CN213715319U

CN213715319U - High-precision wide-range current tester

Info

Publication number: CN213715319U
Application number: CN202022950639.XU
Authority: CN
Inventors: 刘强; 黄伟; 陈委委
Original assignee: Sino Tech Smart Energy Technology Chengdu Co ltd
Current assignee: Sino Tech Smart Energy Technology Chengdu Co ltd
Priority date: 2020-12-08
Filing date: 2020-12-08
Publication date: 2021-07-16
Anticipated expiration: 2030-12-08

Abstract

The utility model provides a high accuracy wide range current tester, this tester include MCU microcomputer control unit, equipment power supply, real-time current display element, data transmission unit, differential signal input +18 AD sampling unit, relay gear control unit and sampling signal input/output unit, MCU microcomputer control unit be connected with equipment power supply, real-time current display element, data transmission unit, differential signal input +18 AD sampling unit, relay gear control unit respectively with sampling signal input/output unit connection. Different current gears of the tester are automatically switched without manual switching, and the detection efficiency is high; the current range is large; the device has a sampling data output function, can be stored in an upper computer database, and can automatically judge whether the energy consumption of the device is qualified or not.

Description

High-precision wide-range current tester

Technical Field

The utility model belongs to the technical field of the current test and specifically relates to a high accuracy wide range current tester is related to.

Background

The existing direct current tester on the market has the following defects:

1. the universal meter adopts a manual gear shifting mode for microampere (muA), milliampere (mA) and ampere (A) gear currents, the manual gear shifting mode meets general research tests or small-range tests and cannot meet the current monitoring requirement of assembly line production wide-range (0 muA-500 mA) working equipment;

2. the requirement of automatic storage, analysis and judgment of the current value cannot be met;

3. the requirement of randomly accessing each position of the circuit without damage cannot be met;

4. the timeline current parameter work requirement cannot be automatically stored.

SUMMERY OF THE UTILITY MODEL

The utility model aims to provide a: aiming at the problems in the prior art, the high-precision wide-range current tester is provided, and the problem of low efficiency of collecting current values of different ranges in each stage by using the existing manual gear shifting for equipment for measuring wide current work is solved.

The invention purpose of the utility model is realized by the following technical scheme:

a high-precision wide-range current tester comprises an MCU microcomputer control unit, an equipment power supply, a real-time current display unit, a data transmission unit, a differential signal input +18 bit AD sampling unit, a relay gear control unit and a sampling signal input/output unit, wherein the MCU microcomputer control unit is respectively connected with the equipment power supply, the real-time current display unit, the data transmission unit, the differential signal input +18 bit AD sampling unit and the relay gear control unit are respectively connected with the sampling signal input/output unit, and the sampling signal input/output unit is provided with a 10 omega resistance sensor and a 1 omega resistance sensor which are connected in parallel.

As a further technical scheme, the model of the MCU microcomputer control unit is STM8S003F3P6 TR.

As a further technical scheme, the model of a main chip of the differential signal input + 18-bit AD sampling unit is MCP 3421.

As a further technical scheme, the relay gear control unit comprises a relay, the model of the relay is G5V-1-5VDC, a pin 10 of the relay is connected with a 1 omega resistance sensor, a pin 9 of the relay is connected with a power supply, a pin 2 of the relay is connected with the positive electrode end of a diode D8 through a resistor R4, the negative electrode end of the diode D8 is connected with the power supply, the pin 2 is connected with the collector electrode of a triode, the base electrode of the triode is respectively connected with a resistor R5 and a resistor R6, the emitter electrode of the triode is grounded, and the other end of the resistor R6 is.

As a further technical solution, the sampling signal input/output unit includes a diode D6, a diode D7, a capacitor C14, a capacitor C15, and a 10 Ω resistance sensor, one end of the 10 Ω resistance sensor is respectively connected to the cathode of the diode D6, the anode of the diode D7, and the capacitor C14, the other end of the capacitor C14 is grounded, the other end of the 10 Ω resistance sensor is respectively connected to the anode of the diode D6, the cathode of the diode D7, and the capacitor C15, and the other end of the capacitor C15 is grounded.

As a further technical scheme, the maximum sampling range of the 10 omega resistance sensor is 0-330 muA.

Compared with the prior art, the utility model has the advantages of it is following:

1. different current gears microampere (mu A), milliampere (mA) and ampere (A) are automatically switched without manual switching, and the detection efficiency is improved.

2. The current range is wide, the current range of the tester is 0 muA-500 mA, while the traditional current measuring equipment is 0-200 uA and 1 mm-200 mA.

3. The device has a sampling data output function, can be stored in an upper computer database, and can automatically judge whether the energy consumption of the device is qualified or not.

Drawings

FIG. 1 is a schematic diagram of the circuit of the present invention;

FIG. 2 shows a MCU microcomputer control unit;

FIG. 3 is a power supply I for the device;

FIG. 4 shows a power supply II for the device;

FIG. 5 is a differential signal input +18 bit AD sampling unit;

FIG. 6 is a debug interface unit;

FIG. 7 is a relay gear control unit;

FIG. 8 is a real-time current display unit I;

FIG. 9 is a real-time current display unit II;

FIG. 10 is a real-time current display unit III;

FIG. 11 is a data transfer unit;

fig. 12 is a sampling signal input/output unit;

fig. 13 is a working principle diagram of the present invention.

Detailed Description

The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

Examples

To the equipment (example: intelligent gas meter, intelligent water gauge and other ultra-low power consumption equipment etc.) that measures the wide current work utilize current manual gear shift to realize the low efficiency problem that the different range current value of each stage gathered, through the utility model discloses can solve completely, the scheme is as follows: as a current collecting device, firstly, the current values of different ranges are required to be accurately collected: the utility model adopts the high-precision sampling resistance and the differential input sampling mode to measure the electricity consumption condition of each link of the equipment, compared with the traditional single-ended input acquisition mode, the scheme per se avoids uncertain factors in the signal acquisition process, thereby ensuring the accuracy of the acquisition value; meanwhile, 18-bit high-precision AD conversion sampling is adopted, so that the fineness of a sampling sample is greatly refined, and the sampling accuracy is guaranteed. The utility model discloses a difference is gathered, so equipment need not consider the current flow direction can influence the normal operating of equipment, also need not consider the power input end who inserts whole circuit or earthing terminal can exert an influence to equipment. The following is described in further detail with reference to the accompanying drawings:

as shown in fig. 1 to 12, the present embodiment provides a high-precision wide-range current tester, which includes an MCU microcomputer control unit, a device power supply, a real-time current display unit, a data transmission unit, a differential signal input +18 bit AD sampling unit, a relay gear control unit, and a sampling signal input/output unit. The MCU microcomputer control unit is respectively connected with the equipment power supply, the real-time current display unit, the data transmission unit, the differential signal input +18 bit AD sampling unit and the relay gear control unit. The differential signal input +18 bit AD sampling unit and the relay gear control unit are respectively connected with the sampling signal input/output unit. The sampling signal input/output unit is provided with a 10 omega resistance sensor and a 1 omega resistance sensor which are connected in parallel. The 10 Ω resistance sensor and the 1 Ω resistance sensor in this embodiment mean that the sensor selects 10 Ω and 1 Ω high-precision (error ± 1 ‰) high-power (1W) resistance. The maximum sampling range of the 10 Ω resistance sensor is 0 μ a to 330 μ a.

The model of the MCU microcomputer control unit is STM8S003F3P6 TR. The master chip model of the differential signal input +18 bit AD sampling unit is MCP 3421. The relay gear control unit comprises a relay, the model of the relay is G5V-1-5VDC, a pin 10 of the relay is connected with a 1 omega resistance sensor, a pin 9 of the relay is connected with a power supply, a pin 2 of the relay is connected with the positive end of a diode D8 through a resistor R4, the negative end of the diode D8 is connected with the power supply, the pin 2 is connected with the collector of a triode, the base of the triode is respectively connected with a resistor R5 and a resistor R6, the emitter of the triode is grounded, and the other end of the resistor R6 is grounded.

The sampling signal input/output unit comprises a diode D6, a diode D7, a capacitor C14, a capacitor C15 and a 10 omega resistor sensor, wherein one end of the 10 omega resistor sensor is respectively connected with the cathode end of the diode D6, the anode end of the diode D7 and the capacitor C14, the other end of the capacitor C14 is grounded, the other end of the 10 omega resistor sensor is respectively connected with the anode end of the diode D6, the cathode end of the diode D7 and the capacitor C15, and the other end of the capacitor C15 is grounded.

The utility model discloses an use a MCU microcomputer control unit, break-make through control relay gear control unit is to exceeding the sensor adjustment of sampling of setting for the range, make its automatic access group number according to range change control sensor, the sensor selects 10 omega and 1 omega high accuracy (error 1 thousandth) high-power (1W) resistance, default access 10 omega this group of sensor increase sensor circuit's shock resistance, when the circuit inserts big energy consumption or surpasss rated operating voltage in the twinkling of an eye protection circuit not receive the impact damage, the biggest sampling range of this group of sensor is 0 muA ~ 330 muA in normal collection process; in order to guarantee the smoothness of range switching, when the collected current value exceeds 250 muA, the MCU microcomputer control unit enables the relay to connect the 1 omega resistance sensor into the sampling group in parallel, the sampling resistance value after parallel connection is 0.1 ohm, and the microcontroller adjusts the ADC conversion amplifier to enable the current range of the whole sampling circuit to be 200 muA-500 mA. The current sampling is higher in precision of each measuring range, and the sampling measuring range is wider (0 muA-500 mA).

Based on the foregoing tester, this embodiment also provides a testing method, as shown in fig. 13, the method includes connecting a sampling signal input/output unit to a device under test, the tester accesses a 10 Ω resistance sensor by default, when the value of the collected current exceeds 250 μ a, an MCU microcomputer control unit sends a control instruction to a relay gear control unit, the relay gear control unit connects the 1 Ω resistance sensor in parallel to the 10 Ω resistance sensor, and the value of the sampled resistance after parallel connection is 0.1 ohm at this time, so that the current range of the whole sampling circuit is 200 μ a-500 mA.

The above description is only exemplary of the present invention and should not be taken as limiting, and all changes, equivalents, and improvements made within the spirit and principles of the present invention should be understood as being included in the scope of the present invention.

Claims

1. The high-precision wide-range current tester is characterized by comprising an MCU (microprogrammed control unit) microcomputer control unit, an equipment power supply, a real-time current display unit, a data transmission unit, a differential signal input +18 bit AD sampling unit, a relay gear control unit and a sampling signal input/output unit, wherein the MCU microcomputer control unit is respectively connected with the equipment power supply, the real-time current display unit, the data transmission unit, the differential signal input +18 bit AD sampling unit and the relay gear control unit are respectively connected with the sampling signal input/output unit, and the sampling signal input/output unit is provided with a 10 omega resistance sensor and a 1 omega resistance sensor which are connected in parallel.

2. The high-precision wide-range current tester as claimed in claim 1, wherein the MCU microcomputer control unit is STM8S003F3P6 TR.

3. The high-precision wide-range current tester as claimed in claim 1, wherein the master chip model of the differential signal input +18 bit AD sampling unit is MCP 3421.

4. The high-precision wide-range current tester as claimed in claim 1, wherein the relay gear control unit comprises a relay, the model of the relay is G5V-1-5VDC, a pin 10 of the relay is connected with a 1 Ω resistance sensor, a pin 9 is connected with a power supply, a pin 2 is connected with a positive terminal of a diode D8 through a resistor R4, a negative terminal of the diode D8 is connected with the power supply, the pin 2 is connected with a collector of a triode, a base of the triode is respectively connected with a resistor R5 and a resistor R6, an emitter of the triode is grounded, and the other end of the resistor R6 is grounded.

5. The high-precision wide-range current tester as claimed in claim 1, wherein the sampling signal input/output unit comprises a diode D6, a diode D7, a capacitor C14, a capacitor C15 and a 10 Ω resistor sensor, one end of the 10 Ω resistor sensor is connected to the cathode of the diode D6, the anode of the diode D7 and the capacitor C14 respectively, the other end of the capacitor C14 is grounded, the other end of the 10 Ω resistor sensor is connected to the anode of the diode D6, the cathode of the diode D7 and the capacitor C15 respectively, and the other end of the capacitor C15 is grounded.

6. A high accuracy wide range current meter as claimed in claim 1, wherein said 10 Ω resistance sensor has a maximum sampling range of 0 μ Α to 330 μ Α.