current detection resistor;
the drain electrode of the first MOS tube is respectively connected with the other end of the thirteenth resistor and the other end of the current detection resistor, the source electrode of the first MOS tube is connected to a direct current load, and the grid electrode of the first MOS tube is connected with the other end of the twelfth resistor.
10. An electric home appliance comprising a direct current load fault detection circuit as claimed in any one of claims 1 to 9.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311874268.3A CN117607749A (en) | 2021-05-25 | 2021-05-25 | Direct current load fault detection circuit and household electrical appliance with same |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110573376.1A CN113296028B (en) | 2021-05-25 | 2021-05-25 | Direct current load fault detection circuit and household electrical appliance with same |
| CN202311874268.3A CN117607749A (en) | 2021-05-25 | 2021-05-25 | Direct current load fault detection circuit and household electrical appliance with same |
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| CN202110573376.1A Division CN113296028B (en) | 2021-05-25 | 2021-05-25 | Direct current load fault detection circuit and household electrical appliance with same |
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| CN202311874268.3A Pending CN117607749A (en) | 2021-05-25 | 2021-05-25 | Direct current load fault detection circuit and household electrical appliance with same |
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| CN113937725A (en) * | 2021-09-07 | 2022-01-14 | 华为数字能源技术有限公司 | Short-circuit protection device, short-circuit protection method of target circuit and power conversion equipment |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100426614C (en) * | 2004-07-29 | 2008-10-15 | 中兴通讯股份有限公司 | High voltage protective device for input of AC electrical source |
| CN201118197Y (en) * | 2007-11-08 | 2008-09-17 | 德力西电气有限公司 | Alternating current voltage under-voltage releasing equipment control circuit |
| JP4793396B2 (en) * | 2008-02-29 | 2011-10-12 | ダイキン工業株式会社 | Overvoltage protection circuit |
| CN201466667U (en) * | 2009-07-31 | 2010-05-12 | 北京七星华创电子股份有限公司 | Protective device of direct current (DC) power supply and load |
| JP2016140118A (en) * | 2015-01-26 | 2016-08-04 | 株式会社村田製作所 | Power supply |
| CN108279387A (en) * | 2018-01-17 | 2018-07-13 | 北京和利时智能技术有限公司 | A kind of apparatus for monitoring power supply |
| CN109873643B (en) * | 2019-03-27 | 2024-03-22 | 上海航嘉电子科技股份有限公司 | A/D sampling circuit and sampling method for alternating current power supply resistance type sensor |
| CN111405275A (en) * | 2020-04-07 | 2020-07-10 | 深圳市金锐显数码科技有限公司 | Direct current power supply circuit and television board card test system |
| CN211744440U (en) * | 2020-05-18 | 2020-10-23 | 重庆工业职业技术学院 | Slow output switch circuit |
| CN111864697B (en) * | 2020-09-01 | 2022-05-24 | 臻驱科技（上海）有限公司 | Overcurrent protection circuit and method and system for judging whether power supply is overhauled |
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| CN113296028A (en) | 2021-08-24 |
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