Power supply device with overload protection and equipment

Abstract

The utility model discloses a power supply device and equipment with overload protection. The power supply device comprises a power supply conversion module, a relay, a current acquisition module, a voltage detection module and a processor, the power supply conversion module is used for converting an input power supply and supplying power to a load; a switch contact of the relay is arranged between the input power supply and the power supply conversion module; the current acquisition module is used for acquiring the input current of the power conversion module and generating a first voltage signal representing the magnitude of the current; the voltage detection module is used for detecting an input voltage value of the voltage reduction module and generating a second voltage signal; the processor is used for controlling the switch contact to be disconnected based on the first voltage signal; and controlling the switch contact to be closed based on the second voltage signal. The power supply device is provided with the relay for cutting off the input power supply during overload, and the processor is adopted to control the on-off state of the switch contact of the relay, so that the accuracy and response speed of overload protection are improved, and the function of automatically recovering power supply after overload protection is realized.

Description

TECHNICAL FIELD

[0001] The present application relates to power supply technology, in particular to a power supply device with overload protection and equipment. BACKGROUND

[0002] Since the electronic equipment is prone to cause fire when overloaded, it has safety hazards. In Europe and the United States, whether it is high-voltage equipment or low-voltage equipment, there are strict safety certification and fire prevention requirements. It is easy to understand that when the device load is too large, the current flowing into the device is too large, which is prone to cause fire; in order to improve the safety of low-voltage equipment, the power of low-voltage equipment is limited in the safety certification and fire prevention requirements, for example, the rated power supply voltage of low-voltage equipment is 24V, the actual power supply voltage should not exceed 30V and the device power should not exceed 15W. However, the full load power of some low-voltage equipment exceeds the limited power requirement, in order to meet the safety certification and fire prevention requirements, the method of setting overload protection measures or the method of structural fire prevention and material fire prevention is usually used to improve the safety of low-voltage equipment.

[0003] Specifically, in the related art, the overload protection measure of low-voltage equipment is usually to set PTC thermistor as a power limiter, which uses the resistance change characteristic of PTC thermistor to limit the current flowing into the low-voltage equipment, so as to prevent the low-voltage equipment from being overloaded. However, setting PTC thermistor is a passive overload protection method, which is difficult to accurately limit the power of the device, and the response time of PTC thermistor is too long, which cannot realize overload protection in a short time when the device is overloaded; since the cost of some low-voltage equipment is low, if the method of structural fire prevention and material fire prevention is used to improve the safety of low-voltage equipment, the cost of low-voltage equipment will be increased. Invention content

[0004] Therefore, the embodiments of the present application provide a power supply device with overload protection and equipment, aiming to improve the accuracy and response speed of the overload protection of the power supply device.

[0005] The technical scheme of the embodiments of the present application is as follows:

[0006] In a first aspect, the embodiments of the present application provide a power supply device with overload protection, which comprises:

[0007] A power conversion module comprising a step-down module, the power conversion module being configured to convert an input power and supply the converted power to a load;

[0008] A relay, the switch contact of the relay being arranged between the input power and the power conversion module;

[0009] A current acquisition module configured to acquire an input current of the power conversion module and generate a first voltage signal representing the size of the current;

[0010] a voltage detection module, configured to detect an input voltage value of the voltage reduction module and generate a second voltage signal;

[0011] a processor, configured to control the switch contact to be opened based on the first voltage signal, and control the switch contact to be closed based on the second voltage signal;

[0012] wherein an output end of the voltage reduction module is connected to the processor, and the power conversion module is further configured to supply power to the processor.

[0013] In some embodiments, the power supply device further comprises:

[0014] a driving module, connected to the processor and the coil of the relay respectively;

[0015] wherein the processor controls the opening and closing state of the switch contact through the driving module.

[0016] In some embodiments, the power conversion module further comprises:

[0017] a rectification module, a power supply end of which is connected to the switch contact;

[0018] wherein a power supply end of the voltage reduction module is connected to an output end of the rectification module.

[0019] In some embodiments, the power conversion module further comprises:

[0020] a first capacitor, arranged at a power supply end of the voltage reduction module.

[0021] In some embodiments, the voltage detection module comprises a plurality of voltage division resistors, and the junctions between the voltage division resistors are connected to the processor.

[0022] In some embodiments, the current collection module comprises a current sampling resistor and an operational amplifier circuit.

[0023] wherein a first end of the current sampling resistor is connected to the switch contact, and a second end of the current sampling resistor is connected to a power supply end of the power conversion module.

[0024] an input end of the operational amplifier circuit is connected to the first end and the second end of the current sampling resistor, and an output end of the operational amplifier circuit is connected to the processor.

[0025] In some embodiments, the switch contact is a normally closed switch contact.

[0026] In some embodiments, the processor is configured to control the switch contact to be opened based on the voltage value of the first voltage signal rising to a first set voltage threshold.

[0027] In some embodiments, the processor is configured to control the switch contact to close based on the voltage value of the second voltage signal falling to a second set voltage threshold.

[0028] In a second aspect, an embodiment of the present application provides a device, comprising the power supply device and the load as described in the first aspect.

[0029] The power supply device with overload protection provided by the embodiments of the present application comprises a power conversion module, a relay, a current collection module, a voltage detection module and a processor. The power conversion module comprises a step-down module, and is configured to convert an input power and supply the converted power to a load. The switch contact of the relay is arranged between the input power and the power conversion module. The current collection module is configured to collect an input current of the power conversion module and generate a first voltage signal representing the current. The voltage detection module is configured to detect an input voltage value of the step-down module and generate a second voltage signal. The processor is configured to control the switch contact to open based on the first voltage signal, and control the switch contact to close based on the second voltage signal. The output end of the step-down module is connected to the processor, and the power conversion module is further configured to supply power to the processor. In this way, the power supply device provided by the embodiments of the present application arranges the relay to cut off the input power in the case of overload, and controls the open and close states of the switch contact of the relay by using the processor, thereby improving the accuracy and response speed of the overload protection and realizing the automatic recovery power supply function after the overload protection. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 FIG. 1 is a structural schematic diagram of a power supply device according to an embodiment of the present application;

[0031] Figure 2 FIG. 2 is a structural schematic diagram of a power supply device according to another embodiment of the present application. DETAILED DESCRIPTION

[0032] The present application will be further described below in conjunction with the drawings and embodiments.

[0033] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs. The terminology used in the description of the present application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present application.

[0034] In the description of this application, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0035] This application provides a power supply device with overload protection, such as... Figure 1 As shown, the power supply device includes: a power conversion module 100, a relay 200, a current acquisition module 300, a voltage detection module 400, and a processor 500. The power conversion module 100 includes a step-down module 101, which converts the input power and supplies it to the load. The switch contacts of the relay 200 are located between the input power and the power conversion module 100. The current acquisition module 300 acquires the input current of the power conversion module 100 and generates a first voltage signal characterizing the current magnitude. The voltage detection module 400 detects the input voltage value of the step-down module 101 and generates a second voltage signal. The processor 500 controls the switch contacts to open based on the first voltage signal and to close based on the second voltage signal. The output terminal of the step-down module 101 is connected to the processor 500, and the power conversion module 100 also supplies power to the processor 500.

[0036] Here, the power conversion module 100 is used to convert the input power into an electrical signal that is compatible with the load. The output terminal of the power conversion module 100 is connected to the load (not shown in the figure). The output terminal of the power conversion module 100 includes at least the output terminal of the step-down module 101, that is, the load connected to the power conversion module 100 can be powered by the step-down module 101 or by other modules or devices inside the power conversion module 100.

[0037] Here, the processor 500 is connected to the coil of the relay 200. The processor 500 controls the opening and closing state of the switch contacts of the relay 200 by controlling the energization state of the coil.

[0038] Here, the switch contacts of relay 200 are connected to the power supply terminal of power conversion module 100. When the switch contacts are closed, the input power is connected to power conversion module 100, and the electrical signal output by power conversion module 100 supplies power to the load and processor 500. When the switch contacts are open, the input power is cut off, and power conversion module 100 cannot continue to supply power to load and processor 500 for a long time.

[0039] It should be noted that the power supply device of the embodiment of the present application sets the relay 200 at the power supply end of the power supply conversion module 100, and controls the opening and closing state of the switching contact of the relay 200 to realize the active overload protection function.

[0040] Specifically, the switching contact of the relay 200 is a normally closed switching contact. The voltage reduction module 101 is used to supply power to the processor 500. After the power supply device is connected to the input power supply, the power supply conversion module 100 is powered on and runs, and the processor 500 runs because the switching contact is a normally closed switching contact.

[0041] Specifically, when the processor 500 runs, the current input current value of the power supply conversion module 100 can be determined based on the first voltage signal sent by the current collection module 300, and the load power of the current power supply device can be obtained based on the resistance value of the connected load or the input voltage of the power supply conversion module 100; if it is determined that the load power of the current power supply device reaches the set power threshold, the switching contact is opened by controlling the coil of the relay 200 to be powered on, so as to cut off the input power supply, so as to prevent the load power from continuously increasing and causing safety problems.

[0042] Exemplarily, the processor 500 is configured to control the switching contact to be opened based on the voltage value of the first voltage signal rising to a first set voltage threshold.

[0043] It can be understood that the current value corresponding to the first set voltage threshold is the input current value of the power supply conversion module 100 corresponding to the set protection power, and the overload protection measure is triggered to control the switching contact to be opened after the processor 500 determines that the voltage value of the first voltage signal rises to the first set voltage threshold, so as to prevent the load power from continuously increasing.

[0044] It can be understood that by setting different first set voltage thresholds, the size of the set protection power can be adjusted; since the switching contact of the relay 200 responds quickly, the power supply device can accurately trigger the overload protection measure when the load power reaches the protection power.

[0045] It can be understood that the power supply device of the embodiment of the present application sets the relay to cut off the input power supply when overloaded, and controls the opening and closing state of the switching contact of the relay by using the processor, which improves the accuracy and response speed of the overload protection compared with the related technology of using a PFC thermistor as a power limiting device.

[0046] Exemplarily, the current collection module 300 includes a current sampling resistor and an operational amplifier circuit. The first end of the current sampling resistor is connected to the switching contact, and the second end of the current sampling resistor is connected to the power supply end of the power supply conversion module 100. The input end of the operational amplifier circuit is connected to the first end and the second end of the current sampling resistor, and the output end of the operational amplifier circuit is connected to the processor 500.

[0047] Here, as shown in Figure 2 the current sampling resistor is a first resistor R1, the operational amplifier circuit 301 includes an operational amplifier OPA, the same input end and the opposite input end of the operational amplifier OPA are connected to two ends of the first resistor R1, the same input end is connected to a second resistor R2 and a third resistor R3, and a fourth resistor R4 is arranged between the opposite input end and the output end. When the current size through the first resistor R1 changes, the first voltage signal output by the output end of the operational amplifier OPA changes accordingly, and the processor 500 can obtain the current load power based on the size of the output voltage of the operational amplifier OPA. It should be noted that, Figure 2 the current collection module 300 shown is only an example of a device that can obtain the input current value of the power conversion module 100, and the specific form of the current collection module 300 is not limited in the embodiments of the present application.

[0048] It should be noted that the power supply device of the embodiments of the present application not only can quickly trigger overload protection, but also can automatically restore the power supply function after triggering the overload protection measure.

[0049] Exemplarily, the power conversion module 100 further includes a first capacitor C1, and the first capacitor C1 is arranged at the power supply end of the step-down module 101.

[0050] It should be noted that when the power supply device is connected to the input power supply and the switching contact of the relay 200 is closed, the input power supply also charges the first capacitor C1; when the switching contact is opened due to triggering the overload protection measure, the input power supply is cut off, at this time, the first capacitor C1 discharges the step-down module 101, and the step-down module 101 and the processor 500 will not stop running immediately; after the processor 500 determines that the input voltage of the step-down module 101 cannot guarantee the normal operation of the step-down module 101 based on the second voltage signal sent by the voltage detection module 400, the coil of the relay 200 is powered off, so that the switching contact is re-closed, the input power supply is re-connected to the power supply device, and the automatic recovery of the power supply is realized, so as to prevent the power supply device from stopping running due to the overload protection time being too long.

[0051] Exemplarily, the voltage detection module 400 includes a plurality of voltage dividing resistors, and the junction between the voltage dividing resistors is connected to the processor 500.

[0052] Here, as shown in Figure 2 the voltage detection module 400 is a voltage dividing circuit, the voltage dividing resistors include a fifth resistor R5 and a sixth resistor R6, the first end of the fifth resistor R5 is connected to the power supply end of the step-down module 101, the second end of the fifth resistor R5 is connected to the first end of the sixth resistor R6, the second end of the sixth resistor R6 is grounded, and the junction between the second end of the fifth resistor R5 and the first end of the sixth resistor R6 is connected to the processor 500.

[0053] It can be understood that the input voltage of the voltage reduction module 101 is converted into a low voltage signal after being divided by the voltage dividing resistor, and is connected to the processor 500.

[0054] Exemplarily, the processor 500 is configured to control the switch contact to be closed based on the voltage value of the second voltage signal falling to a second set voltage threshold.

[0055] It can be understood that the second set voltage threshold can be determined based on the input voltage range of the voltage reduction module 101, and in some embodiments, the second set voltage threshold can be obtained based on the following formula:

[0056] U2 = U min - ΔU

[0057] Wherein, U2 is the second set voltage threshold, U min is the lower limit value of the input voltage when the voltage reduction module 101 is running, and ΔU is a design margin voltage value.

[0058] It should be noted that, Figure 2 The voltage detection module 400 shown is only an example of a device that can obtain the input voltage value of the voltage reduction module 101, and the specific form of the voltage detection module 400 is not limited in the embodiments of the present application.

[0059] Exemplarily, if the input power supply of the power supply device is an alternating current power supply, as Figure 2 shown, the power supply conversion module 100 further includes a rectifier module 102, and the power supply end of the rectifier module 102 is connected to the switch contact; the power supply end of the voltage reduction module 101 is connected to the output end of the rectifier module 102.

[0060] Here, the first capacitor C1 is connected to the output end of the rectifier module 102 as a filter capacitor.

[0061] In some embodiments, the rectifier module 102 can be a bridge rectifier circuit.

[0062] In some embodiments, if the pull-in voltage of the relay 200 is high, as Figure 2 shown, the power supply device further includes a driving module 600, and the driving module 600 is connected to the coil of the relay 200 and the processor 500 respectively. Wherein, the processor 500 controls the opening and closing state of the switch contact through the driving module 600.

[0063] It should be noted that the form of the processor 500 is not limited in the embodiments of the present application. The processor 500 can be a digital signal processor (DSP), a programmable logic device (PLD), a complex programmable logic device (CPLD), a field programmable gate array (FPGA), a general-purpose processor, a controller, a micro controller unit (MCU), a microprocessor, or an electronic element.

[0064] The embodiments of the present application also provide a device including the power supply device and the load. The power supply device is used to supply power to the load of the device, and the input power of the power supply device is the input power connected by the device.

[0065] Here, the device can be an electronic device or a heating device, and the form of the device is not limited in the embodiments of the present application.

[0066] In some embodiments, the processor 500 of the power supply device can also be the processor of the device, and is used to control the operation of the device.

[0067] In an application example of the present application, the rated input voltage of the device is AC 24V, the upper limit value of the input voltage during operation is AC 30V, and the protection power setting is set to 15W.

[0068] It should be noted that "first", "second", and the like are used to distinguish similar objects, and do not necessarily indicate a specific order or sequence.

[0069] In addition, the technical solutions described in the embodiments of the present application can be combined arbitrarily without conflict.

[0070] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art can easily think of changes or replacements within the technical range disclosed in the present application, which should be covered in the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A power supply device having overload protection, characterized by comprising: The power supply device comprises: a power conversion module comprising a step-down module, the power conversion module being configured to supply power to a load after conversion of an input power supply; a relay, switch contacts of the relay being arranged between the input power supply and the power conversion module; a current acquisition module configured to acquire an input current of the power conversion module and generate a first voltage signal representing the magnitude of the current; a voltage detection module configured to detect an input voltage value of the step-down module and generate a second voltage signal; a processor configured to control the switch contacts to open based on the first voltage signal, and control the switch contacts to close based on the second voltage signal; wherein an output end of the step-down module is connected to the processor, and the power conversion module is further configured to supply power to the processor.

2. The power supply device according to claim 1, characterized by The power supply device further comprises: a drive module connected to the processor and a coil of the relay, respectively; wherein the processor controls the opening and closing states of the switch contacts via the drive module.

3. The power supply device according to claim 2, characterized by The power conversion module further comprises: a rectifier module, a power supply end of the rectifier module being connected to the switch contacts; wherein a power supply end of the step-down module is connected to an output end of the rectifier module.

4. The power supply device according to claim 3, characterized by The power conversion module further comprises: a first capacitor, the first capacitor being arranged at a power supply end of the step-down module.

5. The power supply device according to claim 4, wherein The voltage detection module comprises a plurality of voltage dividing resistors, junctions between the voltage dividing resistors being connected to the processor.

6. The power supply device according to claim 1, wherein The current acquisition module comprises a current sampling resistor and an operational amplifier circuit; wherein a first end of the current sampling resistor is connected to the switch contacts, and a second end of the current sampling resistor is connected to a power supply end of the power conversion module; an input end of the operational amplifier circuit is connected to the first end and the second end of the current sampling resistor, and an output end of the operational amplifier circuit is connected to the processor.

7. The power supply device according to any one of claims 1 to 6, characterized by The switch contacts are normally closed switch contacts.

8. The power supply device according to any one of claims 1 to 6, characterized by The processor is configured to control the switch contacts to open based on the voltage value of the first voltage signal rising to a first set voltage threshold.

9. The power supply device according to any one of claims 1 to 6, characterized by The processor is configured to control the switch contacts to close based on the voltage value of the second voltage signal falling to a second set voltage threshold.

10. An apparatus, comprising: The power supply device comprises a load and any one of the power supply devices of claims 1 to 9.

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