CN202600011U

CN202600011U - Automatic resistance tester

Info

Publication number: CN202600011U
Application number: CN 201220281619
Authority: CN
Inventors: 单立群; 刘彦昌; 赵艳超; 陈雷; 韩春娟; 赵宇驰; 刘福来
Original assignee: Northeast Petroleum University
Current assignee: Northeast Petroleum University
Priority date: 2012-06-15
Filing date: 2012-06-15
Publication date: 2012-12-12
Anticipated expiration: 2022-06-15

Abstract

The utility model relates to an automatic resistance tester, which is mainly used for solving the problem that the change of the resistance of an object to be tested cannot be displayed in real time caused by the fact that the existing resistance testing device is mostly built in a multimeter. The automatic resistance tester is characterized in that a resistance terminal voltage extraction circuit, an operational amplifier CA3130, an A/D (Analog-Digital) converter and a single chip microcomputer STM 32 are arranged in a tester shell body, wherein two resistance access terminals of the resistance terminal voltage extraction circuit are respectively connected to corresponding resistance testing connection terminals, a voltage signal output terminal of the resistance terminal voltage extraction circuit is connected to a following signal input terminal of the operational amplifier CA3130, a signal output terminal of the operational amplifier CA3130 is connected to an analog signal input terminal of the A/D converter, and a digital signal output terminal of the A/D converter is connected to a sampled digital signal input terminal of the single chip microcomputer STM 32. According to the automatic resistance tester provided by the utility model, the single chip microcomputer technology is combined with the conventional resistance test circuit, so that the change of the resistance of the object to be tested can be displayed in real time.

Description

Automatic resistance meter

Technical field

The utility model relates to a kind of resistance test device that is applied in the industrial and mining enterprises.

Background technology

Using the resistance test device in industrial and mining enterprises to have much at present, generally all is to be integrated in multimeter or the reometer, through the resistor voltage divider circuit of routine, just can draw the resistance value of object under test through simple computation.This electric resistance measuring apparatus has been used decades, but exist a problem is exactly: can not adjust the resistance range automatically, when the change of object under test resistance, be difficult to realize the real-time demonstration of resistance value.

Summary of the invention

The technical matters of mentioning in order to solve in the background technology; The utility model provides a kind of automatic resistance meter; The automatic resistance meter of this kind combines singlechip technology with conventional resistance test circuit, can realize the adjustment to object range to be measured, when change in resistance, can show in real time.

The technical scheme of the utility model is: the automatic resistance meter of this kind, comprise Instrument shell, and on said Instrument shell, be hinged with panel, on said panel, be fixed with LCDs and button; On the sidewall of said Instrument shell, have groove, at the some resistance test links of said groove internal fixation, by the sidewall extracting power supply cord of said Instrument shell; In addition, include resistance terminal voltage subtraction circuit, CA3130 operational amplifier, A/D converter and STM32 single-chip microcomputer in the said Instrument shell; Wherein, 2 resistance incoming ends of said resistance terminal voltage subtraction circuit are connected respectively to corresponding resistance test link; The voltage signal output end of said resistance terminal voltage subtraction circuit is connected to the signal input part of following of said CA3130 operational amplifier; The signal output part of said CA3130 operational amplifier is connected to the analog signals input end of A/D converter, and the digital quantity signal output terminal of said A/D converter is connected to the sampled digital signal input end of said STM32 single-chip microcomputer; The VT of said STM32 single-chip microcomputer is connected to the signal input part of said LCDs, and the driving circuit signal output part that said button is corresponding is connected to the signal input end of said STM32 single-chip microcomputer.

During concrete the realization, selecting said LCDs is ILI9325 type display screen, and the clock frequency of said STM32 single-chip microcomputer is up to the 72M hertz.

The utlity model has following beneficial effect: this kind resistance meter is a main control chip with 32 STM32 single-chip microcomputers; Adopt resistance series connection dividing potential drop method to convert resistance signal to voltage signal; Through following of high input impedance CA3130 operational amplifier; Then through 12 AD conversion, MCU to the quick computing of voltage signal, analysis and processing after, deliver to LCD and show.Like this, when change in resistance, can show in real time.In addition; In this kind tester; Can combine that relay group control range resistance is realized 0～

Figure 2012202816190100002DEST_PATH_IMAGE002

through loading routine in single-chip microcomputer, the automatic switchover of

～

,

～

, four gears of

～

; Measuring accuracy is up to 1%; And can be through artificial input filter information, measuring resistance also judges whether it is up to standard.In addition; This kind of tester can also drive potentiometer through stepper motor; Potentiometer is adopted a sampling, and the sampling spot resistance is outputed to the relation curve of angulation and resistance on the high-resolution ILI9325 LCD display, make things convenient for the control characteristic of test potential device.

Description of drawings:

Fig. 1 is the structural representation of the utility model.

Fig. 2 is the surface structure synoptic diagram of the utility model.

Fig. 3 is the electrical schematic diagram of the related resistance terminal voltage subtraction of the utility model circuit.

1-LCDs among the figure, 2-panel, 3-button, 4-power lead, 5-resistance test link, 6-groove.

Embodiment:

Below in conjunction with accompanying drawing the utility model is described further:

By shown in Figure 2, the automatic resistance meter of this kind comprises Instrument shell, and its unique distinction is: on said Instrument shell, be hinged with panel 2, on said panel, be fixed with LCDs 1 and button 3; On the sidewall of said Instrument shell, have groove 6, at the some resistance test links 5 of said groove internal fixation, by the sidewall extracting power supply cord 4 of said Instrument shell.

In addition, as shown in Figure 1, also include resistance terminal voltage subtraction circuit, CA3130 operational amplifier, A/D converter and STM32 single-chip microcomputer in the said Instrument shell.Wherein, Said resistance terminal voltage subtraction circuit is as shown in Figure 3; 2 resistance incoming end S1, S2 are connected respectively to corresponding resistance test link 5; The voltage signal output end of said resistance terminal voltage subtraction circuit is connected to the signal input part of following of said CA3130 operational amplifier; The signal output part of said CA3130 operational amplifier is connected to the analog signals input end of A/D converter, and the digital quantity signal output terminal of said A/D converter is connected to the sampled digital signal input end of said STM32 single-chip microcomputer;

The VT of said STM32 single-chip microcomputer is connected to the signal input part of said LCDs 1, and said button 3 corresponding driving circuit signal output parts are connected to the signal input end of said STM32 single-chip microcomputer.

During concrete the realization, LCDs 1 is preferably ILI9325 type display screen, and the clock frequency of said STM32 single-chip microcomputer preferably is up to the 72M hertz.

During use, can resistance test link 5 be inserted at the two ends of object under test, as shown in Figure 3, R8 is a testing resistance, and R7 is a range resistance.Can draw the function that R8 is R7 and

according to Ohm law.Like this; R8 voltage

is followed through the CA3130 operational amplifier; Get into the STM32 single-chip microcomputer through 12 A/D converter conversion backs subsequently; The STM32 single-chip microcomputer can be tried to achieve measured resistance R8 rapidly after calculating according to setting program then, and resistance shows through the output of ILI9325 LCDs.In this example; Can increase some range pilot relays; Respectively with ,

, and

; Be that precision is 0.001 range resistance and is connected, come to control respectively

,

, and

shelves.With range is that

is example; R7=

; Testing resistance R8 is when 0～

changes, and voltage

changes between 0～2.5V.As R8 during greater than

;

will be greater than 2.5V; Single-chip microcomputer just automatically switches to next shelves when detecting greater than 2.5V; Promptly

shelves; The back still just switches to next shelves greater than 2.5V again if trip stop; Promptly

shelves; By that analogy, just measure during up to

less than 2.5V at the gear at place.

This kind of automatic resistance meter combines singlechip technology with conventional resistance test circuit; Both can realize adjustment automatically to object range to be measured; And when change in resistance, can also show change procedure in real time; Therefore, this kind resistance meter has remedied the deficiency of existing electric resistance measuring apparatus technology.

Claims

1. an automatic resistance meter comprises Instrument shell, it is characterized in that: on said Instrument shell, be hinged with panel (2), on said panel, be fixed with LCDs (1) and button (3); On the sidewall of said Instrument shell, have groove (6), at the some resistance test links of said groove internal fixation (5), by the sidewall extracting power supply cord (4) of said Instrument shell;

In addition, include resistance terminal voltage subtraction circuit, CA3130 operational amplifier, A/D converter and STM32 single-chip microcomputer in the said Instrument shell; Wherein, 2 resistance incoming end (S1 of said resistance terminal voltage subtraction circuit; S2) be connected respectively to corresponding resistance test link (5); The voltage signal output end of said resistance terminal voltage subtraction circuit is connected to the signal input part of following of said CA3130 operational amplifier; The signal output part of said CA3130 operational amplifier is connected to the analog signals input end of A/D converter, and the digital quantity signal output terminal of said A/D converter is connected to the sampled digital signal input end of said STM32 single-chip microcomputer;

The VT of said STM32 single-chip microcomputer is connected to the signal input part of said LCDs (1), and the driving circuit signal output part that said button (3) is corresponding is connected to the signal input end of said STM32 single-chip microcomputer.

2. according to the automatic resistance meter described in the claim 1, it is characterized in that: said LCDs (1) is an ILI9325 type display screen, and the clock frequency of said STM32 single-chip microcomputer is the 72M hertz.