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CN-121978395-A - Multipath power sampling device

CN121978395ACN 121978395 ACN121978395 ACN 121978395ACN-121978395-A

Abstract

The invention provides a multipath power sampling device, which relates to the technical field of power measurement and comprises a voltage source, loads, voltage followers, voltage amplifiers, an MCU module and a data processing unit, wherein the positive electrode of the voltage source is respectively connected with one ends of a plurality of groups of loads, the other ends of the plurality of groups of loads are connected with sampling resistors, two ends of each group of loads are connected in parallel with a resistor voltage dividing module, the resistor voltage dividing module is composed of two resistors connected in series, a connecting node between each two resistors is used as a voltage acquisition point, the voltage acquisition is respectively and correspondingly connected with the input ends of different voltage followers, the output end of the voltage followers is connected with the MCU module, the connecting node between each group of loads and the sampling resistor is used as a current signal acquisition point, the current signal acquisition point is respectively and correspondingly connected with the input ends of different voltage amplifiers, and the output end of the voltage amplifiers is connected with the MCU module. The invention greatly improves the test efficiency and the micro-current sampling precision.

Inventors

  • Sui Yuantao
  • JIANG CHENNING
  • SAI AKIRA

Assignees

  • 安徽中家智康科技有限公司

Dates

Publication Date
20260505
Application Date
20260306

Claims (10)

  1. 1. The multipath power sampling device is characterized by comprising a voltage source, a load, a voltage follower, a voltage amplifier, an MCU module and a data processing unit, wherein the positive electrode of the voltage source is respectively connected with one ends of a plurality of groups of loads, and the other ends of the plurality of groups of loads are connected with sampling resistors; The voltage acquisition device comprises a MCU module, a voltage follower, a resistor voltage dividing module, a voltage acquisition point, a voltage acquisition circuit and a voltage acquisition circuit, wherein the two ends of each group of loads are connected in parallel with each other and are provided with two resistors connected in series; the connecting nodes between each group of loads and the sampling resistor are used as current signal acquisition points, and the current signal acquisition points are respectively connected with the input ends of different voltage amplifiers in a one-to-one correspondence manner; the data output end of the MCU module is in communication connection with the processing data unit, and the ADC unit is integrated inside the MCU module.
  2. 2. The multi-path power sampling device according to claim 1, wherein the voltage amplifier is an inverse proportion operation circuit with direct current bias, the voltage amplifier comprises an operational amplifier IC10A, a negative input end of the operational amplifier IC10A is connected with one end of a resistor R104, and the other end of the resistor R104 is connected with a voltage signal Ui collected by a sampling resistor; the positive input end of the operational amplifier IC10A is connected with one end of a resistor R105, and the other end of the resistor R105 is grounded; A capacitor C62 is arranged in parallel between the positive input end and the negative input end of the operational amplifier IC 10A; the positive input end of the operational amplifier IC10A is connected with one end of a resistor R103, and the other end of the resistor R103 is connected with a reference power supply; the negative input end of the operational amplifier IC10A is connected with one end of a resistor R100, and the other end of the resistor R100 is connected with a reference power supply; The power supply end of the operational amplifier IC10A is connected with a reference power supply, the power supply end of the operational amplifier IC10A is connected with one end of a capacitor C60, and the other end of the capacitor C60 is grounded; the output end of the operational amplifier IC10A is connected with one end of a resistor R86, the other end of the resistor R86 is connected with one end of a capacitor C56, and the other end of the capacitor C56 is grounded; Between resistor R86 and capacitor C56 is output signal Uo.
  3. 3. The multi-path power sampling device according to claim 2, wherein the input end of the voltage signal Ui is provided with a clamping protection and power supply circuit, the clamping protection and power supply circuit comprises a voltage stabilizing tube ZD7, an energy storage element E10, a triode Q7, a current limiting resistor RS13 and a resistor R110, the voltage signal Ui is respectively connected with one end of a third capacitor C66, the anode of the voltage stabilizing tube ZD7 and the cathode of the energy storage element E10, the anode of the energy storage element E10 is connected with the emitter of the triode Q7, the base of the triode Q7 is connected with the cathode of the voltage stabilizing tube ZD7, the collector of the triode Q7 is connected to a power supply Vin through the current limiting resistor RS13, and the other end of the third capacitor C66 is connected to the power supply Vin through the resistor R110.
  4. 4. The multi-path power sampling device according to claim 3, wherein the voltage follower comprises an operational amplifier IC10B, wherein the positive input end of the operational amplifier IC10B is respectively connected with one end of a resistor R101 and one end of a capacitor C63, the other end of the resistor R101 is connected with the cathode of a diode TVS8, and the other end of the capacitor C63 is connected with the anode of the diode TVS 8; The resistor R111 is arranged at the next high end of the diode TVS8 in parallel; the positive electrode of the diode TVS8 is grounded, and the negative electrode of the diode TVS8 is connected with the power supply Vin through a resistor R113; the reverse input end of the operational amplifier IC10B is connected with the output end; The output end of the operational amplifier IC10B is connected with one end of a resistor R85, the other end of the resistor R85 is connected with one end of a capacitor C57, and the other end of the capacitor C57 is grounded; between resistor R85 and capacitor C57 is output signal VS8.
  5. 5. The multi-path power sampling device according to claim 4, wherein the reference power supply voltage is 3.3V, the resistance values of the resistor R103 and the resistor R105 are equal, and the ratio of the resistor R87 to the resistor R104 is more than or equal to 10.
  6. 6. The multi-path power sampling apparatus according to claim 5, wherein the resistor R113 and the resistor R111 form a series voltage dividing network.
  7. 7. The multi-path power sampling device of claim 6, wherein the plurality of sets of loads are in an 8-path independent parallel configuration.
  8. 8. The multi-path power sampling device according to claim 7, wherein 12-bit successive approximation type ADCs and more are integrated in the MCU module, and a power calculation module is arranged in the MCU module.
  9. 9. The multi-way power sampling apparatus of claim 8, wherein the processing data unit is an industrial computer, a programmable logic controller, or a cloud server.
  10. 10. The multi-path power sampling apparatus according to claim 9, wherein the voltage source is an external programmable dc power source, an anode of the voltage source is connected to a power input node Vin of each load, and a cathode of the voltage source is connected to a system ground GND.

Description

Multipath power sampling device Technical Field The invention relates to the technical field of power measurement, in particular to a multipath power sampling device. Background With the rapid development of micro-motor technology, low-power fans are increasingly widely applied in the fields of consumer electronics, industrial control, medical equipment and the like. The fan must be subjected to strict functional test before leaving the factory, wherein the running power is one of core indexes for judging whether the product is qualified or not, namely, the power abnormality usually reflects potential defects such as winding short circuit, magnetic steel demagnetization, bearing clamping stagnation, driving plate faults and the like. The existing low-power fan production line detection device generally adopts a single power supply, a single power meter and a manual line replacement mode, the test of a single fan takes about 3-5 seconds, for a production line with tens of devices to operate in parallel, and the device investment is large and the occupied space is wide. The rated current of the low-power fan is usually in the range of 0.1A-1.0A, and the voltage drop on the current sampling resistor is only millivolt level. The conventional operational amplifier circuit has the problems of large input offset voltage, serious temperature drift, sensitive common-mode interference and the like, so that the signal-to-noise ratio of a small signal is low, the power calculation error can reach more than +/-10%, and the bad product missing detection and the bad product false killing coexist. The traditional resistor voltage dividing network is directly connected with the MCU-ADC, when the input impedance of the tested fan fluctuates, the voltage dividing ratio shifts, the voltage sampling precision is deteriorated, and the power calculation accuracy is further affected. Therefore, the existing power sampling device of the low-power fan production line has the problems of low single-channel test efficiency, insufficient weak current sampling precision and voltage sampling influenced by load input impedance. Disclosure of Invention The invention aims to solve the problems that the single-channel test efficiency is low, the weak current sampling precision is insufficient, and the voltage sampling is influenced by the load input impedance in the power sampling device of the existing low-power fan. In order to solve the problems, the invention provides a multipath power sampling device which comprises a voltage source, a load, a voltage follower, a voltage amplifier, an MCU module and a data processing unit, wherein the positive electrode of the voltage source is respectively connected with one ends of a plurality of groups of loads, and the other ends of the plurality of groups of loads are connected with sampling resistors; The voltage acquisition device comprises a MCU module, a voltage follower, a resistor voltage dividing module, a voltage acquisition point, a voltage acquisition circuit and a voltage acquisition circuit, wherein the two ends of each group of loads are connected in parallel with each other and are provided with two resistors connected in series; the connecting nodes between each group of loads and the sampling resistor are used as current signal acquisition points, and the current signal acquisition points are respectively connected with the input ends of different voltage amplifiers in a one-to-one correspondence manner; the data output end of the MCU module is in communication connection with the processing data unit, and the ADC unit is integrated inside the MCU module. Compared with the prior art, the multipath power sampling device provided by the invention has the following beneficial effects: The invention relates to a system, comprising a voltage source, a load, a voltage follower, a voltage amplifier, a Micro Control Unit (MCU) module, a data acquisition and calculation center of the system, a digital converter of the analog world, a data processing unit, a data application layer of the system and a convergence, storage and display platform of test results, wherein the voltage source is an energy input layer of the system, a working power supply of tested equipment, the load is a tested object layer, namely a low-power fan to be tested, the voltage follower is a voltage sampling buffer isolation layer, a high-impedance input buffer of analog signals, the voltage amplifier is a current sampling signal enhancement layer and a weak voltage signal precision amplification and level shifter. The invention greatly improves the test efficiency, supports 8-path parallel synchronous test of the fans by a single device, combines automatic feeding and discharging of the production line, greatly shortens the test beat of the whole line, improves the efficiency by 8 times compared with the traditional single-channel scheme, and greatly reduces the purchase quantity of equipment and the occupied area of th