High-precision voltage and current measuring device and switch

Abstract

The utility model discloses a high-precision voltage and current measuring device and a switch, which are used for measuring the current and the voltage of a first power supply and a second power supply in two power supplies, and the measuring device comprises a voltage sampler, a current sampler and a controller, the voltage sampler is provided with a voltage sampling end and a voltage feedback end, and the current sampler is provided with a current sampling end and a current feedback end. The current sampler is provided with a current sampling end and a current feedback end, the voltage sampling end and the current sampling end are both connected with the first power supply and the second power supply, and the voltage feedback end and the current feedback end are both connected with the controller. The voltage sampler and the current sampler output first sampling voltage and second sampling voltage to the controller through the voltage feedback end and the current feedback end respectively, so that the controller can calculate actual voltage and actual current of the first power supply and the second power supply according to the first sampling voltage and the second sampling voltage. The high-precision voltage and current measuring device provided by the utility model can measure and monitor the voltage and current of two paths of input power supplies in real time.

Description

Technical Field

[0001] The utility model relates to the technical field of high-precision voltage and current measurement, in particular to a high-precision voltage and current measurement device and a switch. Background Art

[0002] Many switches today use redundant power supplies, mostly because they worry that a failure in the main power supply could cause the entire switch to stop working. However, this approach only prevents the switch from being unable to operate due to a prolonged power outage. However, if the switch's power supply voltage drops sharply within a short period of time, causing the switch to restart or other problems to occur, for example, if the POE voltage drops below 30V, the PSE power supply may become abnormal, causing the PD to stop working. The above-mentioned redundant power supply method cannot detect and avoid such situations, and there is no way to know the current in the dual power supplies, and therefore the actual power. Utility Model Content

[0003] The purpose of the utility model is to provide a high-precision voltage and current measuring device, which can measure and monitor the voltage and current of two input power supplies in real time, which is conducive to clearly understanding the status of each power supply and facilitating timely detection of power supply anomalies of terminal equipment.

[0004] Another object of the present invention is to provide a switch that can measure and monitor the voltage and current of two input power supplies used by the switch in real time, which is conducive to clearly understanding the status of each power supply and facilitating timely detection of power supply anomalies of the switch.

[0005] In order to achieve the above object, the utility model discloses a high-precision voltage and current measuring device for measuring the current and voltage of a first power supply and a second power supply in a dual power supply, comprising:

[0006] A voltage sampler, the voltage sampler being provided with a first voltage acquisition terminal, a second voltage acquisition terminal, a first voltage feedback terminal, and a second voltage feedback terminal, the first voltage acquisition terminal being connected to the first power supply, the second voltage acquisition terminal being connected to the second power supply, the first voltage feedback terminal and the second voltage feedback terminal being used to output a first sampled voltage;

[0007] a current sampler, the current sampler being provided with a first current collection terminal, a second current collection terminal, a first current feedback terminal, and a second current feedback terminal, the first current collection terminal being connected to the first power supply, the second current collection terminal being connected to the second power supply, and the first current feedback terminal and the second current feedback terminal being used to output a second sampling voltage;

[0008] A controller is connected to the first voltage feedback terminal, the second voltage feedback terminal, the first current feedback terminal, and the second current feedback terminal, and is used to calculate the actual voltage and actual current of the first power supply and the second power supply based on the first sampled voltage and the second sampled voltage.

[0009] Optionally, the voltage sampler includes a first resistor, a second resistor and a third resistor, the first resistor and the second resistor are connected in series, the first resistor is connected to the first power supply, the second resistor is grounded, one end of the third resistor is connected to the series point of the first resistor and the second resistor, and the other end is connected to the controller.

[0010] Optionally, the voltage sampler includes a fourth resistor, a fifth resistor and a sixth resistor, the fourth resistor and the fifth resistor are connected in series, the fourth resistor is connected to the second power supply, the fifth resistor is grounded, one end of the sixth resistor is connected to the series point of the fourth resistor and the fifth resistor, and the other end is connected to the controller.

[0011] Optionally, the first power supply is provided with a first sampling resistor, the current sampler includes an operational amplifier, the operational amplifier is provided with a first sampling pin and a second sampling pin, the first sampling pin and the second sampling pin are respectively connected to two ends of the first sampling resistor, and the operational amplifier is used to calculate and amplify the voltage difference between the first sampling pin and the second sampling pin.

[0012] Optionally, the operational amplifier is further provided with a first feedback pin connected to the controller, and the current sampler further includes a seventh resistor, an eighth resistor, a ninth resistor, and a tenth resistor, the seventh resistor and the eighth resistor being connected in series to the first sampling pin and the second sampling pin, respectively, two ends of the ninth resistor being connected to the first feedback pin and the first sampling pin, respectively, and two ends of the tenth resistor being connected to the second sampling pin and the ground, respectively.

[0013] Optionally, the second power supply is provided with a second sampling resistor, the current sampler includes an operational amplifier, the operational amplifier is provided with a third sampling pin and a fourth sampling pin, the third sampling pin and the fourth sampling pin are respectively connected to two ends of the second sampling resistor, and the operational amplifier is used to calculate and amplify the voltage difference between the third sampling pin and the fourth sampling pin.

[0014] Optionally, the operational amplifier is further provided with a second feedback pin connected to the controller, and the current sampler further includes an eleventh resistor, a twelfth resistor, a thirteenth resistor and a fourteenth resistor, the eleventh resistor and the twelfth resistor are respectively connected in series to the third sampling pin and the fourth sampling pin, two ends of the thirteenth resistor are respectively connected to the second feedback pin and the third sampling pin, and two ends of the fourteenth resistor are respectively connected to the fourth sampling pin and the ground.

[0015] Optionally, the dual power supply includes a first power supply, a second power supply, and a diode. The first power supply includes a first socket, a first sampling resistor, a first capacitor, and a first magnetic bead. The second power supply includes a second socket, a second sampling resistor, a second capacitor, and a second magnetic bead. The positive electrode of the first socket is connected to the first end of the first magnetic bead and the first end of the first capacitor, the second end of the first magnetic bead is connected to the first input end of the diode, the negative electrode of the first socket is connected to the first end of the first sampling resistor and the second end of the first capacitor, the second end of the first sampling resistor is grounded, the positive electrode of the second socket is connected to the first end of the second magnetic bead and the first end of the second capacitor, the second end of the second magnetic bead is connected to the second input end of the diode, the negative electrode of the second socket is connected to the first end of the second sampling resistor and the second end of the second capacitor, the second end of the second sampling resistor is grounded, and the output end of the diode is connected to a device terminal.

[0016] In order to achieve the above-mentioned other object, the present invention discloses a switch, which includes: a switch body, a dual-path power supply provided on the switch body, and the above-mentioned high-precision voltage and current measuring device.

[0017] The utility model is provided with a voltage sampler and a current sampler to measure the current and voltage of the first power supply and the second power supply in a dual power supply. The voltage sampler is provided with a voltage sampling end and a voltage feedback end, and the current sampler is provided with a current sampling end and a current feedback end. The voltage sampling end and the current sampling end are both connected to the first power supply and the second power supply, and the voltage feedback end and the current feedback end are both connected to a controller. The voltage sampler and the current sampler output the first sampling voltage and the second sampling voltage to the controller through the voltage feedback end and the current feedback end respectively, so that the controller can calculate the actual voltage and actual current of the first power supply and the second power supply based on this, thereby realizing real-time measurement and monitoring of the voltage and current of the two input power supplies, which is conducive to clearly understanding the status of each power supply and facilitating timely discovery of power supply abnormalities of terminal equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a schematic block diagram of a high-precision voltage and current measuring device according to an embodiment of the present utility model.

[0019] Figure 2 This is a circuit structure diagram of a dual-circuit power supply in a high-precision voltage and current measuring device according to an embodiment of the present utility model.

[0020] Figure 3 This is a circuit structure diagram of a voltage sampler in a high-precision voltage and current measurement device according to an embodiment of the present utility model.

[0021] Figure 4 This is a circuit structure diagram of the current sampler in the high-precision voltage and current measurement device according to an embodiment of the present utility model.

[0022] Figure 5 This is a circuit structure diagram of the controller in the high-precision voltage and current measuring device according to an embodiment of the present utility model. DETAILED DESCRIPTION

[0023] In order to explain the technical content, structural features, achieved objectives and effects of the present invention in detail, the following is a detailed description in conjunction with the embodiments and the accompanying drawings.

[0024] See also Figures 1 to 5 The utility model discloses a high-precision voltage and current measuring device for measuring the current and voltage of a first power supply 101 and a second power supply 102 in a dual power supply 100, comprising:

[0025] The voltage sampler 1 is provided with a first voltage acquisition terminal 11, a second voltage acquisition terminal 12, a first voltage feedback terminal 13 and a second voltage feedback terminal 14. The first voltage acquisition terminal 11 is connected to the first power supply 101, the second voltage acquisition terminal 12 is connected to the second power supply 102, and the first voltage feedback terminal 13 and the second voltage feedback terminal 14 are used to output a first sampled voltage;

[0026] The current sampler 2 is provided with a first current collection terminal 21, a second current collection terminal 22, a first current feedback terminal 23 and a second current feedback terminal 24. The first current collection terminal 21 is connected to the first power supply 101, the second current collection terminal 22 is connected to the second power supply 102, and the first current feedback terminal 23 and the second current feedback terminal 24 are used to output a second sampling voltage;

[0027] Controller U1, controller U1 is connected to the first voltage feedback terminal 13, the second voltage feedback terminal 14, the first current feedback terminal 23 and the second current feedback terminal 24, and the controller U1 is used to calculate the actual voltage and actual current of the first power supply 101 and the second power supply 102 according to the first sampling voltage and the second sampling voltage.

[0028] The utility model is provided with a voltage sampler 1 and a current sampler 2 to measure the current and voltage of the first power supply 101 and the second power supply 102 in the dual power supply 100. The voltage sampler 1 is provided with a voltage sampling end and a voltage feedback end, and the current sampler 2 is provided with a current sampling end and a current feedback end. The voltage sampling end and the current sampling end are both connected to the first power supply 101 and the second power supply 102, and the voltage feedback end and the current feedback end are both connected to the controller U1. The voltage sampler 1 and the current sampler 2 output the first sampling voltage and the second sampling voltage to the controller U1 through the voltage feedback end and the current feedback end respectively, so that the controller U1 can calculate the actual voltage and actual current of the first power supply 101 and the second power supply 102 based on this, thereby realizing real-time measurement and monitoring of the voltage and current of the two input power supplies, which is conducive to clearly understanding the status of each power supply and facilitating timely detection of power supply abnormalities of terminal equipment.

[0029] See Figures 1 to 5 The dual power supply 100 includes a first power supply 101, a second power supply 102, and a diode D1. The first power supply 101 includes a first socket J1, a first sampling resistor R4, a first capacitor EC1, and a first magnetic bead L1. The second power supply 102 includes a second socket J2, a second sampling resistor R8, a second capacitor EC2, and a second magnetic bead L2. The positive electrode of the first socket J1 is connected to the first end of the first magnetic bead L1 and the first end of the first capacitor EC1, the second end of the first magnetic bead L1 is connected to the first input end of the diode D1, the negative electrode of the first socket J1 is connected to the first end of the first sampling resistor R4 and the second end of the first capacitor EC1, the second end of the first sampling resistor R4 is grounded, the positive electrode of the second socket J2 is connected to the first end of the second magnetic bead L2 and the second end of the second capacitor EC2, the second end of the second magnetic bead L2 is connected to the second input end of the diode D1, the negative electrode of the second socket J2 is connected to the first end of the second sampling resistor R8 and the second end of the second capacitor EC2, the second end of the second sampling resistor R8 is grounded, and the output end of the diode D1 is connected to the device terminal.

[0030] Specifically, in this embodiment, the first socket J1 and the second socket J2 are connected to the DC-INPUT so that the DC power supply is connected to the switch and forms a first power supply 101 and a second power supply 102. The current of the first power supply 101 is filtered by the first capacitor EC1 and then passes through the first magnetic bead L1 to reach the first positive electrode (third pin) of the diode D1, while the current of the second power supply 102 is filtered by the second capacitor EC2 and then passes through the second magnetic bead L2 to reach the second positive electrode (first pin) of the diode D1. The positive electrodes of the first power supply 101 and the second power supply 102 are integrated into one through the diode D1 and connected to the functional module of the switch to power it. The diode D1 can effectively prevent interference and current backflow of the dual power supply 100.

[0031] See Figures 1 to 5 The voltage sampler 1 includes a first resistor R1, a second resistor R3 and a third resistor R2. The first resistor R1 and the second resistor R3 are connected in series. The first resistor R1 is connected to the first power supply 101. The second resistor R3 is grounded. One end of the third resistor R2 is connected to the series connection point of the first resistor R1 and the second resistor R3, and the other end is connected to the controller U1.

[0032] Specifically, in this embodiment, the first resistor R1 and the second resistor R3 are connected in parallel to the positive electrode PSU_1 of the first power supply 101 in the dual power supply 100. After the first power supply 101 is powered on, the first resistor R1 and the second resistor R3 are responsible for series voltage division (the divided voltage exceeds 0V but does not exceed the operating voltage of the controller U1 3.3V-5V). At this time, the ADC detection pin (pin 25) of the controller U1 collects the sampling voltage ADC_V1 through the third resistor R2, and calculates the actual voltage Va of the first power supply 101 according to the formula Va=Vc*(R1+R3) / R3, where Vc is the sampling voltage ADC_V1, but is not limited to this.

[0033] See Figures 1 to 5 The voltage sampler 1 includes a fourth resistor R5, a fifth resistor R7 and a sixth resistor R6. The fourth resistor R5 and the fifth resistor R7 are connected in series. The fourth resistor R5 is connected to the second power supply 102. The fifth resistor R7 is grounded. One end of the sixth resistor R6 is connected to the series connection point of the fourth resistor R5 and the fifth resistor R7, and the other end is connected to the controller U1.

[0034] Specifically, in this embodiment, the fourth resistor R5 and the fifth resistor R7 are connected in parallel to the positive electrode PSU_2 of the second power supply 102 in the dual power supply 100. After the second power supply 102 is powered on, the fourth resistor R5 and the fifth resistor R7 are responsible for series voltage division (the divided voltage exceeds 0V but does not exceed the operating voltage of the controller U1 3.3V-5V). At this time, the ADC detection pin (the twenty-third pin) of the controller U1 collects the sampling voltage ADC_V2 through the sixth resistor R6, and calculates the actual voltage Va of the first power supply 101 according to the formula Va=Vc*(R5+R7) / R7, where Vc is the sampling voltage ADC_V2, but is not limited to this.

[0035] Specifically, in this embodiment, the controller U1 acts as an MCU to communicate with the switch through the I2C communication bus, so that the controller U1 can output abnormal situation feedback to the switch for processing and recording, and the switch can determine the cause of the abnormality and take actions such as alarms to avoid unnecessary losses and loss of key data. In addition, the controller U1 is provided with a polling cycle with a frequency of 50Hz-500KHz, so as to timely calculate the actual voltage based on the first sampled voltage of the dual power supply 100, so that when the voltage of the dual power supply 100 drops below the specified value, the switch can promptly output an alarm signal or make other responses.

[0036] See Figures 1 to 5 The first power supply 101 is provided with a first sampling resistor R4, and the current sampler 2 includes an operational amplifier U2. The operational amplifier U2 is provided with a first sampling pin 211 and a second sampling pin 212. The first sampling pin 211 and the second sampling pin 212 are respectively connected to the two ends of the first sampling resistor R4. The operational amplifier U2 is used to calculate and amplify the voltage difference between the first sampling pin 211 and the second sampling pin 212.

[0037] By measuring the actual input current of the dual power supply 100 to determine the actual input power of each power supply, it is helpful to clearly understand the status of each power supply.

[0038] See Figures 1 to 5 The operational amplifier U2 is further provided with a first feedback pin 231 connected to the controller U1. The current sampler 2 also includes a seventh resistor R13, an eighth resistor R14, a ninth resistor R11, and a tenth resistor R18. The seventh resistor R13 and the eighth resistor R14 are respectively connected in series to the first sampling pin 211 and the second sampling pin 212. The two ends of the ninth resistor R11 are respectively connected to the first feedback pin 231 and the first sampling pin 211. The two ends of the tenth resistor R18 are respectively connected to the second sampling pin 212 and the ground.

[0039] Specifically, in this embodiment, the second pin (negative input) of the dual operational amplifier U2 is connected to one end of a 0.1R first sampling resistor R4 connected in series with the negative electrode of the first power supply 101 via a 1K seventh resistor R13 connected in series, and the second pin is also connected in parallel with a 12K ninth resistor R11 for output; the third pin (positive input) of the dual operational amplifier U2 is connected to the other end of the first sampling resistor R4 via a 1K eighth resistor R14 connected in series, and is also connected in parallel with a 12K tenth resistor R18 to ground;

[0040] As negative feedback for the operational amplifier U2, after the first power supply 101 is powered on, a 0.1R first sampling resistor R4 is connected in series with its negative circuit, and the voltage of the negative circuit cannot be 0V (ideally, 0V). Therefore, after the negative circuit of the first power supply 101 passes through the first sampling resistor R4, a voltage difference is formed across it, with the voltage of the negative circuit closer to the switch being slightly higher. The operational amplifier U2 is responsible for operationally amplifying this voltage difference (in this embodiment, the amplification factor is 12 times, but is not limited to this, and can be modified based on the amplification factor that can be detected by the pin of the controller U1). The operational amplifier U2 calculates and outputs a second sampled voltage Vi = (R11 / R13) * Vs through the first feedback pin 231 (first pin), where Vs is the input voltage of the operational amplifier U2. The ADC_I1 pin of the controller U1 detects the second sampled voltage amplified by the operational amplifier U2 and obtains the actual circuit current of the first power supply 101 I1 = Vi / 12*0.1 through internal conversion, but is not limited to this.

[0041] See Figures 1 to 5 The second power supply 102 is provided with a second sampling resistor R8. The current sampler 2 includes an operational amplifier U2. The operational amplifier U2 is provided with a third sampling pin 221 and a fourth sampling pin 222. The third sampling pin 221 and the fourth sampling pin 222 are respectively connected to the two ends of the second sampling resistor R8. The operational amplifier U2 is used to calculate and amplify the voltage difference between the third sampling pin 221 and the fourth sampling pin 222.

[0042] By measuring the actual input current of the dual power supply 100 to determine the actual input power of each power supply, it is helpful to clearly understand the status of each power supply.

[0043] See Figures 1 to 5 The operational amplifier U2 is further provided with a second feedback pin 241 connected to the controller U1. The current sampler 2 also includes an eleventh resistor R15, a twelfth resistor R16, a thirteenth resistor R12, and a fourteenth resistor R19. The eleventh resistor R15 and the twelfth resistor R16 are respectively connected in series to the third sampling pin 221 and the fourth sampling pin 222. The two ends of the thirteenth resistor R12 are respectively connected to the second feedback pin 241 and the third sampling pin 221. The two ends of the fourteenth resistor R19 are respectively connected to the fourth sampling pin 222 and the ground.

[0044] Specifically, in this embodiment, the sixth pin (negative input) of the dual operational amplifier U2 is connected to one end of a 0.1R second sampling resistor R8 connected in series with the negative electrode of the second power supply 102 via an eleventh resistor R15 of 1K in series, and a thirteenth resistor R12 of 12K is connected in parallel to the second pin for output; the fifth pin (positive input) of the dual operational amplifier U2 is connected to the other end of the second sampling resistor R8 via a twelfth resistor R16 of 1K in series, and a fourteenth resistor R19 of 12K is connected in parallel to ground;

[0045] As negative feedback for the operational amplifier U2, after the second power supply 102 is powered on, a 0.1R second sampling resistor R8 is connected in series with its negative circuit, and the voltage of the negative circuit cannot be 0V (ideally, 0V). Therefore, after the negative circuit of the second power supply 102 passes through the second sampling resistor R8, a voltage difference is formed across it, with the voltage of the negative circuit closer to the switch being slightly higher. The operational amplifier U2 is responsible for operationally amplifying this voltage difference (in this embodiment, the amplification factor is 12 times, but is not limited to this, and can be modified based on the amplification factor that can be detected by the pin of the controller U1). The operational amplifier U2 outputs a calculated second sampling voltage Vi = (R12 / R15) * Vs through the second feedback pin 241 (pin 7), where Vs is the input voltage of the operational amplifier U2. The ADC_I2 pin of the controller U1 detects the second sampling voltage amplified by the operational amplifier U2 and obtains the actual circuit current of the first power supply 101 I2 = Vi / 12*0.1 through internal conversion, but is not limited to this.

[0046] See also Figures 1 to 5 The utility model discloses a switch, which includes: a switch body, a dual-path power supply 100 arranged on the switch body, and the high-precision voltage and current measuring device as described above.

[0047] The above disclosure is only a preferred embodiment of the present invention, and certainly cannot be used to limit the scope of rights of the present invention. Therefore, equivalent changes made according to the scope of the patent application of the present invention are still within the scope covered by the present invention.

Claims

1. A high-precision voltage and current measuring device for measuring the current and voltage of a first power supply and a second power supply in a dual power supply, characterized in that: include: A voltage sampler, the voltage sampler being provided with a first voltage acquisition terminal, a second voltage acquisition terminal, a first voltage feedback terminal, and a second voltage feedback terminal, the first voltage acquisition terminal being connected to the first power supply, the second voltage acquisition terminal being connected to the second power supply, the first voltage feedback terminal and the second voltage feedback terminal being used to output a first sampled voltage; a current sampler, the current sampler being provided with a first current collection terminal, a second current collection terminal, a first current feedback terminal, and a second current feedback terminal, the first current collection terminal being connected to the first power supply, the second current collection terminal being connected to the second power supply, and the first current feedback terminal and the second current feedback terminal being used to output a second sampling voltage; A controller is connected to the first voltage feedback terminal, the second voltage feedback terminal, the first current feedback terminal, and the second current feedback terminal, and is used to calculate the actual voltage and actual current of the first power supply and the second power supply based on the first sampled voltage and the second sampled voltage.

2. The high-precision voltage and current measuring device according to claim 1, characterized in that: The voltage sampler includes a first resistor, a second resistor and a third resistor, the first resistor and the second resistor are connected in series, the first resistor is connected to the first power supply, the second resistor is grounded, one end of the third resistor is connected to the series point of the first resistor and the second resistor, and the other end is connected to the controller.

3. The high-precision voltage and current measuring device according to claim 1, characterized in that: The voltage sampler includes a fourth resistor, a fifth resistor and a sixth resistor, the fourth resistor and the fifth resistor are connected in series, the fourth resistor is connected to the second power supply, the fifth resistor is grounded, one end of the sixth resistor is connected to the series point of the fourth resistor and the fifth resistor, and the other end is connected to the controller.

4. The high-precision voltage and current measuring device according to claim 1, characterized in that: The first power supply is provided with a first sampling resistor, and the current sampler includes an operational amplifier. The operational amplifier is provided with a first sampling pin and a second sampling pin, the first sampling pin and the second sampling pin are respectively connected to the two ends of the first sampling resistor, and the operational amplifier is used to calculate and amplify the voltage difference between the first sampling pin and the second sampling pin.

5. The high-precision voltage and current measuring device according to claim 4, characterized in that: The operational amplifier is further provided with a first feedback pin connected to the controller. The current sampler further includes a seventh resistor, an eighth resistor, a ninth resistor, and a tenth resistor. The seventh resistor and the eighth resistor are respectively connected in series to the first sampling pin and the second sampling pin. Two ends of the ninth resistor are respectively connected to the first feedback pin and the first sampling pin. Two ends of the tenth resistor are respectively connected to the second sampling pin and the ground.

6. The high-precision voltage and current measuring device according to claim 1, characterized in that: The second power supply is provided with a second sampling resistor, and the current sampler includes an operational amplifier. The operational amplifier is provided with a third sampling pin and a fourth sampling pin, and the third sampling pin and the fourth sampling pin are respectively connected to the two ends of the second sampling resistor. The operational amplifier is used to calculate and amplify the voltage difference between the third sampling pin and the fourth sampling pin.

7. The high-precision voltage and current measuring device according to claim 6, characterized in that: The operational amplifier is further provided with a second feedback pin connected to the controller. The current sampler further includes an eleventh resistor, a twelfth resistor, a thirteenth resistor, and a fourteenth resistor. The eleventh resistor and the twelfth resistor are respectively connected in series to the third sampling pin and the fourth sampling pin. Two ends of the thirteenth resistor are respectively connected to the second feedback pin and the third sampling pin. Two ends of the fourteenth resistor are respectively connected to the fourth sampling pin and the ground.

8. The high-precision voltage and current measuring device according to claim 1, characterized in that: The dual power supply includes a first power supply, a second power supply, and a diode. The first power supply includes a first socket, a first sampling resistor, a first capacitor, and a first magnetic bead. The second power supply includes a second socket, a second sampling resistor, a second capacitor, and a second magnetic bead. The positive electrode of the first socket is connected to the first end of the first magnetic bead and the first end of the first capacitor, the second end of the first magnetic bead is connected to the first input end of the diode, the negative electrode of the first socket is connected to the first end of the first sampling resistor and the second end of the first capacitor, the second end of the first sampling resistor is grounded, the positive electrode of the second socket is connected to the first end of the second magnetic bead and the first end of the second capacitor, the second end of the second magnetic bead is connected to the second input end of the diode, the negative electrode of the second socket is connected to the first end of the second sampling resistor and the second end of the second capacitor, the second end of the second sampling resistor is grounded, and the output end of the diode is connected to a device terminal.

9. A switch, characterized in that: include: A switch body, a dual-path power supply provided on the switch body, and a high-precision voltage and current measuring device as claimed in any one of claims 1 to 8.

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