TEC-based high-precision temperature control system

Abstract

The utility model relates to the field of optical, mechanical and electronic integration, and provides a high-precision temperature control system based on TEC in order to solve the problem of poor stability of the existing TEC temperature control system, which comprises a laser, a laser fixing PCB (printed circuit board), a heat sink block and a TEC semiconductor refrigeration device which are sequentially stacked in a constant-temperature cavity from top to bottom, a first thermistor is further arranged in the heat sink block, a first temperature control circuit and a second temperature control circuit are further arranged in the constant-temperature cavity, a second thermistor and a TEC semiconductor device are arranged in the laser, the second thermistor and the TEC semiconductor device are connected with the first temperature control circuit, and the first temperature control circuit collects the temperature value of the second thermistor. Controlling the temperature of the TEC semiconductor device to rise to a set temperature; the first thermistor and the TEC semiconductor refrigeration device are connected with the second temperature control circuit, the first thermistor is used for collecting the temperature transmitted to the heat sink block by the laser, and the second temperature control circuit collects the temperature value of the first thermistor and controls the TEC semiconductor refrigeration device to be cooled to the set temperature.

Description

Technical Field

[0001] The utility model relates to the field of opto-mechatronics, and particularly to a high-precision temperature control system based on a TEC (Thermoelectric cooler, semiconductor cooler). Background Art

[0002] Opto-mechatronics technology is a new technology that combines mechanical technology with technologies such as lasers and microelectronics. With the continuous development of technology, opto-mechatronics products have become more and more intelligent, adaptive, and green. Among them, an important technology is the TEC temperature control technology, which is mainly used to control the ambient temperature of the laser so that the laser can work under ideal temperature conditions and minimize the influence of temperature on the wavelength change of the laser.

[0003] In actual use, it is necessary to continuously monitor the temperature change of the electronic device. If it is found that the temperature has exceeded the set temperature range, it is necessary to timely adjust the parameters of the TEC temperature controller to control the temperature within the set range. The existing TEC temperature control system is easily affected by the ambient temperature, resulting in the instability of the laser emission wavelength and luminous intensity not meeting the actual application requirements, poor temperature control accuracy, and inability to provide a constant temperature field for the laser. Summary of the Utility Model

[0004] The purpose of the utility model is to solve the technical problems such as poor stability of the existing TEC temperature control system, poor temperature control accuracy, and inability to provide a constant temperature field for the laser, and to propose a high-precision temperature control system based on TEC.

[0005] To achieve the above purpose, the technical solution proposed by the utility model is as follows:

[0006] A high-precision temperature control system based on TEC for controlling the temperature of a laser, including a laser fixing PCB board, a heat sink block, and a TEC semiconductor refrigeration device that are stacked in sequence from top to bottom in a constant temperature cavity. A first thermistor is arranged in the heat sink block, and the laser is fixed on the laser fixing PCB board. The special feature is that:

[0007] It further includes a first temperature control circuit, a second temperature control circuit, a second thermistor, and a TEC semiconductor device. The second thermistor and the TEC semiconductor device are arranged in the laser. The second thermistor and the TEC semiconductor device are connected to the first temperature control circuit. The first temperature control circuit is used to collect the temperature value of the second thermistor and then control and adjust the TEC semiconductor device to raise the temperature of the laser to the set temperature;

[0008] The first thermistor and the TEC semiconductor refrigeration device are connected to the second temperature control circuit. The first thermistor is used to collect the temperature transferred from the laser to the heat sink block, and the second temperature control circuit is used to control and adjust the TEC semiconductor refrigeration device to cool the laser to the set temperature by collecting the temperature value of the first thermistor.

[0009] Further, the first temperature control circuit includes a first temperature control chip U11, a first temperature setting circuit connected to the first temperature control chip U11 for setting the set temperature, a temperature adjustment circuit for adjusting the TEC control voltage, and a TEC network compensation circuit for voltage compensation of the first temperature control circuit;

[0010] The input end of the first temperature control chip U11 is connected to the output end of the second thermistor, and is used to collect the resistance value on the second thermistor and convert it into a corresponding temperature value;

[0011] The output high and output low of the first temperature control chip U11 are respectively connected to TEC1+ and TEC1- of the TEC semiconductor device, and are used to output a driving current by comparing the temperature difference between the temperature value of the second thermistor collected and the set temperature set by the first temperature setting circuit, and drive the TEC semiconductor device to heat the laser to the set temperature.

[0012] Further, the temperature setting circuit includes a potentiometer R39 and a resistor R53. One end of the potentiometer R39 is connected to the reference voltage, the other end is connected to one end of the resistor R53, the other end of the resistor R53 is grounded, and the adjustment end of the potentiometer R39 is connected to the first temperature control chip U11. The set temperature of the system is set by adjusting the resistance value of the potentiometer R39.

[0013] Further, the first temperature control chip U11 is also connected to an alarm circuit, and at least one LED lamp is arranged in the alarm circuit, which is used to monitor and display the actual temperature state of the first temperature control circuit.

[0014] Further, the second temperature control circuit includes a second temperature setting circuit, a differential comparison circuit and a driving circuit; the second temperature setting circuit is used to control the set temperature of the temperature system; the second temperature setting circuit is used to set the set temperature. The output end of the second temperature setting circuit is connected to the non-inverting input end of the comparator in the differential comparison circuit, and the inverting input end of the comparator in the differential comparison circuit is connected to the output end of the first thermistor; the output end of the differential comparison circuit is connected to the input end of the driving circuit, and the output end of the driving circuit is connected to the TEC2+ pin of the TEC semiconductor refrigeration device, and the TEC2- pin of the TEC semiconductor refrigeration device is grounded;

[0015] The differential comparison circuit is used to compare the temperature difference between the first thermistor and the set temperature, and output a driving current through the driving circuit to control the TEC semiconductor refrigeration device to adjust the temperature, so that the laser is cooled to the set temperature.

[0016] Further, the heat sink block and the TEC semiconductor refrigeration device are pasted together with thermal conductive silicone grease.

[0017] Further, an instrument air connection hole is provided on the side wall of the constant temperature cavity, and the constant temperature cavity is connected to the external instrument air through the instrument air connection hole to discharge the excess heat in the constant temperature cavity.

[0018] Further, the model of the first temperature control chip is a 2.5A TEC temperature controller of TECA1-xV-xV-DAH.

[0019] Further, the comparator in the differential comparison circuit uses the model LM258.

[0020] Advantages of the present utility model:

[0021] 【1】The structure of the high-precision temperature control system based on TEC of the present utility model is simple. Through the mutual cooperation of the first temperature control circuit and the second temperature control circuit, the temperature of the laser is kept constant, and the temperature control accuracy is relatively high, which can effectively protect the emission wavelength and light intensity of the laser from being constant.

[0022] 【2】By setting the temperature of the first temperature setting circuit in the first temperature control circuit and the second temperature setting circuit in the second temperature control circuit of the present utility model, the temperature control accuracy of the laser can be effectively guaranteed, and the measurement accuracy of the system can be improved.

[0023] 【3】In the present utility model, the real-time temperature of the laser can be monitored in real time through the alarm circuit, reducing system errors and improving the temperature adjustment accuracy.

[0024] 【4】In the present utility model, the temperature is compared between the first thermistor collected and the set temperature through the differential comparison circuit, and the driving current is output to drive the TEC semiconductor refrigeration device to quickly adjust the temperature of the laser, effectively saving the temperature control time and providing a guarantee for improving the measurement accuracy. Description of the drawings

[0025] Figure 1 It is a schematic structural diagram of a high-precision temperature control system based on TEC of the present utility model;

[0026] Figure 2 It is a schematic circuit diagram of the first temperature control circuit in the embodiment of the present utility model;

[0027] Figure 3This is a schematic circuit diagram of the second temperature control circuit in the embodiment of the present utility model;

[0028] Reference numerals:

[0029] 1 - Laser, 2 - Laser fixed PCB board, 3 - Heat sink block, 4 - First thermistor, 5 - TEC semiconductor refrigeration device, 6 - Constant temperature cavity, 7 - Second thermistor, 8 - TEC semiconductor device, 9 - First temperature control circuit, 10 - Second temperature control circuit, 11 - Instrument air connection hole. Detailed implementation manners

[0030] A high-precision temperature control system based on TEC is used to control the temperature of the laser 1. As Figure 1 shown, it includes a laser fixed PCB board 2, a heat sink block 3, and a TEC semiconductor refrigeration device 5 that are stacked in sequence from top to bottom in the constant temperature cavity 6. A first thermistor 4 is arranged in the heat sink block 3, and the heat sink block 3 and the TEC semiconductor refrigeration device 5 are pasted through thermal conductive silicone grease; the laser 1 is fixed on the laser fixed PCB board 2. An instrument air connection hole 11 is opened on the side wall of the constant temperature cavity 6. The constant temperature cavity 6 is connected to external instrument air through the instrument air connection hole 11 to discharge the excess heat in the constant temperature cavity 6, and the heat of the constant temperature cavity 6 is taken outside the cavity through the instrument air, so as to ensure the constancy of the internal temperature of the cavity.

[0031] The constant temperature cavity 6 further includes a first temperature control circuit 9, a second temperature control circuit 10, a second thermistor 7, and a TEC semiconductor device 8. The second thermistor 7 and the TEC semiconductor device 8 are arranged in the laser 1. The second thermistor 7 and the TEC semiconductor device 8 are connected to the first temperature control circuit 9. The first temperature control circuit 9 is used to collect the temperature value of the second thermistor 7, and then control and adjust the TEC semiconductor device 8 to raise the temperature of the laser 1 to the set temperature, thereby constituting a first-stage temperature control system;

[0032] As Figure 2 shown, the first temperature control circuit 9 includes a first temperature control chip U11. The model of the first temperature control chip U11 is a 2.5A TEC temperature controller of TECA1-xV-xV-DAH. It also includes a first temperature setting circuit for setting the set temperature and connected to the 2nd and 3rd pins of the first temperature control chip U11, a temperature adjustment circuit for adjusting the TEC control voltage and connected to the 5th pin of the first temperature control chip U11, and a TEC network compensation circuit for voltage compensation of the first temperature control circuit 9 and connected to the 6th, 7th, and 8th pins of the first temperature control chip U11; the 4th, 14th, and 15th pins of the first temperature control chip U11 are grounded;

[0033] The first temperature control chip U11 is connected to RT1+ and RT1- of the second thermistor 7 through pins 11 and 10 respectively, where RT1- connected to pin 10 is grounded. The first temperature control chip U11 is used to collect the resistance value on the second thermistor 7 and convert it into a corresponding temperature value;

[0034] The first temperature control chip U11 is connected to TEC1+ and TEC1- of the TEC semiconductor device 8 through pins 13 and 12 respectively, and is used to control the temperature adjustment circuit to adjust the TEC semiconductor device 8 by comparing the temperature difference between the second thermistor 7 and the temperature setting circuit, so that the laser 1 is heated to the set temperature.

[0035] The first thermistor 4 and the TEC semiconductor refrigeration device 5 are connected to the second temperature control circuit 10. The first thermistor 4 is used to collect the temperature transmitted from the laser 1 to the heat sink block 3. The second temperature control circuit 10 is used to control and adjust the TEC semiconductor refrigeration device 5 to cool the laser 1 to the set temperature by collecting the temperature value of the first thermistor 4, thereby constituting a second-stage temperature control system.

[0036] The temperature setting circuit includes a setting chip S5, a potentiometer R39 and a resistor R53. The input end of the potentiometer R39 is connected to pin 2 of the temperature control chip, the output end is connected to the input end of the resistor R53, the output end of the resistor R53 is grounded, the control end of the potentiometer R39 is connected to pin 1 of the setting chip S5, and pin 2 of the setting chip S5 is connected to pin 3 of the temperature control chip. The target temperature of the system is set by adjusting the resistance value of the potentiometer R39; An alarm circuit is also connected to pin 1 of the first temperature control chip U11, and at least one LED lamp is arranged in the alarm circuit for monitoring and displaying the actual temperature state of the first temperature control circuit.

[0037] As Figure 3 shown, the second temperature control circuit 10 includes a second temperature setting circuit, a differential comparison circuit and a drive circuit; The second temperature setting circuit is used to control the set temperature of the temperature system; The second temperature setting circuit is used to set the set temperature. The output end of the second temperature setting circuit is connected to the non-inverting input end of the comparator in the differential comparison circuit. The inverting input end of the comparator in the differential comparison circuit is connected to the output end of the first thermistor 4; The output end of the differential comparison circuit is connected to the input end of the drive circuit, and the output end of the drive circuit is connected to the TEC2+ pin of the TEC semiconductor refrigeration device 5. The TEC2- pin of the TEC semiconductor refrigeration device 5 is grounded;

[0038] The differential comparison circuit is used to compare the temperature difference between the first thermistor 4 and the set temperature, and output a drive current through the drive circuit to control the TEC semiconductor refrigeration device 5 to adjust the temperature, so that the laser 1 is cooled to the set temperature.

[0039] The working principle of the present utility model is as follows: The first temperature control chip U11 collects the resistance value of the second thermistor 7, converts it into a corresponding temperature value, and compares it with the set target temperature value. According to the difference between the collected temperature and the target temperature, a driving current is output to drive the TEC semiconductor device 8 to work, and finally the temperature is adjusted to the target temperature value. When the controlled temperature is within the target temperature error range, the LED indicator light in the figure lights up, indicating that the controlled temperature reaches the target value. The set temperature value of the first temperature control circuit 9 can be adjusted through the potentiometer R39, and the temperature setting method is switched by switching the short-circuit position of S5.

[0040] The heat of the laser 1 is transferred to the heat sink block 3 through the laser fixing PCB board 2 to form the heat source of the second temperature control circuit 10. The collected value of the first thermistor 4 is introduced into the second temperature control circuit 10 through RT2+ and RT2- as the collected temperature of the second temperature control circuit 10, and is compared with the set temperature of the second temperature control circuit 10. According to the difference between the collected temperature and the set temperature, a differential signal is output through the comparator U15. This differential signal outputs a driving current through two MOS transistors Q3 and Q4 to drive the TEC semiconductor device to work, thereby adjusting the temperature to the set target temperature value. The temperature setting value of the second temperature control circuit 10 can be set through the potentiometer R38.

[0041] Through the joint control of the first temperature control circuit 9 and the second temperature control circuit 10, the working temperature error of the laser 1 can be controlled within 0.05 °C, which can effectively protect the emission wavelength and light intensity of the laser 1 from being constant. This provides a guarantee for the improvement of measurement accuracy.

Claims

1. A high-precision temperature control system based on TEC, used for controlling the temperature of a laser (1), comprising a laser fixing PCB board (2), a heat sink block (3) and a TEC semiconductor refrigeration device (5) stacked in sequence from top to bottom in a constant temperature cavity (6), wherein a first thermistor (4) is arranged in the heat sink block (3), and the laser (1) is fixed on the laser fixing PCB board (2), characterized in that: The laser device also comprises a first temperature control circuit (9), a second temperature control circuit (10), a second thermistor (7) and a TEC semiconductor device (8); the second thermistor (7) and the TEC semiconductor device (8) are arranged in the laser device (1); the second thermistor (7) and the TEC semiconductor device (8) are connected to the first temperature control circuit (9); the first temperature control circuit (9) is used for collecting the temperature value of the second thermistor (7) and then controlling and adjusting the TEC semiconductor device (8) so that the temperature of the laser device (1) is raised to a set temperature; The first thermistor (4) and the TEC semiconductor refrigeration device (5) are connected to a second temperature control circuit (10); the first thermistor (4) is used to collect the temperature transmitted from the laser (1) to the heat sink (3); the second temperature control circuit (10) is used to collect the temperature value of the first thermistor (4) and then control and adjust the TEC semiconductor refrigeration device (5) to cool the laser (1) to a set temperature.

2. A high-precision temperature control system based on TEC according to claim 1, characterized in that: The first temperature control circuit (9) comprises a first temperature control chip U11, and a first temperature setting circuit connected to the first temperature control chip U11 for setting a set temperature, a temperature adjustment circuit for adjusting a TEC control voltage, and a TEC network compensation circuit for performing voltage compensation on the first temperature control circuit (9); The input end of the first temperature control chip U11 is connected to the output end of the second thermistor (7), and is used to collect the resistance value on the second thermistor (7) and convert it into a corresponding temperature value; The high output and the low output of the first temperature control chip U11 are respectively connected to TEC1+ and TEC1- of the TEC semiconductor device (8), and are used to output a driving current by comparing the temperature difference between the collected temperature value of the second thermistor (7) and the set temperature of the first temperature setting circuit, so as to drive the TEC semiconductor device (8) to heat the laser (1) to the set temperature.

3. A high-precision temperature control system based on TEC according to claim 2, characterized in that: The temperature setting circuit includes a potentiometer R39 and a resistor R53, one end of the potentiometer R39 is connected to a reference voltage, and the other end is connected to one end of the resistor R53, the other end of the resistor R53 is grounded, and the adjustment end of the potentiometer R39 is connected to the first temperature control chip U11, and the set temperature of the system is set by adjusting the resistance value of the potentiometer R39.

4. A high-precision temperature control system based on TEC according to claim 3, characterized in that: The first temperature control chip U11 is also connected to an alarm circuit, and at least one LED light is provided in the alarm circuit for monitoring and displaying the actual temperature status of the first temperature control circuit.

5. A high-precision temperature control system based on TEC according to any one of claims 2 to 4, characterized in that: The second temperature control circuit (10) comprises a second temperature setting circuit, a differential comparison circuit and a drive circuit; the second temperature setting circuit is used to control the set temperature of the temperature system; the second temperature setting circuit is used to set the set temperature, the output end of the second temperature setting circuit is connected to the non-inverting input end of the comparator in the differential comparison circuit, the first input end of the inverting input end of the comparator in the differential comparison circuit is connected to the output end of the first thermistor (4); the output end of the differential comparison circuit is connected to the input end of the drive circuit, the output end of the drive circuit is connected to the TEC2+ pin of the TEC semiconductor refrigeration device (5), and the TEC2- pin of the TEC semiconductor refrigeration device (5) is grounded; The differential comparison circuit is used to compare the temperature difference between the first thermistor (4) and the set temperature, and to control the TEC semiconductor refrigeration device (5) to adjust the temperature by outputting a driving current through the driving circuit, so that the laser (1) is cooled to the set temperature.

6. The high-precision temperature control system based on TEC according to claim 5, characterized in that: The heat sink block (3) and the TEC semiconductor refrigeration device (5) are bonded together by thermally conductive silicone grease.

7. The high-precision temperature control system based on TEC according to claim 6, characterized in that: An instrument air connection hole (11) is provided on the side wall of the constant temperature cavity (6), and the constant temperature cavity (6) is connected to external instrument air through the instrument air connection hole (11) to discharge excess heat in the constant temperature cavity (6).

8. The high-precision temperature control system based on TEC according to claim 7, characterized in that: The model of the first temperature control chip U11 is a 2.5A TEC temperature controller of TECA1-xV-xV-DAH.

9. The high-precision temperature control system based on TEC according to claim 8, characterized in that: The comparator in the differential comparison circuit is of the type LM258.

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