A control circuit of a TEC, a TEC and a laser

Abstract

The application discloses a control circuit of a TEC, the TEC and a laser, and relates to the field of temperature control, and comprises a switch module, a first end of the switch module being connected with a first end of an adjusting module, and a second end of the switch module being grounded; the adjusting module, a second end of the adjusting module being connected with a power supply, and a third end of the adjusting module being connected with a power supply end of the TEC; a controller, an output end of the controller being connected with a control end of the switch module and a control end of the adjusting module, and the controller being used for sending a conduction signal to the switch module and sending an adjusting signal to the adjusting module when a temperature deviation of the laser from a target temperature is greater than a preset temperature deviation; whether the temperature of the laser needs to be adjusted is determined in advance, the TEC needs to work when the temperature deviation is large, and the switch module is controlled to be turned on at the moment; whether heating or refrigeration is needed at present is determined, the adjusting module is controlled to change the direction of current, and then the heating or refrigerating mode of the TEC is changed, so that the temperature control of the laser is realized. The laser can be heated and refrigerated simultaneously, and the precision of the temperature control of the laser is improved.

Description

Technical Field

[0001] This invention relates to the field of temperature control, and in particular to a control circuit for a TEC, a TEC, and a laser. Background Technology

[0002] In a TDLAS (Tunable Diode Laser Absorption Spectroscopy) system, the laser's output wavelength is a function of its ambient temperature and operating current. By precisely adjusting these two parameters, accurate tuning of the laser wavelength can be achieved, allowing it to scan across the characteristic absorption lines of a gas or stably lock onto the center of an absorption line, thus enabling concentration detection. Typically, the laser requires temperature control, achieved by applying a linear current to control the laser's output wavelength. Absorption peaks are formed in specific spectral bands; if the temperature is unstable, the position of the absorption peak will drift, leading to inaccurate detection data. The lasers typically used have built-in thermistors and thermoelectric coolers (TECs). External circuitry detects the laser's temperature and controls the TEC to stabilize it. While PWM switching of the TEC via a controllable switch cannot change the TEC's control direction, in practical applications, low ambient temperatures may necessitate warming to reach equilibrium. Traditional control methods can only achieve cooling, not heating. Summary of the Invention

[0003] The purpose of this invention is to provide a control circuit for a TEC (Digital Temperature Regulator), a TEC, and a laser. The circuit pre-determines whether temperature adjustment of the laser is needed. When a large temperature deviation occurs, the TEC needs to operate, at which point a control switch module is activated. The system then determines whether heating or cooling is required and controls the adjustment module to change the direction of the current, thereby altering the heating or cooling mode of the TEC and achieving temperature control of the laser. Simultaneous heating and cooling of the TEC can be achieved, improving the accuracy of laser temperature control.

[0004] To solve the above-mentioned technical problems, the present invention provides a control circuit for a TEC, comprising:

[0005] The switch module has its first terminal connected to the first terminal of the adjustment module, and its second terminal grounded.

[0006] The adjustment module has a second end connected to the power supply and a third end connected to the power supply terminal of the TEC.

[0007] The controller, whose output terminal is connected to the control terminal of the switch module and the control terminal of the adjustment module, is used to send a conduction signal to the switch module to control the switch module to conduct when the temperature deviation between the laser and the target temperature is greater than a preset temperature deviation, and to send an adjustment signal to the adjustment module to control the adjustment module to change the direction of the current supplying power to the TEC. The direction of the current is related to the working mode of the TEC, which includes a cooling mode and a heating mode.

[0008] On the other hand, the switching module includes a first controllable switch and a first resistor;

[0009] The control terminal of the first controllable switch serves as the control terminal of the switch module, the first terminal of the first controllable switch serves as the first terminal of the switch module, the second terminal of the first controllable switch is connected to the first terminal of the first resistor, and the second terminal of the first resistor is grounded.

[0010] The first controllable switch is used to turn on when the deviation between the temperature of the TEC and the target temperature is greater than a preset temperature deviation.

[0011] On the other hand, it also includes a second resistor;

[0012] The first end of the second resistor is connected to the control terminal of the first controllable switch, and the second end of the second resistor is grounded.

[0013] The second resistor is used to pull down the level of the control terminal of the first controllable switch.

[0014] On the other hand, it also includes a voltage follower module;

[0015] The input terminal of the voltage follower module is connected to the output terminal of the controller, the output terminal of the voltage follower module is connected to the control terminal of the first controllable switch, and the inverting input terminal of the voltage follower module is connected to the second terminal of the first controllable switch.

[0016] The voltage follower module is used to control the voltage at the second terminal of the first controllable switch to be equal to the voltage output by the controller.

[0017] On the other hand, the voltage follower module includes an operational amplifier, a first capacitor, and a third resistor;

[0018] The non-inverting input terminal of the operational amplifier is connected to the output terminal of the controller, the inverting input terminal of the operational amplifier is connected to the first terminal of the first capacitor and the first terminal of the third resistor, the second terminal of the third resistor is connected to the switching module, and the second terminal of the first capacitor is connected to the control terminal of the switching module.

[0019] The first capacitor and the third resistor are used for feedback, and the operational amplifier is used for voltage regulation.

[0020] On the other hand, the adjustment module includes a second controllable switch, a third controllable switch, a fourth controllable switch and a fifth controllable switch;

[0021] The control terminals of the second, third, fourth, and fifth controllable switches are all connected to the controller. The first terminal of the second controllable switch and the second terminal of the fifth controllable switch are both connected to the power supply. The common terminal of the second terminal of the second controllable switch and the first terminal of the third controllable switch is connected to the positive power supply terminal of the TEC. The common terminal of the third controllable switch and the first terminal of the fourth controllable switch is connected to the first terminal of the switch module. The common terminal of the fourth controllable switch and the first terminal of the fifth controllable switch is connected to the negative power supply terminal of the TEC.

[0022] The controller is specifically used to control the second and fourth controllable switches to be turned on simultaneously and the third and fifth controllable switches to be turned off simultaneously, so as to control the TEC to work in cooling mode, or to control the second and fourth controllable switches to be turned off simultaneously and the third and fifth controllable switches to be turned on simultaneously, so as to control the TEC to work in heating mode.

[0023] On the other hand, it also includes digital-to-analog converters;

[0024] The input terminal of the digital-to-analog converter is connected to the output terminal of the controller, and the output terminal of the digital-to-analog converter is connected to the control terminal of the switching module;

[0025] The digital-to-analog converter is used to convert the control signal output by the controller into a voltage signal.

[0026] On the other hand, when the temperature deviation between the laser and the target temperature is greater than a preset temperature deviation, a conduction signal is sent to the switching module to control the switching module to conduct, and an adjustment signal is sent to the adjustment module to control the adjustment module to change the direction of the current supplying power to the TEC, including:

[0027] Obtain the current temperature of the laser;

[0028] Based on the current temperature and the target temperature of the laser;

[0029] Determine whether the absolute value of the deviation between the current temperature and the target temperature is greater than a preset temperature deviation;

[0030] If so, a first control signal is sent to the control terminal of the switch module to control the switch module to turn on;

[0031] If the deviation is greater than zero, an adjustment signal is sent to the adjustment module to control the adjustment module to change the direction of the current supplying power to the TEC, and adjust the working mode of the TEC to cooling mode. The supply current is positively correlated with the absolute value of the deviation.

[0032] If the deviation is less than zero, an adjustment signal is sent to the adjustment module to control the adjustment module to change the direction of the current supplying power to the TEC and adjust the TEC's operating mode to heating mode.

[0033] To solve the above-mentioned technical problems, the present invention also provides a TEC, including the control circuit of the TEC and the TEC body described above;

[0034] The control circuit of the TEC is used to control the working mode of the TEC body.

[0035] To address the aforementioned technical problems, the present invention also provides a laser, including the aforementioned TEC and a laser body, wherein the TEC is used to control the temperature of the laser body.

[0036] This application provides a control circuit for a TEC (Thermal Design Circuit), the TEC itself, and a laser, relating to the field of temperature control. It includes a switching module with its first terminal connected to the first terminal of an adjustment module and its second terminal grounded; the adjustment module has its second terminal connected to a power supply and its third terminal connected to the power supply terminal of the TEC. A controller, with its output terminal connected to the control terminals of both the switching and adjustment modules, sends an on signal to the switching module and an adjustment signal to the adjustment module when the deviation between the laser's temperature and the target temperature exceeds a preset temperature deviation. It pre-determines whether temperature adjustment of the laser is needed; when the temperature deviation is large, the TEC needs to operate, at which point the switching module is turned on. It determines whether heating or cooling is required and controls the adjustment module to change the direction of the current, thereby changing the heating or cooling mode of the TEC and achieving temperature control of the laser. Simultaneous heating and cooling of the TEC can be achieved, improving the accuracy of laser temperature control. Attached Figure Description

[0037] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the prior art and embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0038] Figure 1A schematic diagram of the control circuit of a TEC provided by the present invention;

[0039] Figure 2 A schematic diagram of another TEC control circuit provided by the present invention. Detailed Implementation

[0040] The core of this invention is to provide a control circuit for a TEC (Digital Temperature Regulator), the TEC itself, and a laser. The circuit pre-determines whether temperature adjustment of the laser is needed. When a large temperature deviation occurs, the TEC needs to operate, at which point a control switch module is activated. The system then determines whether heating or cooling is required and controls the adjustment module to change the direction of the current, thereby altering the heating or cooling mode of the TEC and achieving temperature control of the laser. Simultaneous heating and cooling of the TEC can be achieved, improving the accuracy of laser temperature control.

[0041] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0042] Figure 1 This invention provides a schematic diagram of a control circuit for a TEC (Technology, Electronics, and Devices). The control circuit for the TEC includes:

[0043] Switch module 1 has its first terminal connected to the first terminal of adjustment module 2, and its second terminal grounded.

[0044] Adjust module 2, with the second end connected to the power supply and the third end connected to the power supply terminal of the TEC.

[0045] The controller 3 has its output terminal connected to the control terminal of the switch module 1 and the control terminal of the adjustment module 2. When the temperature deviation between the laser and the target temperature is greater than the preset temperature deviation, it sends a conduction signal to the switch module 1 to control the switch module 1 to conduct and sends an adjustment signal to the adjustment module 2 to control the adjustment module 2 to change the direction of the current supplying power to the TEC. The direction of the current is related to the working mode of the TEC, which includes cooling mode and heating mode.

[0046] In a TDLAS system, the laser's output wavelength is a function of its ambient temperature and operating current. By precisely adjusting these two parameters, accurate tuning of the laser wavelength can be achieved, allowing it to scan across the characteristic absorption lines of the gas or stably lock onto the center of the absorption line, thus enabling concentration detection. Typically, the laser requires temperature control, achieved by applying a linear current to allow the laser to output a controllable wavelength. Absorption peaks are formed in specific spectral bands; if the temperature is unstable, the position of the absorption peak will drift, leading to inaccurate detection data.

[0047] The laser contains a thermistor and a TEC (temperature control unit). The thermistor measures the laser's temperature, and the TEC adjusts it. The thermistor first acquires the laser's temperature; if the acquired temperature deviates from the target temperature, the TEC adjusts the laser's temperature accordingly. The first terminal of switch module 1 is connected to adjustment module 2, which is connected to a power supply. The second terminal of switch module 1 is grounded. Therefore, when switch module 1 is turned on, a circuit is formed, and power is supplied.

[0048] Furthermore, when adjusting the temperature, the system can switch to heating mode when the temperature value fed back by the laser thermistor is lower than the target temperature, and to cooling mode when the temperature value fed back by the laser thermistor is higher than the target temperature. Therefore, adjustment module 2 can adjust the current supplied to the TEC. The third terminal of adjustment module 2 is connected to the power supply terminal of the TEC. By changing the current supplied to the TEC—for example, inputting the current to the TEC from the positive terminal and outputting it from the negative terminal—one current flow direction can be used to set it to cooling mode; conversely, inputting the current to the TEC from the negative terminal and outputting it from the positive terminal—another current flow direction can be used to set it to heating mode. The specific flow direction and corresponding operating mode can be set according to actual needs, and this application does not impose further limitations here.

[0049] Controller 3 outputs two signals: a conduction signal to control the switching module 1 to turn on and off, and an adjustment signal to control the adjustment module 2 to change the direction of the current supplying power to the TEC. After acquiring the laser temperature collected by the thermistor, controller 3 directly determines the operating mode and starts operation, achieving dual control of TEC heating and cooling, resulting in more precise temperature control of the laser.

[0050] This application provides a control circuit for a TEC (Thermal Design Circuit), the TEC itself, and a laser, relating to the field of temperature control. It includes a switch module 1, with its first terminal connected to the first terminal of an adjustment module 2 and its second terminal grounded. The adjustment module 2 has its second terminal connected to a power supply and its third terminal connected to the power supply terminal of the TEC. A controller 3, with its output terminal connected to the control terminals of both the switch module 1 and the adjustment module 2, sends an on signal to the switch module 1 and an adjustment signal to the adjustment module 2 when the deviation between the laser's temperature and the target temperature exceeds a preset temperature deviation. The controller pre-determines whether temperature adjustment of the laser is needed; when the temperature deviation is large, the TEC needs to operate, and in this case, the switch module 1 is turned on. It then determines whether heating or cooling is required and controls the adjustment module 2 to change the direction of the current, thereby changing the heating or cooling mode of the TEC and achieving temperature control of the laser. Simultaneous heating and cooling of the TEC can be achieved, improving the accuracy of laser temperature control.

[0051] Based on the above embodiments:

[0052] Figure 2 A schematic diagram of another TEC control circuit provided by the present invention;

[0053] In some embodiments, the switch module 1 includes a first controllable switch V1 and a first resistor R1;

[0054] The control terminal of the first controllable switch V1 serves as the control terminal of the switch module 1. The first terminal of the first controllable switch V1 serves as the first terminal of the switch module 1. The second terminal of the first controllable switch V1 is connected to the first terminal of the first resistor R1. The second terminal of the first resistor R1 is grounded.

[0055] The first controllable switch V1 is used to turn on when the deviation between the TEC temperature and the target temperature is greater than the preset temperature deviation.

[0056] The control terminal of the first controllable switch V1 is connected to the controller 3. After the first controllable switch V1 is turned on, the power supply is grounded through the adjustment module 2 and the first resistor R1. The current flowing through the first resistor R1 is the current flowing through the TEC. The current flowing through the TEC can also be adjusted by adjusting the resistance value of the first resistor R1. Specifically, the first controllable switch V1 can be a MOSFET, with the gate as the control terminal. PMOS and NMOS transistors can be selected according to actual needs, without the need for a driver chip. The first resistor R1 also serves as a current limiter.

[0057] In some embodiments, a second resistor R2 is also included;

[0058] The first end of the second resistor R2 is connected to the control terminal of the first controllable switch V1, and the second end of the second resistor R2 is grounded.

[0059] The second resistor R2 is used to pull down the level of the control terminal of the first controllable switch V1.

[0060] Considering that the TEC will start working when the first controllable switch V1 is turned on, the on / off control of the first controllable switch V1 needs to be more precise to avoid incorrect heating or cooling due to accidental activation. If the control terminal of the first controllable switch V1 is directly connected to the controller 3, the voltage of the controller 3 may mislead the first controllable switch V1 to turn on. Therefore, a second resistor R2 is set up. The second resistor R2 pulls the control terminal of the first controllable switch V1 to ground, so that the first controllable switch V1 is in the off mode when it is not working.

[0061] In some embodiments, a voltage follower module is also included;

[0062] The input terminal of the voltage follower module is connected to the output terminal of the controller 3, the output terminal of the voltage follower module is connected to the control terminal of the first controllable switch V1, and the inverting input terminal of the voltage follower module is connected to the second terminal of the first controllable switch V1.

[0063] The voltage follower module is used to control the voltage at the second terminal of the first controllable switch V1 to be equal to the voltage output by the controller 3.

[0064] In order to more accurately control the current when the TEC is working, the current affects the working efficiency of the TEC. The current flowing through the first resistor R1 is the working current of the TEC. However, the signal output by the controller 3 during the control process is the signal that drives the first controllable switch V1 to conduct. Considering the conduction voltage drop of the first controllable switch V1, it is not possible to accurately control the current flowing through the first resistor R1.

[0065] Therefore, a voltage follower module was set up. The voltage follower module adjusts its own gain so that the voltage output by the controller 3 is equal to the voltage at the second terminal of the first controllable switch V1.

[0066] In some embodiments, the voltage follower module includes an operational amplifier U1, a first capacitor C1, and a third resistor R3;

[0067] The non-inverting input terminal of the operational amplifier U1 is connected to the output terminal of the controller 3. The inverting input terminal of the operational amplifier U1 is connected to the first terminal of the first capacitor C1 and the first terminal of the third resistor R3 respectively. The second terminal of the third resistor R3 is connected to the switching module 1. The second terminal of the first capacitor C1 is connected to the control terminal of the switching module 1.

[0068] The first capacitor C1 and the third resistor R3 are used for feedback, and the operational amplifier U1 is used for voltage regulation.

[0069] Specifically, the amplifier circuit changes the amplification factor by adjusting the external resistor of operational amplifier U1. In this invention, the structural gain is 1. The function of the third resistor R3 is to enable the amplifier to operate in emitter follower mode with a gain of 1. The function of the first capacitor C1 is to stabilize the closed-loop of operational amplifier U1 and prevent oscillation.

[0070] Furthermore, the third resistor R3 serves as current limiting protection. Alternatively, R3 can be omitted; the wire can be connected from the second terminal of the first controllable switch V1 to the inverting input terminal of the operational amplifier U1. This can be configured according to actual needs. The first capacitor C1 improves loop stability; this branch can be omitted.

[0071] In some embodiments, the adjustment module 2 includes a second controllable switch V2, a third controllable switch V3, a fourth controllable switch V4, and a fifth controllable switch V5;

[0072] The control terminals of the second controllable switch V2, the third controllable switch V3, the fourth controllable switch V4, and the fifth controllable switch V5 are all connected to the controller 3. The first terminal of the second controllable switch V2 and the second terminal of the fifth controllable switch V5 are both connected to the power supply. The second terminal of the second controllable switch V2 is connected to the first terminal of the third controllable switch V3, and the common terminal of the connection is connected to the positive power supply terminal of the TEC. The second terminal of the third controllable switch V3 is connected to the first terminal of the fourth controllable switch V4, and the common terminal of the connection is connected to the first terminal of the switch module 1. The second terminal of the fourth controllable switch V4 is connected to the first terminal of the fifth controllable switch V5, and the common terminal of the connection is connected to the negative power supply terminal of the TEC.

[0073] The controller 3 is specifically used to control the second controllable switch V2 and the fourth controllable switch V4 to be turned on simultaneously and the third controllable switch V3 and the fifth controllable switch V5 to be turned off simultaneously, so as to control the TEC to work in the cooling mode, or to control the second controllable switch V2 and the fourth controllable switch V4 to be turned off simultaneously and the third controllable switch V3 and the fifth controllable switch V5 to be turned on simultaneously, so as to control the TEC to work in the heating mode.

[0074] The control signals of the second controllable switch V2 and the fourth controllable switch V4 are the same, and the control signals of the third controllable switch V3 and the fifth controllable switch V5 are the same. The control signals of the second controllable switch V2 and the fourth controllable switch V4 are inversely related to the control signals of the third controllable switch V3 and the fifth controllable switch V5. The control signals of the second controllable switch V2, the fourth controllable switch V4, the third controllable switch V3, and the fifth controllable switch V5 are controlled by the processor. When the control signals of the second controllable switch V2 and the fourth controllable switch V4 are valid, the second controllable switch V2 and the fourth controllable switch V4 are turned on. At this time, the control signals of the third controllable switch V3 and the fifth controllable switch V5 are invalid, and the third controllable switch V3 and the fifth controllable switch V5 are turned off. Current flows in from TEC+ and flows out from TEC-. At this time, the TEC operates in cooling mode. When the control signals of the third controllable switch V3 and the fifth controllable switch V5 are valid, the third controllable switch V3 and the fifth controllable switch V5 are turned on. At this time, the control signals of the second controllable switch V2 and the fourth controllable switch V4 are invalid, and the second controllable switch V2 and the fourth controllable switch V4 are turned off. The current flows in from TEC- and flows out from TEC+. At this time, TEC is working in heating mode.

[0075] In some embodiments, a digital-to-analog converter is also included;

[0076] The input terminal of the digital-to-analog converter is connected to the output terminal of the controller 3, and the output terminal of the digital-to-analog converter is connected to the control terminal of the switch module 1;

[0077] The digital-to-analog converter is used to convert the control signal output by controller 3 into a voltage signal.

[0078] It should be noted that controller 3 is an FPGA, so a digital-to-analog converter (DAC) is set up. Based on the FPGA programmable gate array, the DAC input voltage value is controlled by hardware VHDL programming to control the TEC current value. At the same time, the FPGA controls the TEC conduction direction, thereby realizing TEC heating or cooling.

[0079] In some embodiments, when the temperature deviation between the laser and the target temperature is greater than a preset temperature deviation, a conduction signal is sent to the switch module 1 to control the switch module 1 to conduct, and an adjustment signal is sent to the adjustment module 2 to control the adjustment module 2 to change the direction of the current supplying power to the TEC, including:

[0080] Obtain the current temperature of the laser;

[0081] Based on the current temperature and the target temperature of the laser;

[0082] Determine whether the absolute value of the deviation between the current temperature and the target temperature is greater than the preset temperature deviation;

[0083] If so, a first control signal is sent to the control terminal of switch module 1 to control switch module 1 to be turned on;

[0084] If the deviation is greater than zero, an adjustment signal is sent to the adjustment module 2 to control the adjustment module 2 to change the direction of the current supplying power to the TEC, and adjust the TEC's operating mode to cooling mode. The supply current is positively correlated with the absolute value of the deviation.

[0085] If the deviation is less than zero, an adjustment signal is sent to the adjustment module 2 to control the adjustment module 2 to change the direction of the current supplying power to the TEC, and adjust the TEC's working mode to heating mode.

[0086] When the temperature value fed back by the laser thermistor is lower than the target temperature, the system can be adjusted to heating mode; when the temperature value fed back by the laser thermistor is higher than the target temperature, the system can be adjusted to cooling mode. Furthermore, to improve control efficiency, when the temperature value fed back by the laser thermistor and the target temperature differ significantly, the DAC can output a large voltage to provide the TEC with a large operating current, improving temperature control efficiency. When the temperature value fed back by the laser thermistor and the target temperature differ very little, the DAC can output a smaller voltage to provide the TEC with a smaller operating current, improving temperature control accuracy. This design can be tested in both high and low temperature operating environments. A bidirectional, linearly controllable TEC control circuit is implemented directly using FPGA software resources.

[0087] The present invention also provides a TEC, including the control circuit of the TEC and the TEC body described above;

[0088] The TEC's control circuit is used to control the operating mode of the TEC itself.

[0089] The description of the TEC provided in this application is based on the above embodiments and will not be repeated here.

[0090] The present invention also provides a laser, including the aforementioned TEC, and further including a laser body, wherein the TEC is used to control the temperature of the laser body.

[0091] The description of the laser provided in this application is similar to that in the above embodiments and will not be repeated here.

[0092] It should also be noted that, in this specification, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0093] Those skilled in the art will further recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both. To clearly illustrate the interchangeability of hardware and software, the components and steps of the various examples have been generally described in terms of functionality in the foregoing description. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of this invention.

[0094] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A control circuit for a TEC, characterized in that, include: The switch module has its first terminal connected to the first terminal of the adjustment module, and its second terminal grounded. The adjustment module has a second end connected to the power supply and a third end connected to the power supply terminal of the TEC. The controller's output terminal is connected to the control terminal of the switch module and the control terminal of the adjustment module, and is used to obtain the current temperature of the laser. Based on the current temperature and the target temperature of the laser; Determine whether the absolute value of the deviation between the current temperature and the target temperature is greater than a preset temperature deviation; If so, a first control signal is sent to the control terminal of the switch module to control the switch module to conduct, forming a circuit, and the adjustment module is powered on; If the deviation is greater than zero, an adjustment signal is sent to the adjustment module to control the adjustment module to change the direction of the current supplying power to the TEC and adjust the TEC's operating mode to cooling mode. The supply current is positively correlated with the absolute value of the deviation, and the direction of the current is related to the TEC's operating mode, which includes cooling mode and heating mode. If the deviation is less than zero, an adjustment signal is sent to the adjustment module to control the adjustment module to change the direction of the current supplying power to the TEC and adjust the TEC's operating mode to heating mode.

2. The control circuit of TEC as described in claim 1, characterized in that, The switching module includes a first controllable switch and a first resistor; The control terminal of the first controllable switch serves as the control terminal of the switch module, the first terminal of the first controllable switch serves as the first terminal of the switch module, the second terminal of the first controllable switch is connected to the first terminal of the first resistor, and the second terminal of the first resistor is grounded. The first controllable switch is used to turn on when the deviation between the temperature of the TEC and the target temperature is greater than a preset temperature deviation.

3. The control circuit of TEC as described in claim 2, characterized in that, It also includes a second resistor; The first end of the second resistor is connected to the control terminal of the first controllable switch, and the second end of the second resistor is grounded. The second resistor is used to pull down the level of the control terminal of the first controllable switch.

4. The control circuit of TEC as described in claim 2, characterized in that, It also includes a voltage follower module; The input terminal of the voltage follower module is connected to the output terminal of the controller, the output terminal of the voltage follower module is connected to the control terminal of the first controllable switch, and the inverting input terminal of the voltage follower module is connected to the second terminal of the first controllable switch. The voltage follower module is used to control the voltage at the second terminal of the first controllable switch to be equal to the voltage output by the controller.

5. The control circuit of TEC as described in claim 4, characterized in that, The voltage follower module includes an operational amplifier, a first capacitor, and a third resistor; The non-inverting input terminal of the operational amplifier is connected to the output terminal of the controller, the inverting input terminal of the operational amplifier is connected to the first terminal of the first capacitor and the first terminal of the third resistor, the second terminal of the third resistor is connected to the switching module, and the second terminal of the first capacitor is connected to the control terminal of the switching module. The first capacitor and the third resistor are used for feedback, and the operational amplifier is used for voltage regulation.

6. The control circuit of TEC as described in claim 1, characterized in that, The adjustment module includes a second controllable switch, a third controllable switch, a fourth controllable switch, and a fifth controllable switch; The control terminals of the second, third, fourth, and fifth controllable switches are all connected to the controller. The first terminal of the second controllable switch and the second terminal of the fifth controllable switch are both connected to the power supply. The common terminal of the second terminal of the second controllable switch and the first terminal of the third controllable switch is connected to the positive power supply terminal of the TEC. The common terminal of the third controllable switch and the first terminal of the fourth controllable switch is connected to the first terminal of the switch module. The common terminal of the fourth controllable switch and the first terminal of the fifth controllable switch is connected to the negative power supply terminal of the TEC. The controller is specifically used to control the second and fourth controllable switches to be turned on simultaneously and the third and fifth controllable switches to be turned off simultaneously, so as to control the TEC to work in cooling mode, or to control the second and fourth controllable switches to be turned off simultaneously and the third and fifth controllable switches to be turned on simultaneously, so as to control the TEC to work in heating mode.

7. The control circuit of TEC as described in claim 1, characterized in that, It also includes digital-to-analog converters; The input terminal of the digital-to-analog converter is connected to the output terminal of the controller, and the output terminal of the digital-to-analog converter is connected to the control terminal of the switching module; The digital-to-analog converter is used to convert the control signal output by the controller into a voltage signal.

8. A TEC, characterized in that, Includes the control circuit and TEC body of the TEC as described in any one of claims 1 to 7; The control circuit of the TEC is used to control the working mode of the TEC body.

9. A laser, characterized in that, The device includes the TEC as described in claim 8, and also includes a laser body, wherein the TEC is used to perform temperature control on the laser body.

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