CN219039215U - Small resistance detection circuit, device and system - Google Patents
Small resistance detection circuit, device and system Download PDFInfo
- Publication number
- CN219039215U CN219039215U CN202223296872.6U CN202223296872U CN219039215U CN 219039215 U CN219039215 U CN 219039215U CN 202223296872 U CN202223296872 U CN 202223296872U CN 219039215 U CN219039215 U CN 219039215U
- Authority
- CN
- China
- Prior art keywords
- constant current
- switch
- resistor
- current source
- universal meter
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Landscapes
- Measurement Of Resistance Or Impedance (AREA)
Abstract
The utility model provides a small-resistance detection circuit, a device and a system, wherein the circuit is respectively connected with a measured resistor and a universal meter, and the measured resistor is connected with a detection end of the universal meter; the small-resistance detection circuit comprises a constant current source and a processing module; the constant current source is connected with the resistor to be tested, and the processing module is respectively connected with the constant current source and the universal meter in a communication way; wherein: the constant current source is used for providing constant current; the processing module is used for acquiring the measured resistance voltage detected by the universal meter, determining the resistance value of the measured resistor according to the constant current and the measured resistance voltage, wherein the resistance value of the measured resistor is smaller than the resistance value corresponding to the minimum resistance gear of the universal meter. Through setting up the current source to can provide suitable constant current based on the needs of measured resistance, detect resistance voltage through the universal meter simultaneously, can accurately detect measured resistance based on ohm's law.
Description
Technical Field
The present utility model relates to the field of integrated circuit testing, and in particular, to a small resistance detection circuit, device and system.
Background
The minimum resistance gear of the existing universal meter is 100 omega, and the minimum resistance gear of some universal meters can reach 10 omega; if the resistance value is smaller, for example, the small resistor of 10mΩ is detected, the current applied by the multimeter is smaller, so that the minimum resistance gear of the multimeter cannot meet the precision requirement of the small resistor.
Disclosure of Invention
The utility model mainly aims to provide a small-resistance detection circuit, a small-resistance detection device and a small-resistance detection system, and aims to solve the problem that a universal meter in the prior art cannot meet the precision requirement for small-resistance detection.
In order to achieve the above purpose, the present utility model provides a small resistance detection circuit, which is respectively connected with a measured resistance and a multimeter, wherein the measured resistance is connected with a detection end of the multimeter; the small-resistance detection circuit comprises a constant current source and a processing module; the constant current source is connected with the resistor to be tested, and the processing module is respectively connected with the constant current source and the universal meter in a communication way; wherein:
the constant current source is used for providing constant current;
the processing module is used for acquiring the measured resistance voltage detected by the universal meter, determining the resistance value of the measured resistor according to the constant current and the measured resistance voltage, wherein the resistance value of the measured resistor is smaller than the resistance value corresponding to the minimum resistance gear of the universal meter.
Optionally, the circuit further comprises a current calibration module and a switch module; the current calibration module is respectively connected with the constant current source and the universal meter through the switch module, and the measured resistor is respectively connected with the constant current source and the universal meter through the switch module; the control end of the switch module is connected with the processing module;
the switch module is used for controlling the current calibration module to be connected with the constant current source and the universal meter or controlling the measured resistor to be connected with the constant current source and the universal meter;
and the processing module is used for determining the constant current of the constant current source when the current calibration module is connected with the constant current source and the universal meter.
Optionally, the current calibration module comprises at least one calibration resistor; the switch module comprises a first switch unit and at least one second switch unit, and the measured resistor is connected with the constant current source and the universal meter through the first switch unit; each calibration resistor is connected with the constant current source and the universal meter through one second switch unit respectively; the resistance value of each calibration resistor is different.
Optionally, the second switch unit includes a first sub-switch, a second sub-switch, a third sub-switch, and a fourth sub-switch; wherein:
the first end of the first sub-switch is connected with the first end of the calibration resistor, the second end of the first sub-switch is connected with the positive electrode of the constant current source and the high end of the universal meter respectively, the second sub-switch is connected between the first end of the calibration resistor and the high end of the universal meter, the first end of the third sub-switch is connected with the second end of the calibration resistor, the second end of the third sub-switch is connected with the negative electrode of the constant current source and the low end of the universal meter respectively, the first end of the fourth sub-switch is connected with the second end of the calibration resistor, and the second end of the fourth sub-switch is connected with the negative electrode of the constant current source and the low end of the universal meter respectively.
Optionally, the calibration resistor is a low temperature drift resistor.
Optionally, the switch module includes a third switch unit, and the constant current source is connected with the measured resistor and the current calibration module through the third switch unit.
Optionally, the switch module includes a fourth switch unit, and the constant current source is connected with the multimeter through the fourth switch unit.
Optionally, the processing module includes a switch control unit and a calculation unit; the switch control unit is connected with the control end of the switch module, the calculation unit is respectively connected with the constant current source and the universal meter in a communication way, and the switch control unit is connected with the calculation unit;
the switch control unit is used for switching the switch state of the switch module and sending a state signal corresponding to the switch state to the calculation unit;
the calculating unit is used for determining the constant current of the constant current source according to the state signal or determining the resistance value of the measured resistor according to the constant current and the measured resistor voltage.
In addition, in order to achieve the above object, the present utility model also provides a small resistance detection device including a housing and a small resistance detection circuit as described above.
In addition, in order to achieve the purpose, the utility model also provides a small resistance detection system, which comprises a universal meter, a measured resistance and the small resistance detection circuit.
The utility model provides a small-resistance detection circuit, a device and a system, wherein the circuit is respectively connected with a measured resistor and a universal meter, and the measured resistor is connected with a detection end of the universal meter; the small-resistance detection circuit comprises a constant current source and a processing module; the constant current source is connected with the resistor to be tested, and the processing module is respectively connected with the constant current source and the universal meter in a communication way; wherein: the constant current source is used for providing constant current; the processing module is used for acquiring the measured resistance voltage detected by the universal meter and determining the resistance value of the measured resistor according to the constant current and the measured resistance voltage. Through setting up the current source to can provide suitable constant current based on the needs of measured resistance, detect resistance voltage through the universal meter simultaneously, can accurately detect measured resistance based on ohm's law.
Drawings
In order to more clearly illustrate the embodiments of the present utility model or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described, and it is obvious that the drawings in the following description are only some embodiments of the present utility model, and other drawings may be obtained according to the structures shown in these drawings without inventive effort for a person skilled in the art.
FIG. 1 is a functional block diagram of an embodiment of a small resistance detection circuit according to the present utility model;
FIG. 2 is a functional block diagram of another embodiment of a small resistance detection circuit according to the present utility model;
fig. 3 is a circuit configuration diagram of the small resistance detection circuit of the present utility model applied to the embodiment of fig. 2.
The achievement of the objects, functional features and advantages of the present utility model will be further described with reference to the accompanying drawings, in conjunction with the embodiments.
Reference numerals illustrate:
| reference numerals | Name of the name | Reference numerals | Name of the |
| 100 | Constant |
400 | |
| 200 | |
420 | |
| 300 | |
430 | Third switch unit |
| R1 | Calibration resistor | 440 | Fourth switch unit |
| 440-1 | Positive pole sub-switch | 440-2 | Negative pole sub-switch |
| K1～K4 | First to |
410 | First switch unit |
Detailed Description
It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the utility model.
The following description of the embodiments of the present utility model will be made clearly and fully with reference to the accompanying drawings, in which it is evident that the embodiments described are only some, but not all embodiments of the utility model. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to be within the scope of the utility model.
It should be noted that all directional indicators (such as up, down, left, right, front, and rear are used in the embodiments of the present utility model) are merely for explaining the relative positional relationship, movement conditions, and the like between the components in a certain specific posture (as shown in the drawings), and if the specific posture is changed, the directional indicators are changed accordingly.
Furthermore, the description of "first," "second," etc. in this disclosure is for descriptive purposes only and is not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include at least one such feature. In addition, the technical solutions of the embodiments may be combined with each other, but it is necessary to base that the technical solutions can be realized by those skilled in the art, and when the technical solutions are contradictory or cannot be realized, the combination of the technical solutions should be considered to be absent and not within the scope of protection claimed in the present utility model.
The utility model provides a small resistance detection circuit which is applied to a small resistance detection device, referring to fig. 1, fig. 1 is a functional block diagram of an embodiment of the small resistance detection circuit of the utility model. In this embodiment, the circuit is connected to a measured resistor and a multimeter, respectively, and the measured resistor is connected to a detection end of the multimeter; the small resistance detection circuit comprises a constant current source 100 and a processing module 200; the constant current source 100 is connected with the resistor to be tested, and the processing module 200 is respectively connected with the constant current source 100 and the universal meter in a communication manner; wherein:
the constant current source 100 is used for providing constant current;
the processing module 200 is configured to obtain the measured resistance voltage detected by the multimeter, and determine a resistance value of the measured resistor according to the constant current and the measured resistance voltage, where the resistance value of the measured resistor is smaller than a resistance value corresponding to a minimum resistance gear of the multimeter.
When the existing ATE (Automatic Test Equipment ) is used for calibrating a VI source, an external resistor is required to be used for lap joint, and before the external resistor is lapped, the resistance value of the external resistor is required to be detected, for example, the detection of the resistance value of the external resistor is realized through a six-bit half multimeter; however, based on different VI source current gears, the external resistor to be lapped has different resistance values, when the external resistor has smaller resistance value, for example, the external resistor has resistance value of 0.1 Ω, and the minimum resistance gear of the six-bit half multimeter has 10 Ω, at this time, if the external resistor resistance value is directly detected by the six-bit half multimeter, the obtained resistance value is difficult to meet the precision requirement, thereby influencing the current calibration precision of the VI source.
The constant current source 100 can provide stable current output, the precision of the constant current source 100 is higher than the precision required by the measured resistor, and the constant current source 100 can be specifically set based on the actual measured resistor, and generally, the precision is required to be within 0.1%. Meanwhile, in order to avoid the influence of temperature on the test result, a constant current source 100 with good constant current temperature drift characteristics, such as a temperature coefficient value smaller than 100ppm, can be selected.
In the detection process, firstly, the constant current required to be output by the constant current source 100 is determined based on the resistance value of the measured resistor, and the determination principle is that the voltage value of the measured resistor and the constant current corresponding to the ohm law can be accurately detected by the existing voltage gear of the universal meter; after determining the constant current, a voltage gear of the multimeter is selected based on the corresponding resistance value.
After determining the voltage gear of the multimeter and the constant current of the constant current source 100, the processing module 200 obtains the measured resistance voltage and the constant current detected by the multimeter, and obtains the resistance value of the measured resistance through ohm's law.
According to the embodiment, the current source is arranged, so that proper constant current can be provided based on the requirement of the measured resistor, meanwhile, the resistor voltage is detected through the universal meter, and the measured resistor can be accurately detected based on ohm's law.
Further, referring to fig. 2, the circuit further includes a current calibration module 300 and a switch module 400; the current calibration module 300 is respectively connected with the constant current source 100 and the universal meter through the switch module 400, and the measured resistor is respectively connected with the constant current source 100 and the universal meter through the switch module 400; the control end of the switch module 400 is connected with the processing module 200;
the switch module 400 is configured to control the current calibration module 300 to be connected with the constant current source 100 and the multimeter, or control the measured resistor to be connected with the constant current source 100 and the multimeter;
the processing module 200 is configured to determine a constant current of the constant current source 100 when the current calibration module 300 is connected to the constant current source 100 and the multimeter.
The current calibration module 300 is used for calibrating the constant current of the constant current source 100. It can be understood that there is a difference between the constant current outputted from the constant current source 100 and the set output current due to an error or loss of the constant current source 100 itself or the like; if the set output current is directly used as the constant current actually output by the constant current source 100, the measured resistance value obtained by the subsequent calculation will be inaccurate, so the current calibration module 300 is set in this embodiment to calibrate the constant current actually output by the constant current source 100, and then calculate the measured resistance value based on the calibrated constant current.
The current calibration module 300 or the measured resistance is switched to be connected with the constant current source 100 and the multimeter by controlling different states of the switch module 400; it can be understood that, in the process of specifically detecting the measured resistor, the current calibration module 300 is connected to the constant current source 100 and the multimeter through the switch module 400, and at this time, the processing module 200 determines the constant current of the constant current source 100 through the current calibration module 300; the measured resistor is then connected to the constant current source 100 and the multimeter via the switching module 400, at which point the processing module 200 determines the resistance value of the measured resistor based on the determined constant current and the resistance voltage detected by the multimeter.
Further, referring to fig. 3, the current calibration module 300 includes at least one calibration resistor R1; the switch module 400 includes a first switch unit 410 and at least one second switch unit 420, and the measured resistor is connected to the constant current source 100 and the multimeter through the first switch unit 410; each calibration resistor R1 is connected with the constant current source 100 and the universal meter through a second switch unit 420 respectively; the resistance value of each calibration resistor R1 is different.
Further, the switching module 400 includes a fourth switching unit 440, and the constant current source 100 is connected to the current sensing terminal AMPS of the multimeter through the fourth switching unit 440.
It can be understood that the multimeter can calibrate the constant current within a certain range, and the constant current source 100 is directly connected to the multimeter through the fourth switch unit 440 to determine the constant current through the current detection end AMPS of the multimeter; in particular, when the current source is connected, the positive and negative poles of the constant current source need to form a loop with the detection end of the multimeter, so that the fourth switch unit 440 may be provided to include a positive sub-switch 440-1 and a negative sub-switch 440-2, where the positive sub-switch 440-1 is connected between the positive pole of the constant current source 100 and the current detection end AMPS, and the negative sub-switch 440-2 is connected between the negative pole of the constant current source 100 and the low end LO of the multimeter.
When the constant current exceeds the current detection range of the universal meter, the constant current cannot be directly calibrated, and in the embodiment, the constant current is indirectly calibrated by setting the calibration resistor R1; specifically, the calibration resistor R1 is set, and calibration of the constant current is achieved through ohm's law, it can be understood that the resistance value of the calibration resistor R1 should be definite because the constant current needs to be determined through ohm's law, so that the resistance value of the calibration resistor R1 needs to be directly measured by the multimeter in setting, and the calibration resistor R1 can be specifically set based on the supporting condition of the resistance value by the multimeter in practical application; after the resistance value of the calibration resistor R1 is detected by the universal meter, the second switch unit 420 connects the constant current to the calibration resistor R1, and at this time, the calibration voltage of the calibration resistor R1 is detected by the universal meter, so that the constant current is determined by the calibration voltage and the resistance value of the calibration resistor R1.
It can be appreciated that, based on different constant currents, voltages at two ends of the same resistor are different, so that voltage gears of the multimeter can meet the detection of the calibration voltage, and different constant currents can be matched with a proper calibration resistor R1, so that the calibration voltage can be detected by the multimeter.
Further, the second switch unit 420 includes a first sub-switch K1, a second sub-switch K2, a third sub-switch K3, and a fourth sub-switch K4; wherein:
the first end of the first sub-switch K1 is connected with the first end of the calibration resistor R1, the second end of the first sub-switch K1 is connected with the positive pole of the constant current source 100 and the high end HI of the universal meter respectively, the second sub-switch K2 is connected between the first end of the calibration resistor R1 and the high end HI of the universal meter, the first end of the third sub-switch K3 is connected with the second end of the calibration resistor R1, the second end of the third sub-switch K3 is connected with the negative pole of the constant current source 100 and the low end LO of the universal meter respectively, the first end of the fourth sub-switch K4 is connected with the second end of the calibration resistor R1, and the second end of the fourth sub-switch K4 is connected with the negative pole of the constant current source 100 and the low end LO of the universal meter respectively.
The constant current source 100 can be connected or disconnected with the measured resistor through the first sub switch K1 and the third sub switch K3; the multimeter can be connected or disconnected with the resistor to be measured through the second sub-switch K2 and the fourth sub-switch K4.
It can be appreciated that when detecting voltage parameters such as the calibration voltage, the measured resistor voltage, etc., the multimeter can be connected in two-wire system, that is, connected to two ends of the resistor to be measured through a high-end HI and a low-end LO, and for the second switch unit 420, the switching action performed can be to close the first sub-switch K1 and the third sub-switch K3. In order to improve the detection accuracy when detecting the resistance value of the calibration resistor, four-wire connection may be adopted, that is, two high-end HI and two low-end LO are connected to two ends of the calibration resistor, and for the second switch unit 420, the switching action performed may be to close the first to fourth sub-switches K1 to K4.
It should be noted that, the sub-switch may be a relay switch according to an actual application scenario and a suitable device needs to be selected.
It should be noted that the first switch unit 410 may be configured in the same manner as the second switch unit 420, and will not be described again.
The second switching unit 420 in this embodiment can realize connection/disconnection of the calibration resistor R1 with the multimeter and the constant current source 100.
Further, the calibration resistor R1 is a low-temperature drift resistor.
Because the power of the low-temperature drift resistor is larger and is less affected by temperature, the error caused by temperature can be reduced as much as possible, and therefore, the constant current can be calibrated more accurately. The low temperature drift resistance may be a resistance having a temperature coefficient of 25 ppm/DEG C or less.
Further, the switching module 400 includes a third switching unit 430, and the constant current source 100 is connected to the measured resistor and the current calibration module 300 through the third switching unit 430.
In practical applications, when the measured resistor/current calibration module 300 switches connection, a thermoelectric voltage will be generated at the resistor lap joint, i.e. at the corresponding second switch unit 420, and when the measured resistor voltage or the calibration voltage is smaller, the thermoelectric voltage will greatly affect the result of resistor detection or constant current calibration.
The influence of the thermoelectric voltage is eliminated by providing the third switching unit 430 in the present embodiment; specifically:
when the constant current is calibrated, the constant current source 100 and the current calibration module 300 are connected through the third switch unit 430, the first calibration voltage VB1 obtained by the detection of the current calibration module 300 by the universal meter is obtained, then the constant current source 100 and the current calibration module 300 are disconnected through the third switch unit 430, the second calibration voltage VB2, VB1-VB 2=VB 3 obtained by the detection of the current calibration module 300 by the universal meter is obtained, the third calibration voltage VB3 is the calibration voltage after the influence of thermoelectric voltage is eliminated, the resistance value of the calibration resistor R1 corresponding to the current calibration module 300 is R1, and the calibrated constant current I=VB 3/R1 can be obtained.
When the resistance value of the measured resistor is detected, the constant current source 100 is connected with the measured resistor through the third switch unit 430, the first measured resistor voltage VC1 obtained by detecting the measured resistor through the universal meter is obtained, then the constant current source 100 is disconnected with the measured resistor through the third switch unit 430, the second measured resistor voltage VC2, VC1-VC 2=VC 3 obtained by detecting the measured resistor through the universal meter is obtained, the third measured resistor voltage VC3 is the measured resistor voltage after the influence of thermoelectric voltage is eliminated, the calibrated constant current is I, and the resistance value RB=VC 3/I of the measured resistor can be obtained.
The embodiment can eliminate the influence of the thermoelectric voltage on the resistance detection and the constant current calibration.
Further, the processing module 200 includes a switch control unit and a calculation unit; the switch control unit is connected with the control end of the switch module 400, the calculation unit is respectively connected with the constant current source 100 and the universal meter in a communication way, and the switch control unit is connected with the calculation unit;
the switch control unit is configured to switch a switch state of the switch module 400, and send a state signal corresponding to the switch state to the computing unit;
the calculating unit is configured to determine a constant current of the constant current source 100 according to the status signal, or determine a resistance value of the measured resistor according to the constant current and the measured resistor voltage.
Under different switching states of the switching control unit, the connection relationship among the constant current source 100, the universal meter, the measured resistor and the current calibration module 300 is different, so that parameters to be determined by the calculation unit are also different; such as:
when the switch control unit connects the constant current source 100, the measured resistor and the universal meter, the calculation unit needs to obtain constant current and measured resistor voltage to determine the resistance value of the measured resistor;
when the switch control unit connects the constant current source 100, the current calibration module 300 and the universal meter, the calculation unit needs to obtain the resistance value and the calibration voltage of the calibration resistor R1 to determine the constant current;
when the switch control unit connects the constant current source 100 with the multimeter, the calculation unit needs to determine a constant current;
when the switch control unit connects the measured resistor/current calibration module 300 with the multimeter, the calculation unit needs to determine the thermoelectric voltage;
therefore, the calculation unit needs to determine the parameters to be determined according to the state of the switch control unit.
The operation of a small resistance detection circuit according to the present utility model is described below based on two sets of actual parameters:
1. the resistance value of the measured resistor is 0.1 omega, the minimum resistance gear of the universal meter is 100 omega, and the deviation of the gear test exceeds the precision requirement of 0.1 omega, so that the resistance value of the measured resistor cannot be directly detected; other parameters include the resistance value of the calibration resistor R1 is 100 omega, and the output current of the constant current source 100 is 100mA;
1. connecting the calibration resistor R1 with a universal meter, and detecting the resistance value of the calibration resistor R1 through the universal meter to obtain RZ;
2. connecting the constant current source 100 with a calibration resistor R1, and measuring a calibration voltage VB1 through a 10V gear of a universal meter;
3. disconnecting the constant current source 100 and measuring the calibration voltage VB2 by using a 100mV gear of the universal meter;
4. calculating constant current iz= (VB 1-VB 2)/RZ of the constant current source 100;
5. the calibration resistor R1 is disconnected, and the measured resistor is respectively connected with the universal meter and the constant current source 100;
6. measuring the measured resistance voltage VC1 by using a universal meter at a 100mV gear;
7. switching off the constant current source 100, and measuring the measured resistor voltage VC2 by using a universal meter 100mV voltage rail;
8. and calculating the resistance RC of the measured resistor, wherein RC= (VC 1-VC 2)/IZ.
2. The resistance value of the measured resistor is 0.001 omega, the minimum resistance gear of the universal meter is 100 omega, and the deviation of the gear test exceeds the precision requirement of 0.001 omega, so that the resistance value of the measured resistor cannot be directly detected; other parameters include the resistance value of the calibration resistor R1 being 0.1 omega, and the output current of the constant current source 100 being 10A;
1. RZ is obtained by detecting the resistance value of the calibration resistor R1 by means of the above example (in this example, the function of current calibration can be realized by the original position of the measured resistor);
2. connecting the constant current source 100 with a calibration resistor R1, and measuring a calibration voltage VB1 through a 1V gear of the universal meter;
3. disconnecting the constant current source 100 and measuring the calibration voltage VB2 using the 1V gear of the multimeter;
4. calculating constant current iz= (VB 1-VB 2)/RZ of the constant current source 100;
5. the calibration resistor R1 is disconnected, and the measured resistor is respectively connected with the universal meter and the constant current source 100;
6. measuring the measured resistance voltage VC1 by using a universal meter at a 100mV gear;
7. switching off the constant current source 100, and measuring the measured resistor voltage VC2 by using a universal meter 100mV voltage rail;
8. and calculating the resistance RC of the measured resistor, wherein RC= (VC 1-VC 2)/IZ.
The utility model further comprises a small resistance detection device, which comprises a shell and a small resistance detection circuit, wherein the structure of the small resistance detection circuit can refer to the embodiment, and the details are not repeated here. It should be noted that, since the small resistance detection device of the present embodiment adopts the technical scheme of the small resistance detection circuit, the small resistance detection device has all the beneficial effects of the small resistance detection circuit.
The utility model also comprises a small resistance detection system, which comprises a multimeter, a measured resistor and a small resistance detection circuit, wherein the structure of the small resistance detection circuit can refer to the embodiment, and the details are not repeated here. It should be noted that, since the small resistance detection system of the present embodiment adopts the technical scheme of the small resistance detection circuit, the small resistance detection system has all the beneficial effects of the small resistance detection circuit.
It should be noted that, in this document, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or system that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or system. Without further limitation, an element defined by the phrase "comprising one does not exclude the presence of other like elements in a process, method, article, or system that comprises the element. The foregoing embodiment numbers of the present utility model are merely for the purpose of description, and do not represent the advantages or disadvantages of the embodiments.
The foregoing description is only of the preferred embodiments of the present utility model, and is not intended to limit the scope of the utility model, but rather is intended to cover any equivalents of the structures or equivalent processes disclosed herein or in the alternative, which may be employed directly or indirectly in other related arts.
Claims (10)
1. The small-resistance detection circuit is characterized by being connected with a resistor to be detected and a universal meter respectively, wherein the resistor to be detected is connected with a detection end of the universal meter; the small-resistance detection circuit comprises a constant current source and a processing module; the constant current source is connected with the resistor to be tested, and the processing module is respectively connected with the constant current source and the universal meter in a communication way; wherein:
the constant current source is used for providing constant current;
the processing module is used for acquiring the measured resistance voltage detected by the universal meter, determining the resistance value of the measured resistor according to the constant current and the measured resistance voltage, wherein the resistance value of the measured resistor is smaller than the resistance value corresponding to the minimum resistance gear of the universal meter.
2. The small resistance detection circuit of claim 1, wherein the circuit further comprises a current scaling module and a switching module; the current calibration module is respectively connected with the constant current source and the universal meter through the switch module, and the measured resistor is respectively connected with the constant current source and the universal meter through the switch module; the control end of the switch module is connected with the processing module;
the switch module is used for controlling the current calibration module to be connected with the constant current source and the universal meter or controlling the measured resistor to be connected with the constant current source and the universal meter;
and the processing module is used for determining the constant current of the constant current source when the current calibration module is connected with the constant current source and the universal meter.
3. The small resistance detection circuit of claim 2, wherein the current scaling module comprises at least one scaling resistor; the switch module comprises a first switch unit and at least one second switch unit, and the measured resistor is connected with the constant current source and the universal meter through the first switch unit; each calibration resistor is connected with the constant current source and the universal meter through one second switch unit respectively; the resistance value of each calibration resistor is different.
4. The small-resistance detection circuit according to claim 3, wherein the second switching unit includes a first sub-switch, a second sub-switch, a third sub-switch, and a fourth sub-switch; wherein:
the first end of the first sub-switch is connected with the first end of the calibration resistor, the second end of the first sub-switch is connected with the positive electrode of the constant current source and the high end of the universal meter respectively, the second sub-switch is connected between the first end of the calibration resistor and the high end of the universal meter, the first end of the third sub-switch is connected with the second end of the calibration resistor, the second end of the third sub-switch is connected with the negative electrode of the constant current source and the low end of the universal meter respectively, the first end of the fourth sub-switch is connected with the second end of the calibration resistor, and the second end of the fourth sub-switch is connected with the negative electrode of the constant current source and the low end of the universal meter respectively.
5. A small resistance detection circuit according to claim 3, wherein the nominal resistance is a low temperature drift resistance.
6. The small-resistance detection circuit according to claim 2, wherein the switching module includes a third switching unit, and the constant current source is connected to the measured resistance and the current calibration module through the third switching unit.
7. The small resistance detection circuit according to claim 2, wherein the switching module includes a fourth switching unit, and the constant current source is connected to the multimeter through the fourth switching unit.
8. The small-resistance detection circuit according to claim 2, wherein the processing module includes a switch control unit and a calculation unit; the switch control unit is connected with the control end of the switch module, the calculation unit is respectively connected with the constant current source and the universal meter in a communication way, and the switch control unit is connected with the calculation unit;
the switch control unit is used for switching the switch state of the switch module and sending a state signal corresponding to the switch state to the calculation unit;
the calculating unit is used for determining the constant current of the constant current source according to the state signal or determining the resistance value of the measured resistor according to the constant current and the measured resistor voltage.
9. A small resistance detection apparatus, characterized in that the small resistance detection apparatus comprises a housing and the small resistance detection circuit according to any one of claims 1 to 8.
10. A small resistance test system comprising a multimeter, a resistor under test and a small resistance test circuit according to any one of claims 1 to 8.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202223296872.6U CN219039215U (en) | 2022-12-08 | 2022-12-08 | Small resistance detection circuit, device and system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202223296872.6U CN219039215U (en) | 2022-12-08 | 2022-12-08 | Small resistance detection circuit, device and system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN219039215U true CN219039215U (en) | 2023-05-16 |
Family
ID=86279830
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202223296872.6U Active CN219039215U (en) | 2022-12-08 | 2022-12-08 | Small resistance detection circuit, device and system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN219039215U (en) |
-
2022
- 2022-12-08 CN CN202223296872.6U patent/CN219039215U/en active Active
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| EP3480605B1 (en) | Current detection system, method and device | |
| CN106841734A (en) | A kind of current sensor and electric current detecting method based on current divider | |
| CN109085510B (en) | Circuit and method for on-line detection and automatic calibration of currents of multiple charge and discharge channels | |
| CN102109579B (en) | Signal monitoring system for controlling electric light source and signal monitoring method | |
| EP2273277A1 (en) | Internal self-check resistance bridge and method | |
| CN109828173A (en) | A kind of load-detecting system and its load detection method | |
| CN112198442A (en) | Battery electric quantity detection method and detection system | |
| CN112305290B (en) | Current detection device | |
| CN106932745A (en) | Calibration circuit and system | |
| CN110967662A (en) | Calibration method of DC leakage current sensor for insulation monitoring of DC system | |
| CN219039215U (en) | Small resistance detection circuit, device and system | |
| CN114156982A (en) | BMS system zero drift compensation circuit and method | |
| CN116125163A (en) | Resistance testing device and resistance testing method | |
| CN217007520U (en) | Precision current sensor circuit based on sampling resistor | |
| CN115932401A (en) | Kelvin-based test circuit, test method and test device | |
| CN114371344A (en) | Initiating explosive device resistance measuring circuit and measuring method | |
| CN213364907U (en) | Charging signal detection circuit and vehicle-mounted equipment | |
| CN113904684B (en) | Resistance network circuit for measuring ADC (analog to digital converter) | |
| CN113804962B (en) | Metering chip and measuring system | |
| CN114485764B (en) | Self-calibration and anti-drift device for weak signal measurement | |
| KR101897522B1 (en) | Internal Resistance Measuring Device | |
| CN113702711A (en) | Resistance test circuit and resistance test method | |
| CN114007897B (en) | Charging signal detection circuit and vehicle-mounted equipment | |
| CN216013480U (en) | Voltage measurement chip and voltage measurement circuit | |
| CN217561943U (en) | CAN bus terminal resistance detection circuit for automobile controller detection |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant |