CN110739672A - Surge current control circuit and control method thereof - Google Patents
Surge current control circuit and control method thereof Download PDFInfo
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- CN110739672A CN110739672A CN201911008454.2A CN201911008454A CN110739672A CN 110739672 A CN110739672 A CN 110739672A CN 201911008454 A CN201911008454 A CN 201911008454A CN 110739672 A CN110739672 A CN 110739672A
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- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H9/00—Emergency protective circuit arrangements for limiting excess current or voltage without disconnection
- H02H9/02—Emergency protective circuit arrangements for limiting excess current or voltage without disconnection responsive to excess current
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Abstract
The application provides surge current limiting circuits and a control method thereof, which relate to the technical field of current control equipment, wherein in the control method, according to the measurement and judgment of each electric quantity parameter in the circuit, the control of the connection state of a limiting resistor in the surge current limiting circuit is realized by controlling a switch circuit, when the circuit is electrified, a current limiting resistor is controlled to be connected with a filter capacitor, the surge current generated in the circuit when the circuit is electrified can be limited, the control of the circuit is realized by a control chip, the input voltage, the output voltage and the normal numerical range corresponding to the limit value of the current limiting resistor can be flexibly changed, so that the current limiting resistor can adapt to different circuit systems, does not need to use a thermistor, has small temperature drift and strong impact resistance, can be stable under different temperature environments such as high temperature, normal temperature, low temperature and the like, can not drift along with the temperature change, and can also ensure that the circuit performance does not change when the circuit is repeatedly switched on and switched on.
Description
Technical Field
The application relates to the field of current limiting circuits, in particular to surge current control circuits and control methods thereof.
Background
In daily use, the most common electric energy source is used in commercial power, capacitors with large capacity are needed on the input side of a direct current converter for filtering, large surge currents exist when the direct current converter is started to be powered on, and the surge currents need to be limited to avoid damaging other devices.
Disclosure of Invention
In view of the above, the present application provides inrush current control circuits and control methods thereof, which can solve the above problems.
The technical scheme provided by the application is as follows:
A control method of surge current limiting circuit, which is applied to a surge current limiting circuit, the surge current limiting circuit includes an EMI filter, a rectifying circuit, a filter capacitor, a current limiting resistor, a switch circuit and a control chip, the EMI filter is connected with an AC input end for filtering AC input by the AC input end, the rectifying circuit is connected with the EMI filter for rectifying the filtered AC and outputting the rectified AC, the filter capacitor is connected with an output end of the rectifying circuit for filtering the rectified AC, the current limiting resistor is connected with the filter capacitor, the other is connected with a load for limiting surge current generated by the filter capacitor at the moment when the surge current limiting circuit is electrified, the switch circuit is used for controlling the current limiting resistor to be connected with the filter capacitor when being opened or short-circuiting the current limiting resistor when being closed, the control chip is used for detecting the input voltage of AC input by the AC input end, the output voltage of the rectifying circuit and the voltage of the current limiting resistor and controlling the switch circuit to be opened or closed, the control method includes:
when the surge current limiting circuit is powered on, the switching circuit is controlled to be opened, so that the current limiting resistor is connected with the filter capacitor to charge the filter capacitor;
when the charging time of the filter capacitor reaches a preset time, detecting the input voltage, the output voltage of the rectifying circuit and the voltage of the current-limiting resistor;
judging whether the input voltage is within a preset normal range, judging whether the difference value between the input voltage and the output voltage is smaller than a preset difference value, and judging whether the voltage of the current-limiting resistor is smaller than a preset voltage;
when input voltage is located and predetermines normal range, just input voltage with output voltage's difference is less than predetermineeing the difference, simultaneously current limiting resistor's voltage is less than predetermineeing voltage, control the switching circuit short circuit current limiting resistor, so that rectifier circuit way is to the load power supply.
, the step of controlling the switching circuit to short the current limiting resistor to cause the rectifying circuit to supply power to the load includes:
when the time length that the input voltage is located in the preset normal range exceeds the preset time length, the time length that the difference value of the input voltage and the output voltage is smaller than the preset difference value exceeds the preset time length, and meanwhile, the time length that the voltage of the current-limiting resistor is smaller than the preset voltage exceeds the preset time length, the current-limiting resistor is in short circuit.
Further , the method further includes:
and when the input voltage exceeds the preset normal range, or the difference value between the input voltage and the output voltage is greater than or equal to a preset difference value, or the voltage of the current-limiting resistor is greater than or equal to a preset voltage, controlling the current-limiting resistor to be connected with the filter capacitor.
, after the rectifying circuit supplies power to the load, the method further comprises:
detecting whether the input voltage is within the preset normal range;
when the input voltage is detected to exceed the preset normal range, the switch circuit is controlled to be opened, so that the current-limiting resistor is connected with the filter capacitor;
when the input voltage is detected to be within the preset normal range, the switch circuit is kept closed, the current-limiting resistor is short-circuited, and the rectifying circuit is kept supplying power to the load.
, the switch circuit is FET or solid state relay, the current limiting resistance is wire wound resistance.
The application also provides surge current limiting circuits, which comprise an EMI filter, a rectifying circuit, a filter capacitor, a current limiting resistor, a switch circuit and a control chip, wherein the EMI filter is connected with an alternating current input end and used for filtering alternating current input by the alternating current input end, the rectifying circuit is connected with the EMI filter and used for rectifying and outputting the filtered alternating current, the filter capacitor is connected with an output end of the rectifying circuit and used for filtering the rectified alternating current, the current limiting resistor end is connected with the filter capacitor, the other end is connected with a load and used for limiting surge current generated by the filter capacitor at the moment when the surge current limiting circuit is electrified, the switch circuit is used for controlling the current limiting resistor to be connected with the filter capacitor when the switch circuit is opened or closed or short-circuiting the current limiting resistor when the switch circuit is closed, the control chip is used for detecting input voltage of the alternating current input by the alternating current input end, output voltage of the rectifying circuit and voltage of the current limiting resistor and controlling the switch circuit to be opened or closed, and the control chip is used for:
when the surge current limiting circuit is powered on, the switching circuit is controlled to be opened, so that the current limiting resistor is connected with the filter capacitor to charge the filter capacitor;
when the charging time of the filter capacitor reaches a preset time, detecting the input voltage, the output voltage of the rectifying circuit and the voltage of the current-limiting resistor;
judging whether the input voltage is within a preset normal range, judging whether the difference value between the input voltage and the output voltage is smaller than a preset difference value, and judging whether the voltage of the current-limiting resistor is smaller than a preset voltage;
when input voltage is located and predetermines normal range, just input voltage with output voltage's difference is less than predetermineeing the difference, simultaneously current limiting resistor's voltage is less than predetermineeing voltage, control the switching circuit short circuit current limiting resistor, so that rectifier circuit way is to the load power supply.
, the control chip is specifically configured to:
when the time length that the input voltage is located in the preset normal range exceeds the preset time length, the time length that the difference value of the input voltage and the output voltage is smaller than the preset difference value exceeds the preset time length, and meanwhile, the time length that the voltage of the current-limiting resistor is smaller than the preset voltage exceeds the preset time length, the current-limiting resistor is in short circuit.
Further , the control chip is further configured to:
and when the input voltage exceeds the preset normal range, or the difference value between the input voltage and the output voltage is greater than or equal to a preset difference value, or the voltage of the current-limiting resistor is greater than or equal to a preset voltage, controlling the current-limiting resistor to be connected with the filter capacitor.
, after the rectifying circuit supplies power to the load, the control chip is further configured to:
detecting whether the input voltage is within the preset normal range;
when the input voltage is detected to exceed the preset normal range, the switch circuit is controlled to be opened, so that the current-limiting resistor is connected with the filter capacitor;
when the input voltage is detected to be within the preset normal range, the switch circuit is kept closed, the current-limiting resistor is short-circuited, and the rectifying circuit is kept supplying power to the load.
, the switch circuit is a FET or a solid state relay, and the current limiting resistor is a wire wound resistor.
The control method of the surge current limiting circuit provided by the embodiment of the application is characterized in that according to measurement and judgment of each electric quantity parameter in the surge current limiting circuit, control of the connection state of the limiting resistor in the surge current limiting circuit is realized through control of the switching circuit, when the circuit is powered on, the limiting resistor is controlled to be connected with the filter capacitor, surge current generated in the circuit when the circuit is powered on can be limited, the control of the circuit is realized through the control chip, input voltage, output voltage and a normal numerical range corresponding to limit value of the limiting resistor can be flexibly changed, and therefore the control method can be suitable for different circuit systems.
In order to make the aforementioned objects, features and advantages of the present application more comprehensible, preferred embodiments accompanied with figures are described in detail below.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are required to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present application and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained from the drawings without inventive effort.
Fig. 1 is a schematic diagram of kinds of inrush current limiting circuits provided in an embodiment of the present application.
Fig. 2 is another schematic diagram of inrush current limiting circuits provided in this embodiment of the present application.
Fig. 3 is a schematic flowchart of methods for controlling an inrush current limiting circuit according to an embodiment of the present disclosure.
Fig. 4 is another flowchart of a control method of inrush current limiting circuits according to an embodiment of the present disclosure.
Icon: 10-an inrush current limiting circuit; 101-an EMI filter; 102-a rectifying circuit; 103-a filter capacitor; 104-current limiting resistor; 105-a switching circuit; 106-a control chip; 107-input voltage detection circuit; 108-output voltage detection circuit; 109-current limiting resistance voltage detection circuit; 20-load.
Detailed Description
The embodiments of the present application, generally described and illustrated in the figures herein, can be arranged and designed in a wide variety of different configurations and therefore, the following detailed description of the embodiments of the present application, which is provided in the accompanying drawings, is not intended to limit the scope of the claimed application, but is merely representative of selected embodiments of the application.
It should be noted that like reference numerals and letters refer to like items in the following figures, and thus once a item is defined in figures, it need not be further defined and explained by in subsequent figures.
The embodiment of the present application provides methods for controlling an inrush current limiting circuit, which are applied to an inrush current limiting circuit 10, as shown in fig. 1, where the inrush current limiting circuit 10 includes an EMI filter 101, a rectifying circuit 102, a filter capacitor 103, a current limiting resistor 104, a switch circuit 105, and a control chip 106, where the EMI filter 101 is connected to an ac input terminal for filtering ac input from the ac input terminal, the rectifying circuit 102 is connected to the EMI filter 101 for rectifying and outputting the filtered ac, the filter capacitor 103 is connected to an output terminal of the rectifying circuit 102 for filtering the rectified ac, a current limiting resistor 104 is connected to the filter capacitor 103, and another is connected to a load 20 for limiting an inrush current generated by the filter capacitor 103 when the inrush current limiting circuit 10 is powered on, the switch circuit 105 is used for controlling the switch resistor 104 to be connected to the filter capacitor 103 when opened, or short-circuiting the switch resistor 104 when closed, and the control chip 106 is used for detecting an input voltage of the ac input from the ac input terminal, an output voltage of the rectifying circuit 102, and the switch circuit 106 is capable of detecting parameters of detecting the input voltage of detecting circuit 109 and detecting parameters of detecting the input voltage as shown in fig. 2.
The control method provided by the embodiment of the present application is applied to the above circuit, and as shown in fig. 4, the following steps may be executed by the control chip 106.
Step S101, when the inrush current limiting circuit 10 is powered on, controlling the switch circuit 105 to open, so that the current limiting resistor 104 is connected to the filter capacitor 103, so as to charge the filter capacitor 103.
The circuit can generate large surge currents in the circuit when being powered on, and the surge currents can damage the load 20 or other devices if not limited, a thermistor can be connected with a capacitor in series, the thermistor is used for limiting the surge currents, but the thermistor is sensitive to temperature, so that the phenomenon of difficult starting can occur under low-temperature conditions, the effect of limiting the surge currents is poor under high-temperature conditions, and the defect of insufficient current suppression capability exists when the power supply is repeatedly switched on and off.
In the inrush current limiting circuit 10 according to the embodiment of the present application, the current limiting resistor 104 does not use a thermistor, and the connection relationship between the current limiting resistor and the filter capacitor 103 is controlled by the switch circuit 105. The control chip 106 may be connected to the ac input end, and when there is current at the ac input end, it may be detected that the inrush current limiting circuit 10 is powered on, and at this time, the control chip 106 may generate a control instruction to control the switch circuit 105 to be turned on. The switch circuit 105 may be connected in parallel with the current limiting resistor 104, and when the switch circuit 105 is turned on, the current limiting resistor 104 is connected to the filter capacitor 103. When the switch circuit 105 is closed, the current limiting resistor 104 is short-circuited, and the filter capacitor 103 is directly connected to the load 20. The switching circuit 105 may be turned on when the inrush current limiting circuit 10 is powered on according to an instruction of the control chip 106, and the filter capacitor 103 may be charged by the input alternating current. Since the current limiting resistor 104 is connected to the charging circuit of the filter capacitor 103, the current limiting resistor 104 can limit the magnitude of the charging current.
The current limiting resistor 104 can be a wire-wound resistor, has small temperature drift and strong shock resistance, and can realize stable performance at high temperature, normal temperature and low temperature without drifting along with the temperature. When the switch is repeatedly switched on and switched off, the performance can be ensured not to change. The switch circuit 105 may include a field effect transistor or a solid-state relay, and controls the connection state of the current limiting resistor 104 through the field effect transistor or the solid-state relay, and the field effect transistor or the solid-state relay has a small internal resistance, has the characteristics of small heat generation amount and high efficiency during normal operation, and is applicable to a high-power use scene.
Step S102, when the time length for waiting for charging the filter capacitor 103 reaches th preset time length, detecting the magnitude of the input voltage, the output voltage of the rectifier circuit 102, and the voltage of the current limiting resistor 104.
The filter capacitor 103 starts to be charged under the action of current, the control chip 106 can record charging time, the control chip 106 can take a time point of generating a control instruction for the switch circuit 105 as a starting time of the charging time, the th preset time can be more than 5 times of a charging time constant of the filter capacitor 103, and different filter capacitors 103 have different charging time constants.
Step S103, determining whether the input voltage is within a preset normal range, determining whether a difference between the input voltage and the output voltage is smaller than a preset difference, and determining whether the voltage of the current limiting resistor 104 is smaller than a preset voltage.
The control chip 106 may pre-record a preset normal range corresponding to the input voltage, calculate a normal difference between the output voltage and the input voltage according to the condition of the load 20 input by the operator, and determine the preset voltage in a normal state according to the actual parameters of the current limiting resistor 104. After the charging time of the filter capacitor 103 exceeds the preset time, the control chip 106 may determine the collected input voltage, output voltage, and voltage of the current limiting resistor 104.
Step S104, when the input voltage is within a preset normal range, and the difference between the input voltage and the output voltage is smaller than a preset difference, and the voltage of the current limiting resistor 104 is smaller than a preset voltage, controlling the switch circuit 105 to short-circuit the current limiting resistor 104, so that the rectifier circuit 102 supplies power to the load 20.
When the control chip 106 determines that all the parameters are normal, it may be determined that the inrush current is limited, the inrush current limiting circuit 10 may normally supply power to the load 20, at this time, the control chip 106 may generate a control instruction, the switching circuit 105 may be closed according to the control instruction, the closed switching circuit 105 short-circuits the current limiting resistor 104, and the inrush current limiting circuit 10 may supply power to the load 20.
The condition that the control chip 106 controls the switch circuit 105 to short the current-limiting resistor 104 is not single , the input voltage, the output voltage and the voltage of the current-limiting resistor 104 are all required to meet the preset conditions, and the control chip 106 generates an instruction for controlling the switch circuit 105 to be closed only if the three conditions are met simultaneously.
In another embodiments, other determination conditions may also be adopted, for example, the current-limiting resistor 104 may be shorted when a duration when the input voltage is within a preset normal range exceeds a second preset duration, and a duration when a difference between the input voltage and the output voltage is smaller than a preset difference exceeds the second preset duration, and a duration when the voltage of the current-limiting resistor 104 is smaller than the preset voltage exceeds the second preset duration, that is, the input voltage, the output voltage, and the voltage of the current-limiting resistor 104 not only need to satisfy the preset normal condition, but also need to exceed the preset duration when each parameter satisfies the preset normal condition, for example, the preset duration may be set to 0.1s, and only when each parameter satisfies the normal condition, and exceeds the preset duration, the control chip 106 may generate an instruction for controlling the switch to be turned on.
If the control chip 106 detects and judges the input voltage, the output voltage and the voltage of the current limiting resistor 104 after waiting for for a preset time period, if at least parameters of the three parameters do not meet normal conditions, the control chip 106 does not generate an instruction for controlling the switch circuit 105 to be closed, but continues to control the switch circuit 105 to be in an open state, so that the current limiting resistor 104 continues to be connected with the filter capacitor 103.
After waiting for the preset time duration , the control chip 106 may detect parameters such as the input voltage, the output voltage, and the voltage of the current limiting resistor 104 in a preset period before generating no instruction for controlling the switch circuit 105 to close until each parameter satisfies a preset normal condition.
As shown in fig. 3, after the rectifier circuit 102 supplies power to the load 20, the method further includes the following steps.
Step S105, detecting whether the input voltage is within the preset normal range.
When the rectifier circuit 102 supplies power to the load 20, the current limiting resistor 104 is in a short-circuited state, and the inrush current limiting circuit 10 is in a normal operation state. In order to prevent the circuit from generating surge current again and to prevent the load 20 from generating transient power variation, the control chip 106 may also monitor the magnitude of the input voltage in real time after the rectifying circuit 102 supplies power to the load 20.
Step S106, when it is detected that the input voltage exceeds the preset normal range, controlling the switch circuit 105 to be turned on, so that the current limiting resistor 104 is connected to the filter capacitor 103.
Step S107, when it is detected that the input voltage is within the preset normal range, the switch circuit 105 is kept closed, the current limiting resistor 104 is short-circuited, and the rectifier circuit 102 is kept supplying power to the load 20.
The control chip 106 is preset with a corresponding normal range of the input voltage in a normal working state, and when the input voltage is detected to exceed the normal range, the control chip 106 can immediately generate an instruction for controlling the switch circuit 105 to open, so that the current limiting resistor 104 is changed from a short-circuited state to a state connected with the filter capacitor 103, and the current limiting resistor 104 limits the surge current which may appear in the surge current limiting circuit 10, thereby ensuring the safety of the circuit.
To sum up, in the inrush current limiting circuit control method provided in the embodiment of the present application, the control of the connection state of the limiting resistor in the inrush current limiting circuit 10 is realized by measuring and determining each electric quantity parameter in the inrush current limiting circuit 10 and controlling the switching circuit 105, when the circuit is powered on, the current limiting resistor 104 is controlled to be connected to the filter capacitor 103, so as to limit the inrush current generated in the circuit when the circuit is powered on, the control of the circuit is realized by the control chip 106, and the input voltage, the output voltage, and the normal value range corresponding to the limit value of the current limiting resistor 104 can be flexibly changed, so that the method can adapt to different circuit systems, and the current limiting resistor 104 does not need to use a thermistor, has small temperature drift and strong impact resistance, and under different temperature environments such as high temperature, normal temperature, low temperature, and the like, the performance of the current limiting resistor 104 is stable and does not drift with the temperature change, and when the circuit is repeatedly switched on and switched on, the circuit.
The application also provides surge current limiting circuits, which comprise an EMI filter, a rectifying circuit, a filter capacitor, a current limiting resistor, a switch circuit and a control chip, wherein the EMI filter is connected with an alternating current input end and used for filtering alternating current input by the alternating current input end, the rectifying circuit is connected with the EMI filter and used for rectifying and outputting the filtered alternating current, the filter capacitor is connected with an output end of the rectifying circuit and used for filtering the rectified alternating current, the current limiting resistor end is connected with the filter capacitor, the other end is connected with a load and used for limiting surge current generated by the filter capacitor at the moment when the surge current limiting circuit is electrified, the switch circuit is used for controlling the current limiting resistor to be connected with the filter capacitor when the switch circuit is opened or closed or short-circuiting the current limiting resistor when the switch circuit is closed, the control chip is used for detecting input voltage of the alternating current input by the alternating current input end, output voltage of the rectifying circuit and voltage of the current limiting resistor and controlling the switch circuit to be opened or closed, and the control chip is used for:
when the surge current limiting circuit is powered on, the switching circuit is controlled to be opened, so that the current limiting resistor is connected with the filter capacitor to charge the filter capacitor;
when the charging time of the filter capacitor reaches a preset time, detecting the input voltage, the output voltage of the rectifying circuit and the voltage of the current-limiting resistor;
judging whether the input voltage is within a preset normal range, judging whether the difference value between the input voltage and the output voltage is smaller than a preset difference value, and judging whether the voltage of the current-limiting resistor is smaller than a preset voltage;
when input voltage is located and predetermines normal range, just input voltage with output voltage's difference is less than predetermineeing the difference, simultaneously current limiting resistor's voltage is less than predetermineeing voltage, control the switching circuit short circuit current limiting resistor, so that rectifier circuit way is to the load power supply.
, the control chip is specifically configured to:
when the time length that the input voltage is located in the preset normal range exceeds the preset time length, the time length that the difference value of the input voltage and the output voltage is smaller than the preset difference value exceeds the preset time length, and meanwhile, the time length that the voltage of the current-limiting resistor is smaller than the preset voltage exceeds the preset time length, the current-limiting resistor is in short circuit.
Further , the control chip is further configured to:
and when the input voltage exceeds the preset normal range, or the difference value between the input voltage and the output voltage is greater than or equal to a preset difference value, or the voltage of the current-limiting resistor is greater than or equal to a preset voltage, controlling the current-limiting resistor to be connected with the filter capacitor.
, after the rectifying circuit supplies power to the load, the control chip is further configured to:
detecting whether the input voltage is within the preset normal range;
when the input voltage is detected to exceed the preset normal range, the switch circuit is controlled to be opened, so that the current-limiting resistor is connected with the filter capacitor;
when the input voltage is detected to be within the preset normal range, the switch circuit is kept closed, the current-limiting resistor is short-circuited, and the rectifying circuit is kept supplying power to the load.
, the switch circuit is a FET or a solid state relay, and the current limiting resistor is a wire wound resistor.
It should be noted that like reference numerals and letters refer to like elements in the following figures, and thus , once is defined in figures, it is not necessary to further define or interpret in the following figures.
The above description is only for the specific embodiments of the present application, but the scope of the present application is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present application, and shall be covered by the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.
Claims (10)
- The control method of surge current limiting circuits is characterized in that the control method is applied to a surge current limiting circuit, the surge current limiting circuit comprises an EMI filter, a rectifying circuit, a filter capacitor, a current limiting resistor, a switch circuit and a control chip, the EMI filter is connected with an alternating current input end and used for filtering alternating current input by the alternating current input end, the rectifying circuit is connected with the EMI filter and used for rectifying and outputting filtered alternating current, the filter capacitor is connected with an output end of the rectifying circuit and used for filtering rectified alternating current, the current limiting resistor end is connected with the filter capacitor, the other end is connected with a load and used for limiting surge current generated by the filter capacitor at the moment when the surge current limiting circuit is electrified, the switch circuit is used for controlling the current limiting resistor to be connected with the filter capacitor when the switch circuit is opened or short-circuited when the switch circuit is closed, and the control chip is used for detecting input voltage of alternating current input by the alternating current input end, output voltage of the rectifying circuit and voltage of the current limiting resistor and controlling the switch circuit to be opened or closed, and the control method comprises the following steps:when the surge current limiting circuit is powered on, the switching circuit is controlled to be opened, so that the current limiting resistor is connected with the filter capacitor to charge the filter capacitor;when the charging time of the filter capacitor reaches a preset time, detecting the input voltage, the output voltage of the rectifying circuit and the voltage of the current-limiting resistor;judging whether the input voltage is within a preset normal range, judging whether the difference value between the input voltage and the output voltage is smaller than a preset difference value, and judging whether the voltage of the current-limiting resistor is smaller than a preset voltage;when input voltage is located and predetermines normal range, just input voltage with output voltage's difference is less than predetermineeing the difference, simultaneously current limiting resistor's voltage is less than predetermineeing voltage, control the switching circuit short circuit current limiting resistor, so that rectifier circuit way is to the load power supply.
- 2. The inrush current limiting circuit control method of claim 1, wherein the step of controlling the switching circuit to short the current limiting resistor so that the rectifying circuit supplies power to the load comprises:when the time length that the input voltage is located in the preset normal range exceeds the preset time length, the time length that the difference value of the input voltage and the output voltage is smaller than the preset difference value exceeds the preset time length, and meanwhile, the time length that the voltage of the current-limiting resistor is smaller than the preset voltage exceeds the preset time length, the switch circuit is controlled to be in short circuit with the current-limiting resistor.
- 3. The inrush current limiting circuit control method of claim 1, further comprising:and when the input voltage exceeds the preset normal range, or the difference value between the input voltage and the output voltage is greater than or equal to a preset difference value, or the voltage of the current-limiting resistor is greater than or equal to a preset voltage, controlling the switch circuit to enable the current-limiting resistor to be connected with the filter capacitor.
- 4. The inrush current limiting circuit control method of claim 1, wherein after the rectifying circuit supplies power to the load, the method further comprises:detecting whether the input voltage is within the preset normal range;when the input voltage is detected to exceed the preset normal range, the switch circuit is controlled to be opened, so that the current-limiting resistor is connected with the filter capacitor;when the input voltage is detected to be within the preset normal range, the switch circuit is kept closed, the current-limiting resistor is short-circuited, and the rectifying circuit is kept supplying power to the load.
- 5. The method of any , wherein the switch circuit is a FET or a solid state relay, and the current limiting resistor is a wire wound resistor.
- 6, surge current limiting circuits, which are characterized by comprising an EMI filter, a rectifying circuit, a filter capacitor, a current limiting resistor, a switching circuit and a control chip, wherein the EMI filter is connected with an AC input end and used for filtering AC input by the AC input end, the rectifying circuit is connected with the EMI filter and used for rectifying and outputting filtered AC, the filter capacitor is connected with an output end of the rectifying circuit and used for filtering rectified AC, a current limiting resistor end is connected with the filter capacitor, another end is connected with a load and used for limiting surge current generated by the filter capacitor at the moment when the surge current limiting circuit is electrified, the switching circuit is used for controlling the current limiting resistor to be connected with the filter capacitor when the switching circuit is opened or short-circuited when the switching circuit is closed, the control chip is used for detecting the input voltage of AC input by the AC input end, the output voltage of the rectifying circuit and the voltage of the current limiting resistor and controlling the switching circuit to be opened or closed, and the control chip is also used for:when the surge current limiting circuit is powered on, the switching circuit is controlled to be opened, so that the current limiting resistor is connected with the filter capacitor to charge the filter capacitor;when the charging time of the filter capacitor reaches a preset time, detecting the input voltage, the output voltage of the rectifying circuit and the voltage of the current-limiting resistor;judging whether the input voltage is within a preset normal range, judging whether the difference value between the input voltage and the output voltage is smaller than a preset difference value, and judging whether the voltage of the current-limiting resistor is smaller than a preset voltage;when input voltage is located and predetermines normal range, just input voltage with output voltage's difference is less than predetermineeing the difference, simultaneously current limiting resistor's voltage is less than predetermineeing voltage, control the switching circuit short circuit current limiting resistor, so that rectifier circuit way is to the load power supply.
- 7. The inrush current limiting circuit of claim 6, wherein the control chip is specifically configured to:when the time length that the input voltage is located in the preset normal range exceeds the preset time length, the time length that the difference value of the input voltage and the output voltage is smaller than the preset difference value exceeds the preset time length, and meanwhile, the time length that the voltage of the current-limiting resistor is smaller than the preset voltage exceeds the preset time length, the switch circuit is controlled to be in short circuit with the current-limiting resistor.
- 8. The inrush current limiting circuit of claim 6, wherein the control chip is further configured to:and when the input voltage exceeds the preset normal range, or the difference value between the input voltage and the output voltage is greater than or equal to a preset difference value, or the voltage of the current-limiting resistor is greater than or equal to a preset voltage, controlling the switch circuit to enable the current-limiting resistor to be connected with the filter capacitor.
- 9. The inrush current limiting circuit of claim 6, wherein the control chip, after the rectifying circuit supplies power to the load, is further configured to:detecting whether the input voltage is within the preset normal range;when the input voltage is detected to exceed the preset normal range, the switch circuit is controlled to be opened, so that the current-limiting resistor is connected with the filter capacitor;when the input voltage is detected to be within the preset normal range, the switch circuit is kept closed, the current-limiting resistor is short-circuited, and the rectifying circuit is kept supplying power to the load.
- 10. The inrush current limiting circuit of any of claims 6 to 9, , wherein the switching circuit is a fet or a solid state relay and the current limiting resistor is a wire wound resistor.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911008454.2A CN110739672A (en) | 2019-10-22 | 2019-10-22 | Surge current control circuit and control method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911008454.2A CN110739672A (en) | 2019-10-22 | 2019-10-22 | Surge current control circuit and control method thereof |
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| CN110739672A true CN110739672A (en) | 2020-01-31 |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112968616A (en) * | 2021-02-19 | 2021-06-15 | 北京泰力控科技有限公司 | AC-DC converter and AC-DC conversion system |
| CN113346467A (en) * | 2021-03-20 | 2021-09-03 | 南京户能电子科技有限公司 | Surge protection circuit and alternating current charging circuit |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105978358A (en) * | 2012-03-28 | 2016-09-28 | Mks仪器股份有限公司 | Compact, configurable power supply for energizing ozone-producing cells |
| CN208016076U (en) * | 2018-04-04 | 2018-10-26 | 旭源电子（珠海）有限公司 | A kind of surge current suppression circuit and LED drive power |
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Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105978358A (en) * | 2012-03-28 | 2016-09-28 | Mks仪器股份有限公司 | Compact, configurable power supply for energizing ozone-producing cells |
| CN208016076U (en) * | 2018-04-04 | 2018-10-26 | 旭源电子（珠海）有限公司 | A kind of surge current suppression circuit and LED drive power |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112968616A (en) * | 2021-02-19 | 2021-06-15 | 北京泰力控科技有限公司 | AC-DC converter and AC-DC conversion system |
| CN113346467A (en) * | 2021-03-20 | 2021-09-03 | 南京户能电子科技有限公司 | Surge protection circuit and alternating current charging circuit |
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