Novel PTC (Positive Temperature Coefficient) self-constant-temperature control device

Abstract

The utility model discloses a novel PTC (Positive Temperature Coefficient) self-constant temperature control device, which comprises a temperature output device used for controlling the on-off of a heating element; the temperature sampling device is electrically connected with the heating element and is used for collecting working parameters of the heating element; and the temperature control device is connected between the temperature output device and the temperature sampling device and is used for adjusting the output state of the heating element based on the working parameters so as to realize constant temperature control. According to the utility model, by utilizing the resistance-temperature characteristic and Ohm's law of the heating body, accurate temperature control without an additional temperature sensor and related sensing lines is realized, and the manufacturing complexity and cost of the heating body are obviously reduced. Meanwhile, by optimizing the structure of the control circuit, the number of needed electronic elements is greatly reduced, the failure rate and the production cost are reduced, and the economic benefits of the device are improved. In addition, the device simplifies the overall design while ensuring accurate temperature control, is suitable for large-scale production, and has a wide market application prospect.

Description

Technical Field

[0001] The utility model relates to a temperature control device, in particular to a novel PTC self - constant temperature control device. Background Art

[0002] At present, the existing heating control devices on the market generally have problems such as complex control circuits, many electronic components, high failure rates, and high costs. In the prior art, to achieve constant temperature control, it is usually necessary to add a temperature feedback device, such as a temperature sensor and its related sensing wires, on the heating element to accurately detect the temperature and feedback it to the control circuit, so as to adjust the heating power. However, this technical solution not only increases the complexity of the manufacturing process of the heating element, but also leads to an increase in production costs. In addition, in the process of achieving precise temperature control for the existing heating control devices, multiple sensing wires are usually required for feedback, further increasing the complexity and cost of the system. Summary of the Invention

[0003] In order to solve the above problems, the utility model provides a novel PTC self - constant temperature control device, which can simultaneously achieve a novel technical solution for precise temperature control, so as to reduce costs and improve market competitiveness.

[0004] The utility model is realized through the following technical solutions: A novel PTC self - constant temperature control device includes a temperature output device for controlling the on - off of a heating element;

[0005] A temperature sampling device, electrically connected to the heating element, for collecting the operating parameters of the heating element;

[0006] A temperature control device, connected between the temperature output device and the temperature sampling device, for adjusting the output state of the heating element based on the operating parameters to achieve constant temperature control.

[0007] As a preferred technical solution, the temperature output device includes:

[0008] A switch unit for controlling the on - off state of the heating element;

[0009] A bias circuit for providing an operating voltage for the switch unit;

[0010] A heating element, whose resistance - temperature characteristic is used to control the temperature output.

[0011] As a preferred technical solution, the temperature sampling device includes:

[0012] A harmonic filtering module for removing harmonic components in the collected signal;

[0013] A current sampling module for collecting the current signal passing through the heating element;

[0014] An amplification module for amplifying the current signal and outputting a control signal to a temperature control device.

[0015] As a preferred technical solution, the temperature control device includes:

[0016] A reference voltage module for providing a reference voltage signal;

[0017] A comparison module for comparing the amplified signal with the reference voltage and outputting a control signal to the switching unit to adjust the on / off state of the heating element;

[0018] An adjustable module for adjusting the reference voltage signal to set the required constant temperature control temperature.

[0019] As a preferred technical solution, the temperature control device further includes:

[0020] A cold start module for providing an initial reference voltage when the device is initially started to ensure the safe start of the heating element;

[0021] An isolation module for electrically isolating the control signals between different circuit units to prevent mutual interference.

[0022] The beneficial effects of the present utility model are as follows: By utilizing the resistance-temperature characteristics of the heating element itself and Ohm's law, the present utility model realizes precise temperature control without an additional temperature sensor and its related sensing wires, significantly reducing the manufacturing complexity and cost of the heating element. At the same time, by optimizing the structure of the control circuit, the number of required electronic components is greatly reduced, the failure rate and production cost are lowered, and the economic benefits of the device are improved. In addition, while ensuring precise temperature control, the overall design of the device is simplified, suitable for large-scale production, and has a wide market application prospect. Description of the Drawings

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present utility model. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0024] Figure 1 It is the circuit schematic diagram of the present utility model. Detailed Embodiments

[0025] All features disclosed in this specification, or all steps in any method or process disclosed, except for mutually exclusive features and / or steps, can be combined in any way.

[0026] Any feature disclosed in this specification (including any appended claims, abstract and drawings), unless specifically recited, may be replaced by other equivalent or alternative features with similar purposes. That is, unless specifically recited, each feature is only an example of a series of equivalent or similar features.

[0027] As Figure 1 shown, a novel PTC self-constant temperature control device of the present utility model includes a temperature output device for controlling the on / off of a heating element;

[0028] wherein, it further includes a temperature sampling device electrically connected to the heating element for collecting the operating parameters of the heating element;

[0029] wherein, it further includes a temperature control device connected between the temperature output device and the temperature sampling device for adjusting the output state of the heating element based on the operating parameters to achieve constant temperature control.

[0030] In this embodiment, the temperature output device includes:

[0031] a switch unit for controlling the on / off state of the heating element;

[0032] a bias circuit for providing an operating voltage for the switch unit;

[0033] a heating element whose resistance-temperature characteristic is used to control the temperature output.

[0034] As a preferred technical solution, the temperature sampling device includes:

[0035] a harmonic filtering module for removing harmonic components in the collected signal;

[0036] a current sampling module for collecting the current signal passing through the heating element;

[0037] an amplification module for amplifying the current signal and outputting a control signal to the temperature control device.

[0038] In this embodiment, the temperature control device includes:

[0039] a reference voltage module for providing a reference voltage signal;

[0040] a comparison module for comparing the amplified signal with the reference voltage and outputting a control signal to the switch unit to adjust the on / off state of the heating element;

[0041] an adjustable module for adjusting the reference voltage signal to set the required constant temperature control temperature.

[0042] In this embodiment, the temperature control device further includes:

[0043] A cold start module, which is used to provide an initial reference voltage when the device is started for the first time to ensure the safe start of the heating element;

[0044] An isolation module, which is used to electrically isolate the control signals between different circuit units to prevent interference with each other.

[0045] Specifically, as shown in Figure 1 The temperature output device is composed of Q1, R2, R3, and PR1. Q1 is a switching transistor that controls the heating on and off. R2 and R3 form a bias circuit.

[0046] The temperature sampling device is composed of C3, R6, C2, R9, R10, and R11, and U2B. C3 and C2 are harmonic filtering circuits. R11 is a current sampling circuit. R6, R9, R10, and U2B form a current amplification circuit, and Vout = Vi * (R9 + R10) / R10.

[0047] The temperature control device is composed of R5, R8, R4, VR1, C4, U1B, U3B, C1, A1, and A2. C1 is a power supply harmonic filtering circuit. C4 is a reference harmonic filtering circuit. R5, R8, U3B, and REF2 form a cold start reference threshold circuit. A1 and A2 are isolation diodes. R4, VR1, and U1B form a temperature adjustment circuit that can adjust the temperature value output by the heating element.

[0048] Workflow:

[0049] Startup phase: When powered on - it is known from the voltage division of R5 and R8 that the REF2 level is higher than FB1. The output of pin 7 of U3B is high level, the output of pin 1 of Q1 is high level, Q1 conducts, and there is current flowing through PR1. PR1 heats up, and a loop is formed to the ground through the sampling resistor R11. According to Ohm's law, when there is current flowing through R11, a voltage drop is generated, V = R11 * IR. The voltage passes through C3 to filter harmonics and is input to pin 5 of U2B. The voltage signal is amplified and flows out from pin 7 to FB1, and at the same time enters pin 5 of U1B and pin 6 of U3B. When the voltage signal of FB1 is greater than REF1, the output of pin 7 of U1B is high level, and heating continues. According to the RT characteristic of PR1, the higher the temperature - the greater the resistance - the smaller the current, and FB1 becomes smaller and smaller. When REF1 is greater than FB1, the output of pin 7 of U1B is low level, and heating is turned off, entering the next startup phase. VR1 can adjust the reference point to set the constant temperature value.

[0050] The above is only a specific implementation of the utility model, but the protection scope of the utility model is not limited thereto. Any changes or substitutions that are not conceived through creative work should be included in the protection scope of the utility model. Therefore, the protection scope of the utility model should be based on the protection scope defined in the claims.

Claims

1. A novel PTC self-constant temperature control device, characterized in that, Comprising: A temperature output device for controlling the on / off of a heating element; A temperature sampling device electrically connected to the heating element for collecting the operating parameters of the heating element; A temperature control device connected between the temperature output device and the temperature sampling device for adjusting the output state of the heating element based on the operating parameters to achieve constant temperature control.

2. The novel PTC self-constant temperature control device according to claim 1, wherein: The temperature output device includes: A switch unit for controlling the on / off state of the heating element; A bias circuit for providing an operating voltage to the switch unit; A heating element whose resistance-temperature characteristic is used to control the temperature output.

3. The novel PTC self-constant temperature control device according to claim 1, wherein: The temperature sampling device includes: A harmonic filtering module for removing harmonic components in the collected signal; A current sampling module for collecting the current signal passing through the heating element; An amplification module for amplifying the current signal and outputting a control signal to the temperature control device.

4. The novel PTC self-constant temperature control device according to claim 2, wherein: The temperature control device includes: A reference voltage module for providing a reference voltage signal; A comparison module for comparing the amplified signal with the reference voltage and outputting a control signal to the switch unit to adjust the on / off state of the heating element; An adjustable module for adjusting the reference voltage signal to set the required constant temperature control temperature.

5. The novel PTC self-constant temperature control device according to claim 1, characterized in that: The temperature control device further includes: A cold start module for providing an initial reference voltage when the device is initially started to ensure the safe start of the heating element; An isolation module for electrically isolating the control signals between different circuit units to prevent interference with each other.

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