TEC temperature control module

Abstract

The utility model provides a TEC temperature control module, which comprises a control unit, an H-bridge circuit and a current detection unit, and is characterized in that a cathode loop of the H-bridge circuit is electrically connected with an input end of the current detection unit, and an output end of the current detection unit is electrically connected with the control unit; according to the utility model, the current sampling resistor is connected in series in the DC negative electrode loop of the H-bridge circuit, when the voltage value on the resistor is greater than the preset value, the switch tube is driven and an overcurrent signal is sent to the control module, and the control module blocks an output signal of a driving end when detecting that the level of an overcurrent pin is changed from high to low. The MOS tube in the H-bridge circuit is protected from being damaged, so that the safety of current detection of the TEC temperature control module is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of flip - flops, and particularly to a TEC temperature control module. Background Art

[0002] A semiconductor cooler (Thermo Electric Cooler, TEC), also known as a thermoelectric cooler (or thermoelectric cooling or heating device), is a temperature - regulating device made using the Peltier effect of semiconductor materials and is commonly used for temperature control in electronic devices. The TEC generates a temperature difference by applying a voltage between two different materials, thereby achieving the effect of cooling or heating.

[0003] In the current - detection control technology of the TEC temperature control module, a current sensor is usually used to measure the current of the TEC. The current sensor can be non - contact, such as a Hall - effect sensor or a magnetoresistive sensor. These sensors can monitor the current of the TEC in real - time and convert it into a voltage signal. By connecting the current sensor to a control circuit, the monitoring and regulation of the TEC current can be achieved. The control circuit can judge the direction and magnitude of the TEC current according to the voltage signal provided by the current sensor and adjust the magnitude of the current as needed. In this way, precise control of the TEC can be achieved.

[0004] Currently, the current - detection control circuit in the existing technology needs to use a current sensor and a complex adjustment circuit, with relatively low safety and high circuit cost. Summary of the Utility Model

[0005] In view of this, the problem to be solved by the utility model is to provide a TEC temperature control module.

[0006] To solve the above - mentioned technical problems, the technical solution adopted by the utility model is:

[0007] A TEC temperature control module includes a control unit, an H - bridge circuit, and a current - detection unit. The negative - pole circuit of the H - bridge circuit is electrically connected to the input end of the current - detection unit, and the output end of the current - detection unit is electrically connected to the control unit;

[0008] Among them, the current - detection unit includes a sampling resistor. The sampling resistor is connected to a switching circuit through a third filter capacitor, and the switching circuit is connected to the control unit. When the current signal collected by the sampling resistor is greater than a preset value, the control unit is used to control the H - bridge circuit to turn off by detecting the signal of the conduction of the switching circuit.

[0009] Further, the control unit includes a first driving end, a second driving end, a third driving end, and a fourth driving end, wherein a first signal output by the first driving end and a second signal output by the second driving end are in opposite directions, and a third signal output by the third driving end and a fourth signal output by the fourth driving end are in opposite directions.

[0010] Specifically, the H-bridge circuit includes a first MOS transistor, a second MOS transistor, a third MOS transistor, and a fourth MOS transistor. The first MOS transistor is electrically connected to the first driving end, the second MOS transistor is electrically connected to the second driving end, the third MOS transistor is electrically connected to the third driving end, and the fourth MOS transistor is electrically connected to the fourth driving end.

[0011] Further, the TEC temperature control module further includes a voltage conversion unit, which is electrically connected to the H-bridge circuit and is used to convert alternating current into direct current to supply power to the H-bridge circuit.

[0012] Further, the TEC temperature control module further includes a filtering unit, which is electrically connected to the output end of the H-bridge circuit. After the H-bridge circuit performs voltage inversion, it is filtered by the filtering unit to supply power to the TEC.

[0013] Further, the TEC temperature control module further includes a temperature acquisition unit, which is electrically connected to the control unit. The temperature acquisition unit is used to acquire the temperature sampling signal on the TEC, and the control unit is used to receive the temperature sampling signal and perform PID adjustment through the error between the temperature sampling signal and the set temperature value.

[0014] Specifically, the filtering unit is an LC filtering circuit composed of a first inductor and a second capacitor.

[0015] Specifically, the first signal and the third signal are reverse signals with a phase shift of 180 degrees.

[0016] Specifically, the switching circuit uses a triode or a MOS transistor.

[0017] The advantages and positive effects of the present utility model are:

[0018] By connecting a current sampling resistor in series in the DC negative electrode loop of the H-bridge circuit, when the voltage value on the resistor is greater than the preset value, the switching tube will be driven to report the overcurrent signal to the control module. The control module will detect that the level of the overcurrent pin changes from high to low, and then block the output signal of the driving end to protect the MOS transistors in the H-bridge circuit from being damaged, so as to improve the safety of current detection of the TEC temperature control module. Description of the Drawings

[0019] The accompanying drawings are used to provide a further understanding of the present utility model and constitute a part of the specification. Together with the embodiments of the present utility model, they are used to explain the present utility model and do not constitute a limitation to the present utility model. In the drawings:

[0020] Figure 1 is an overall structural diagram of a TEC temperature control module of the present utility model;

[0021] Figure 2 is a general circuit diagram of a TEC temperature control module of the present utility model;

[0022] In the figure: 1 - control unit; 11 - first driving end; 12 - first driving end; 13 - third driving end; 14 - fourth driving end; 2 - H-bridge circuit; 3 - filtering unit; 4 - current detection unit; 5 - temperature acquisition unit; 6 - voltage conversion unit. Detailed implementation manners

[0023] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present utility model.

[0024] It should be noted that when a component is referred to as being "fixed to" another component, it can be directly on the other component or there may also be an intermediate component. When a component is considered to be "connected to" another component, it can be directly connected to the other component or there may be an intermediate component at the same time. When a component is considered to be "disposed on" another component, it can be directly disposed on the other component or there may be an intermediate component at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are only for the purpose of illustration.

[0025] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present utility model belongs. The terms used herein in the specification of the present utility model are only for the purpose of describing specific embodiments and are not intended to limit the present utility model. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0026] Such as Figure 1 - Figure 2As shown in the figure, the utility model provides a TEC temperature control module, which includes a control unit 1, an H-bridge circuit 2 and a current detection unit 4. The negative electrode circuit of the H-bridge circuit 2 is electrically connected to the input end of the current detection unit 4, and the output end of the current detection unit 4 is electrically connected to the control unit 1;

[0027] Among them, the current detection unit 4 includes a sampling resistor. The sampling resistor is connected to a switching circuit through a third filter capacitor. The switching circuit is connected to the control unit 1. When the current signal collected by the sampling resistor is greater than a preset value, the control unit 1 is used to control the H-bridge circuit 2 to turn off by detecting the signal of the conduction of the switching circuit.

[0028] In this solution, a current sampling resistor is connected in series in the DC negative electrode circuit of the H-bridge circuit 2. When the voltage value on the resistor is greater than the preset value, the switching tube will be driven to open, and the overcurrent signal will be reported to the control module. The control module will control the H-bridge circuit 2 to turn off by detecting the signal of the conduction of the switching circuit, so as to improve the safety of current detection of the TEC temperature control module.

[0029] Specifically, the control module can adopt an integrated circuit chip, such as a single-chip microcomputer (STM32 series). The output value of the single-chip microcomputer is converted into 4 PWM signals with a frequency of 50KHz. Specifically, the single-chip microcomputer includes a first driving end 11, a second driving end 12, a third driving end 13 and a fourth driving end 14. Among them, the first signal output by the first driving end 11 and the second signal output by the second driving end 12 are opposite, and the third signal output by the third driving end 13 and the fourth signal output by the fourth driving end 14 are opposite. In a specific implementation, the first signal and the third signal are reverse signals with a phase shift of 180 degrees to drive the H-bridge circuit 2 to perform inversion, and the first signal to the fourth signal are all PWM signals.

[0030] Reference Figure 2 Regarding the current detection unit 4 in the shown part, a first sampling resistor R1 is arranged in the negative electrode circuit of the H-bridge circuit 2. The current on the first sampling resistor R1 is unidirectional, and then it is filtered by a third filter capacitor C3. When the current is too large, a higher sampling voltage will be obtained on the first sampling resistor R1. If it is greater than the preset value (designed as 0.7V in this solution), the triode Q5 (MOS tube can be used) will be driven to conduct, and the single-chip microcomputer will detect that the level of the overcurrent signal pin changes from high to low, and then block the output of the PWM signal.

[0031] Specifically, the H-bridge circuit 2 includes a first MOS transistor Q1, a second MOS transistor Q2, a third MOS transistor Q3, and a fourth MOS transistor Q4. The first MOS transistor Q1 is electrically connected to the first driving end 11, the second MOS transistor Q2 is electrically connected to the second driving end 12, the third MOS transistor Q3 is electrically connected to the third driving end 13, and the fourth MOS transistor Q4 is electrically connected to the fourth driving end 14. The output value of the control module is converted into 4 PWM signals with a frequency of 50KHz (i.e., corresponding to the first signal to the fourth signal), which drive the 4 MOS transistors in the H-bridge circuit 2 to perform inversion, so that the output frequency reaches 100KHz.

[0032] Further, the TEC temperature control module further includes a filtering unit 3. The filtering unit 3 is electrically connected to the output end of the H-bridge circuit 2. After the H-bridge circuit 2 inverts the voltage, it is filtered by the filtering unit 3 to supply power to the TEC. Specifically, the filtering unit 3 is an LC filtering circuit composed of a first inductor L1 and a second capacitor C2. The two ends of the second capacitor C2 are output and connected to the TEC. In this way, a bidirectional variable DC voltage with very small ripple is obtained through the filtering unit 3 to supply power to the TEC.

[0033] Further, the TEC temperature control module further includes a voltage conversion unit 6. The voltage conversion unit 6 is electrically connected to the H-bridge circuit 2. The voltage conversion unit 6 uses AC / DC boost inversion to convert the AC mains into 24V DC power to supply power to the subsequent H-bridge circuit 2.

[0034] Further, the TEC temperature control module further includes a temperature acquisition unit 5. The temperature acquisition unit 5 is electrically connected to the control unit 1. The temperature acquisition unit 5 is used to acquire the temperature sampling signal on the TEC, and the control unit 1 is used to receive the temperature sampling signal and perform PID adjustment through the error with the set temperature value. Specifically, the temperature acquisition unit 5 uses a temperature sampling resistor RT1, and the temperature sampling resistor RT1 is an NTC thermistor.

[0035] The single-chip microcomputer uses digital PID adjustment control. The input is the voltage value generated by the temperature sampling resistor RT1, and the output is 4 PWM signals. When the actual temperature differs greatly from the set temperature (more than 2 degrees), the comparison mode is adopted, which can not only heat or cool the ETC at full speed to accelerate the approach speed to the set temperature, but also avoid the situation that if the PID adjustment is turned on, the Ki accumulation will be too large, resulting in a large overshoot. In this way, the PID parameters can be changed in real time, which is convenient for the rapid and stable temperature control of the TEC.

[0036] Combined with Figure 2 , the working principle of the present invention will be described below:

[0037] During operation, the pre-stage DC power supply first converts the mains power through AC / DC conversion to generate a 24V DC voltage to supply power to the subsequent H-bridge circuit 2. The temperature sampling resistor RT1 collects the temperature sampling signal on the TEC and transmits it to the single-chip microcomputer. The single-chip microcomputer receives this temperature sampling signal and demodulates this signal, converting the voltage signal into a real-time temperature signal. The error between the real-time temperature signal and the set temperature value is adjusted by PID, and the output value is converted into 4 PWM signals with a frequency of 50KHz to drive the 4 MOS transistors in the H-bridge circuit 2 for inversion, so that the output frequency reaches 100KHz. Finally, through the LC filter circuit, a bidirectional variable DC voltage with very small ripple is obtained to supply power to the TEC.

[0038] At the same time, a first sampling resistor R1 is added to the negative pole of the DC loop to sample the current of the TEC, and then filtered through the third filter capacitor C3. When the current is too large, a higher sampling voltage is obtained on the first sampling resistor R1. If it is greater than 0.7V, the triode Q5 will be driven to conduct. The single-chip microcomputer will detect that the level of the overcurrent signal pin changes from high to low, and then block the PWM output to protect the MOS transistors in the H-bridge circuit from being damaged.

[0039] The above has described the embodiments of the present invention in detail, but the content described is only the preferred embodiments of the present invention and cannot be considered as limiting the implementation scope of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope covered by this patent.

Claims

1. A TEC temperature control module, characterized in that: It includes a control unit, an H-bridge circuit and a current detection unit, wherein the negative pole loop of the H-bridge circuit is electrically connected to the input end of the current detection unit, and the output end of the current detection unit is electrically connected to the control unit; Wherein, the current detection unit includes a sampling resistor, the sampling resistor is connected to a switching circuit via a third filter capacitor, the switching circuit is connected to the control unit, and when the current signal collected by the sampling resistor is greater than a preset value, the control unit is used to control the H-bridge circuit to shut down by detecting the signal of the switching circuit being turned on.

2. A TEC temperature control module according to claim 1, characterized in that: The control unit includes a first driving end, a second driving end, a third driving end and a fourth driving end, wherein a first signal output by the first driving end is opposite to a second signal output by the second driving end, and a third signal output by the third driving end is opposite to a fourth signal output by the fourth driving end.

3. A TEC temperature control module according to claim 2, characterized in that: The H-bridge circuit includes a first MOS tube, a second MOS tube, a third MOS tube and a fourth MOS tube, the first MOS tube is electrically connected to the first driving end, the second MOS tube is electrically connected to the second driving end, the third MOS tube is electrically connected to the third driving end, and the fourth MOS tube is electrically connected to the fourth driving end.

4. A TEC temperature control module according to claim 1, characterized in that: The TEC temperature control module further includes a voltage conversion unit, which is electrically connected to the H-bridge circuit and is used to convert alternating current into direct current to power the H-bridge circuit.

5. The TEC temperature control module according to claim 1, characterized in that: The TEC temperature control module further includes a filtering unit, which is electrically connected to the output end of the H-bridge circuit. After the H-bridge circuit inverts the voltage, the voltage is filtered by the filtering unit to supply power to the TEC.

6. The TEC temperature control module according to claim 1, characterized in that: The TEC temperature control module also includes a temperature acquisition unit, which is electrically connected to the control unit. The temperature acquisition unit is used to collect a temperature sampling signal on the TEC. The control unit is used to receive the temperature sampling signal and perform PID adjustment based on the error between the temperature sampling signal and the set temperature value.

7. A TEC temperature control module according to claim 6, characterized in that: The filtering unit is an LC filtering circuit composed of a first inductor and a second capacitor.

8. The TEC temperature control module according to claim 2, characterized in that: The first signal and the third signal are inverse signals with a phase shift of 180 degrees.

9. The TEC temperature control module according to claim 1, characterized in that: The switch circuit adopts a triode or a MOS tube.

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