Power supply device and medical system

Abstract

A power supply device and a medical system belong to the field of medical power supply technology. The power supply device can make the switching between the constant voltage mode and the constant current mode more accurate according to the judgment conditions of the applied voltage combined with the preset voltage threshold and the preset time length; it switches to the constant voltage mode only when the applied voltage is lower than the preset voltage threshold and lasts for the preset time length, which can avoid misjudgment caused by instantaneous voltage fluctuations and ensure the stability of mode switching; further, the impedance change of the load within the preset time length is calculated according to the applied voltage and the applied current, and when the impedance change is higher than the preset impedance change threshold, it switches to the constant current mode, and avoids the adverse effect of drastic voltage changes on the load by limiting the current; when the impedance change is lower than or equal to the preset impedance change threshold, the constant voltage mode is maintained to ensure stable voltage output and meet the load requirements.

Description

Technical Field

[0001] The present invention belongs to the technical field of medical power supplies, and in particular relates to a power supply device and a medical system. Background Art

[0002] Existing power supply devices can usually only provide a fixed constant voltage or current. However, in some application scenarios, it may be necessary to provide constant voltage and current at the same time. For example, for some sensitive electronic equipment or charging equipment in medical systems. In order to solve this problem, many developers have tried to develop some power supply devices that can provide both constant voltage and constant current. However, in the process of switching between constant voltage and constant current modes, there are often problems such as unstable control and inaccurate switching, which affects the use effect and reliability of the power supply device. Summary of the invention

[0003] In view of this, an embodiment of the present invention provides a power supply device and a medical system, which aim to solve the problem that when a traditional power supply device switches between constant voltage and constant current modes, inaccurate switching is caused by unstable control, thereby affecting the use effect and reliability of the power supply device.

[0004] A first aspect of an embodiment of the present invention provides a power supply device, the power supply device comprising:

[0005] An input terminal for receiving an input voltage;

[0006] Output terminal, used to output a set target voltage or a set target current;

[0007] A receiving module, used for receiving external applied voltage and applied current;

[0008] A switching power supply module is used to generate a DC voltage according to an input voltage, and output a set target voltage through a constant voltage mode, or output a set target current to an output terminal through a constant current mode; a control module is used to compare an applied voltage with a preset voltage threshold, and when the applied voltage is lower than the preset voltage threshold within a preset time, control the switching power supply module to switch to a constant voltage mode; when the applied voltage exceeds the preset voltage threshold, calculate the impedance change of the load according to the applied voltage and the applied current within a preset time, and when the impedance change is higher than a preset impedance change threshold, control the switching power supply module to switch to a constant current mode, and when the impedance change is lower than or equal to the preset impedance change threshold, control the switching power supply module to maintain a constant voltage mode.

[0009] In one embodiment, the power supply device further includes: an indication voltage generating module, configured to generate an action indication voltage to the control module.

[0010] In one embodiment, the indication voltage generating module includes a signal conversion module, a differential amplifier and an adjustable voltage source; the signal conversion module is used to generate a current indication voltage that is linearly related to the applied current; the differential amplifier is used to add the current indication voltage and the voltage output by the adjustable voltage source to generate an action indication voltage.

[0011] In one embodiment, the control module is further used to determine the current working state of the power supply device according to the action indication voltage.

[0012] In one embodiment, a switching power supply module includes a switching element, a converter circuit, a current feedback circuit, and a voltage feedback circuit; the switching element is used to adjust the on and off time according to a pulse width modulation signal to ensure that the output current matches the set target current, or ensure that the output voltage matches the set target voltage; the converter circuit is used to convert the input voltage into an output voltage or an output current; the current feedback circuit is used to monitor the output current in real time, and generate a first pulse width modulation signal to the switching element according to the difference between the output current and the set target current; the voltage feedback circuit is used to monitor the output voltage in real time, and generate a second pulse width modulation signal to the switching element according to the difference between the output voltage and the set target voltage.

[0013] In one embodiment, the current feedback circuit includes: a first current sensor, a first differential amplifier and a first pulse width modulation circuit; the first current sensor is used to monitor the output current and input the output current to the first differential amplifier; the first differential amplifier is used to compare the output current with the set target current to generate a current error signal; the first pulse width modulation circuit is used to generate a first pulse width modulation signal according to the current error signal.

[0014] In one embodiment, the voltage feedback circuit includes: a first voltage sensor, a second differential amplifier and a second pulse width modulation circuit; the first voltage sensor is used to monitor the output voltage and input the output voltage to the second differential amplifier; the second differential amplifier is used to compare the output voltage with a set target voltage to generate a voltage error signal; the second pulse width modulation circuit is used to generate a second pulse width modulation signal according to the voltage error signal.

[0015] In one embodiment, the control module includes a voltage comparison circuit, a programmable logic controller and a control terminal; the voltage comparison circuit is used to compare the applied voltage within a preset time length with a preset voltage threshold, and when the applied voltage within the preset time length is lower than the preset voltage threshold, a first control signal is generated to the control terminal; when the applied voltage exceeds the preset voltage threshold, the applied voltage and applied current within the preset time length are input to the programmable logic controller; the programmable logic controller is used to calculate the impedance change of the load according to the applied voltage and the applied current, and when the impedance change is higher than the preset impedance change threshold, a second control signal is generated to the control terminal; when the impedance change is lower than or equal to the preset impedance change threshold, a first control signal is generated to the control terminal; the control terminal is connected to the switching power supply module, and is used to control the switching power supply module to switch to a constant voltage mode according to the first control signal, and to control the switching power supply module to switch to a constant current mode according to the second control signal.

[0016] In one embodiment, the voltage comparison circuit includes a second voltage sensor, a second current sensor and a logic circuit, the second voltage sensor is used to monitor the applied voltage; the second current sensor is used to monitor the applied current; the logic circuit is used to compare the applied voltage within a preset time period with a preset voltage threshold, and output a first control signal based on the comparison result, or output the applied voltage and applied current to the programmable logic controller based on the comparison result.

[0017] A second aspect of an embodiment of the present application provides a medical system, comprising the power supply device as described in the first aspect above.

[0018] The beneficial effects of the embodiments of the present application are as follows: the input terminal receives the input voltage, and the output terminal outputs the set target voltage or the set target current; the receiving module receives the external applied voltage and applied current; the switching power supply module generates a DC voltage according to the input voltage, and outputs the set target voltage through the constant voltage mode, or outputs the set target current to the output terminal through the constant current mode; the control module makes the switching between the constant voltage mode and the constant current mode more accurate by combining the judgment conditions of the applied voltage with the preset voltage threshold and the preset time; the constant voltage mode is switched only when the applied voltage is lower than the preset voltage threshold and lasts for a preset time, which can avoid misjudgment caused by instantaneous voltage fluctuations and ensure the stability of mode switching; further, the control module calculates the impedance change of the load within the preset time according to the applied voltage and the applied current, and switches to the constant current mode when the impedance change is higher than the preset impedance change threshold; if the impedance change is lower than or equal to the preset impedance change threshold, the constant voltage mode is maintained, which can effectively prevent the power output from being overloaded or damaged when the load changes too much. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0020] Figure 1 A schematic diagram of the circuit structure of a power supply device provided in one embodiment of the present application;

[0021] Figure 2 A schematic diagram of the circuit structure of a power supply device provided in another embodiment of the present application;

[0022] Figure 3 A schematic diagram of the circuit structure of an indication voltage generating module provided in an embodiment of the present application;

[0023] Figure 4 A schematic diagram of the circuit structure of a switching power supply module provided in one embodiment of the present application;

[0024] Figure 5 A schematic diagram of the circuit structure of a current feedback circuit provided in one embodiment of the present application;

[0025] Figure 6 A schematic diagram of a current structure of a voltage feedback circuit provided in an embodiment of the present application;

[0026] Figure 7 A schematic diagram of the circuit structure of a control module provided in one embodiment of the present application. DETAILED DESCRIPTION

[0027] The following embodiments of the technical solution of the present application are described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present application.

[0028] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0029] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.

[0030] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0031] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of the associated objects, indicating that there may be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0032] In the description of the embodiments of the present application, the term "multi-frame" refers to more than two (including two).

[0033] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the embodiments of the present application.

[0034] The present application provides a power supply device and a medical system. The power supply device is applied to the medical system. Figure 1 As shown, Figure 1 This is a schematic diagram of the circuit structure of a power supply device provided in one embodiment of the present application. Figure 1It can be seen that the power supply device 10 includes: an input terminal 100 for receiving an input voltage; an output terminal 200 for outputting a set target voltage or a set target current; a receiving module 300 for receiving an external applied voltage and an applied current; a switching power supply module 400 for generating a DC voltage according to the input voltage, and outputting a set target voltage through a constant voltage mode, or outputting a set target current to the output terminal 200 through a constant current mode; a control module 500 for comparing the applied voltage with a preset voltage threshold, and when the applied voltage is lower than the preset voltage threshold within a preset time, controlling the switching power supply module 400 to switch to the constant voltage mode; when an applied voltage exceeds the preset voltage threshold within a preset time, calculating the impedance change of the load according to the applied voltage and the applied current within the preset time, if the impedance change of the load is higher than the preset impedance change threshold, controlling the switching power supply module 400 to switch to the constant current mode, and if the impedance change is lower than or equal to the preset impedance change threshold, controlling the switching power supply module 400 to maintain the constant voltage mode.

[0035] In the present application, the external applied voltage is a voltage signal applied to the power supply device 10 by an external system such as a load control device, a monitoring device or other regulating device. For example, the load is a medical device, and the control system or monitoring system of the medical device generates a corresponding applied voltage by monitoring the voltage demand of the medical device. The power supply device 10 receives the applied voltage through the receiving module 300 and inputs it to the control module 500, so that the control module 500 determines the working state of the power supply device 10 according to the applied voltage. The applied current is a current signal applied to the power supply device 10 by an external system, and the applied current generally reflects the current demand of the load. The power supply device 10 receives the applied current through the receiving module 300 and inputs it to the control module 500, so that the control module 500 further determines the impedance change of the load according to the applied voltage and the applied current.

[0036] The applied voltage is judged by the control module. When the applied voltage is lower than the preset voltage threshold within the preset time, the control switches to the constant voltage mode. In the constant voltage mode, the power supply device will maintain a stable voltage output, which can avoid misjudgment caused by instantaneous voltage fluctuations and ensure the stability of mode switching; when the applied voltage is higher than the preset voltage threshold within the preset time, it is further judged whether to switch to the constant current mode by the load impedance change. Specifically, when the load impedance change is higher than the preset impedance change threshold, it means that the load change is relatively large. In this case, the constant voltage mode cannot effectively cope with the drastic change of the load, and the power supply device switches to the constant current mode. In the constant current mode, the power supply device supplies power according to the set target current, and will not cause excessive voltage fluctuations due to load mutations, which can effectively avoid overcurrent problems caused by load mutations; and when the load impedance change is less than or equal to the preset impedance change threshold, it means that the electrical characteristics of the load are stable. At this time, the constant voltage mode is selected to ensure stable voltage output and meet load requirements.

[0037] See also Figure 2 As shown, Figure 2 This is a schematic diagram of the circuit structure of a power supply device provided in another embodiment of the present application. Figure 2 It can be seen that in the present application, the power supply device 10 also includes: an indication voltage generating module 600, which is used to generate an action indication voltage and output it to the control module 500. The control module 500 is also used to judge the current working state of the power supply device 10 according to the action indication voltage, so as to make corresponding adjustments or responses. Through the feedback of the action indication voltage, the control module 500 can detect the working abnormality or failure of the power supply device 10 in time. For example, when the power supply device 10 is in an abnormal state, the action indication voltage may deviate from the normal value. The control module 500 can identify the fault according to the action indication voltage and take measures, such as switching the working mode or issuing a warning, so as to enhance the self-diagnosis and troubleshooting capabilities of the power supply device 10.

[0038] For example, Figure 3 As shown, Figure 3 This is a schematic diagram of the circuit structure of the indicator voltage generation module provided in one embodiment of the present application. Figure 3It can be seen that the indication voltage generation module 600 includes: a signal conversion module 610, a differential amplifier 620 and an adjustable voltage source 630. Among them, the signal conversion module 610 is used to generate a current indication voltage that is linearly related to the applied current; the current indication voltage can reflect the change of the load current. The differential amplifier 620 is used to add the current indication voltage to the voltage output by the adjustable voltage source 630 to generate an action indication voltage. Among them, the voltage output by the adjustable voltage source 630 is dynamically adjustable. In the present application, the control module 500 adjusts the voltage output by the adjustable voltage source 630 according to the received applied voltage to reflect the change of the applied voltage. Optionally, the voltage output by the adjustable voltage source 630 is linearly related to the applied voltage, and the differential amplifier 620 adds the current indication voltage to the voltage output by the adjustable voltage source 630 to generate an action indication voltage. The action indication voltage can reflect the comprehensive changes of the applied current and the applied voltage, thereby providing the control module 500 with key working state feedback information. The control module 500 can determine whether the current working state of the power supply device meets the demand of the load by monitoring the action indication voltage.

[0039] In the present application, by generating a current indication voltage that is linearly related to the applied current, and adding the current indication voltage to the voltage output by the adjustable voltage source 630 that is linearly related to the applied voltage, an action indication voltage that can reflect the comprehensive change of the applied current and the applied voltage is generated. The control module 500 determines the current working mode of the power supply device 10 according to the action indication voltage, and determines whether the working mode needs to be switched. For example, the control module 500 determines whether the action indication voltage obtained by superimposing the current indication voltage and the voltage of the adjustable voltage source 630 meets the preset conditions to determine the current working mode of the power supply device 10 and determine whether the working mode needs to be switched (for example, switching between a constant voltage mode and a constant current mode). Since the output voltage of the adjustable voltage source 630 is dynamically adjustable, the power supply device 10 can adjust its output voltage so that the action indication voltage can timely reflect the changing characteristics of the load, so that the power supply device 10 can quickly and accurately adapt to the needs of different loads, dynamically adjust the working mode, and ensure that the power supply device 10 always operates in the most suitable working mode, thereby improving the stability and reliability of the power supply device 10.

[0040] See also Figure 4 , Figure 4 This is a schematic diagram of the circuit structure of a switching power supply module provided in an embodiment of the present application. Figure 4It can be seen that in the present application, the switching power supply module 400 includes a switching element 410, a converter circuit 420, a current feedback circuit 430 and a voltage feedback circuit 440; the switching element 410 is used to adjust the on and off time according to the pulse width modulation signal to ensure that the output current matches the set target current, or ensure that the output voltage matches the set target voltage; the converter circuit 420 is used to convert the input voltage into an output voltage or an output current; the current feedback circuit 430 is used to monitor the output current in real time, and generate a first pulse width modulation signal to the switching element 410 according to the difference between the output current and the set target current; the voltage feedback circuit 440 is used to monitor the output voltage in real time, and generate a second pulse width modulation signal to the switching element 410 according to the difference between the output voltage and the set target voltage.

[0041] In the present application, the target voltage or target current can be precisely adjusted through the coordinated work of the switch element 410, the converter circuit 420, the current feedback circuit 430, and the voltage feedback circuit 440. The on and off time of the switch element 410 is adjusted by the first pulse width modulation signal or the second pulse width modulation signal, respectively, so as to ensure the stability of the output and meet different load requirements.

[0042] The current feedback circuit 430 can monitor the output current in real time, and generate a first pulse width modulation signal according to the difference between the output current and the set target current, and adjust the on and off time of the switching element 410, thereby ensuring that the power supply device can maintain the set target current, avoiding the output current being too large or too small, and effectively reducing the fluctuation caused by the current deviation.

[0043] The voltage feedback circuit 440 can monitor the output voltage in real time, and generate a second pulse width modulation signal according to the difference between the output voltage and the set target voltage, and adjust the switching period of the switching element 410, thereby ensuring that the output voltage remains at the set target voltage to adapt to the needs of load changes and avoid load damage caused by voltage instability.

[0044] For example, Figure 5 As shown, Figure 5 The circuit structure diagram of the current feedback circuit provided by an embodiment of the present application is shown in FIG. Figure 5 It can be seen that the current feedback circuit 430 includes: a first current sensor 431, a first differential amplifier 432 and a first pulse width modulation circuit 433; the first current sensor 431 is used to monitor the output current and input the output current to the first differential amplifier 432; the first differential amplifier 432 is used to compare the output current with the set target current to generate a current error signal; the first pulse width modulation circuit 433 is used to generate a first pulse width modulation signal according to the current error signal.

[0045] In one embodiment, Figure 6 As shown, Figure 6 This is a schematic diagram of the current structure of a voltage feedback circuit provided in an embodiment of the present application. Figure 6 It can be seen that the voltage feedback circuit 440 includes: a first voltage sensor 441, a second differential amplifier 442 and a second pulse width modulation circuit 443; the first voltage sensor 441 is used to monitor the output voltage and input the output voltage to the second differential amplifier 442; the second differential amplifier 442 is used to compare the output voltage with the set target voltage to generate a voltage error signal; the second pulse width modulation circuit 443 is used to generate a second pulse width modulation signal according to the voltage error signal.

[0046] The current feedback circuit 430 monitors the output current in real time and compares it with the target current. When there is an error between the output current and the target current, a first pulse width modulation signal is generated. The first pulse width modulation signal increases or decreases the current output by adjusting the on-time of the switch element 410. Specifically, the first pulse width modulation signal increases the current output by increasing the on-time of the switch element 410 until the set target current is reached. The first pulse width modulation signal reduces the current output by shortening the on-time of the switch element 410 to keep the current near the target current.

[0047] The voltage feedback circuit 440 monitors the output voltage in real time and compares it with the target voltage. When there is an error between the output voltage and the target voltage, a second pulse width modulation signal is generated. The second pulse width modulation signal adjusts the output voltage by adjusting the on-time of the switch element 410. Specifically, the second pulse width modulation signal increases the output voltage by increasing the on-time of the switch element 410 until the set target voltage is reached. The second pulse width modulation signal reduces the output voltage by shortening the on-time of the switch element 410 to keep the voltage near the target value.

[0048] Specifically, the first pulse width modulation signal and the second pulse width modulation signal respectively adjust the conduction time of the switch element 410 through different duty cycles. The duty cycle of the first pulse width modulation signal is related to the current error between the output current and the target current, and the duty cycle of the second pulse width modulation signal is related to the voltage error between the output voltage and the target voltage. Exemplarily, when the output current is lower than the target current, the duty cycle of the first pulse width modulation signal increases, that is, the high level duration of the first pulse width modulation signal increases, thereby increasing the current output; when the output current is higher than the target current, the duty cycle of the first pulse width modulation signal decreases, thereby reducing the current output. When the output voltage is lower than the target voltage, the high level duration of the second pulse width signal increases, thereby increasing the voltage output; when the output voltage is higher than the target voltage, the high level duration of the second pulse width signal decreases, thereby reducing the voltage output.

[0049] In one embodiment, Figure 7 As shown, Figure 7 This is a schematic diagram of the circuit structure of a control module provided in one embodiment of the present application. Figure 7 It can be seen that the control module 500 includes a voltage comparison circuit 510, a programmable logic controller 520 and a control terminal 530; the voltage comparison circuit 510 is used to compare the applied voltage within a preset time length with a preset voltage threshold, and when the applied voltage within the preset time length is lower than the preset voltage threshold, a first control signal is generated to the control terminal 530; when the applied voltage exceeds the preset voltage threshold, the applied voltage and the applied current within the preset time length are input to the programmable logic controller 520; the programmable logic controller 520 is used to calculate the impedance change of the load according to the applied voltage and the applied current, and when the impedance change of the load is lower than or equal to the preset impedance change threshold, a first control signal is generated to the control terminal 530, and when the impedance change of the load is higher than the preset impedance change threshold, a second control signal is generated to the control terminal 530; the control terminal 530 is connected to the switching power supply module 400, and is used to control the switching power supply module 400 to switch to a constant voltage mode according to the first control signal, and to control the switching power supply module 400 to switch to a constant current mode according to the second control signal.

[0050] By comparing the applied voltage with the preset voltage threshold and setting a preset duration, misoperation or unnecessary power mode switching caused by short-term voltage fluctuations can be effectively avoided. Further, the impedance change of the load is introduced to determine whether the load is in normal working condition. If the impedance of the load changes greatly, it means that the electrical characteristics of the load have changed significantly, which may cause instability in current and voltage. In this case, the constant voltage mode may not be able to effectively cope with the drastic changes in the load, because the voltage remains unchanged, but the current may exceed the safe range, causing damage to the load or power supply overload. Therefore, by maintaining the constant voltage mode when the load impedance changes slightly, the stable output of the voltage is ensured to meet the load requirements; and when the load impedance changes greatly, in order to protect the load and the power supply device, the drastic changes in voltage are avoided by switching to the constant current mode to limit the current to avoid adverse effects on the load.

[0051] Exemplarily, in the present application, the voltage comparison circuit 510 includes a second voltage sensor, a second current sensor and a logic circuit; the second voltage sensor is used to monitor the applied voltage; the second current sensor is used to monitor the applied current; the logic circuit is used to compare the applied voltage within a preset time period and a preset voltage threshold, and output a first control signal based on the comparison result, or output the applied voltage and applied current to the programmable logic controller based on the comparison result.

[0052] Through the above analysis, it can be known that the power supply device provided by the present application receives the input voltage by the input terminal, and the output terminal outputs the set target voltage or the set target current; the receiving module receives the external applied voltage and applied current; the switching power supply module generates a DC voltage according to the input voltage, and outputs the set target voltage through the constant voltage mode, or outputs the set target current to the output terminal through the constant current mode; the control module makes the switching between the constant voltage mode and the constant current mode more accurate by combining the judgment conditions of the preset voltage threshold and the preset duration according to the applied voltage; only when the applied voltage is lower than the preset voltage threshold and lasts for a preset duration, it switches to the constant voltage mode, which can avoid misjudgment caused by instantaneous voltage fluctuations and ensure the stability of mode switching; further, the control module calculates the impedance change of the load within the preset duration according to the applied voltage and the applied current, and switches to the constant current mode when the impedance change is higher than the preset impedance change threshold; if the impedance change is lower than or equal to the preset impedance change threshold, the constant voltage mode is maintained. It can not only effectively prevent the power output from being overloaded or damaged when the load changes too much, but also ensure the stable output of the voltage and meet the load requirements.

[0053] In addition, an embodiment of the present application also provides a medical system, which includes the power supply device shown in the above embodiment.

[0054] Those skilled in the art can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example for illustration. In actual applications, the above-mentioned functions can be distributed and completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiments can be integrated into a processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of this application. The specific working process of the units and modules in the above-mentioned system can refer to the corresponding process in the aforementioned method embodiment, which will not be repeated here.

[0055] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0056] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A power supply device, characterized in that: The power supply device comprises: An input terminal for receiving an input voltage; Output terminal, used to output a set target voltage or a set target current; A receiving module, used for receiving external applied voltage and applied current; A switching power supply module, configured to generate a DC voltage according to the input voltage, and output the target voltage in a constant voltage mode, or output the target current to the output terminal in a constant current mode; A control module is used to compare the applied voltage with a preset voltage threshold, and when the applied voltage is lower than the preset voltage threshold within a preset time, control the switching power supply module to switch to a constant voltage mode; if the applied voltage exceeds the preset voltage threshold, calculate the impedance change of the load according to the applied voltage and the applied current within the preset time, if the impedance change is higher than a preset impedance change threshold, control the switching power supply module to switch to a constant current mode, and if the impedance change is lower than or equal to the preset impedance change threshold, control the switching power supply module to maintain the constant voltage mode.

2. The power supply device according to claim 1, characterized in that: The power supply device further comprises an indication voltage generating module, and the indication voltage generating module is used to generate an action indication voltage to the control module.

3. The power supply device according to claim 2, characterized in that: The indication voltage generating module comprises: a signal conversion module, a differential amplifier and an adjustable voltage source; the signal conversion module is used to generate a current indication voltage which is linearly related to the applied current; the differential amplifier is used to add the current indication voltage to the voltage output by the adjustable voltage source to generate the action indication voltage.

4. The power supply device according to claim 2, characterized in that: The control module is further used to determine the current working state of the power supply device according to the action indication voltage.

5. The power supply device according to claim 1, characterized in that: The switching power supply module includes a switching element, a converter circuit, a current feedback circuit and a voltage feedback circuit; The switch element is used to adjust the on and off time according to the first pulse width modulation signal to ensure that the output current matches the set target current, or to adjust the on and off time according to the second pulse width modulation signal to ensure that the output voltage matches the set target voltage; The converter circuit is used to convert the input voltage into an output voltage or an output current; The current feedback circuit is used to monitor the output current in real time and generate a first pulse width modulation signal to the switch element according to the difference between the output current and the target current; The voltage feedback circuit is used to monitor the output voltage in real time and generate a second pulse width modulation signal to the switch element according to the difference between the output voltage and the target voltage.

6. The power supply device according to claim 5, characterized in that: The current feedback circuit includes: a first current sensor, a first differential amplifier and a first pulse width modulation circuit; the first current sensor is used to monitor the output current and input the output current to the first differential amplifier; the first differential amplifier is used to compare the output current with the target current to generate a current error signal; the first pulse width modulation circuit is used to generate the first pulse width modulation signal according to the current error signal.

7. The power supply device according to claim 5, characterized in that: The voltage feedback circuit includes: a first voltage sensor, a second differential amplifier and a second pulse width modulation circuit; the first voltage sensor is used to monitor the output voltage and input the output voltage to the second differential amplifier; the second differential amplifier is used to compare the output voltage with the target voltage to generate a voltage error signal; the second pulse width modulation circuit is used to generate the second pulse width modulation signal according to the voltage error signal.

8. The power supply device according to claim 1, wherein: The control module includes a voltage comparison circuit, a programmable logic controller and a control terminal; The voltage comparison circuit is used to compare the applied voltage within a preset time period with a preset voltage threshold, and when the applied voltage within the preset time period is lower than the preset voltage threshold, generate a first control signal to the control terminal; When the applied voltage exceeds the preset voltage threshold, the applied voltage and the applied current within a preset time period are input into the programmable logic controller; The programmable logic controller is used to calculate the impedance change of the load according to the applied voltage and the applied current, and generate a second control signal to the control terminal when the impedance change is higher than a preset impedance change threshold; When the impedance change is lower than or equal to a preset impedance change threshold, generating the first control signal to the control terminal; The control terminal is connected to the switching power supply module, and is used to control the switching power supply module to switch to a constant voltage mode according to the first control signal, and to control the switching power supply module to switch to a constant current mode according to the second control signal.

9. The power supply device according to claim 8, characterized in that: The voltage comparison circuit includes a second voltage sensor, a second current sensor and a logic circuit; the second voltage sensor is used to monitor the applied voltage; the second current sensor is used to monitor the applied current; the logic circuit is used to compare the applied voltage within a preset time period with a preset voltage threshold, and output a first control signal according to the comparison result, or output the applied voltage and applied current to the programmable logic controller according to the comparison result.

10. A medical system, characterized in that: Comprising the power supply device according to any one of claims 1 to 8.

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