Data acquisition instrument

Abstract

The utility model discloses a data acquisition instrument. In the data acquisition instrument, the input end of a first power supply module is used for inputting an external power supply, the output end of the first power supply module is connected with the first input end of a power supply multiplexer, the output end of a second power supply module is connected with the second input end of the power supply multiplexer, and the output end of the power supply multiplexer serves as the power supply end of the data acquisition instrument; the first power module is used for outputting a first voltage signal according to an external power supply. The second power module is used for outputting a second voltage signal; the power multiplexer is used for gating the first input end and the output end of the power multiplexer when the first voltage signal is larger than a first voltage threshold value, and gating the second input end and the output end of the power multiplexer when the first voltage signal is smaller than the first voltage threshold value and the second voltage signal is larger than or equal to a second voltage threshold value. Seamless switching of the power supply modes of the data acquisition instrument and priority setting of the power supply modes are realized.

Description

Technical Field

[0001] The embodiments of the utility model relate to the technical field of data acquisition, and in particular to a data acquisition instrument. Background Art

[0002] The data acquisition device needs to be installed near the flow meter to collect flow meter data. The installation environment of the flow meter is relatively complex, which makes the installation environment of the data acquisition device relatively loaded. For example, the flow meter can be installed in indoor and outdoor environments such as pressure regulating cabinets, metering rooms, and unmanned pressure regulating stations. The data acquisition device also needs to be installed in the same environment. The power supply conditions of different installation environments are different. In order to adapt to different power supply conditions, the data acquisition device has different power supply methods. In the existing technology, the data acquisition device cannot achieve seamless switching when switching power supply methods, which reduces the reliability of the data acquisition device. Utility Model Content

[0003] The utility model provides a data acquisition instrument to improve the reliability of the data acquisition instrument.

[0004] In a first aspect, an embodiment of the present utility model provides a data acquisition instrument, comprising a first power supply module, a second power supply module and a power multiplexer;

[0005] The input end of the first power supply module is used to input an external power supply, the output end of the first power supply module is connected to the first input end of the power multiplexer, the output end of the second power supply module is connected to the second input end of the power multiplexer, and the output end of the power multiplexer serves as the power end of the data acquisition instrument; the first power supply module is used to output a first voltage signal according to the external power supply; the second power supply module is used to output a second voltage signal; the power multiplexer is used to select the first input end and output end of the power multiplexer when the first voltage signal is greater than a first voltage threshold, and select the second input end and output end of the power multiplexer when the first voltage signal is less than the first voltage threshold and the second voltage signal is greater than or equal to the second voltage threshold.

[0006] Optionally, the power multiplexer includes a gating unit and a voltage dividing unit;

[0007] The first input end of the gating unit is connected to the input end of the voltage divider unit and serves as the first input end of the power multiplexer. The second input end of the gating unit serves as the second input end of the power multiplexer. The output end of the voltage divider unit is connected to the detection end of the gating unit, and the output end of the gating unit serves as the output end of the power multiplexer.

[0008] Optionally, the voltage dividing unit includes a first voltage dividing resistor and a second voltage dividing resistor;

[0009] The first end of the first voltage-dividing resistor serves as the input end of the voltage-dividing unit, the second end of the first voltage-dividing resistor is connected to the first end of the second voltage-dividing resistor and serves as the output end of the voltage-dividing unit, and the second end of the second voltage-dividing resistor is grounded.

[0010] Optionally, the data acquisition instrument further includes at least one voltage conversion module, which is connected to the output end of the power multiplexer and is used to perform voltage conversion on the voltage output by the power multiplexer.

[0011] Optionally, the data acquisition instrument includes a first voltage conversion module and a second voltage conversion module;

[0012] The input end of the first voltage conversion module and the input end of the second voltage conversion module are both connected to the output end of the power multiplexer. The first voltage conversion module is used to perform voltage conversion on the voltage output by the power multiplexer to form a first output voltage; the second voltage conversion module is used to perform voltage conversion on the voltage output by the power multiplexer to form a second output voltage; wherein the voltage values of the first output voltage and the second output voltage are different.

[0013] Optionally, the first power supply module includes an anti-reverse connection and overvoltage protection unit and a voltage reduction unit;

[0014] The input end of the anti-reverse connection and overvoltage protection unit is used to input the external power supply, the output end of the anti-reverse connection and overvoltage protection unit is connected to the input end of the step-down unit, and the output end of the step-down unit is connected to the first input end of the power multiplexer; the anti-reverse connection and overvoltage protection unit is used to perform anti-reverse connection and overvoltage protection on the external power supply, and the step-down unit is used to step down the external power supply to form the first voltage signal.

[0015] Optionally, the anti-reverse connection and overvoltage protection unit includes an anti-reverse connection MOS tube and an overvoltage protection subunit;

[0016] The drain of the anti-reverse connection MOS transistor is used to input the external power supply, the source of the anti-reverse connection MOS transistor is connected to the input end of the overvoltage protection subunit, and the gate of the anti-reverse connection MOS transistor is connected to the fixed potential end. The anti-reverse connection MOS transistor is used to be turned on when the voltage of the external power supply is positive and turned off when the voltage of the external power supply is negative; the output end of the overvoltage protection subunit is connected to the input end of the step-down unit, and the overvoltage protection subunit is used to perform overvoltage protection when the voltage of the external power supply is greater than a preset threshold.

[0017] Optionally, the overvoltage protection subunit includes a voltage stabilizing diode, a first resistor, a transistor and an overvoltage protection MOS tube;

[0018] The first end of the first resistor, the emitter of the transistor, and the source of the overvoltage protection MOS transistor are connected to the source of the anti-reverse connection MOS transistor, the second end of the first resistor is connected to the cathode of the voltage regulator diode and the base of the transistor, and the anode of the voltage regulator diode is grounded; the collector of the transistor is connected to the gate of the overvoltage protection MOS transistor, and the drain of the overvoltage protection MOS transistor serves as the output end of the overvoltage protection subunit.

[0019] Optionally, the first power supply module also includes a current limiting circuit; the input end of the current limiting circuit is used to input the external power supply, the output end of the current limiting circuit is connected to the input end of the anti-reverse connection and overvoltage protection unit, and the current limiting circuit is used to limit the current of the external power supply.

[0020] Optionally, the first power module further includes a voltage limiting circuit, which is connected between the output end of the step-down unit and the first input end of the power multiplexer, and is used to limit the voltage of the first voltage signal.

[0021] The technical solution of the embodiment of the utility model is to connect the output end of the first power module to the first input end and the detection end of the power multiplexer, and the output end of the second power module to the second input end of the power multiplexer. The power multiplexer is used to select the first input end and the output end of the power multiplexer when the first voltage signal is greater than the first voltage threshold, and select the second input end and the output end of the power multiplexer when the first voltage signal is less than the first voltage threshold and the second voltage signal is greater than or equal to the second voltage threshold. This can make the power supply priority of the external power supply higher than the power supply priority of the internal energy storage power supply. This can not only reduce the power loss of the second power module and improve the utilization rate of power when the external power supply is available, but also ensure the power supply reliability of the data acquisition instrument when the external power supply is unstable. In addition, the power multiplexer has relatively low power consumption and fast switching speed, thereby reducing the power consumption of the data acquisition instrument and extending the life of the second power module. At the same time, it can achieve seamless switching of the power supply mode of the data acquisition instrument without affecting the normal operation of the load end of the data acquisition instrument, avoiding the impact of unexpected situations such as power outages on the operation of the load end. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 A schematic diagram of a power supply structure of a data acquisition device provided in an embodiment of the utility model;

[0023] Figure 2 A schematic structural diagram of a power multiplexer provided in an embodiment of the present utility model;

[0024] Figure 3 A schematic diagram of the power supply structure of another data acquisition device provided in an embodiment of the present utility model;

[0025] Figure 4 A schematic structural diagram of a first voltage conversion module provided in an embodiment of the present utility model;

[0026] Figure 5 A schematic structural diagram of a second voltage conversion module provided in an embodiment of the present utility model;

[0027] Figure 6 This is a structural diagram of a first power supply module provided in an embodiment of the present utility model. DETAILED DESCRIPTION

[0028] The present invention will be further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are intended only to illustrate the present invention and are not intended to limit the present invention. It should also be noted that, for ease of description, the accompanying drawings only illustrate portions relevant to the present invention, not all of its components.

[0029] Figure 1 The power supply structure diagram of a data acquisition instrument provided by the embodiment of the present utility model is shown in FIG. Figure 1 As shown, the data acquisition instrument includes a first power supply module 110, a second power supply module 120 and a power multiplexer 130; the input terminal VIN1 of the first power supply module 110 is used to input an external power supply, the output terminal VOUT1 of the first power supply module 110 is connected to the first input terminal VIN11 of the power multiplexer 130, the output terminal VOUT2 of the second power supply module 120 is connected to the second input terminal VIN12 of the power multiplexer 130, and the output terminal VOUT3 of the power multiplexer 130 serves as the power supply terminal of the data acquisition instrument; the first power supply module 110 is used to output a first voltage signal according to the external power supply; the second power supply module 120 is used to output a second voltage signal; the power multiplexer 130 is used to select the first input terminal VIN11 and the output terminal VOUT3 of the power multiplexer 130 when the first voltage signal is greater than a first voltage threshold, and select the second input terminal VIN12 and the output terminal VOUT3 of the power multiplexer 130 when the first voltage signal is less than the first voltage threshold and the second voltage signal is greater than or equal to the second voltage threshold.

[0030] Specifically, the first power module 110 and the second power module 120 can provide different power supply modes for the data acquisition instrument. For example, the first power module 110 can be a voltage conversion module. When an external power source is input to the input terminal VIN1 of the first power module 110, the external power source can be converted to a voltage to power the data acquisition instrument. The second power module 120 can be an energy storage power source, such as a battery, for directly powering the data acquisition instrument. The power multiplexer 130 can select between the first input terminal VIN11 and the second input terminal VIN12 and convert them into a single output. When the data acquisition instrument is installed in an environment with an external power source, and the first voltage signal output by the first power module 110 is greater than a first voltage threshold, it can be determined that the external power source input to the first power module 110 has a relatively high voltage. In this case, the power multiplexer 130 selects the first input terminal VIN11 and the output terminal VOUT3. The first voltage signal output by the first power module 110 is supplied via the output terminal VOUT3 of the power multiplexer 130, thereby enabling the external power source to serve as the power supply for the data acquisition instrument. When the first voltage signal output by the first power module 110 is less than the first voltage threshold, and the second voltage signal is greater than or equal to the second voltage threshold, it can be determined that the external power supply voltage input to the first power module 110 is relatively low, or no external power supply is input, and the voltage provided by the second power module 120 is relatively high, that is, the second power module 120 has sufficient power. At this time, the power multiplexer 130 selects the second input terminal VIN12 and the output terminal VOUT3, and the second voltage signal output by the second power module 120 is supplied through the output terminal VOUT3 of the power multiplexer 130, thereby enabling the energy storage power supply within the data acquisition instrument to serve as the power supply for the data acquisition instrument.

[0031] Thus, when the external power supply voltage is relatively high, the power multiplexer 130 automatically switches between the first input terminal VIN11 and the output terminal VOUT3, allowing the external power supply to serve as the power source for the data acquisition instrument. When there is no external power supply or the external power supply voltage is relatively low, and the second power supply module 120 has sufficient power, the power multiplexer 130 automatically switches between the second input terminal VIN12 and the output terminal VOUT3, allowing the internal energy storage power supply to serve as the power source for the data acquisition instrument. This allows the external power supply to be prioritized over the internal energy storage power supply. This not only reduces power loss and improves power utilization in the second power supply module 120 when an external power supply is available, but also ensures reliable power supply to the data acquisition instrument when the external power supply is unstable. Furthermore, the power multiplexer 130 consumes relatively low power. By switching the power supply status of the first power supply module 110 and the second power supply module 120 through the power multiplexer 130, the power consumption of the data acquisition instrument can be reduced, extending the life of the second power supply module 120. For example, the voltage drop between the input and output of the power multiplexer 130 is less than 10 mV, which can reduce the power loss of the second power module 120 and extend the life of the second power module 120. Furthermore, the power multiplexer 130 has low static power consumption, with its maximum static current not exceeding 5 μA and a typical value of approximately 1.3 μA at room temperature. This effectively reduces the power consumption of the data acquisition instrument and extends the life of the second power module 120. Furthermore, the power multiplexer 130 switches back and forth quickly between the first input terminal VIN11 and the second input terminal VIN12, enabling seamless switching of the data acquisition instrument's power supply mode without affecting the normal operation of the data acquisition instrument's load, thereby preventing the impact of unexpected events such as power outages on the load's operation.

[0032] The technical solution of this embodiment connects the output of the first power module to the first input and detection terminal of a power multiplexer, and the output of the second power module to the second input of the power multiplexer. The power multiplexer is configured to select the first input and output of the power multiplexer when the first voltage signal is greater than a first voltage threshold, and select the second input and output of the power multiplexer when the first voltage signal is less than the first voltage threshold and the second voltage signal is greater than or equal to the second voltage threshold. This allows the external power supply to have a higher priority than the internal energy storage power supply. This not only reduces the power loss of the second power module and improves the power utilization rate when an external power supply is available, but also ensures the power supply reliability of the data acquisition instrument when the external power supply is unstable. In addition, the power multiplexer has relatively low power consumption and fast switching speed, thereby reducing the power consumption of the data acquisition instrument and extending the life of the second power module. At the same time, seamless switching of the power supply mode of the data acquisition instrument is achieved without affecting the normal operation of the load end of the data acquisition instrument, thus avoiding the impact of unexpected situations such as power outages on the operation of the load end.

[0033] Figure 2 This is a schematic diagram of the structure of a power multiplexer provided by an embodiment of the present utility model. Figure 2 As shown, the power multiplexer 130 includes a gating unit 131 and a voltage dividing unit 132; the first input terminal vin1 of the gating unit 131 is connected to the input terminal of the voltage dividing unit 132 and serves as the first input terminal VIN11 of the power multiplexer 130, the second input terminal vin2 of the gating unit 131 serves as the second input terminal VIN12 of the power multiplexer 130, the output terminal of the voltage dividing unit 132 is connected to the detection terminal PR of the gating unit 131, and the output terminal of the gating unit 131 serves as the output terminal VOUT3 of the power multiplexer 130.

[0034] Specifically, Table 1 is a logic diagram of the input and output signals of a gating unit provided by an embodiment of the present invention. Among them, VIN1 is the first voltage signal input to the first input terminal vin1 of the gating unit 131, and VIN2 is the second voltage signal input to the second input terminal vin2 of the gating unit 131. As shown in Tables 1 and Figure 2 As shown, the output terminal VOUT1 of the first power supply module 110 is connected to the first input terminal vin1 of the selection unit 131 and the input terminal of the voltage dividing unit 132. The voltage dividing unit 132 divides the first voltage signal VIN1. When the first voltage signal VIN1 is greater than the first voltage threshold, the voltage dividing unit 132 divides the first voltage signal VIN1 and outputs a divided voltage V PR Greater than the first detection voltage threshold V ref The selection unit 131 is based on the divided voltage V input from the detection terminal PR. PRThe first input terminal vin1 and the output terminal of the gating unit 131 are selected so that the voltage of the output terminal VOUT3 of the gating unit 131 is the first voltage signal VIN1, thereby enabling the external power supply to serve as the power supply of the data acquisition instrument. When the first voltage signal VIN1 is less than the first voltage threshold and the second voltage signal VIN2 is greater than or equal to the second voltage threshold, the voltage dividing unit 132 divides the first voltage signal VIN1 and outputs a divided voltage V PR Less than the first detection voltage threshold V ref , and the second voltage signal VIN2 is greater than or equal to the second voltage threshold (Table 1 shows that the second voltage threshold is 1.6V). The selection unit 131 receives the divided voltage V according to the detection terminal PR. PR The second input terminal vin2 and the output terminal of the gating unit 131 are selected with the second voltage signal VIN2, so that the voltage of the output terminal VOUT3 of the gating unit 131 is the second voltage signal VIN2, thereby realizing that the energy storage power supply in the data acquisition instrument can be used as the power supply of the data acquisition instrument.

[0035] Table 1

[0036] VIN1 VIN2 ST VOUT3 <![CDATA[H(V PR >In ref )]]> X H VIN1 <![CDATA[L(V PR <In ref )]]> ≥1.6V L VIN2

[0037] In addition, continue to refer to Figure 2 As shown in Table 1, the gating unit 131 further includes an indicator pin ST, which is connected to the first input terminal vin1 of the gating unit 131 via a pull-up resistor and is used to indicate the input status of the first input terminal vin1 of the gating unit 131. When the indicator pin ST is at a high level, it indicates that the first voltage signal VIN1 input to the first input terminal vin1 of the gating unit 131 is valid, and the second voltage signal VIN2 input to the second input terminal vin2 of the gating unit 131 is in an indifferent state. When the indicator pin ST is at a low level, it indicates that the first voltage signal VIN1 is not input to the first input terminal vin1 of the gating unit 131, and the second voltage signal VIN2 input to the second input terminal vin2 of the gating unit 131 is valid.

[0038] Continue to refer Figure 2 The voltage dividing unit 132 includes a first voltage dividing resistor R1 and a second voltage dividing resistor R2; the first end of the first voltage dividing resistor R1 serves as the input end of the voltage dividing unit 132, the second end of the first voltage dividing resistor R1 is connected to the first end of the second voltage dividing resistor R2, and serves as the output end of the voltage dividing unit 132, and the second end of the second voltage dividing resistor R2 is grounded GND.

[0039] Specifically, the first end of the first voltage-dividing resistor R1 serves as the input end of the voltage-dividing unit 132, and is used to input the first voltage signal. When the second end of the second voltage-dividing resistor R2 is grounded to GND, the voltage across the first voltage-dividing resistor R1 and the second voltage-dividing resistor R2 is the voltage of the first voltage signal. At this time, the voltage is divided by the first voltage-dividing resistor R1 and the second voltage-dividing resistor R2, so that the ratio of the divided voltage output by the voltage-dividing unit 132 to the first voltage signal is r2 / (r1+r2); wherein r1 is the resistance value of the first voltage-dividing resistor R1, and r2 is the resistance value of the second voltage-dividing resistor R2. Thus, the first voltage signal can be determined based on the divided voltage and the resistance values of the first voltage-dividing resistor R1 and the second voltage-dividing resistor R2. Thus, whether the first voltage signal is greater than the first voltage threshold can be determined based on the divided voltage, so that the power supply priority of the external power supply is higher than the power supply priority of the internal energy storage power supply.

[0040] Figure 3 This is a schematic diagram of the power supply structure of another data acquisition device provided by the embodiment of the present utility model. Figure 3 As shown, the data acquisition instrument further includes at least one voltage conversion module 140 . The voltage conversion module 140 is connected to the output terminal VOUT3 of the power multiplexer 130 . The voltage conversion module 140 is used to perform voltage conversion on the voltage output by the power multiplexer 130 .

[0041] Specifically, voltage conversion module 140 can convert the voltage output by power multiplexer 130 to provide a stable voltage for the data acquisition instrument's load. When the data acquisition instrument includes two or more voltage conversion modules 140, different voltage conversion modules 140 can convert the voltage output by power multiplexer 130 to output different voltage signals, thereby meeting the power requirements of different loads and expanding the applicability of the data acquisition instrument. Exemplarily, voltage conversion module 140 can be a buck-boost DC-DC converter.

[0042] Figure 4 This is a structural diagram of a first voltage conversion module provided by an embodiment of the present utility model. Figure 5 This is a schematic diagram of the structure of a second voltage conversion module provided by an embodiment of the present utility model. Figures 3 to 5As shown, the data acquisition instrument includes a first voltage conversion module 141 and a second voltage conversion module 142; the input end of the first voltage conversion module 141 and the input end of the second voltage conversion module 142 are both connected to the output end VOUT3 of the power multiplexer 130, and the first voltage conversion module 141 is used to perform voltage conversion on the voltage output by the power multiplexer 130 to form a first output voltage Vcc1; the second voltage conversion module 145 is used to perform voltage conversion on the voltage output by the power multiplexer 130 to form a second output voltage Vcc2; wherein, the voltage values of the first output voltage Vcc1 and the second output voltage Vcc2 are different.

[0043] Specifically, the first output voltage Vcc1 output by the first voltage conversion module 141 can meet the power supply requirements of one type of load. The second output voltage Vcc2 output by the second voltage conversion module 142 can meet the power supply requirements of another type of load. By configuring the data acquisition instrument to include the first voltage conversion module 141 and the second voltage conversion module 142, the power supply requirements of multiple loads can be met, thereby expanding the scope of use of the data acquisition instrument.

[0044] Figure 6 This is a schematic diagram of the structure of a first power supply module provided by an embodiment of the present utility model. Figure 6 As shown, the first power supply module 110 includes an anti-reverse connection and overvoltage protection unit 111 and a step-down unit 112; the input end of the anti-reverse connection and overvoltage protection unit 111 is used to input an external power supply, the output end of the anti-reverse connection and overvoltage protection unit 111 is connected to the input end of the step-down unit 112, and the output end of the step-down unit 112 is connected to the first input end VIN11 of the power multiplexer 130; the anti-reverse connection and overvoltage protection unit 111 is used to perform anti-reverse connection and overvoltage protection on the external power supply, and the step-down unit 112 is used to step down the external power supply to form a first voltage signal.

[0045] Specifically, the input end of the anti-reverse connection and overvoltage protection unit 111 inputs an external power supply. When the positive and negative poles of the external power supply are reversed, and / or the voltage range of the external power supply exceeds the voltage range that the data acquisition instrument can withstand, the anti-reverse connection and overvoltage protection unit 111 can disconnect the path between the external power supply and the step-down unit 112, thereby preventing the external power supply from abnormally damaging the data acquisition instrument and improving the safety of the data acquisition instrument. In addition, it can support a wide voltage input of the external power supply, thereby improving the adaptability of the data acquisition instrument. For example, the voltage range of the external power supply can be 5V-15V.

[0046] It should be noted that, in some embodiments, the data acquisition instrument may further include an anti-reverse connection unit, which is disposed between the second power module 120 and the power multiplexer 130 to prevent damage to the data acquisition instrument when the second power module 120 is reversely connected.

[0047] Continue to refer Figure 6 The anti-reverse polarity and overvoltage protection unit 111 includes an anti-reverse polarity MOS transistor M1 and an overvoltage protection subunit 1111; the drain of the anti-reverse polarity MOS transistor M1 is used to input an external power supply, the source of the anti-reverse polarity MOS transistor M1 is connected to the input end of the overvoltage protection subunit 1111, and the gate of the anti-reverse polarity MOS transistor M1 is connected to the fixed potential end. The anti-reverse polarity MOS transistor M1 is used to turn on when the voltage of the external power supply is positive and to turn off when the voltage of the external power supply is negative; the output end of the overvoltage protection subunit 1111 is connected to the input end of the step-down unit 112, and the overvoltage protection subunit 1111 is used to perform overvoltage protection when the voltage of the external power supply is greater than a preset threshold.

[0048] Specifically, Figure 6 In the example shown in FIG, the anti-reverse connection MOS transistor M1 is a P-type MOS transistor. The fixed potential terminal can be a ground terminal GND. Figure 6 The gate of the exemplary reverse polarity MOS transistor M1 is grounded to GND via a resistor. When the drain of the reverse polarity MOS transistor M1 is connected to the positive voltage of the external power supply, the drain potential of the reverse polarity MOS transistor M1 is much higher than the gate potential of the reverse polarity MOS transistor M1, the reverse polarity MOS transistor M1 is turned on, and the external power can be normally output to the overvoltage protection subunit 1111. When the drain of the reverse polarity MOS transistor M1 is connected to the negative voltage of the external power supply, the drain potential of the reverse polarity MOS transistor M1 is lower than the gate potential of the reverse polarity MOS transistor M1, and the reverse polarity MOS transistor M1 is turned off. This can limit the external power input to the overvoltage protection subunit 1111 when the external power supply is reversed, thus achieving reverse polarity protection for the data acquisition instrument.

[0049] Continue to refer Figure 6 The overvoltage protection subunit 111 includes a voltage stabilizing diode D1, a first resistor R11, a transistor Q1, and an overvoltage protection MOS transistor M2. The first end of the first resistor R11, the emitter of the transistor Q1, and the source of the overvoltage protection MOS transistor M2 are connected to the source of the reverse connection protection MOS transistor M1. The second end of the first resistor R11 is connected to the cathode of the voltage stabilizing diode D1 and the base of the transistor Q1. The anode of the voltage stabilizing diode D1 is grounded GND. The collector of the transistor Q1 is connected to the gate of the overvoltage protection MOS transistor M2. The drain of the overvoltage protection MOS transistor M2 serves as the output end of the overvoltage protection subunit 1111.

[0050] Specifically, Figure 6The example in the figure shows that transistor Q1 is an N-type transistor and overvoltage protection MOS transistor M2 is a P-type MOS transistor. When the external power supply is positively connected, the anti-reverse connection MOS transistor M1 is turned on, and the external power is transmitted through the anti-reverse connection MOS transistor M1 to the first end of the first resistor R11, the emitter of transistor Q1, and the source of the overvoltage protection MOS transistor M2. When the voltage of the external power supply is within the voltage range that the data acquisition instrument can withstand, the voltage regulator diode D1 can stabilize the base potential of transistor Q1 at a fixed potential, causing transistor Q1 to be in the off state. At this time, the gate of the overvoltage protection MOS transistor M2 is grounded to GND through a resistor, that is, the gate of the overvoltage protection MOS transistor M2 is at a low level, which can control the overvoltage protection MOS transistor M2 to be turned on. The external power can then be transmitted to the step-down unit 112 through the overvoltage protection MOS transistor M2. When the voltage of the external power supply exceeds the voltage range that the data acquisition instrument can withstand, the cathode potential of the voltage-stabilizing diode D1 remains essentially unchanged, the base potential of the transistor Q1 also remains unchanged, and the emitter potential of the transistor Q1 increases. When the potential difference between the base and emitter of the transistor Q1 exceeds the conduction threshold of the transistor Q1, the transistor Q1 turns on, and the potential difference between the collector and emitter of the transistor Q1 decreases, which in turn reduces the potential difference between the gate and source of the overvoltage protection MOS transistor M2. When the potential difference is less than the conduction threshold of the overvoltage protection MOS transistor M2, the overvoltage protection MOS transistor M2 turns off. The external power cannot be transmitted to the step-down unit 112 through the overvoltage protection MOS transistor M2, thus achieving overvoltage protection for the data acquisition instrument.

[0051] Continue to refer Figure 6 The first power supply module 110 also includes a current limiting circuit 113; the input end of the current limiting circuit 113 is used to input an external power supply, and the output end of the current limiting circuit 113 is connected to the input end of the anti-reverse connection and overvoltage protection unit 111, and the current limiting circuit 113 is used to limit the current of the external power supply.

[0052] Specifically, Figure 6 The current limiting circuit 113 is exemplarily shown to include a first current limiting resistor R4 and a second current limiting resistor R5 connected in parallel. The first current limiting resistor R4 and the second current limiting resistor R5 can limit the current of the input external power supply, and then output it to the anti-reverse connection and overvoltage protection unit 111 to avoid damage to the anti-reverse connection and overvoltage protection unit 111 due to excessive current of the external power supply.

[0053] Continue to refer Figure 6 The first power module 110 further includes a voltage limiting circuit 114, which is connected between the output end of the step-down unit 112 and the first input end VIN11 of the power multiplexer 130. The voltage limiting circuit 114 is used to limit the voltage of the first voltage signal.

[0054] Specifically, Figure 6exemplarily shows that a filter circuit is provided between the voltage limiting circuit 114 and the voltage reducing unit 112, for filtering the first voltage signal output by the voltage reducing unit 112. Figure 6 As shown, the filter circuit includes a filter capacitor C1. The voltage limiting circuit 114 includes a first voltage limiting diode D2 and a second voltage limiting diode D3. The cathode of the first voltage limiting diode D2 and the cathode of the second voltage limiting diode D3 are both connected to the output end of the step-down unit 112 through the filter circuit, and the anode of the first voltage limiting diode D2 and the anode of the second voltage limiting diode D3 are both grounded GND. After the step-down unit 112 outputs the first voltage signal, the filter capacitor C1 filters the first voltage signal to reduce the output ripple. At the same time, when the external power supply fluctuates, the stability of the first voltage signal can be improved. The first voltage limiting diode D2 and the second voltage limiting diode D3 limit the voltage of the first voltage signal to prevent damage to the subsequent circuit when the step-down unit 112 is abnormal.

[0055] Note that the above are merely preferred embodiments of the present invention and the technical principles employed. Those skilled in the art will appreciate that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, readjustments, and substitutions are possible for those skilled in the art without departing from the scope of protection of the present invention. Therefore, while the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments and may include many other equivalent embodiments without departing from the scope of the present invention. The scope of the present invention is determined by the scope of the appended claims.

Claims

1. A data acquisition instrument, characterized in that: It includes a first power supply module, a second power supply module and a power multiplexer; The input end of the first power module is used to input an external power supply, the output end of the first power module is connected to the first input end of the power multiplexer, the output end of the second power module is connected to the second input end of the power multiplexer, and the output end of the power multiplexer serves as the power end of the data acquisition instrument; The first power supply module is used to output a first voltage signal according to the external power supply; The second power supply module is used to output a second voltage signal; The power multiplexer is configured to enable a first input terminal and an output terminal of the power multiplexer when the first voltage signal is greater than a first voltage threshold, and enable a second input terminal and an output terminal of the power multiplexer when the first voltage signal is less than the first voltage threshold and the second voltage signal is greater than or equal to a second voltage threshold.

2. The data acquisition instrument according to claim 1, characterized in that: The power multiplexer includes a gating unit and a voltage dividing unit; The first input end of the gating unit is connected to the input end of the voltage divider unit and serves as the first input end of the power multiplexer. The second input end of the gating unit serves as the second input end of the power multiplexer. The output end of the voltage divider unit is connected to the detection end of the gating unit, and the output end of the gating unit serves as the output end of the power multiplexer.

3. The data acquisition instrument according to claim 2, characterized in that: The voltage dividing unit includes a first voltage dividing resistor and a second voltage dividing resistor; The first end of the first voltage-dividing resistor serves as the input end of the voltage-dividing unit, the second end of the first voltage-dividing resistor is connected to the first end of the second voltage-dividing resistor and serves as the output end of the voltage-dividing unit, and the second end of the second voltage-dividing resistor is grounded.

4. The data acquisition device according to any one of claims 1 to 3, characterized in that: It also includes at least one voltage conversion module, which is connected to the output end of the power multiplexer and is used to perform voltage conversion on the voltage output by the power multiplexer.

5. The data acquisition instrument according to claim 4, characterized in that: The data acquisition instrument includes a first voltage conversion module and a second voltage conversion module; The input end of the first voltage conversion module and the input end of the second voltage conversion module are both connected to the output end of the power multiplexer. The first voltage conversion module is used to perform voltage conversion on the voltage output by the power multiplexer to form a first output voltage; the second voltage conversion module is used to perform voltage conversion on the voltage output by the power multiplexer to form a second output voltage; wherein the voltage values of the first output voltage and the second output voltage are different.

6. The data acquisition instrument according to claim 1, characterized in that: The first power supply module includes an anti-reverse connection and overvoltage protection unit and a step-down unit; The input end of the anti-reverse connection and overvoltage protection unit is used to input the external power supply, the output end of the anti-reverse connection and overvoltage protection unit is connected to the input end of the step-down unit, and the output end of the step-down unit is connected to the first input end of the power multiplexer; the anti-reverse connection and overvoltage protection unit is used to perform anti-reverse connection and overvoltage protection on the external power supply, and the step-down unit is used to step down the external power supply to form the first voltage signal.

7. The data acquisition instrument according to claim 6, characterized in that: The anti-reverse connection and overvoltage protection unit includes an anti-reverse connection MOS tube and an overvoltage protection subunit; The drain of the anti-reverse connection MOS transistor is used to input the external power supply, the source of the anti-reverse connection MOS transistor is connected to the input end of the overvoltage protection subunit, and the gate of the anti-reverse connection MOS transistor is connected to the fixed potential end. The anti-reverse connection MOS transistor is used to be turned on when the voltage of the external power supply is positive and turned off when the voltage of the external power supply is negative; the output end of the overvoltage protection subunit is connected to the input end of the step-down unit, and the overvoltage protection subunit is used to perform overvoltage protection when the voltage of the external power supply is greater than a preset threshold.

8. The data acquisition instrument according to claim 7, characterized in that: The overvoltage protection subunit includes a voltage stabilizing diode, a first resistor, a transistor and an overvoltage protection MOS tube; The first end of the first resistor, the emitter of the transistor, and the source of the overvoltage protection MOS transistor are connected to the source of the anti-reverse connection MOS transistor, the second end of the first resistor is connected to the cathode of the voltage regulator diode and the base of the transistor, and the anode of the voltage regulator diode is grounded; the collector of the transistor is connected to the gate of the overvoltage protection MOS transistor, and the drain of the overvoltage protection MOS transistor serves as the output end of the overvoltage protection subunit.

9. The data acquisition instrument according to claim 6, characterized in that: The first power supply module also includes a current limiting circuit; the input end of the current limiting circuit is used to input the external power supply, the output end of the current limiting circuit is connected to the input end of the anti-reverse connection and overvoltage protection unit, and the current limiting circuit is used to limit the current of the external power supply.

10. The data acquisition instrument according to claim 6, characterized in that: The first power module further includes a voltage limiting circuit connected between the output end of the step-down unit and the first input end of the power multiplexer, and configured to limit the voltage of the first voltage signal.

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