Anti-interference NTC temperature frequency conversion detection circuit

Abstract

The utility model relates to an anti-interference NTC temperature frequency conversion detection circuit, which comprises an NTC integrating circuit and a comparison generation circuit, the NTC integrating circuit comprises a thermistor, a first comparator, a first voltage division circuit and a first capacitor, the positive phase input end of the NTC integrating circuit is connected to the voltage division output end of the first voltage division circuit, and the negative phase input end of the NTC integrating circuit is connected to the voltage division output end of the second voltage division circuit. The inverting input end is connected to the first end of the thermistor, the output end is connected to one end of the first capacitor, the second end of the thermistor is connected to the positive electrode of the direct-current power supply, and the first end is further connected to the other end of the first capacitor; the comparison generation circuit comprises a second voltage division circuit, a second comparator, a sixth resistor, an MOS switching tube and an output terminal, the normal-phase input end of the second voltage division circuit is connected to the voltage division output end of the second voltage division circuit, and the inverted-phase input end of the second voltage division circuit is connected to the output end of the first comparator and the drain electrode of the MOS switching tube; and the output end is connected to one section of the sixth resistor, the grid electrode of the MOS switch tube and the output terminal. Compared with the prior art, the utility model has the advantages of strong anti-interference capability, good stability and the like.

Description

TECHNICAL FIELD

[0001] The utility model relates to temperature sampling circuit field especially is related to an anti -interference NTC temperature frequency conversion detection circuit. BACKGROUND

[0002] Thermistor is widely used in temperature sampling, and further applied to the control of including heat dissipation fan, heat pump and other executive devices.

[0003] But some scenarios may face the sampling of remote sampling, that is, the position of the temperature required to be collected and the installation position of the executed action device are too far away, at this time the line between the sampling signal and the controller is too long, the signal attenuation is serious, and finally leads to the unideal control effect.

[0004] In the prior art, analog signals are converted into digital signals to realize the anti-interference problem of remote sampling, but in the prior art, the overall circuit structure is complex, depends on some large-scale integrated circuits, the reliability is not high and the maintenance process is difficult. UTILITY MODEL CONTENT

[0005] The utility model relates to an anti -interference NTC temperature frequency conversion detection circuit.

[0006] The utility model can realize the purpose by the following technical scheme:

[0007] An anti -interference NTC temperature frequency conversion detection circuit, including NTC integration circuit and comparison generating circuit,

[0008] The NTC integration circuit includes thermistor, first comparator, first voltage dividing circuit and first capacitor, the positive input end of NTC integration circuit is connected to the voltage dividing output end of first voltage dividing circuit, the inverting input end is connected to the first end of thermistor, the output end is connected to one end of first capacitor, the second end of thermistor is connected to the anode of direct current power supply, and the first end is also connected to the other end of first capacitor, one end of first voltage dividing circuit is connected to the anode of direct current power supply, and the other end is grounded;

[0009] The comparison generating circuit includes second voltage dividing circuit, second comparator, sixth resistance and MOS switch tube, output terminal, the positive input end of second voltage dividing circuit is connected to the voltage dividing output end of second voltage dividing circuit, the inverting input end is connected to the output end of first comparator and the drain of MOS switch tube, the output end is connected to the one end of sixth resistance, the gate of MOS switch tube and output terminal, the other end of sixth resistance is connected to the anode of direct current power supply, one end of second voltage dividing circuit is connected to the anode of direct current power supply, and the other end is grounded, the source of MOS switch tube is connected to the first end of thermistor.

[0010] The first voltage dividing circuit comprises a first resistor and a second resistor connected in sequence.

[0011] The first resistor and the second resistor have equal resistance values.

[0012] The second voltage dividing circuit comprises a third resistor and a fourth resistor connected in sequence.

[0013] The third resistor has a resistance value of 5 times that of the fourth resistor, one end of the third resistor is connected to one end of the fourth resistor, the other end of the third resistor is grounded, and the other end of the fourth resistor is connected to the positive pole of the direct current power supply.

[0014] The MOS switch tube is an N-channel field effect tube.

[0015] The direct current power supply is a 12V power supply.

[0016] A fifth resistor is arranged between the output end of the first comparator and the inverting input end of the second comparator.

[0017] The fifth resistor has the same resistance value as the sixth resistor.

[0018] The output terminal is an aviation plug.

[0019] Compared with the prior art, the utility model has the following beneficial effects:

[0020] 1. An integral circuit is formed by using a thermistor to obtain a voltage corresponding to the resistance value of the current thermistor, and a high level signal is generated based on a comparison generating circuit, and the capacitor of the integral circuit is discharged to generate a pulsating wave, so that the resistance change is converted into a pulsating frequency waveform with different widths, which overcomes the defects of poor long-distance transmission effect and easy interference of analog sampling, and does not depend on large-scale integrated circuits, and has high reliability.

[0021] 2. The fifth resistor has the same resistance value as the sixth resistor, so that the detection range is wider. DRAWINGS

[0022] Figure 1 It is a structural schematic diagram of the utility model;

[0023] Figure 2 It is a circuit principle schematic diagram of the utility model;

[0024] Wherein: 1, NTC integral circuit, 2, comparison generating circuit, U1A, first comparator, U2A, second comparator, R1, first resistor, R2, second resistor, R3, third resistor, R4, fourth resistor, R5, fifth resistor, R6, sixth resistor, NTC1, thermistor, C1, first capacitor, Q1, MOS switch tube, fout, output terminal. DETAILED DESCRIPTION

[0025] The utility model will be described in detail below in combination with the drawings and specific embodiments. The embodiments are implemented on the premise of the technical scheme of the utility model, and detailed implementation modes and specific operation processes are given, but the protection scope of the utility model is not limited to the following embodiments.

[0026] It should be noted that similar reference numerals and letters indicate similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0027] In the description of the utility model, it should be pointed out that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the utility model and simplifying the description, and therefore cannot be understood as indicating or implying that the indicated device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the utility model. In addition, the terms "proximal end", "distal end", "third" are only for description purposes and cannot be understood as indicating or implying relative importance. Physical quantities in formulas, such as no separate marking, should be understood as basic quantities of international system of units, or derived quantities derived from basic quantities by multiplication, division, differentiation or integration, etc.

[0028] In addition, the terms "horizontal", "vertical", "overhanging" and the like do not mean that the components must be absolutely horizontal or overhanging, but can be slightly inclined. For example, "horizontal" only means that its direction is more horizontal relative to "vertical", and does not mean that the structure must be completely horizontal, but can be slightly inclined.

[0029] In the description of the utility model, it should also be pointed out that, unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection" should be broadly understood, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the communication between two elements. For ordinary skilled in the art, the specific meaning of the above terms in the utility model can be understood according to the specific circumstances.

[0030] Some embodiments of the utility model will be described in detail below in combination with the drawings. In the case of no conflict, the following embodiments and features in the embodiments can be combined with each other.

[0031] An anti-interference NTC temperature frequency conversion detection circuit, such as Figure 1 and Figure 2As shown, it comprises an NTC integration circuit 1 and a comparison generating circuit 2;

[0032] The NTC integration circuit 1 comprises a thermistor NTC1, a first comparator U1A, a first voltage dividing circuit and a first capacitor C1, the non-inverting input terminal of the NTC integration circuit 1 is connected to the voltage dividing output terminal of the first voltage dividing circuit, the inverting input terminal is connected to the first terminal of the thermistor NTC1, the output terminal is connected to one terminal of the first capacitor C1, the second terminal of the thermistor NTC1 is connected to the positive pole of a direct current power supply, the first terminal is also connected to the other terminal of the first capacitor C1, one terminal of the first voltage dividing circuit is connected to the positive pole of the direct current power supply, and the other terminal is grounded.

[0033] The comparison generating circuit 2 comprises a second voltage dividing circuit, a second comparator U1B, a sixth resistor R6 and a MOS switch Q1, and an output terminal fout, the non-inverting input terminal of the second voltage dividing circuit is connected to the voltage dividing output terminal of the second voltage dividing circuit, the inverting input terminal is connected to the output terminal of the first comparator U1A and the drain of the MOS switch Q1, the output terminal is connected to one terminal of the sixth resistor R6, the gate of the MOS switch Q1 and the output terminal fout, the other terminal of the sixth resistor R6 is connected to the positive pole of the direct current power supply, one terminal of the second voltage dividing circuit is connected to the positive pole of the direct current power supply, and the other terminal is grounded, and the source of the MOS switch Q1 is connected to the first terminal of the thermistor NTC1.

[0034] In the present application, the thermistor NTC1 is used to form an integration circuit to obtain the voltage corresponding to the resistance value of the thermistor NTC1, and based on the comparison generating circuit 2, a high level signal is generated, and the capacitor of the integration circuit is discharged to generate a pulsating wave, so that the resistance change is converted into a pulsating frequency waveform with different widths, which overcomes the disadvantages of poor effect of analog sampling long distance transmission and easy interference, and does not depend on large scale integrated circuits, and has high reliability.

[0035] In most embodiments, the first voltage dividing circuit comprises a first resistor R1 and a second resistor R2 connected in sequence, and in the present embodiment, the resistance values of the first resistor R1 and the second resistor R2 are equal. Similarly, in most embodiments, the second voltage dividing circuit comprises a third resistor R3 and a fourth resistor R4 connected in sequence. And in the present embodiment, the resistance value of the third resistor R3 is 5 times the resistance value of the fourth resistor R4, one terminal of the third resistor R3 is connected to one terminal of the fourth resistor R4, and the other terminal is grounded, and the other terminal of the fourth resistor R4 is connected to the positive pole of the direct current power supply. In addition, in the present embodiment, the direct current power supply is a 12V power supply. In this way, the voltage at the non-inverting input terminal of the first comparator U1A is 6V, and the voltage at the non-inverting input terminal of the second comparator U1B is 10V.

[0036] Generally, the first resistance R1 and the second resistance R2, the third resistance R3 and the fourth resistance R4 are fixed value resistances, which can be selected from color ring resistances.

[0037] In this embodiment, the MOS switch tube Q1 is an N-channel field effect tube, and the fifth resistance R5 is arranged between the output end of the first comparator U1A and the inverting input end of the second comparator U1B. In addition, in this embodiment, the resistance value of the fifth resistance R5 is consistent with that of the sixth resistance R6, thereby having a wider detection range.

[0038] In some embodiments, the output terminal fout is an aviation plug, which improves the convenience of plugging.

[0039] In this embodiment, the resistance change is converted into a pulse frequency waveform with different widths, which has stronger stability in long distance transmission. This circuit overcomes the shortcomings of poor effect and easy interference of analog sampling in long distance transmission.

Claims

1. An anti-interference NTC temperature frequency conversion detection circuit, characterized in that, The NTC integrating circuit comprises a thermistor, a first comparator, a first voltage dividing circuit and a first capacitor. The NTC integrating circuit comprises a thermistor, a first comparator, a first voltage dividing circuit and a first capacitor. The NTC integrating circuit comprises a thermistor, a first comparator, a first voltage dividing circuit and a first capacitor.

2. The anti-interference NTC temperature frequency conversion detection circuit according to claim 1, characterized in that, The NTC integrating circuit comprises a thermistor, a first comparator, a first voltage dividing circuit and a first capacitor.

3. The anti-interference NTC temperature frequency conversion detection circuit according to claim 2, characterized in that, The NTC integrating circuit comprises a thermistor, a first comparator, a first voltage dividing circuit and a first capacitor.

4. The anti-interference NTC temperature frequency conversion detection circuit according to claim 1, characterized in that, The NTC integrating circuit comprises a thermistor, a first comparator, a first voltage dividing circuit and a first capacitor.

5. The anti-interference NTC temperature frequency conversion detection circuit according to claim 4, characterized in that, The NTC integrating circuit comprises a thermistor, a first comparator, a first voltage dividing circuit and a first capacitor.

6. The anti-interference NTC temperature frequency conversion detection circuit according to claim 1, characterized in that, The NTC integrating circuit comprises a thermistor, a first comparator, a first voltage dividing circuit and a first capacitor.

7. The anti-interference NTC temperature frequency conversion detection circuit according to claim 1, characterized in that, The NTC integrating circuit comprises a thermistor, a first comparator, a first voltage dividing circuit and a first capacitor.

8. The anti-interference NTC temperature frequency conversion detection circuit according to claim 1, characterized in that, The NTC integrating circuit comprises a thermistor, a first comparator, a first voltage dividing circuit and a first capacitor.

9. The anti-interference NTC temperature frequency conversion detection circuit according to claim 8, characterized in that, The NTC integrating circuit comprises a thermistor, a first comparator, a first voltage dividing circuit and a first capacitor.

10. The anti-interference NTC temperature frequency conversion detection circuit according to claim 1, characterized in that, The NTC integrating circuit comprises a thermistor, a first comparator, a first voltage dividing circuit and a first capacitor. The NTC integrating circuit comprises a thermistor, a first comparator, a first voltage dividing circuit and a first capacitor. The NTC integrating circuit comprises a thermistor, a first comparator, a first voltage dividing circuit and a first capacitor. The NTC integrating circuit comprises a thermistor, a first comparator, a first voltage dividing circuit and a first capacitor. The NTC integrating circuit comprises a thermistor, a first comparator, a first voltage dividing circuit and a first capacitor. The NTC integrating circuit comprises a thermistor, a first comparator, a first voltage dividing circuit and a first capacitor. The NTC integrating circuit comprises a thermistor, a first comparator, a first voltage dividing circuit and a first capacitor. The NTC integrating circuit comprises a thermistor, a first comparator, a first voltage dividing circuit and a first capacitor. The NTC integrating circuit comprises a thermistor, a first comparator, a first voltage dividing circuit and a first capacitor. The NTC integrating circuit comprises a thermistor, a first comparator, a first voltage dividing circuit and a first capacitor. The NTC integrating circuit comprises a thermistor, a first comparator, a first voltage dividing circuit and a first capacitor. The NTC integrating circuit comprises a thermistor, a first comparator, a first voltage dividing circuit and a first capacitor. The NTC integrating circuit comprises a thermistor, a first comparator, a first voltage dividing circuit and a first capacitor. The NTC integrating circuit comprises a thermistor, a first comparator, a first voltage dividing circuit and a first capacitor. The NTC integrating circuit comprises a thermistor, a first comparator, a first voltage dividing circuit and a first capacitor. The NTC integrating circuit comprises a thermistor, a first comparator, a first voltage dividing circuit and a first capacitor. The NTC integrating circuit comprises a thermistor, a first comparator, a first voltage dividing circuit and a first capacitor. The NTC integrating circuit comprises a thermistor, a first comparator, a first voltage dividing circuit and a first capacitor. The NTC integrating circuit comprises a thermistor, a first comparator, a first voltage dividing circuit and a first capacitor. The NTC integrating circuit comprises a thermistor, a first comparator, a first voltage dividing circuit and a first capacitor. The NTC integrating circuit comprises a thermistor, a first comparator, a first voltage dividing circuit and a first capacitor. The NTC integrating circuit comprises a thermistor, a first comparator, a first voltage dividing circuit and a first capacitor. The NTC integrating circuit comprises a thermistor, a first comparator, a first voltage dividing circuit and a first capacitor. The NTC integrating circuit comprises a thermistor, a first comparator, a first voltage dividing circuit and a first capacitor. The NTC integrating circuit comprises a thermistor, a first comparator, a first voltage dividing circuit and a first capacitor. The NTC integrating circuit comprises a thermistor, a first comparator, a first voltage dividing circuit and a first capacitor. The NTC integrating circuit comprises a thermistor, a first comparator, a first voltage dividing circuit and a first capacitor. The NTC integrating circuit comprises a thermistor, a first comparator, a first voltage dividing circuit and a first capacitor. The NTC integrating circuit comprises a thermistor, a first comparator, a first voltage dividing circuit and a first capacitor. The NTC integrating circuit comprises a thermistor, a first comparator, a first voltage dividing circuit and a first capacitor. The NTC integrating circuit comprises a thermistor, a first comparator, a first voltage dividing circuit and a first capacitor. The NTC integrating circuit comprises a thermistor,

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