Power supply circuit compatible with multiple power supplies and electronic sphygmomanometer

Abstract

The utility model provides a power supply circuit compatible with multiple power supplies and an electronic sphygmomanometer, and relates to the technical field of power management. The power supply circuit comprises a control module and a power supply module. The power supply module at least comprises a driving unit and a plurality of power supply units, and the power supply units correspond to different power supply main bodies; the output end of each power supply unit is connected with the input end of the driving unit, and the control module is further connected with the driving unit. Wherein the driving unit comprises a plurality of power supply channels; the output end of each power supply channel serves as the output end of the driving unit and is connected with the power supply end of the load. And the control module is used for sending a control signal to the driving unit and adjusting the on or off state of the switching tube in the driving unit so as to conduct the corresponding power supply channel and further supply power to the load through the corresponding power supply unit. On the basis, the technical problem that multiple power supply modes cannot be compatible in the prior art can be relieved on the basis that the device specifications are reduced.

Description

Technical Field

[0001] This utility model relates to the field of power management technology, and in particular to a power supply circuit compatible with multiple power supplies and an electronic blood pressure monitor. Background Technology

[0002] Currently, the power supply requirements of electronic blood pressure monitors are becoming increasingly diverse. Typically, the main power supply methods for electronic blood pressure monitors are Type-C power supply, dry cell battery power supply, and lithium battery power supply, with voltages of 5V, 6V, and 4.2V respectively. Due to the different power supply voltages, technicians usually choose one energy storage power source, such as dry cell batteries or lithium batteries. Therefore, the current technology for electronic blood pressure monitors mainly uses either a Type-C power supply combined with dry cell batteries, or a Type-C power supply combined with lithium batteries.

[0003] However, since lithium batteries need to be charged, and TYPE-C, dry cell batteries and lithium batteries have different voltages, they cannot be used together. Although this can be accomplished by two sets of circuit systems, the two power supply systems are independent and need to be implemented on different PCBs, which increases the component specifications of the electronic blood pressure monitor.

[0004] Therefore, there is an urgent need for an electronic blood pressure monitor that can be compatible with multiple power supply modes while reducing the size of components. Utility Model Content

[0005] The purpose of this invention is to provide a power supply circuit and electronic blood pressure monitor that are compatible with multiple power sources, which can alleviate the technical problem of incompatibility with multiple power supply modes in the prior art by reducing the size of the components.

[0006] In a first aspect, this utility model provides a power supply circuit compatible with multiple power sources, including: a control module and a power supply module; the power supply module includes at least a drive unit and multiple power supply units, each power supply unit corresponding to a different power supply entity; the output terminal of each power supply unit is connected to the input terminal of the drive unit, and the control module is also connected to the drive unit.

[0007] The drive unit includes multiple power supply channels; the output end of each power supply channel serves as the output end of the drive unit and is connected to the power supply end of the load.

[0008] The control module is used to send control signals to the drive unit to adjust the on or off state of the switching transistors in the drive unit, so as to turn on the corresponding power supply channel and then supply power to the load through the corresponding power supply unit.

[0009] Optionally, the drive unit includes a first input terminal and a second input terminal; the multiple power supply units include a main power supply unit, which is connected to the drive unit through the first input terminal and forms a main power supply channel; the remaining power supply units other than the main power supply unit are connected to the drive unit through the second input terminal.

[0010] Among them, when the power supply units other than the main power supply unit include a rechargeable power source,

[0011] The main power supply unit is used to supply power to the rechargeable power source;

[0012] The main power supply unit is also used to supply power to the load through the main power supply channel.

[0013] Optionally, the driving unit includes a first diode, with a first end of the first diode connected to a first input terminal and a second end of the first diode connected to a load.

[0014] Optionally, the driving unit includes a first switching transistor, a second switching transistor, and a first resistor; the control terminals of the first switching transistor and the second switching transistor are both connected to the control module; the first terminal of the first switching transistor is connected to the second input terminal and the first terminal of the first resistor; the second terminal of the first switching transistor is connected to the second terminal of the first resistor and the first terminal of the second switching transistor; the second terminal of the second switching transistor serves as the output terminal of the driving unit and is connected to the load.

[0015] When powered solely by a rechargeable power source, the control module sends a first control command to the drive unit, causing the first switch to turn off and the second switch to turn on.

[0016] Optionally, the drive unit further includes a circuit breaker, a first current-limiting resistor, and a first pull-down resistor; the first terminal of the circuit breaker is connected to the second input terminal; the second terminal of the circuit breaker is connected to the first terminal of the first switching transistor; the control terminal of the second switching transistor is connected to the input terminal of the control module through the first current-limiting resistor; and the control terminal of the second switching transistor is grounded through the first pull-down resistor.

[0017] Optionally, when the power supply unit also includes a non-rechargeable power source, the drive unit further includes a third switching transistor, a fourth switching transistor, a second pull-down resistor, a second current-limiting resistor, a third pull-down resistor, and a pull-up resistor;

[0018] The first terminal of the third switch is connected to the first input terminal and the first terminal of the second pull-down resistor; the second terminal of the second pull-down resistor is connected to the second terminal of the third switch and grounded; the third terminal of the third switch is connected to the first terminal of the second current-limiting resistor, the first terminal of the pull-up resistor, and the second input terminal; the second terminal of the pull-up resistor is connected to the second input terminal; the first terminal of the second current-limiting resistor is connected to the first terminal of the fourth switch; the second terminal of the fourth switch is connected to the first terminal of the third pull-down resistor and the control terminal of the first switch; the second terminal of the third pull-down resistor is grounded; the third terminal of the fourth switch is connected to the first terminal of the first switch.

[0019] When powered only by a non-rechargeable power source, the control module sends a second control command to the drive unit to turn on the first switch, turn on the second switch, turn off the third switch, and turn off the fourth switch.

[0020] Optionally, the drive unit further includes a third current-limiting resistor; the first end of the third current-limiting resistor is connected to the first input terminal; and the second end of the third current-limiting resistor is connected to the first end of the third switching transistor.

[0021] Optionally, the power module also includes a conversion unit, the input of which is connected to the output of the main power supply unit, and the output of which is connected to the charging end of the rechargeable power supply.

[0022] The conversion unit is used to convert the output voltage of the main power supply unit into the power supply for the rechargeable power supply.

[0023] Optionally, the power module further includes a filtering unit; the first end of the filtering unit is connected to the output end of the drive unit; the second end of the filtering unit serves as the output end of the power module and is connected to the load.

[0024] Secondly, this utility model provides an electronic blood pressure monitor, comprising: a load and a power supply circuit compatible with multiple power sources as described in any of the first aspects above, wherein the power supply circuit is connected to the load.

[0025] The present invention provides a power supply circuit compatible with multiple power sources and an electronic blood pressure monitor, which has the following beneficial effects:

[0026] The power supply circuit in this application includes a control module and a power supply module. The power supply module includes at least a drive unit and multiple power supply units, each corresponding to a different power supply source. The output terminal of each power supply unit is connected to the input terminal of the drive unit, and the control module is also connected to the drive unit. The drive unit includes multiple power supply channels; the output terminal of each power supply channel serves as the output terminal of the drive unit and is connected to the power supply terminal of the load. The control module sends control signals to the drive unit to adjust the on / off state of the switching transistors in the drive unit, thereby activating the corresponding power supply channel and supplying power to the load through the corresponding power supply unit. Based on this, this application can alleviate the technical problem of incompatibility between multiple power supply modes in the prior art while reducing device specifications. Attached Figure Description

[0027] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0028] Figure 1 A schematic diagram of a power supply circuit compatible with multiple power sources provided for an embodiment of this utility model;

[0029] Figure 2 This is one of the structural schematic diagrams of the power module in the embodiments of this utility model;

[0030] Figure 3 This is one of the circuit schematic diagrams of the driving unit in the embodiments of this utility model;

[0031] Figure 4 This is the second circuit schematic diagram of the driving unit in this embodiment of the present invention;

[0032] Figure 5 This is the third circuit schematic diagram of the driving unit in this embodiment of the present invention;

[0033] Figure 6 This is the second schematic diagram of the power module in the embodiment of this utility model;

[0034] Figure 7 This is a circuit diagram of the power module in an embodiment of the present invention;

[0035] Figure 8 This is the fourth circuit schematic diagram of the driving unit in this embodiment of the present invention;

[0036] Figure 9 This is the third schematic diagram of the power module structure in the embodiments of this utility model;

[0037] Figure 10 This is a circuit diagram of the power supply circuit in an embodiment of the present invention.

[0038] Icons: 100 - Power supply circuit; 200 - Load; 101 - Control module; 102 - Power module; 201 - Drive unit; 202 - Power supply unit; 201A - First input terminal; 201B - Second input terminal; 203 - Conversion unit; 204 - Filtering unit; 301 - Main power supply unit; 302 - Other power supply units besides the main power supply unit; Q1 - First switching transistor; Q2 - Second switching transistor; R1 - First resistor; F1 - Circuit breaker; R2 - First current limiting resistor; R3 - First pull-down resistor; Q3 - Third switching transistor; Q4 - Fourth switching transistor; R4 - Second pull-down resistor; R5 - Second current limiting resistor; R6 - Third pull-down resistor; R7 - Pull-up resistor; R8 - Third current limiting resistor; C1 - First capacitor; R9 - Second resistor; R10 - Third resistor; C2 - Second capacitor; C3 - Third capacitor; D1 - First diode. Detailed Implementation

[0039] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. The components of the embodiments of this utility model described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0040] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0041] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0042] In the description of this utility model, it should be noted that the terms "first", "second", "third", etc. are used only for distinguishing descriptions and should not be construed as indicating or implying relative importance.

[0043] Furthermore, in the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the term "connection" should be interpreted broadly. For example, it 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 utility model based on the specific circumstances.

[0044] The following detailed description, in conjunction with the accompanying drawings, outlines some embodiments of the present invention. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0045] As described in the background section, conventional electronic blood pressure monitors are not compatible with the charging methods of various power sources, such as TYPE-C, dry cell batteries, and lithium batteries.

[0046] Based on this, this application provides an electronic blood pressure monitor solution that can alleviate the technical problem of incompatibility with multiple power supply modes in the prior art while reducing the size of the components.

[0047] Please refer to Figure 1 , Figure 1 A schematic diagram of a power supply circuit compatible with multiple power sources is shown. In this embodiment, the power supply circuit 100 includes: a control module 101 and a power module 102. The power module 102 includes at least a drive unit 201 and multiple power supply units 202, each power supply unit 202 corresponding to a different power supply body. The output terminal of each power supply unit 202 is connected to the input terminal of the drive unit 201, and the control module 101 is also connected to the drive unit 201.

[0048] The drive unit 201 includes multiple power supply channels; the output end of each power supply channel serves as the output end of the drive unit 201 and is connected to the power supply end of the load 200.

[0049] The control module 101 is used to send control signals to the drive unit to adjust the on or off state of the switching transistor in the drive unit so as to turn on the corresponding power supply channel and then supply power to the load through the corresponding power supply unit.

[0050] It should be noted that the power supply entity described in this embodiment can be understood as: using different charging methods, each charging method can correspond to different power supply protocols and / or different interface methods, and the combination of the above charging methods can be set according to the protocol or application scenario, including but not limited to power supply methods such as TYPE-C, dry cell batteries, lithium batteries, and USB PD (Power Delivery).

[0051] This embodiment can adjust the on and / or off status of the switching transistor under the drive unit through the control module, thereby switching the power supply mode to ensure the normal operation of the electronic blood pressure monitor and improve the compatibility of the electronic blood pressure monitor.

[0052] This embodiment does not limit the structure of the power module. In one possible implementation, please refer to... Figure 1 Based on this, please refer to Figure 2 , Figure 2 A schematic diagram of a power supply module is shown; wherein, the driving unit 201 includes a first input terminal 201A and a second input terminal 201B; a plurality of power supply units 202 include a main power supply unit 301, which is connected to the driving unit 201 through the first input terminal 201A and forms a main power supply channel; the other power supply units 302 besides the main power supply unit are connected to the driving unit 201 through the second input terminal 201B.

[0053] When the power supply units 302 other than the main power supply unit include a rechargeable power source, the main power supply unit 301 is used to supply power to the rechargeable power source; the main power supply unit 301 is also used to supply power to the load 200 through the main power supply channel.

[0054] In this embodiment, the main power supply unit 301 can be powered by TYPE-C. For example, the main power supply unit 301 can receive external power through the VBUS pin of the USB-TYPE-C connector.

[0055] To reduce the complexity of the power supply circuit components, in this embodiment, the driving unit 201 can be configured as a diode. Please refer to [the relevant documentation / reference]. Figure 2 Based on, refer to Figure 3 , Figure 3 The diagram shows one of the circuit schematics of the driving unit in this embodiment. In this embodiment, the driving unit 201 may include a first diode D1. The first end (anode) of the first diode D1 is connected to the first input terminal 201A, and the second end (cathode) of the first diode D1 is connected to the load 200.

[0056] Therefore, when an external power source powers the electronic blood pressure monitor via a USB-TYPE-C connector, the first diode D1 can directly power the back-end load 200.

[0057] When the power supply units 302 other than the main power supply unit include a rechargeable power supply, the external power supply can also supply power to the rechargeable power supply through the USB-TYPE-C connector.

[0058] Furthermore, in one possible implementation, the control module in this embodiment can also be implemented via a USB-TYPE-C connector, that is, by sending control commands, such as high level or low level, to the drive unit through the VBUS pin on the USB-TYPE-C connector.

[0059] Please Figure 3 Based on, refer to Figure 4 , Figure 4 This diagram illustrates another circuit schematic of the driving unit in this embodiment. The driving unit 201 includes a first switch Q1, a second switch Q2, and a first resistor R1. The control terminals of both the first switch Q1 and the second switch Q2 are connected to the control module 101. The first terminal of the first switch Q1 is connected to the second input terminal 201B and the first terminal of the first resistor R1. The second terminal of the first switch Q1 is connected to the second terminal of the first resistor R1 and the first terminal of the second switch Q2. The second terminal of the second switch Q2 serves as the output terminal of the driving unit 201 and is connected to the load 200.

[0060] When powered solely by a rechargeable power source, the control module 101 sends a first control command to the drive unit 201 to turn off the first switch Q1 and turn on the second switch Q2.

[0061] In this embodiment, when powered only by a rechargeable power supply, the voltage output by the rechargeable power supply can power the downstream load 200 through the first resistor R1 and the second switch Q2.

[0062] Furthermore, to ensure the stability of the drive unit 201, please... Figure 4 Based on, refer to Figure 5 , Figure 5 Another circuit diagram of the driving unit in this embodiment is shown. In this embodiment, the driving unit 201 also includes a circuit breaker F1, a first current-limiting resistor R2, and a first pull-down resistor R3.

[0063] The circuit breaker F1 is connected to the second input terminal 201B; the circuit breaker F1 is connected to the first terminal of the first switch Q1; the control terminal of the second switch Q2 is connected to the input terminal of the control module 101 through the first current limiting resistor R2; and the control terminal of the second switch Q2 is grounded through the first pull-down resistor R3.

[0064] To reduce the structural bulk of the electronic blood pressure monitor, in this embodiment, the power supply units 302, excluding the main power supply unit, can be connected in parallel. For example, when the power supply unit 202 also includes a non-rechargeable power supply, the non-rechargeable power supply and the rechargeable power supply can share a single output port.

[0065] In one possible implementation method, please Figure 2Based on, refer to Figure 6 , Figure 6 The diagram shows the structure of the power module in this embodiment. When the power supply voltage of the main power supply unit 301 is different from the voltage of the rechargeable power supply, the power module 102 in this embodiment also includes a conversion unit 203. The input terminal of the conversion unit 203 is connected to the output terminal of the main power supply unit 301, and the output terminal of the conversion unit 203 is connected to the charging terminal of the rechargeable power supply.

[0066] The conversion unit 203 can be used to convert the output voltage of the main power supply unit 301 into a power supply for a rechargeable power source.

[0067] In this embodiment, the conversion unit can use a charging chip, such as the CE3221 chip. When the main power supply unit 301 uses a USB-TYPE-C connector, please... Figure 6 Based on, refer to Figure 7 , Figure 7 The diagram shows the circuit principle of the power module in this embodiment. The VBUS pin of the USB-TYPE-C connector is connected to the VIN pin of the CE3221 chip, which is also grounded through a first capacitor C1. The CE pin of the CE3221 chip is grounded through a second resistor R9. Simultaneously, the IREF pin of the CE3221 chip is connected to the first end of a third resistor R10 and the first end of a second capacitor C2. The BAT pin of the CE3221 chip is connected to the first end of a third capacitor C3. The second ends of the third resistor R10, the second capacitor C2, the third capacitor C3, and the TEMP pin of the CE3221 chip are all grounded. In this embodiment, the BAT pin of the CE3221 chip serves as the output terminal of the conversion unit, supplying power to the rechargeable power source.

[0068] Please Figure 5 Based on, refer to Figure 8 , Figure 8 Another circuit diagram of the driving unit 201 in this embodiment is shown. When the power supply unit 202 also includes a non-rechargeable power supply, the driving unit 201 also includes a third switch Q3, a fourth switch Q4, a second pull-down resistor R4, a second current-limiting resistor R5, a third pull-down resistor R6, and a pull-up resistor R7.

[0069] The first terminal of the third switch Q3 is connected to the first input terminal 201A and the first terminal of the second pull-down resistor R4; the second terminal of the second pull-down resistor R4 is connected to the second terminal of the third switch Q3 and grounded; the third terminal of the third switch Q3 is connected to the first terminal of the second current-limiting resistor R5, the first terminal of the pull-up resistor R7, and the second input terminal 201B; the second terminal of the pull-up resistor R7 is connected to the second input terminal 201B; the first terminal of the second current-limiting resistor R5 is connected to the first terminal of the fourth switch Q4; the second terminal of the fourth switch Q4 is connected to the first terminal of the third pull-down resistor R6 and the control terminal of the first switch Q1; the second terminal of the third pull-down resistor R6 is grounded; the third terminal of the fourth switch Q4 is connected to the first terminal of the first switch Q1.

[0070] When powered only by a non-rechargeable power source, the control module 101 sends a second control command to the drive unit 201 to turn on the first switch Q1, turn on the second switch Q2, turn off the third switch Q3, and turn off the fourth switch Q4.

[0071] In this embodiment, when powered only by a non-rechargeable power supply, the base of the third switch Q3 is grounded through the second pull-down resistor R4, and the third switch Q3 is in the off state. The voltage output by the non-rechargeable power supply can power the base of the fourth switch Q4 through the circuit breaker F1, the pull-up resistor R7, and the second current-limiting resistor R5, and the fourth switch Q4 is in the off state. Correspondingly, the gate of the first switch Q1 is grounded through the third pull-down resistor R6, and the first switch Q1 is in the on state. Similarly, the gate of the second switch Q2 is grounded through the first pull-down resistor R3, and the second switch Q2 is in the on state. Based on this, the non-rechargeable power supply can power the downstream load 200 through the first switch Q1 and the second switch Q2.

[0072] Please continue to refer to this. Figure 8 In this embodiment, the driving unit 201 further includes a third current-limiting resistor R8; the first end of the third current-limiting resistor R8 is connected to the first input terminal 201A; and the second end of the third current-limiting resistor R8 is connected to the first end of the third switching transistor Q3.

[0073] When the non-rechargeable power supply and the main power supply unit 301 work together, since the supply voltages of the non-rechargeable power supply and the main power supply unit 301 are different (for example, in this embodiment, the non-rechargeable power supply can be a dry cell battery with a supply voltage of 6V and the main power supply unit 301 with a supply voltage of 5V), the base voltage of the third switch Q3 is 5V, and the third switch Q3 is in the on state; the base voltage of the fourth switch Q4 is 0V, and the fourth switch Q4 is in the on state; the gate voltage of the first switch Q1 is 6V, and the first switch Q1 is in the off state; the gate voltage of the second switch Q2 is 6V, and the second switch Q2 is in the on state. Under these working conditions, the dry cell battery power supply does not supply power to the downstream load 200; it only supplies power to the downstream load 200 through the first diode via the main power supply unit 301.

[0074] To ensure the stability of the output voltage of the power supply circuit 100, please... Figure 1 Based on, refer to Figure 9 , Figure 9 This diagram shows another structural schematic of the power module in this embodiment. In this embodiment, the power module 102 further includes a filter unit 204. The first end of the filter unit 204 is connected to the output end of the drive unit 201. The second end of the filter unit 204 serves as the output end of the power module 102 and is connected to the load 200.

[0075] In one possible implementation method, please Figure 9 Based on, refer to Figure 10 , Figure 10 The circuit diagram of the power supply circuit 100 in this embodiment is shown. The filter unit may include multiple capacitors, which are connected in parallel. The first end of the parallel connection between each capacitor is connected to the output terminal of the drive unit 201, and the second end of the parallel connection between each capacitor is grounded.

[0076] The USB-TYPE-C connector has two GND pins grounded, CC1 and CC2 pins grounded via resistors, and two VBUS pins connected together to receive external power and control signals. The SHELL pin is also grounded.

[0077] Based on this, the power supply circuit provided by this utility model can alleviate the technical problem of incompatibility with multiple power supply modes in the prior art while reducing the size of the components.

[0078] Following the same approach as the previous embodiment, this utility model also provides an electronic blood pressure monitor, including: a load and a power supply circuit compatible with multiple power sources as described in any of the first aspects above, wherein the power supply circuit is connected to the load.

[0079] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model.

Claims

1. A power supply circuit compatible with multiple power sources, characterized by comprising: The utility model relates to a power supply device, including: Control module, power module; The power module at least includes drive unit, a plurality of power supply unit, each power supply unit corresponds different power supply subject; The output end of each power supply unit is connected with the input end of drive unit respectively, and the control module is also connected with drive unit; Wherein, the drive unit includes a plurality of power supply channels;The output end of each power supply channel is as the output end of drive unit, and is connected with the power supply end of load; The control module is used to send control signal to drive unit, adjusts the on or off state of switch tube in drive unit, to switch on corresponding power supply channel, and then supplies power for load through corresponding power supply unit.

2. The power supply circuit according to claim 1, characterized in that, The drive unit includes first input end, second input end;The plurality of power supply units include main power supply unit, and the main power supply unit is connected with drive unit through first input end and constitutes main power supply channel;The rest power supply unit except main power supply unit is connected with drive unit through second input end; Wherein, when the rest power supply unit except main power supply unit includes rechargeable power supply, The main power supply unit is used to supply power for rechargeable power supply; The main power supply unit is also used to supply power for load through main power supply channel.

3. The power supply circuit of claim 2, wherein, The drive unit includes first diode, and the first end of first diode is connected with first input end;The second end of first diode is connected with load.

4. The power supply circuit of claim 2, wherein, The drive unit includes first switch tube, second switch tube, first resistance;The control end of first switch tube and second switch tube is connected with control module;The first end of first switch tube is connected with second input end and the first end of first resistance;The second end of first switch tube is connected with the second end of first resistance and the first end of second switch tube;The second end of second switch tube is as the output end of drive unit, and is connected with load; Wherein, when only supplying power through rechargeable power supply, the control module is used to send first control instruction to drive unit, and makes first switch tube close and second switch tube switch on.

5. The power supply circuit of claim 4, wherein, The drive unit also includes circuit breaker, first current-limiting resistance, first pull-down resistance;The first end of circuit breaker is connected with second input end;The second end of circuit breaker is connected with the first end of first switch tube;The control end of second switch tube is connected with the input end of control module through first current-limiting resistance;The control end of second switch tube is connected with ground through first pull-down resistance.

6. The power supply circuit of claim 4, wherein, When the power supply unit also includes non-rechargeable power supply, the drive unit also includes third switch tube, fourth switch tube, second pull-down resistance, second current-limiting resistance, third pull-down resistance, pull-up resistance; The first end of the third switch tube is connected with the first input end and the first end of the second pull-down resistor; the second end of the second pull-down resistor is connected with the second end of the third switch tube and grounded; the third end of the third switch tube is connected with the first end of the second current-limiting resistor, the first end of the pull-up resistor and the second input end respectively; the second end of the pull-up resistor is connected with the second input end; the first end of the second current-limiting resistor is connected with the first end of the fourth switch tube; the second end of the fourth switch tube is connected with the first end of the third pull-down resistor and the control end of the first switch tube respectively; the second end of the third pull-down resistor is grounded; the third end of the fourth switch tube is connected with the first end of the first switch tube. When powered only by the non-rechargeable power supply, the control module is configured to send a second control instruction to the driving unit, so that the first switch tube is turned on, the second switch tube is turned on, the third switch tube is turned off, and the fourth switch tube is turned off.

7. The power supply circuit of claim 6, wherein, The driving unit further comprises a third current-limiting resistor; the first end of the third current-limiting resistor is connected with the first input end; and the second end of the third current-limiting resistor is connected with the first end of the third switch tube.

8. The power supply circuit of claim 2, wherein, The power supply module further comprises a conversion unit, the input end of the conversion unit is connected with the output end of the main power supply unit, and the output end of the conversion unit is connected with the charging end of the rechargeable power supply. The conversion unit is configured to convert the output voltage of the main power supply unit into the power supply of the rechargeable power supply.

9. The power supply circuit of claim 1, wherein, The power supply module further comprises a filtering unit; the first end of the filtering unit is connected with the output end of the driving unit; and the second end of the filtering unit is taken as the output end of the power supply module and connected with the load.

10. An electronic sphygmomanometer characterized by comprising: The power supply circuit comprises: a load and the compatible multi-power supply circuit according to any one of claims 1 to 9, wherein the compatible multi-power supply circuit is connected with the load.

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