CN213022023U - Selection circuit for multi-path temperature detection circuit - Google Patents
Selection circuit for multi-path temperature detection circuit Download PDFInfo
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- CN213022023U CN213022023U CN202021588535.2U CN202021588535U CN213022023U CN 213022023 U CN213022023 U CN 213022023U CN 202021588535 U CN202021588535 U CN 202021588535U CN 213022023 U CN213022023 U CN 213022023U
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Abstract
The utility model relates to a selection circuit for a multi-path temperature detection circuit, which comprises a plurality of detection units; the selection circuit comprises a plurality of first amplifiers correspondingly connected with the detection units and a plurality of diodes correspondingly connected with the first amplifiers, wherein the positive input end of the first amplifier is connected with the output end of the detection unit, the negative input end of the first amplifier is connected with the first end of the diode, the second end of the diode is connected with the output end of the first amplifier, the first ends of the diodes are connected in parallel, and the parallel node is used as the output end of the selection circuit. The utility model is used for multichannel temperature detection circuit can select the highest temperature signal among the multichannel temperature signal to export, through carrying out the accuse to the highest risk temperature, when having saved analog quantity acquisition port, has reduced the risk that the product became invalid because of the high temperature, has reduced the cost of product.
Description
Technical Field
The utility model relates to a temperature detect circuit especially relates to a selection circuit for multichannel temperature detect circuit.
Background
When a product has a plurality of high-temperature risk positions, the temperature needs to be collected as much as possible so as to reduce the failure risk of the product. However, the analog quantity acquisition ports with a larger number are required to perform multi-channel temperature detection, and the cost of the analog quantity acquisition ports with a larger number is undoubtedly higher, so that the multi-channel temperature detection is difficult to be implemented for low-cost products.
SUMMERY OF THE UTILITY MODEL
An object of the utility model is to provide a selection circuit for multichannel temperature detection circuit can carry out the accuse to the highest risk temperature, reduces the risk that the product became invalid because of the high temperature, has saved the analog quantity simultaneously and has gathered the port and reduced the cost of product.
In order to achieve the above object, the present invention provides a selection circuit for a multi-path temperature detection circuit, which comprises a plurality of detection units; the selection circuit comprises a plurality of first amplifiers correspondingly connected with the detection units and a plurality of diodes correspondingly connected with the first amplifiers, wherein the positive input end of the first amplifier is connected with the output end of the detection unit, the negative input end of the first amplifier is connected with the first ends of the diodes, the second ends of the diodes are connected with the output end of the first amplifier, the first ends of the diodes are connected in parallel, and the parallel node is used as the output end of the selection circuit.
The utility model discloses insert each temperature signal and selectively output the highest temperature signal, only need an analog quantity gather the port gather this highest temperature signal can, through carrying out the accuse to the highest risk temperature, when having saved analog quantity and gathered the port, reduced the risk that the product became invalid because of the high temperature, reduced the cost of product.
The utility model discloses a further improvement that is used for multichannel temperature detect circuit's selection circuit lies in:
the detection unit comprises a thermistor and a first resistor;
the first end of the first resistor is connected with a power supply, and the second end of the first resistor is connected with the first end of the thermistor;
the first end of the thermistor is used as the output end of the detection unit, and the second end of the thermistor is grounded.
The utility model discloses a further improvement that is used for multichannel temperature detect circuit's selection circuit lies in, thermistor is NTC resistance, the first end of diode is anodal, the second end of diode is the negative pole.
The utility model discloses a further improvement that is used for multichannel temperature detect circuit's selection circuit lies in, detecting element still include with thermistor parallel second resistance.
The utility model discloses a further improvement of selection circuit for multichannel temperature-detecting circuit lies in, positive input, negative input end and the output of first amplifier are connected with third resistance, fourth resistance and fifth resistance respectively, the other end of third resistance is connected detecting element's output, the other end of fourth resistance is connected the first end of diode, the other end of fifth resistance is connected the second end of diode.
The utility model discloses a further improvement of selection circuit for multichannel temperature detect circuit lies in, selection circuit's output is connected with the comparator.
The utility model discloses a further improvement that is used for multichannel temperature detect circuit's selection circuit lies in:
the comparator comprises a second amplifier, a sixth resistor, a seventh resistor, an eighth resistor and a ninth resistor;
a first end of the sixth resistor is connected to the output end of the selection circuit, a second end of the sixth resistor is connected to the positive input end of the second amplifier and the first end of the seventh resistor, respectively, and a second end of the seventh resistor is connected to the output end of the second amplifier;
the first end of the eighth resistor is connected to a power supply, the second end of the eighth resistor is connected to the negative input end of the second amplifier and the first end of the ninth resistor respectively, and the second end of the ninth resistor is grounded.
The utility model discloses a further improvement of selection circuit for multichannel temperature detect circuit lies in, the comparator still includes tenth resistance, the first termination power supply of tenth resistance, second end are connected the output of second amplifier.
Drawings
Fig. 1 is a schematic circuit diagram of a first embodiment of the present invention.
Fig. 2 is a schematic circuit diagram of a second embodiment of the present invention.
Detailed Description
Since a larger number of analog quantity acquisition ports are often required to be provided for performing multi-path temperature detection, and the larger number of analog quantity acquisition ports undoubtedly require higher cost, it is often difficult to implement multi-path temperature detection for low-cost products. To this problem, the utility model provides a selection circuit for multichannel temperature detection circuit can select the highest temperature signal among the multichannel temperature signal that multichannel temperature detection circuit gathered to export, through carrying out the accuse to the highest risk temperature, when having saved analog quantity collection port, has reduced the risk that the product became invalid because of the high temperature, has reduced the cost of product.
The present invention will be described in further detail with reference to the accompanying drawings and specific embodiments.
The present invention provides a first embodiment, please refer to fig. 1, the multi-path temperature detecting circuit includes two detecting units S1; the selection circuit S2 includes two first amplifiers U1 connected to the two detection units S1 and two diodes D1 connected to the two first amplifiers U1, a positive input terminal of the first amplifier U1 is connected to an output terminal of the corresponding detection unit S1, a negative input terminal of the first amplifier U1 is connected to a first terminal of the corresponding diode D1, and a second terminal of the diode D1 is connected to an output terminal of the first amplifier U1; the first terminals of the two diodes D1 are connected in parallel and the parallel node is used as the output terminal of the selection circuit S2.
In the present embodiment, the two detecting units S1 are respectively used for detecting two high temperature risk positions, and converting the detected temperature signals into the first voltage signal V1 for output; the two first amplifiers U1 in the selection circuit S2 are both connected to be followers, and according to the characteristics of the followers, the first voltage signal V1 connected to the first amplifier U1 is output by an output end at approximately 1: 1; in addition, by the unidirectional conduction action of the diode D1 and the parallel connection relationship of the diodes D1, the output terminal of the selection circuit S2 can only output the minimum voltage value or the maximum voltage value of the two first voltage signals V1, and whether the minimum voltage value or the maximum voltage value is output depends on the detection unit S1, specifically: when the temperature signal collected by the detection unit S1 is higher and the converted voltage signal is smaller, the selection circuit S2 outputs the first voltage signal V1 of the minimum voltage value; when the temperature signal collected by the detection unit S1 is higher and the converted voltage signal is larger, the selection circuit S2 outputs the first voltage signal V1 with the maximum voltage value; the connection direction of the diode D1 in the selection circuit S2 determines whether the minimum voltage value or the maximum voltage value is outputted, that is, the selection circuit S2 outputs the minimum voltage value when the first terminal of the diode D1 is positive and the second terminal is negative, and otherwise outputs the maximum voltage value.
Fig. 1 shows only two detection circuits S1, and in practical applications, the detection circuits S1 can be configured according to the number of high-temperature risk positions of the product, and accordingly, the selection circuit S2 performs adaptive adjustment.
Through the selection circuit S2, the functions of accessing all the temperature signals collected by the multiple temperature detection circuits (i.e., the first voltage signal V1 output by the detection unit S1) and selecting the highest temperature signal (i.e., the corresponding first voltage signal V1 with the minimum voltage value or the maximum voltage value, i.e., the second voltage signal V2) for output can be realized. Only one analog quantity acquisition port is needed to acquire the highest temperature signal, and the highest risk temperature is controlled, so that the analog quantity acquisition port is saved, the risk of failure of the product due to high temperature is reduced, and the cost of the product is reduced.
Preferably, the sensing unit S1 includes a thermistor RT1 and a first resistor R1;
the first end of the first resistor R1 is connected with a power supply VCC, and the second end is connected with the first end of the thermistor RT 1;
the first terminal of the thermistor RT1 is used as the output terminal of the detecting unit S1, and the second terminal of the thermistor RT1 is grounded.
In this embodiment, the thermistor RT1 is placed at a high-temperature risk position in a product, since the resistance value of the thermistor RT1 changes with the change of temperature, the temperature signal at each high-temperature risk position in the product can be converted into the first voltage signal V1 by collecting the voltage across the thermistor RT1, and the detection circuit S1 establishes the proportional relationship between the first voltage signal V1 and the temperature signal by adopting the way of dividing the voltage by the first resistor R1.
Specifically, the method comprises the following steps: when the thermistor RT1 is an NTC thermistor with negative temperature coefficient, according to the characteristics of the NTC thermistor, the higher the sensed temperature signal is, the lower the resistance value is, the lower the voltage value at both ends is, and at this time, the second voltage signal V2 output by the selection circuit S2 should be the first voltage signal V1 with the minimum voltage value; when the thermistor RT1 is a PTC thermistor with a positive temperature coefficient, the second voltage signal V2 outputted by the selection circuit S2 should be the first voltage signal V1 with the maximum voltage value.
Preferably, the thermistor RT1 is an NTC resistor (i.e., a negative temperature coefficient thermistor), and the higher the temperature sensed by the NTC resistor, the lower the resistance thereof, and the lower the voltage value across the NTC resistor (i.e., the first voltage signal V1). In order to ensure that the second voltage signal V2 outputted by the selection circuit S2 is the first voltage signal V1 corresponding to the highest temperature signal, in the present embodiment, the first terminal of the diode D1 is a positive terminal, and the second terminal of the diode D1 is a negative terminal.
Preferably, in order to adjust the first voltage signal V1 within a designated range, and to facilitate configuration and calculation of the selection circuit, the sensing unit S1 further includes a second resistor R2 connected in parallel with the thermistor RT 1.
Preferably, in order to facilitate impedance matching of each follower in the selection circuit S2 to the corresponding first voltage signal V1 (i.e., the temperature signal), the positive input terminal, the negative input terminal and the output terminal of the first amplifier U1 are respectively connected to a third resistor R3, a fourth resistor R4 and a fifth resistor R5, the other end of the third resistor R3 is connected to the output terminal of the detection unit S1, the other end of the fourth resistor R4 is connected to the first end of the diode D1, and the other end of the fifth resistor R5 is connected to the second end of the diode D1.
Since the second voltage signal V2 is an analog signal, it is necessary for the subsequent module to have an analog acquisition port to receive the analog signal, and for the low-cost product without the analog acquisition port, the present invention further provides a second embodiment, as shown in fig. 2, the output terminal of the selection circuit S2 is connected to a comparator S3.
The second voltage signal V2 is compared with the set reference voltage by the comparator S3, and a low level or a high level is output as a malfunction alarm signal. The highest risk temperature can be controlled without an analog quantity acquisition port, the risk of product failure due to high temperature is reduced, and the cost of the product is further reduced.
Preferably, in the case of using an NTC resistor as the thermistor RT1, the comparator S3 includes a second amplifier U2, a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, and a ninth resistor R9;
a first end of the sixth resistor R6 is connected to the output end of the selection circuit S2, a second end of the sixth resistor R6 is connected to the positive input end of the second amplifier U2 and the first end of the seventh resistor R7, respectively, a second end of the seventh resistor R7 is connected to the output end of the second amplifier U2, and an output end OUT of the second amplifier U2 outputs a low-level signal as a fault alarm signal;
the first end of the eighth resistor R8 is connected to the power VCC, the second end is connected to the negative input terminal of the second amplifier U2 and the first end of the ninth resistor R9, and the second end of the ninth resistor R9 is grounded.
In this embodiment, the reference voltage of the comparator S3 is determined by dividing the voltage of the eighth resistor R8 and the ninth resistor R9, and the reference voltage value corresponds to the set temperature when a fault alarm is required according to the proportional relationship between the first voltage signal V1 and the temperature signal, so that the highest temperature signal can send out a low level signal for alarm when the highest temperature signal exceeds the set temperature (i.e. the second voltage signal V2 is lower than the reference voltage).
Preferably, the comparator S3 further includes a tenth resistor R10, a first terminal of the tenth resistor R10 is connected to the power source VCC, and a second terminal thereof is connected to the output terminal OUT of the second amplifier U2. By pulling up the tenth resistor R10, sufficient electrical support is provided for the output OUT.
The above is only a preferred embodiment of the present invention, and the present invention is not limited to the above embodiments, and although the present invention has been disclosed with the above preferred embodiments, but the present invention is not limited to the above embodiments, and any skilled person familiar with the art can make some changes or modifications to equivalent embodiments without departing from the technical scope of the present invention, but all the technical matters of the present invention are within the scope of the technical solution of the present invention.
Claims (7)
1. A selection circuit for a multi-path temperature detection circuit comprises a plurality of detection units, and is characterized in that the selection circuit comprises a plurality of first amplifiers correspondingly connected with the detection units and a plurality of diodes correspondingly connected with the first amplifiers, a positive input end of each first amplifier is connected with an output end of the detection unit, a negative input end of each first amplifier is connected with a first end of each diode, a second end of each diode is connected with an output end of the corresponding first amplifier, first ends of the diodes are connected in parallel and take parallel nodes as output ends of the selection circuit, and the output end of the selection circuit is connected with a comparator.
2. The selection circuit for a multiple temperature sensing circuit of claim 1, wherein:
the detection unit comprises a thermistor and a first resistor;
the first end of the first resistor is connected with a power supply, and the second end of the first resistor is connected with the first end of the thermistor;
the first end of the thermistor is used as the output end of the detection unit, and the second end of the thermistor is grounded.
3. The selection circuit of claim 2, wherein the thermistor is an NTC resistor, the first terminal of the diode is a positive terminal, and the second terminal of the diode is a negative terminal.
4. The selection circuit for a multiple temperature sensing circuit of claim 2, wherein said sensing unit further comprises a second resistor in parallel with said thermistor.
5. The selection circuit for multiple temperature detection circuits according to claim 1, wherein a positive input terminal, a negative input terminal and an output terminal of the first amplifier are respectively connected to a third resistor, a fourth resistor and a fifth resistor, the other terminal of the third resistor is connected to the output terminal of the detection unit, the other terminal of the fourth resistor is connected to the first terminal of the diode, and the other terminal of the fifth resistor is connected to the second terminal of the diode.
6. The selection circuit for a multiple temperature sensing circuit of claim 1, wherein:
the comparator comprises a second amplifier, a sixth resistor, a seventh resistor, an eighth resistor and a ninth resistor;
a first end of the sixth resistor is connected to the output end of the selection circuit, a second end of the sixth resistor is connected to the positive input end of the second amplifier and the first end of the seventh resistor, respectively, and a second end of the seventh resistor is connected to the output end of the second amplifier;
the first end of the eighth resistor is connected to a power supply, the second end of the eighth resistor is connected to the negative input end of the second amplifier and the first end of the ninth resistor respectively, and the second end of the ninth resistor is grounded.
7. The selection circuit of claim 6, wherein the comparator further comprises a tenth resistor, a first terminal of the tenth resistor is connected to the power supply, and a second terminal of the tenth resistor is connected to the output terminal of the second amplifier.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202021588535.2U CN213022023U (en) | 2020-08-03 | 2020-08-03 | Selection circuit for multi-path temperature detection circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202021588535.2U CN213022023U (en) | 2020-08-03 | 2020-08-03 | Selection circuit for multi-path temperature detection circuit |
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| Publication Number | Publication Date |
|---|---|
| CN213022023U true CN213022023U (en) | 2021-04-20 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202021588535.2U Active CN213022023U (en) | 2020-08-03 | 2020-08-03 | Selection circuit for multi-path temperature detection circuit |
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| Country | Link |
|---|---|
| CN (1) | CN213022023U (en) |
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- 2020-08-03 CN CN202021588535.2U patent/CN213022023U/en active Active
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