Resistance simulation device and temperature measurement calibration device

Abstract

The embodiment of the utility model provides a resistance simulation device and a temperature measurement calibration device, and belongs to the field of electrical technology. The resistance simulation device comprises a controller, a multi-path simulation switch and a plurality of resistors connected in series, and each resistor has a known resistance value and is in bridge connection with one path of the multi-path simulation switch; the controller controls each path of the multi-path analog switch to be switched off or switched on, so that the resistor corresponding to the path of analog switch in the switched-on state is short-circuited, the analog resistor is the sum of the resistance values of the resistors corresponding to the analog switches in the switched-off state, and the switch withstand voltage of the multi-path analog switch is determined according to the effective voltage range of the resistance simulation device. The resistance simulation device provided by the utility model can quickly obtain the resistance value of the simulation resistor without collecting and reading any resistance value.

Description

TECHNICAL FIELD

[0001] The utility model relates to electrical technology field, specifically relates to a resistance simulation device and temperature measurement calibration device. BACKGROUND

[0002] In prior art, the calibration temperature sensing element is usually simulated by external equipment first, and then the resistance value of the temperature sensing element under the corresponding environment temperature is collected and read, and finally the temperature resistance table of the temperature sensing element is completed through the corresponding relationship of different environment temperatures and resistance values of the temperature sensing element recorded for many times. That is to say, the corresponding resistance value of the temperature sensing element at the specified temperature needs to be measured at any time during the calibration process. However, if the environment temperature fluctuates during the collection and reading of the resistance value, it will cause errors in the calibration, and repeatedly controlling the environment temperature to rise and fall also prolongs the calibration process. Therefore, a resistance simulation device capable of quickly and accurately obtaining the resistance value of the simulated resistance is needed. SUMMARY

[0003] The purpose of the utility model embodiment is to provide a resistance simulation device, which can quickly and accurately obtain the resistance value of the simulated resistance.

[0004] In order to achieve the above purpose, the utility model embodiment provides a resistance simulation device, which comprises a controller, a multi-channel analog switch and a plurality of resistors connected in series, wherein,

[0005] Each of the plurality of resistors has a known resistance value and is connected across one channel of the multi-channel analog switch;

[0006] The controller controls each channel of the multi-channel analog switch to be open or closed, so that the resistance corresponding to the closed channel of the analog switch is short-circuited, and the simulated resistance is the sum of the resistance values of the resistors corresponding to the open channels of the analog switch,

[0007] Wherein, the switch withstand voltage of the multi-channel analog switch is determined according to the effective voltage range of the resistance simulation device.

[0008] Optionally, the multi-channel analog switch has N channels, the number of the plurality of resistors is N+1, and N is an integer greater than 2.

[0009] Further, the plurality of resistors includes one basic resistor and N adjusting resistors, and each of the N channels of the multi-channel analog switch is connected in parallel with one of the N adjusting resistors.

[0010] Optionally, the multi-channel analog switch is an analog switch chip.

[0011] Optionally, the controller independently controls each channel of the multi-channel analog switch to be open or closed.

[0012] Optionally, the controller is a single-chip microcomputer.

[0013] Optionally, the plurality of resistors are integrated resistors with different resistance values.

[0014] In another aspect, the utility model embodiment further provides a temperature measurement calibration device for calibrating a temperature-resistance table of a temperature sensing element, comprising the resistance simulation device of the application, and the controller is used for controlling the multi-way analog switch, so that the simulation resistance is equivalent to the resistance of the temperature sensing element to be calibrated at a plurality of known temperatures.

[0015] Optionally, the values of the plurality of known temperatures are determined according to the temperature-resistance table of the temperature sensing element.

[0016] Optionally, the resistance values of the plurality of resistors are determined according to the temperature-resistance table of the temperature sensing element.

[0017] According to the above technical solution, each of the plurality of resistors is connected across one of the plurality of analog switches, so that the corresponding resistor can be short-circuited by closing the analog switch. The controller is used for controlling each of the plurality of analog switches to be opened or closed. When the resistance values of the plurality of resistors are known, the resistance value of the simulation resistance can be quickly obtained without collecting and reading any resistance value.

[0018] Other features and advantages of the utility model embodiment will be described in detail in the following specific embodiment part. BRIEF DESCRIPTION OF DRAWINGS

[0019] The accompanying drawings are used to provide a further understanding of the utility model embodiment, and constitute a part of the specification, and are used to explain the utility model embodiment together with the following specific embodiment, but do not constitute the limitation to the utility model embodiment. In the drawings:

[0020] Figure 1 It is the circuit schematic view of the resistance simulation device of the application one embodiment;

[0021] Figure 2 It is the circuit schematic view of the resistance simulation device of the application another embodiment;

[0022] Figure 3 It is the circuit schematic view of the temperature measurement calibration device of the application one embodiment.

[0023] EXPLANATION OF REFERENCE NUMERALS

[0024] 1- controller;

[0025] 2- analog load output terminal;

[0026] 3- multi-way analog switch;

[0027] 4- temperature sensing element;

[0028] 5- resistance simulation device. DETAILED DESCRIPTION

[0029] The specific embodiments of the utility model embodiments are described in detail below in conjunction with the drawings. It should be understood that the specific embodiments described herein are only used to illustrate and explain the utility model embodiments, and are not used to limit the utility model embodiments.

[0030] The utility model embodiment provides a resistance simulation device, Figure 1 The circuit arrangement of the resistance simulation device is shown, wherein R0, R1, R2,..., Rn are a plurality of resistors in series, K1, K2,..., Kn are n analog switches of the multi-way analog switch 3, the n analog switches are respectively used to short one resistor in R1 to Rn in series, and the terminals DO1, DO2,..., Don of the controller 1 control the opening or closing of the analog switches K1, K2,..., Kn respectively. When K1, K2,..., Kn are all in the open state, the equivalent analog resistance of the plurality of resistors R0, R1, R2,..., Rn in series is R0+R1+R2+...+Rn, and when one or more of K1, K2,..., Kn are in the closed state, the closed analog switch will short the corresponding resistor, and the equivalent analog resistance of the plurality of resistors R0, R1, R2,..., Rn in series is the sum of the resistance values of the resistors corresponding to the analog switches in the open state. That is to say, for the resistance simulation device of the embodiment, when the resistance values of the plurality of resistors R0, R1, R2,..., Rn in series are all known, the resistance value of any resistor does not need to be measured, and the current analog resistance can be obtained only by calculating the sum of the resistance values of the resistors corresponding to the analog switches in the open state, or when a specific analog resistance is required, the controller 1 can control the opening or closing state of the n analog switches of the multi-way analog switch 3, so that the sum of the resistance values of the resistors corresponding to the analog switches in the open state is the current required analog resistance.

[0031] In the embodiment, the controller 1 is a single-chip microcomputer, which independently controls each analog switch to open or close, but the application is not limited thereto, and the skilled person can set the control logic and select a suitable controller according to the resistance to be simulated.

[0032] In the embodiment, the plurality of resistors R0, R1, R2,..., Rn in series are all integrated resistors with different resistance values, which reduces the resistance value drift caused by temperature and ensures the stability of the output analog resistance.

[0033] It should be noted that the minimum analog resistance that can be obtained by the resistance simulation device in the embodiment is R0, the maximum analog resistance is R0+R1+R2+...+Rn, and the analog resistance that can be obtained is the resistance sum of any 0-n resistance combinations of R0+R1, R2,...Rn. That is, R0 is the base resistance in the embodiment. However, the base resistance is not necessarily included in the application. When the required analog resistance can be 0, the base resistance can also be excluded, so that each resistance in series can be short-circuited by the corresponding analog switch.

[0034] It should also be noted that in the actual scene of using the resistance simulation device of the utility model, the controller is usually powered and the multiple resistances R0, R1, R2,...Rn in series are usually loaded with voltage. The embodiment only exemplarily shows how to obtain part of the current of the analog resistance, and the technician can set the power supply and other accessories according to the application scene.

[0035] Compared with the prior art, the technical advantages of the embodiment are as follows:

[0036] 1. The current resistance value to be simulated can be quickly obtained

[0037] When the resistance values of the multiple resistances R0, R1, R2,...Rn in series are known, the corresponding resistance in the multiple resistances can be short-circuited by controlling the closing of the specific analog switch in the corresponding multiple analog switches, so that the current resistance value to be simulated can be quickly obtained.

[0038] 2. The temperature measurement calibration of the temperature sensing element can be quickly completed

[0039] When the resistance simulation device in the embodiment is used for the temperature measurement calibration of the temperature sensing element, the controller controls the multiple analog switches, and then controls the resistance value of the effective resistance, reduces the resistance instability caused by the contact jitter, and reduces the actual measurement time required;

[0040] 3. When the resistance simulation device in the embodiment is used to obtain the required analog resistance, only the resistance values of the multiple resistances R0, R1, R2,...Rn in series need to be set, each analog switch is independently controlled to be opened or closed by the single-chip microcomputer, and then each resistance with a different resistance value in the series resistance is controlled to be effective or ineffective, so that the analog resistance of any 0-n resistance combinations can be obtained.

[0041] 4. The multiple resistances use integrated resistors, which can reduce the resistance value drift caused by temperature and ensure the stability of the output analog resistance.

[0042] Figure 2 Another embodiment of the resistance simulation device of the application is as follows: Figure 2As shown, R0, R1, R2, R3, R4, R5, R6, R7, and R8 are connected in series. The MAX4802A is an 8-channel analog switch chip. Each of the 8 switches in the MAX4802A is used to short-circuit one of the resistors R1 to R8 in the series connection. The microcontroller is used to control the on / off state of the 8 switches in the MAX4802A. When all 8 switches are in the off state, the equivalent analog resistance of the multiple resistors R0-R8 in series is R0+R1+R2+......+Rn. When one or more of the 8 switches are in the closed state, the closed analog switch will short-circuit the corresponding resistor, so that the equivalent analog resistance of the multiple resistors R0-R8 in series is the sum of the resistance values ​​of the resistors corresponding to the analog switches in the off state. In other words, for the resistor simulation device in this embodiment, when the resistance values ​​of the multiple resistors R0-Rn8 connected in series are known, it is not necessary to measure the resistance value of any resistor. The current analog resistance can be determined by calculating the sum of the resistance values ​​of the resistors corresponding to the analog switches in the open state. Alternatively, when a specific analog resistance is required, the open or closed state of the 8-way switch of the MAX4802A can be controlled by the microcontroller so that the sum of the resistance values ​​of the resistors corresponding to the analog switches in the open state is the required analog resistance.

[0043] It should be noted that in actual scenarios where the resistance simulation device of this utility model is used, it is usually necessary to power the controller and apply voltage to the multiple resistors R0, R1, R2, ... Rn connected in series. This embodiment only provides an example of how to obtain a portion of the current of the simulated resistor. Technicians can set the power supply and other accessories according to the application scenario.

[0044] This utility model embodiment provides a temperature measurement calibration device. Figure 3 The circuit layout of the temperature measurement calibration device is shown. Figure 1 In the illustrated embodiment, the analog resistance output terminal of the resistance simulation device 5 is connected across the two ends of the temperature sensing element 4. A current monitoring device of the same model is used to monitor I1 and I2. When I1 = I2, it indicates that the analog resistance output by the resistance simulation device is equivalent to the resistance of the calibrated temperature sensing element 4 at the current known temperature. A record of the current temperature value and the analog resistance value of the resistance simulation device 5 can be recorded in the temperature resistance table. Adjusting the current ambient temperature causes a change in the resistance of the temperature sensing element 4, and accordingly, the analog resistance of the resistance simulation device 5 is adjusted so that the output analog resistance is equivalent to the resistance of the calibrated temperature sensing element 4 at the new temperature. A record of the current temperature value and the analog resistance value of the resistance simulation device 5 is added to the temperature resistance table. The ambient temperature is continuously adjusted, and the above operation is repeated until the calibration requirements of the temperature resistance table are met.

[0045] It should be noted that this utility model does not limit the use of current monitoring equipment to monitor I1 and I2, and I1 = I2 is used to characterize the analog resistance output by the resistance simulation device as equivalent to the current resistance of the temperature sensing element 4. Technicians can use other known means to determine the multiple relationship between the analog resistance and the current resistance of the temperature sensing element 4, and the current resistance of the temperature sensing element 4 can be determined by the multiple of the analog resistance as equivalent to the current resistance of the temperature sensing element 4.

[0046] In this embodiment, the temperature sensing element can be a resistance temperature detector (RTD) or a thermocouple. For example, the equivalent resistance value of PT100 under different ambient temperatures can be simulated using the resistance simulation device 5 of this application.

[0047] In some implementations, multiple known temperature values ​​are determined based on a temperature resistance table of the temperature sensing element. For example, when the temperature sensing element is PT100, the ambient temperature is controlled to be the typical temperature value of PT100, and the resistance value of PT100 at each typical temperature is calibrated.

[0048] In some implementations, the resistance values ​​of multiple resistors are determined based on a temperature resistance table of the temperature sensing element. For example, when the temperature sensing element is PT100, the resistance values ​​of multiple resistors connected in series in the resistance simulation device 5 are selected so that their simulated resistance values ​​match the resistance values ​​of PT100 in typical application scenarios, and the temperature value at which the resistance value of PT100 is equivalent to the simulated resistance of the resistance simulation device 5 is calibrated.

[0049] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0050] The above are merely embodiments of this application and are not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims

1. A resistive analog device, characterized by, The resistance simulation device comprises: a controller, a multi-path analog switch and a plurality of resistors connected in series, wherein, each of the plurality of resistors has a known resistance value and is connected across one path of the multi-path analog switch; the controller controls each path of the multi-path analog switch to be open or closed, and the corresponding resistor of the closed path is short-circuited, and the analog resistance is the sum of the resistance values of the resistors corresponding to the analog switches in the open state, wherein the switch withstand voltage of the multi-path analog switch is determined according to the effective voltage range of the resistance simulation device.

2. The resistive analog device of claim 1, wherein, The multi-path analog switch has N paths, and the number of the plurality of resistors is N+1, and N is an integer greater than 2.

3. The resistive analog device of claim 2, wherein, The plurality of resistors comprises one base resistor and N adjusting resistors, wherein each of the N paths of the multi-path analog switch is connected in parallel with one of the N adjusting resistors.

4. The resistive analog device of claim 3, wherein, The multi-path analog switch is an analog switch chip.

5. The resistive analog device of any of claims 1 to 4, wherein, The controller independently controls each path of the multi-path analog switch to be open or closed.

6. The resistive analog device of claim 5, wherein, The controller is a single-chip microcomputer.

7. The resistive analog device of claim 1, wherein, The plurality of resistors are integrated resistors with different resistance values.

8. A temperature measuring calibration device for calibrating a temperature-resistance table of a temperature sensing element, characterized by The resistance simulation device according to any one of claims 1 to 7, wherein the controller controls the multi-path analog switch, and the analog resistance is equivalent to the resistance of the temperature-sensing element at a plurality of known temperatures under calibration.

9. The temperature measurement calibration device of claim 8, wherein, The number of the plurality of known temperatures is determined according to a temperature-resistance table of the temperature-sensing element.

10. The temperature measurement calibration device of claim 8, wherein, The resistance values of the plurality of resistors are determined according to a temperature-resistance table of the temperature-sensing element.

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