CN210089883U - Temperature sampling circuit - Google Patents
Temperature sampling circuit Download PDFInfo
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- CN210089883U CN210089883U CN201920747456.2U CN201920747456U CN210089883U CN 210089883 U CN210089883 U CN 210089883U CN 201920747456 U CN201920747456 U CN 201920747456U CN 210089883 U CN210089883 U CN 210089883U
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Abstract
The utility model provides a temperature sampling circuit, which is connected in parallel between one end of a temperature sensor and the ground through a resistance matching circuit and a voltage dividing circuit, and the resistance value of the resistance matching circuit is adjustable; when the type or model of the temperature sensor is changed, the resistance value of the corresponding temperature sensor at the same temperature is changed, the parallel resistance value of the voltage division circuit and the resistance matching circuit can be changed by adjusting the resistance value of the resistance matching circuit, and then the voltage value at the parallel connection position of the voltage division circuit and the resistance matching circuit is adjusted to the acceptable sampling range of the controller, so that the temperature sampling circuit is adaptive to the corresponding temperature sensor, and the compatibility of the temperature sampling circuit to the type of the temperature sensor is improved.
Description
Technical Field
The utility model relates to a power electronic technology field, in particular to temperature sampling circuit.
Background
Temperature sensor need just can transmit the temperature signal who obtains to the AD sample connection of controller through corresponding temperature sampling circuit, and temperature sampling circuit among the prior art carries out circuit design to the temperature sensor of a certain section concrete model usually, and each temperature sensor corresponds a set of temperature sampling circuit promptly.
However, in practical application, the types of the temperature sensors are more, for example, the temperature sensors of the whole vehicle include NTC, PT100, PT1000 and the like; when the temperature sensor changes the model, the circuit parameters of the temperature sampling circuit need to be redesigned, so that the hardware version is increased, the hardware maintenance is not facilitated, and the circuit compatibility is not strong.
SUMMERY OF THE UTILITY MODEL
The utility model provides a temperature sampling circuit to promote the compatibility to the temperature sensor type.
In order to achieve the purpose, the technical scheme provided by the application is as follows:
a temperature sampling circuit, comprising: a voltage division circuit and a resistor matching circuit; wherein:
the resistor matching circuit and the voltage division circuit are connected between one end of the temperature sensor and the ground in parallel;
the resistance value of the resistance matching circuit is adjustable.
Preferably, the resistance matching circuit includes at least one controlled branch, the controlled branch is connected in parallel with the voltage dividing circuit, and a control end of the controlled branch is connected to an I/O port of the controller.
Preferably, the controlled branch comprises: the first resistor and the switching tube are connected in series;
and the control end of the switching tube is the control end of the controlled branch.
Preferably, the resistance matching circuit comprises an adjustable resistor.
Preferably, the voltage dividing circuit includes a third resistor.
Preferably, the method further comprises the following steps: a current limiting circuit;
the current limiting circuit is connected between the other end of the temperature sensor and the power supply.
Preferably, the current limiting circuit comprises a second resistor.
Preferably, the method further comprises the following steps: the device comprises a front-stage filter circuit, a conditioning circuit and a rear-stage filter circuit;
the connection points of the temperature sensor, the voltage division circuit and the resistor matching circuit are connected with an AC sampling port of the controller sequentially through the pre-stage filter circuit, the conditioning circuit and the post-stage filter circuit.
Preferably, the pre-filter circuit includes: a first LC filter and an operational amplifier;
the input end of the first LC filter is connected with the connection point of the temperature sensor and the voltage division circuit;
the output end of the first LC filter is connected with the non-inverting input end of the operational amplifier;
and the inverting input end and the output end of the operational amplifier are connected with the input end of the conditioning circuit.
Preferably, the conditioning circuit is a linear conditioning circuit.
Preferably, the post-stage filter circuit includes: a second LC filter;
the input end of the second LC filter is connected with the output end of the conditioning circuit;
and the output end of the second LC filter is connected with the AC sampling port of the controller.
The utility model provides a temperature sampling circuit, which is connected in parallel between one end of a temperature sensor and the ground through a resistance matching circuit and a voltage dividing circuit, and the resistance value of the resistance matching circuit is adjustable; when the type or model of the temperature sensor is changed, the resistance value of the corresponding temperature sensor at the same temperature is changed, the parallel resistance value of the voltage division circuit and the resistance matching circuit can be changed by adjusting the resistance value of the resistance matching circuit, and then the voltage value at the parallel connection position of the voltage division circuit and the resistance matching circuit is adjusted to the acceptable sampling range of the controller, so that the temperature sampling circuit is adaptive to the corresponding temperature sensor, and the compatibility of the temperature sampling circuit to the type of the temperature sensor is improved.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.
Fig. 1 is a schematic structural diagram of a temperature sampling circuit provided in an embodiment of the present invention;
fig. 2 is a circuit diagram of a temperature sampling circuit according to an embodiment of the present invention.
Detailed Description
The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.
The utility model provides a temperature sampling circuit to promote the compatibility to the temperature sensor type.
Specifically, referring to fig. 1, the temperature sampling circuit includes: a voltage divider circuit 102 and a resistance matching circuit 103; wherein:
the resistor matching circuit 103 and the voltage division circuit 102 are connected between one end of the temperature sensor and the ground in parallel; the equivalent resistance of the connected temperature sensor in the series branch is Rx, the connection point with the voltage divider circuit 102 is Temp-, and the connection point of the other end thereof with other circuits is Temp +.
Moreover, the resistance value of the resistance matching circuit 103 is adjustable; in order to realize adjustable resistance value, the resistance matching circuit 103 can be realized by an adjustable resistor or a plurality of series-parallel connected resistance branches, and the switching of each resistance branch is controllable, so that the function of adjustable overall resistance value is realized; the practical application can be determined according to the specific situation, and the method is not limited herein and is within the protection scope of the present application.
The connection points of the temperature sensor, the voltage divider circuit 102 and the resistor matching circuit 103 are connected with the AC sampling port of the controller through other subsequent circuits. The controller may be a DSP (Digital Signal Processing), or may be another control chip, and is not limited in detail here. In addition, in practical application, the I/O port of the controller may be used to output the control signal of the resistor branch, so as to realize the function of adjusting the resistance value of the resistor matching circuit 103.
In the temperature sampling circuit provided by this embodiment, the resistor matching circuit 103 and the voltage dividing circuit 102 are connected in parallel between one end of the temperature sensor and the ground, and the resistance value of the resistor matching circuit 103 is adjustable; when the type or model of the temperature sensor is changed, so that the resistance value of the corresponding temperature sensor at the same temperature is changed, the parallel resistance value of the voltage division circuit 102 and the resistance matching circuit 103 can be changed by adjusting the resistance value of the resistance matching circuit 103, and then the voltage value at the parallel connection position of the voltage division circuit 102 and the resistance matching circuit 103 is adjusted to the sampling range acceptable by the controller, so that the temperature sampling circuit is adapted to the corresponding temperature sensor, and the compatibility of the temperature sampling circuit to the type of the temperature sensor is improved.
Another embodiment of the present invention provides a specific temperature sampling circuit, based on the above-mentioned embodiment and fig. 1, preferably, as shown in fig. 2, the resistance matching circuit 103 includes at least one controlled branch, the controlled branch is connected in parallel with the voltage dividing circuit 102, and the control end of the controlled branch is connected to the I/O port of the controller. Fig. 2 illustrates an example of a controlled branch, in practical applications, a plurality of controlled branches may be connected in parallel, which is not specifically limited herein and is within the protection scope of the present application depending on the application environment.
The controlled branch circuit has the main function of controlling the switching of the self resistor according to the received control signal so as to change the resistance value of the controlled branch circuit connected with the voltage division circuit 102 in parallel; therefore, preferably, the controlled branch comprises only: a first resistor R1 and a switch tube Q1 which are connected in series; the control end of the switching tube Q1 is the control end of the controlled branch, and receives a control signal Vtemp _ sel; and the control signal Vtemp _ sel is derived from the I/O port of the controller.
In practical applications, the switching tube Q1 may be implemented by a Metal-Oxide-semiconductor field-Effect Transistor (MOSFET), or may be implemented by other devices, such as an IGBT (Insulated Gate Bipolar Transistor), a triode, and the like, which is not specifically limited herein and is within the protection scope of the present application depending on the application environment.
A controller, such as the DSP shown in fig. 2, configures the control signal of the switching tube Q1 for different temperature sensors; specifically, if the corresponding resistance value of a certain temperature sensor is smaller at the same temperature, the I/O port of the DSP may send a high level (taking the example that the switching tube Q1 adopts a MOSFET as an example), so as to turn on the switching tube Q1, and connect the first resistor R1 to the voltage dividing circuit 102, so that the voltage at the connection point Temp-satisfies the voltage dividing range. When the corresponding resistance value of a certain temperature sensor is larger at the same temperature, the I/O port of the DSP sends low level to turn off the switch tube Q1, the first resistor R1 is cut off and separated from the voltage division circuit 102, and therefore the voltage at the connection point Temp-is adjusted to be within the acceptable sampling range of the DSP.
Another embodiment of the present invention provides a complete temperature sampling circuit, and on the basis of the above embodiment, it is preferable that, as shown in fig. 1, the temperature sampling circuit further includes: a current limiting circuit 101, a pre-stage filter circuit 104, a conditioning circuit 105 and a post-stage filter circuit 106; wherein:
the current limiting circuit 101 is connected between the other end of the temperature sensor and a power supply VCC;
the connection point of the temperature sensor, the voltage divider circuit 102 and the resistor matching circuit 103 is connected with the AC sampling port of the controller sequentially through the pre-filter circuit 104, the conditioning circuit 105 and the post-filter circuit 106.
And, referring to fig. 2, a preferred implementation form of the above-mentioned circuits is:
the current limiting circuit 101 includes a second resistor R2, and the voltage dividing circuit 102 includes a third resistor R3. The second resistor R2, the equivalent resistor Rx of the temperature sensor, and the third resistor R3 are connected in series between the power source VCC and the ground in this order.
The main function of the second resistor R2 is to limit the current and prevent the short circuit to the ground caused by the temperature sensor; the third resistor R3 is a voltage dividing resistor, and its main function is to convert the temperature signal of the temperature sensor into a recognizable voltage signal.
As shown in fig. 2, the pre-filter circuit 104 includes: a first LC filter and an operational amplifier; wherein: the input end of the first LC filter is connected with the connection point of the temperature sensor and the voltage division circuit 102; the output end of the first LC filter is connected with the non-inverting input end of the operational amplifier; the inverting input and output of the operational amplifier are connected to the input of the conditioning circuit 105.
The first LC filter comprises a fourth resistor R4 and a first capacitor C1; wherein: one end of the fourth resistor R4 is the input end of the first LC filter; the other end of the fourth resistor R4 is connected with one end of the first capacitor C1, and the connection point is the output end of the first LC filter; the other terminal of the first capacitor C1 is connected to ground.
When the temperature sensor is used to collect the temperature of the motor, the pre-filter circuit 104 mainly functions to filter out interference signals from the motor.
And the post-filter circuit 106 includes: a second LC filter; wherein: the input of the second LC filter is connected to the output of the conditioning circuit 105; and the output end of the second LC filter outputs a voltage signal Vtemp _ DSP and is connected with the AC sampling port of the controller.
The second LC filter comprises a fifth resistor R5 and a second capacitor C2; wherein: one end of the fifth resistor R5 is the input end of the second LC filter; the other end of the fifth resistor R5 is connected with one end of the second capacitor C2, and the connection point is the output end of the second LC filter; the other terminal of the second capacitor C2 is connected to ground.
The conditioning circuit 105 is a linear conditioning circuit, and the linear conditioning circuit is used for performing linear operation on the voltage signal Vin obtained after temperature conversion and filtering, so that the sampling precision and the resolution of the circuit are improved.
According to the temperature sampling circuit provided by the embodiment, the control signal Vtemp _ sel output by the I/O port is configured through software, so that the temperature sensors of at least two different models can be compatible on the basis that the same temperature sampling circuit is used without changing hardware parameters, the more the number of the controlled branches is, the more the types of the temperature sensors can be compatible are, for example, NTC, PT100, PT1000 and other finished automobile motor temperature sensors are, and the hardware version and the maintenance cost of the temperature sampling circuit are reduced.
It is worth to be noted that, in the prior art, temperature segmented sampling is generally adopted to improve the sampling precision, but the precision of the temperature segmented point is poor; the temperature sampling circuit provided by the embodiment improves the sampling precision through a superposition difference mode, and further can achieve the purpose of high-precision sampling of the motor temperature.
In addition, the controller in the prior art generally needs to adopt a plurality of ADC sampling paths to determine the fault state of the temperature sensor, which causes resource waste of the AD port.
In the temperature sampling circuit provided by the embodiment, only one AD sampling port is needed, whether a transmission line of the motor temperature sensor has a fault can be identified by judging the range of the voltage value of the AD port, and an additional fault judgment circuit can be saved; specifically, the temperature sampling circuit identifies different types of faults as shown in table 1:
TABLE 1 identification of different types of faults by temperature sampling circuit
It can be seen from table 1 that the temperature sampling circuit can judge whether the temperature sensor has a fault by using the temperature sampling port (AD sampling port in table 1 and above) to acquire a close voltage range.
The embodiments of the present invention are described in a progressive manner, each embodiment is mainly described as different from the other embodiments, and the same similar parts between the embodiments are referred to each other.
The above description is only for the preferred embodiment of the present invention, and is not intended to limit the present invention in any way. Although the present invention has been described with reference to the preferred embodiments, it is not intended to limit the present invention. The invention is not limited to the embodiments described herein, but is capable of other embodiments according to the invention, and may be used in various other applications, including, but not limited to, industrial. Therefore, any simple modification, equivalent change and modification made to the above embodiments by the technical entity of the present invention all still fall within the protection scope of the technical solution of the present invention, where the technical entity does not depart from the content of the technical solution of the present invention.
Claims (11)
1. A temperature sampling circuit, comprising: a voltage division circuit and a resistor matching circuit; wherein:
the resistor matching circuit and the voltage division circuit are connected between one end of the temperature sensor and the ground in parallel;
the resistance value of the resistance matching circuit is adjustable.
2. The temperature sampling circuit according to claim 1, wherein the resistor matching circuit comprises at least one controlled branch, the controlled branch is connected in parallel with the voltage dividing circuit, and a control end of the controlled branch is connected with an I/O port of the controller.
3. The temperature sampling circuit of claim 2, wherein the controlled branch comprises: the first resistor and the switching tube are connected in series;
and the control end of the switching tube is the control end of the controlled branch.
4. The temperature sampling circuit of claim 1, wherein the resistance matching circuit comprises an adjustable resistance.
5. The temperature sampling circuit of any of claims 1-4, wherein the voltage divider circuit comprises a third resistor.
6. The temperature sampling circuit of any of claims 1-4, further comprising: a current limiting circuit;
the current limiting circuit is connected between the other end of the temperature sensor and the power supply.
7. The temperature sampling circuit of claim 6, wherein the current limiting circuit comprises a second resistor.
8. The temperature sampling circuit of any of claims 1-4, further comprising: the device comprises a front-stage filter circuit, a conditioning circuit and a rear-stage filter circuit;
the connection points of the temperature sensor, the voltage division circuit and the resistor matching circuit are connected with an AC sampling port of the controller sequentially through the pre-stage filter circuit, the conditioning circuit and the post-stage filter circuit.
9. The temperature sampling circuit of claim 8, wherein the pre-filter circuit comprises: a first LC filter and an operational amplifier;
the input end of the first LC filter is connected with the connection point of the temperature sensor and the voltage division circuit;
the output end of the first LC filter is connected with the non-inverting input end of the operational amplifier;
and the inverting input end and the output end of the operational amplifier are connected with the input end of the conditioning circuit.
10. The temperature sampling circuit of claim 8, wherein the conditioning circuit is a linear conditioning circuit.
11. The temperature sampling circuit of claim 8, wherein the post-filter circuit comprises: a second LC filter;
the input end of the second LC filter is connected with the output end of the conditioning circuit;
and the output end of the second LC filter is connected with the AC sampling port of the controller.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
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CN201920747456.2U CN210089883U (en) | 2019-05-23 | 2019-05-23 | Temperature sampling circuit |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
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CN201920747456.2U CN210089883U (en) | 2019-05-23 | 2019-05-23 | Temperature sampling circuit |
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CN210089883U true CN210089883U (en) | 2020-02-18 |
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CN201920747456.2U Active CN210089883U (en) | 2019-05-23 | 2019-05-23 | Temperature sampling circuit |
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- 2019-05-23 CN CN201920747456.2U patent/CN210089883U/en active Active
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