Temperature control device based on analog device

Abstract

The utility model discloses a temperature control device based on an analog device. The temperature control device comprises a temperature sensor, a voltage conversion circuit, a reference voltage circuit, a filter, a comparator, a temperature adjusting circuit, a hysteresis adjusting circuit and a control output circuit. The temperature sensor is connected to the voltage conversion circuit, the output of the voltage conversion circuit is connected to the comparator after passing through the filter, and the reference voltage circuit generates reference voltage and transmits the reference voltage to the voltage conversion circuit; the temperature adjusting circuit is connected to the comparator, the hysteresis adjusting circuit is connected to the comparator after passing through the reference voltage circuit, the comparator is connected to the control output circuit, and the control output circuit outputs a temperature control signal to temperature adjusting equipment. The temperature regulation circuit is high in temperature regulation stability, simple in circuit and low in cost.

Description

Technical Field

[0001] The utility model belongs to the technical field of temperature control, and in particular relates to a temperature control device based on an analog device. Background Art

[0002] With the rapid development of science and technology, people's demand for temperature control accuracy is increasing, and temperature control devices are also constantly evolving and innovating. Industrial furnaces, electric furnaces, boilers and other high-temperature equipment have extremely high requirements for temperature stability and accuracy during the production process. Early temperature control mainly relied on mechanical and electrical methods, such as thermocouple controllers. Although these devices met the needs to a certain extent, they had problems such as low accuracy and slow response speed.

[0003] With the advancement of science and technology and the increasing requirements for temperature control accuracy in the fields of industry, medical treatment, and home, traditional temperature control devices have been unable to meet the needs of modern applications. Most of the temperature control devices in the prior art have problems such as insufficient accuracy, slow response speed, and poor stability. Especially under complex and changing environmental conditions, their performance is particularly poor, and the circuits are complex and the cost is high. Utility Model Content

[0004] In order to overcome the shortcomings of the prior art methods, the purpose of the utility model is to provide a temperature control device based on analog devices, which has strong temperature regulation stability, simple circuit and low cost.

[0005] In order to achieve the above purpose, the technical solution adopted by the utility model is: a temperature control device based on analog devices,

[0006] The beneficial effects of adopting the technical solution are as follows: a temperature control device based on analog devices, comprising: a temperature sensor, a voltage conversion circuit, a reference voltage circuit, a filter, a comparator, a temperature adjustment circuit, a hysteresis adjustment circuit and a control output circuit; the temperature sensor is connected to the voltage conversion circuit, the output of the voltage conversion circuit is connected to the comparator after passing through the filter, the reference voltage circuit generates a reference voltage and transmits it to the voltage conversion circuit; the temperature adjustment circuit is connected to the comparator, the hysteresis adjustment circuit is connected to the comparator after passing through the reference voltage circuit, the comparator is connected to the control output circuit, and the control output circuit outputs a temperature control signal to the temperature adjustment device.

[0007] Furthermore, the voltage conversion circuit adopts a bridge circuit composed of resistors.

[0008] Furthermore, the filter is an RC filter.

[0009] Furthermore, the comparison circuit uses a comparison operational amplifier, the inverting input terminal of the amplifier is connected to the reference voltage circuit and the temperature adjustment circuit; the non-inverting input terminal of the amplifier is connected to the output terminal of the filter.

[0010] Furthermore, the temperature regulating circuit adopts an adjustable resistor.

[0011] Furthermore, the hysteresis adjustment circuit includes an adjustable resistor R1, a first fixed resistor R2 and a first capacitor C1, and the first fixed resistor R2 and the first capacitor C1 are connected in parallel and then connected in series with the adjustable resistor R1.

[0012] Furthermore, a hysteresis feedback circuit is provided, which is connected between the input terminal and the output terminal of the comparator;

[0013] The hysteresis feedback circuit includes a diode D1, an adjustable resistor R3 and a second capacitor C2. The diode D1 and the adjustable resistor R3 are connected in series and then connected in parallel with the second capacitor C2.

[0014] Furthermore, a manual adjustment circuit is provided on the control output circuit, comprising a toggle switch K, a diode D2 and a fixed resistor R4 connected in series in sequence.

[0015] Furthermore, the control output circuit outputs a temperature control signal to an adjustment indicator light.

[0016] The temperature controller provided by the utility model is mainly composed of analog devices, which improves the stability of temperature control and reduces the cost of products.

[0017] The temperature controller proposed by the utility model mainly realizes the over-temperature start-up of the cooling device, so that the temperature is controlled at a certain temperature. The main application areas are cooling systems in various industries, such as water heaters, power capacitor cabinets, cabinets, etc. This temperature control circuit has the advantages of simple structure, stable and reliable operation, and low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a structural schematic diagram of a temperature control device based on an analog device of the utility model;

[0019] Figure 2 It is a structural schematic diagram of an optimized implementation scheme in an embodiment of the utility model. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solution and advantages of the utility model clearer, the utility model is further described below with reference to the accompanying drawings.

[0021] In this embodiment, see Figure 1As shown, a temperature control device based on analog devices includes: a temperature sensor, a voltage conversion circuit, a reference voltage circuit, a filter, a comparator, a temperature adjustment circuit, a hysteresis adjustment circuit and a control output circuit; the temperature sensor is connected to the voltage conversion circuit, the output of the voltage conversion circuit is connected to the comparator after passing through the filter, the reference voltage circuit generates a reference voltage and transmits it to the voltage conversion circuit; the temperature adjustment circuit is connected to the comparator, the hysteresis adjustment circuit is connected to the comparator after passing through the reference voltage circuit, the comparator is connected to the control output circuit, and the control output circuit outputs a temperature control signal to the temperature adjustment device.

[0022] Among them, the temperature sensor can be PT100, NTC temperature sensor, thermocouple, etc. Appropriate temperature sensors can be selected for different occasions. PT100 can be used for high temperature accuracy; NTC temperature sensor can be used in general occasions; thermocouple is suitable for relatively high temperature applications.

[0023] Reference voltage circuit: The reference voltage circuit mainly generates a stable reference voltage, which is used to provide a stable reference signal to the voltage conversion and comparison circuits.

[0024] Control output circuit: This part of the circuit consists of optical coupling relays, which mainly control external temperature control devices and / or adjust indicator lights.

[0025] Preferably, the voltage conversion circuit uses a bridge circuit composed of resistors, so as to convert the temperature signal into a voltage signal, which is convenient for subsequent circuits to process the signal.

[0026] Preferably, the filter adopts an RC filter, which is mainly composed of a resistor, an inductor and a capacitor. This circuit can filter out various high-frequency interference signals generated in the temperature sensor circuit and retain the effective temperature signal, thereby ensuring the reliability of the comparator and improving the temperature control accuracy.

[0027] Preferably, the comparison circuit uses a comparison operational amplifier, the inverting input terminal of the amplifier is connected to a reference voltage circuit and a temperature adjustment circuit for comparing the input temperature signal; the same-direction input terminal of the amplifier is connected to the output terminal of the filter, and the output terminal of the filter outputs a processed temperature sensor signal.

[0028] Preferably, the temperature regulating circuit adopts an adjustable resistor, and adjusting the resistance value of the adjustable resistor can change the corresponding voltage of the comparator regulator, thereby changing the output of the comparator.

[0029] Preferably, Figure 2 As shown, the hysteresis adjustment circuit includes an adjustable resistor R1, a first fixed resistor R2 and a first capacitor C1. The first fixed resistor R2 and the first capacitor C1 are connected in parallel and then connected in series with the adjustable resistor R1.

[0030] The function of the first capacitor C1 is to filter out the interference signal in the circuit; the first fixed resistor R2 is a fixed high-precision low-temperature drift power resistor; the adjustable resistor R1 is a high-precision adjustable resistor. The input voltage of the reference voltage circuit can be changed through the adjustable resistor R1, thereby adjusting the input reference voltage of the comparator. The voltage input to the comparator changes with the change of temperature. When the input voltage is higher than the reference voltage, the comparator outputs a high level to control the output circuit, thereby starting the cooling device to start cooling; at this time, the hysteresis feedback circuit also starts to work, and the reference voltage of the comparator will also increase at the same time. If the input temperature signal becomes smaller at this time, the output level of the comparator will not change, and the cooling device will continue to work. Only when the temperature drops to the set lower limit, that is, when the reference voltage is less than the input circuit voltage, the comparator outputs a low level to control the output circuit to stop the cooling device from working.

[0031] As an optimization solution of the above embodiment, Figure 2 As shown, a hysteresis feedback circuit is also provided, which is connected between the input terminal and the output terminal of the comparator;

[0032] The hysteresis feedback circuit includes a diode D1, an adjustable resistor R3 and a second capacitor C2. The diode D1 and the adjustable resistor R3 are connected in series and then connected in parallel with the second capacitor C2.

[0033] The main function of the diode D1 is to clamp the output voltage of the comparator; the function of the second capacitor C2 is filtering; the adjustable resistor R3 is a high-precision adjustable resistor used for feedback adjustment before leaving the factory.

[0034] The main purpose of this circuit is that when the temperature drops to a certain value of the set temperature, the control output circuit will be reversed, realizing the hysteresis process of temperature control, and the repeated action of the set temperature up and down will not occur.

[0035] As an optimization solution of the above embodiment, Figure 2 As shown, a manual adjustment circuit is provided on the control output circuit, including a toggle switch K, a diode D2 and a fixed resistor R4 which are sequentially connected in series.

[0036] The function of the toggle switch K is to switch between automatic temperature control and forced start of the cooling device; the diode D2 here is used for rectification; the fixed resistor R4 is used for protection and current limiting. When the toggle switch K is closed, regardless of the external temperature, the output end of the comparison circuit will be forced to output a high level, thereby starting the cooling device to start cooling; when the toggle switch K is opened, the device starts to control the start and stop of the cooling device.

[0037] As an optimization solution of the above embodiment, Figure 1As shown, the control output circuit outputs a temperature control signal to the adjustment indicator light.

[0038] The above shows and describes the basic principle, main features and advantages of the utility model. Those skilled in the art should understand that the utility model is not limited by the above embodiments. The above embodiments and descriptions are only for explaining the principle of the utility model. Without departing from the spirit and scope of the utility model, the utility model may have various changes and improvements, which fall within the scope of the utility model to be protected. The scope of protection of the utility model is defined by the attached claims and their equivalents.

Claims

1. A temperature control device based on an analog device, characterized in that: include: A temperature sensor, a voltage conversion circuit, a reference voltage circuit, a filter, a comparator, a temperature adjustment circuit, a hysteresis adjustment circuit and a control output circuit; the temperature sensor is connected to the voltage conversion circuit, the output of the voltage conversion circuit is connected to the comparator after passing through the filter, the reference voltage circuit generates a reference voltage and transmits it to the voltage conversion circuit; the temperature adjustment circuit is connected to the comparator, the hysteresis adjustment circuit is connected to the comparator after passing through the reference voltage circuit, the comparator is connected to the control output circuit, and the control output circuit outputs a temperature control signal to the temperature adjustment device.

2. A temperature control device based on an analog device according to claim 1, characterized in that: The voltage conversion circuit adopts a bridge circuit composed of resistors.

3. A temperature control device based on an analog device according to claim 1, characterized in that: The filter is an RC filter.

4. A temperature control device based on an analog device according to claim 1, characterized in that: The comparator adopts a comparison operational amplifier, the reverse input end of the amplifier is connected to the reference voltage circuit and the temperature adjustment circuit; the same-direction input end of the amplifier is connected to the output end of the filter.

5. The temperature control device based on analog device according to claim 1, characterized in that: The temperature regulating circuit adopts an adjustable resistor.

6. The temperature control device based on analog device according to claim 1, characterized in that: The hysteresis adjustment circuit includes an adjustable resistor R1, a first fixed resistor R2 and a first capacitor C1. The first fixed resistor R2 and the first capacitor C1 are connected in parallel and then connected in series with the adjustable resistor R1.

7. A temperature control device based on an analog device according to claim 6, characterized in that: A hysteresis feedback circuit is also provided, which is connected between the input terminal and the output terminal of the comparator; The hysteresis feedback circuit includes a diode D1, an adjustable resistor R3 and a second capacitor C2. The diode D1 and the adjustable resistor R3 are connected in series and then connected in parallel with the second capacitor C2.

8. The temperature control device based on analog device according to claim 1, characterized in that: A manual adjustment circuit is arranged on the control output circuit, comprising a toggle switch K, a diode D2 and a fixed resistor R4 which are sequentially connected in series.

9. The temperature control device based on analog device according to claim 1, characterized in that: The control output circuit outputs a temperature control signal to the adjustment indicator light.

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