Circuit for realizing accurate temperature control

Abstract

The utility model provides a circuit for realizing accurate temperature control, which comprises a comparison module and an execution module, and the comparison module is connected with the execution module. The comparison module receives an external temperature signal and generates a control signal based on the deviation between the external temperature signal and a set reference value; the execution module receives the control signal and drives a drive circuit in the execution module to change the current direction so as to achieve the refrigerating or heating function. An external temperature signal is directly received through the comparison module and compared with a set reference value, a corresponding control signal is generated, then the current direction is changed by the execution module according to the control signal, and accurate constant-temperature control over the pump laser is achieved. The circuit structure is simplified, the manufacturing cost is reduced, and the response speed and stability of temperature control are improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to electronic circuit field especially relates to a circuit for realizing temperature accurate control. BACKGROUND

[0002] Laser as the core device of modern photoelectric technology, has wide application in communication, medical treatment, industrial processing and other fields. Among them, the temperature stability of pump laser has decisive influence on the performance of overall system, and temperature fluctuation will lead to output wavelength drift, power instability and other problems, seriously influence application effect. At present, the commonly used temperature control scheme mainly adopts linear control mode, that is, through linear adjustment of the current flowing through thermoelectric cooler (TEC) to realize temperature regulation.

[0003] But the existing laser still has some can improve place. For example, its power consumption is relatively high, and the voltage drop on the power device will cause part of the energy to be converted into heat; in terms of efficiency, although the typical efficiency is between 30-50%, but still has the room for improvement. These problems increase the overall size and cost of the system to some extent, and have a certain influence on energy utilization efficiency, thereby limiting the popularization degree of pump laser in portable and low-power application scenarios. SUMMARY

[0004] The utility model discloses a kind of circuits for realizing temperature accurate control, comprising: comparison module and execution module, the comparison module is connected with execution module;

[0005] The utility model provides a kind of circuits for realizing temperature accurate control, comprising: comparison module and execution module, the comparison module is connected with execution module;

[0006] The comparison module receives external temperature signal, and generates control signal based on the deviation of the external temperature signal and set reference value;

[0007] The execution module includes first diode, second diode, first MOS tube, second MOS tube, third diode, fourth diode, third MOS tube and fourth MOS tube;

[0008] When the comparison module outputs high level signal, the first MOS tube and the fourth MOS tube are turned on, and the first diode and the fourth diode are turned on to form a loop to cool down;

[0009] When the comparison module outputs low level signal, the second MOS tube and the third MOS tube are turned on, and the second diode and the third diode are turned on to form a loop to heat.

[0010] Further, the comparison module includes:

[0011] The first amplification circuit comprises a first operational amplifier, a positive input end of the first operational amplifier is connected with a reference voltage, and an inverting input end is connected with the external temperature signal;

[0012] The second amplification circuit comprises a second operational amplifier, a positive input end of the second operational amplifier is connected with the reference voltage, and an inverting input end receives a difference signal output by the first operational amplifier;

[0013] The second operational amplifier amplifies the difference signal.

[0014] Further, the first amplification circuit further comprises a first resistor and a second resistor;

[0015] One end of the first resistor is connected with the reference voltage, and the other end is connected with the positive input end of the first operational amplifier;

[0016] One end of the second resistor is connected with the external temperature signal and the inverting input end of the first operational amplifier respectively, and the other end is connected with a capacitor in series.

[0017] Further, the second amplification circuit further comprises a third resistor;

[0018] One end of the third resistor is connected with an output end of the first operational amplifier, and the other end is connected with an inverting input end of the second operational amplifier and a fourth resistor respectively.

[0019] Further, a negative electrode of the first diode and a positive electrode of the second diode are connected with an output end of the second amplification circuit through a fifth resistor;

[0020] A negative electrode of the third diode and a positive electrode of the fourth diode are connected with an output end of the first amplification circuit through a sixth resistor.

[0021] Further, a positive electrode of the first diode is connected with one end of a seventh resistor and a gate of a first MOS tube respectively, the other end of the seventh resistor is connected with an external voltage source, a source of the first MOS tube is connected with the external voltage source, and a drain is connected with a first port of a thermoelectric refrigerator;

[0022] A negative electrode of the second diode is connected with a gate of a second MOS tube, a source of the second MOS tube is grounded, and a drain is connected with the first port of the thermoelectric refrigerator.

[0023] Further, a negative electrode of the third diode and a positive electrode of the fourth diode are connected with the sixth resistor.

[0024] Further, the anode of the third diode is connected with one end of an eighth resistor and the gate of a third MOS transistor, the other end of the eighth resistor is connected with an external voltage source, the source of the third MOS transistor is connected with the external voltage source, and the drain is connected with a second port of the thermoelectric refrigerator.

[0025] The anode of the fourth diode is connected with the gate of a fourth MOS transistor, the source of the fourth MOS transistor is grounded, and the drain is connected with the second port of the thermoelectric refrigerator.

[0026] Compared with the prior art, the utility model at least has following beneficial effects: through comparing module receives external temperature signal directly and compares with setting reference value, produces corresponding control signal, then by execution module changes current direction according to control signal, realizes accurate thermostatic control to pump laser, not only simplifies circuit structure, reduces manufacturing cost, still improved temperature control's response speed and stability, can effectively restrain the output power and wavelength drift of pump laser because of temperature fluctuation, promotes the working performance and service life of laser. BRIEF DESCRIPTION OF DRAWINGS

[0027] In order to more clearly illustrate the technical scheme in the embodiment of the utility model or prior art, below will to the embodiment or prior art description needed to use the drawing briefly introduce, obviously, below description's drawing only is the embodiment of the utility model, for the ordinary skill in the art person to come to, under the premise of not paying creative labor, can also obtain other drawings according to the provided drawing.

[0028] Fig. 1 It is the module schematic diagram of temperature accurate control circuit in an embodiment of the utility model;

[0029] Fig. 2 It is the specific circuit connection schematic diagram of temperature accurate control circuit in an embodiment of the utility model;

[0030] Among them, first operational amplifier-YF13D;Second operational amplifier-YF13C;First resistance-R275;Second resistance-R280;Third resistance-R273;Fourth resistance-R274;Fifth resistance-R318;Sixth resistance-R281;Seventh resistance-R269;Eighth resistance-R278;Capacitor-C204;First diode-D7;Second diode-D8;Third diode-D9;Fourth diode-D10;First MOS tube-Q19;Second MOS tube-MOS10;Third MOS tube-Q20;Fourth MOS tube-MOS12;First port-TECL-;Second port-TECL+. DETAILED DESCRIPTION

[0031] The utility model will be described in more detail below in conjunction with the schematic diagram, wherein the preferred embodiment of the utility model is shown, it should be understood that the utility model described herein can be modified by the person skilled in the art, and still realize the advantageous effect of the utility model. Therefore, the following description should be understood as widely known by the person skilled in the art, and not as a limitation on the utility model.

[0032] It should be noted that, in this paper, such as the first and second relationship terms are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between the entities or operations. Moreover, the term "includes" "contains" or any other variant thereof is intended to cover non-exclusive inclusion, so that the process, method, article or equipment including a series of elements not only includes those elements, but also includes other elements not explicitly listed, or includes elements inherent in such process, method, article or equipment.

[0033] The utility model will be described in more detail below in conjunction with the schematic diagram, wherein the preferred embodiment of the utility model is shown, it should be understood that the utility model described herein can be modified by the person skilled in the art, and still realize the advantageous effect of the utility model. Therefore, the following description should be understood as widely known by the person skilled in the art, and not as a limitation on the utility model.

[0034] The embodiment provides a kind of circuit for realizing temperature accurate control, please refer to Figs. 1-2 , comprising: comparison module and execution module, the comparison module is connected with execution module.

[0035] The comparison module receives external temperature signal PUMP1 TEMP, and control signal is generated based on the deviation of the external temperature signal PUMP1 TEMP and set reference value.

[0036] The execution module includes first diode D7, second diode D8, first MOS tube Q19, second MOS tube MOS10, third diode D9, fourth diode D10, third MOS tube Q20 and fourth MOS tube MOS12.

[0037] When the comparison module outputs high level signal, the first MOS tube Q19 and the fourth MOS tube MOS12 are turned on, the first diode D7 and the fourth diode D10 are turned on to form a loop and refrigerate.

[0038] When the comparison module outputs low level signal, the second MOS tube MOS10 and the third MOS tube Q20 are turned on, the second diode D8 and the third diode D9 are turned on to form a loop and heat.

[0039] Specifically, the comparison module processes the temperature deviation signal through two-stage amplification circuits, wherein the first-stage amplification circuit is used for preliminary comparison and amplification, and the second-stage amplification circuit is used for further amplification processing. The execution module adopts an H-bridge structure, and switches the current direction by controlling the conduction state of the MOS tube. By accurately controlling the conduction timing of the MOS tube, the rapid switching of the refrigeration and heating functions can be realized, thereby improving the response speed of temperature control.

[0040] Further, the comparison module comprises:

[0041] The first amplification circuit comprises a first operational amplifier YF13D, wherein the positive input end of the first operational amplifier YF13D is connected with a reference voltage, and the inverting input end is connected with the external temperature signal PUMP1 TEMP.

[0042] The second amplification circuit comprises a second operational amplifier YF13C, wherein the positive input end of the second operational amplifier YF13C is connected with the reference voltage, and the inverting input end receives the difference signal output by the first operational amplifier YF13D.

[0043] The second operational amplifier YF13C amplifies the difference signal.

[0044] Please refer to Fig. 2 , the pin 12 of the first operational amplifier YF13D is the positive input end, the pin 13 is the inverting input end, and the pin 14 is the output end; the pin 10 of the second operational amplifier YF13C is the positive input end, the pin 9 is the inverting input end, and the pin 8 is the output end. In the embodiment, the first amplification circuit further comprises a first resistor R275 and a second resistor R280. One end of the first resistor R275 is connected with the reference voltage, and the other end is connected with the positive input end of the first operational amplifier YF13D. One end of the second resistor R280 is respectively connected with the external temperature signal PUMP1 TEMP and the inverting input end of the first operational amplifier YF13D, and the other end is connected with a capacitor C204 in series. Specifically, the first amplification circuit is used for receiving the external temperature signal PUMP1 TEMP and comparing it with the reference voltage to generate a difference signal. The second amplification circuit further amplifies the difference signal to improve the control precision. The first resistor R275 and the second resistor R280 constitute a voltage division network for setting the reference voltage of the first operational amplifier YF13D. The capacitor C204 is used for filtering high-frequency noise interference. The third resistor R273 and the fourth resistor R274 constitute a feedback network for adjusting the gain of the second operational amplifier YF13C.

[0045] The first resistor R275 is used to input the reference voltage after voltage division to the positive input terminal of the operational amplifier, wherein the resistance value can be selected from the range of 1kΩ to 10kΩ according to the voltage division requirement. The second resistor R280 and the external temperature sensor form a signal input path, and the resistance value is 5kΩ±1%, which is used to match the output impedance of the sensor. The capacitor C204 is a 0.1μF ceramic capacitor, which forms an RC filter network with the second resistor R280, and can effectively suppress high-frequency interference.

[0046] As a preferred embodiment, the first resistor R275 and the second resistor R280 can adopt 0805 packaged thick film resistors, and the working temperature range covers-40℃ to 125℃. Further, the capacitor C204 can be arranged in parallel on the back of the circuit board, and connected with the second resistor R280 through a via hole, so as to optimize the layout space.

[0047] As another preferred embodiment, the capacitor C204 in the first amplification circuit is used to filter high-frequency noise and improve signal stability. The fourth resistor R274 in the second amplification circuit can be used to adjust the amplification factor to adapt to different control requirements.

[0048] Through the design of the two-stage amplification circuit, high-precision detection and processing of the temperature signal can be realized. The first-stage amplification circuit completes preliminary comparison and difference extraction, and the second-stage amplification circuit precisely amplifies the difference signal. This structure has higher sensitivity and stability compared with the single-stage amplification scheme, and can more accurately reflect the temperature change. At the same time, the reasonable configuration of resistors and capacitors effectively suppresses noise interference and improves the anti-interference ability of the system. Compared with the direct connection mode, the voltage division resistor network can flexibly adjust the comparison threshold, and the filter design can eliminate high-frequency noise in the sensor signal, thereby improving the temperature detection precision.

[0049] The second amplification circuit further includes a third resistor R273. One end of the third resistor R273 is connected to the output terminal of the first operational amplifier YF13D, and the other end is respectively connected to the inverting input terminal of the second operational amplifier YF13C and the fourth resistor R274.

[0050] The third resistor R273 plays a key role in the second amplification circuit, and the selection of its resistance value directly affects the amplification factor and signal processing accuracy. As a preferred embodiment, the third resistor R273 can be a precision metal film resistor with a resistance value ranging from 1 kΩ to 10 kΩ and a temperature coefficient controlled within 50 ppm / °C. Further, the ratio of the third resistor R273 to the fourth resistor R274 determines the amplification factor of the second operational amplifier YF13C, with a typical ratio of 1:10 to 1:100. For example, when a higher gain is required, a third resistor R273 with a resistance value of 2 kΩ can be used in conjunction with a fourth resistor R274 with a resistance value of 200 kΩ. In addition, the third resistor R273 should be placed close to the operational amplifier pin to reduce the influence of the capacitor C204 on high-frequency signals.

[0051] By adding the third resistor R273 and optimizing its parameter configuration, the signal processing capability of the comparison module can be effectively improved. The second operational amplifier YF13C can accurately amplify the difference signal output by the first stage, thereby enhancing the detection sensitivity of the system to small temperature changes. Compared with the traditional scheme of directly using single-stage amplification, this two-stage amplification structure reduces the temperature detection error, and by reasonably setting the resistance ratio, adjustable amplification gain can be achieved without increasing the circuit complexity. In specific implementation, the welding of the third resistor R273 should use reflow soldering process to ensure reliable connection.

[0052] Further, the negative electrode of the first diode D7 and the positive electrode of the second diode D8 are connected to the output terminal of the second amplification circuit through the fifth resistor R318.

[0053] The negative electrode of the third diode D9 and the positive electrode of the fourth diode D10 are connected to the output terminal of the first amplification circuit through the sixth resistor R281.

[0054] Further, the anode of the first diode D7 is connected to one end of the seventh resistor R269 and the gate of the first MOS tube Q19, the other end of the seventh resistor R269 is connected to an external voltage source, the source of the first MOS tube Q19 is connected to the external voltage source, and the drain is connected to the first port TECL- of the thermoelectric cooler.

[0055] The negative electrode of the second diode D8 is connected to the gate of the second MOS tube MOS10, the source of the second MOS tube MOS10 is grounded, and the drain is connected to the first port TECL- of the thermoelectric cooler.

[0056] In one possible embodiment, the first diode D7 and the second diode D8 are fast recovery diodes with a reverse recovery time less than 100 ns to reduce switching loss.

[0057] Please refer to Fig. 2, pin 1 of the first MOS Q19 is the gate, pin 2 is the source, and pin 3 is the drain; pin 1 of the second MOS MOS10 is the gate, pin 2 is the source, and pin 3 is the drain. In this embodiment, the first MOS Q19 is a PMOS, and the second MOS MOS10 is an NMOS, with a conduction resistance less than 50 mΩ. The seventh resistor R269 has a resistance range of 1 kΩ to 10 kΩ, for limiting the gate drive current. The voltage of the external voltage source is 12 V to 24 V, providing operating voltage for the MOS. As a preferred embodiment, the first diode D7 and the second diode D8 can be replaced by Schottky diodes to further reduce the on-voltage drop. By adopting the bridge arm structure of the combination of double diodes and double MOS, efficient switching of the current direction can be achieved.

[0058] Further, the negative electrode of the third diode D9 and the positive electrode of the fourth diode D10 are connected to the sixth resistor R281.

[0059] Further, the positive electrode of the third diode D9 is connected to one end of the eighth resistor R278 and the gate of the third MOS Q20, the other end of the eighth resistor R278 is connected to an external voltage source, the source of the third MOS Q20 is connected to the external voltage source, and the drain is connected to the second port TECL+ of the thermoelectric cooler.

[0060] The negative electrode of the fourth diode D10 is connected to the gate of the fourth MOS MOS12, the source of the fourth MOS MOS12 is grounded, and the drain is connected to the second port TECL+ of the thermoelectric cooler.

[0061] Specifically, the third diode D9 and the fourth diode D10 adopt a reverse parallel structure, in which the third diode D9 is used to turn on at a low-level signal, and the fourth diode D10 is used to turn on at a high-level signal. As a preferred embodiment, the third diode D9 and the fourth diode D10 can adopt Schottky diodes to reduce the on-voltage drop and switching loss. Further, the resistance range of the eighth resistor R278 is preferably 1 kΩ to 10 kΩ, for limiting the gate drive current.

[0062] Please refer to Fig. 2 , pin 1 of the third MOS Q20 is the gate, pin 2 is the source, and pin 3 is the drain; pin 1 of the fourth MOS MOS12 is the gate, pin 2 is the source, and pin 3 is the drain. In this embodiment, the third MOS Q20 is a PMOS, and the fourth MOS MOS12 is an NMOS, with a conduction resistance less than 0.1 Ω to ensure low power loss.

[0063] By setting the diode pair, cooperating with the switch control of the MOS tube, the efficient switching of the current direction is realized. Compared with the traditional linear control scheme, the structure has faster response speed and higher energy conversion efficiency, and reduces the heating problem of the power device. Since the switch control is adopted, the voltage drop on the power device is reduced, and the energy loss can be controlled below 10%, thereby effectively solving the technical problems of large power consumption and low efficiency in the traditional scheme.

[0064] Further, when the comparison module outputs a high-level signal, the first MOS tube Q19 and the fourth MOS tube MOS12 are turned on, and the first diode D7 and the fourth diode D10 are turned on to form a loop.

[0065] When the comparison module outputs a low-level signal, the second MOS tube MOS10 and the third MOS tube Q20 are turned on, and the second diode D8 and the third diode D9 are turned on to form a loop.

[0066] When the comparison module outputs a high-level signal, the first MOS tube Q19 and the fourth MOS tube MOS12 are turned on, and the first diode D7 and the fourth diode D10 are turned on at this time, the current path is: external power supply VIN→first MOS tube Q19→first diode D7→fourth diode D10→fourth MOS tube MOS12→ground, forming a closed loop, at this time, the current flows from the first port TECL- of the thermoelectric cooler to the second port TECL+.

[0067] When the comparison module outputs a low-level signal, the second MOS tube MOS10 and the third MOS tube Q20 are turned on, and the current path is: external power supply VIN→third MOS tube Q20→third diode D9→second diode D8→second MOS tube MOS10→ground, forming a closed loop. At this time, the current flows from the second port TECL+ of the thermoelectric cooler to the first port TECL-, which produces a temperature effect opposite to the high-level signal.

[0068] The above application of specific examples to the utility model is described, which is only used to help understand the utility model, and does not limit the utility model. For the skilled person in the technical field to which the utility model belongs, according to the idea of the utility model, a number of simple deductions, deformations or substitutions can be made.

Claims

1. A circuit for implementing temperature accurate control, characterized by The circuit for realizing temperature accurate control comprises a comparison module and an execution module, the comparison module is connected with the execution module. The comparison module receives an external temperature signal, and generates a control signal based on a deviation of the external temperature signal from a set reference value. The execution module comprises a first diode, a second diode, a first MOS tube, a second MOS tube, a third diode, a fourth diode, a third MOS tube and a fourth MOS tube. When the comparison module outputs a high-level signal, the first MOS tube and the fourth MOS tube are turned on, the first diode and the fourth diode are turned on to form a loop to perform refrigeration. When the comparison module outputs a low-level signal, the second MOS tube and the third MOS tube are turned on, the second diode and the third diode are turned on to form a loop to perform heating. The comparison module comprises:

2. The circuit for implementing temperature precision control according to claim 1, wherein, A first amplification circuit comprising a first operational amplifier, a positive input end of the first operational amplifier being connected with a reference voltage, and an inverting input end being connected with the external temperature signal; A second amplification circuit comprising a second operational amplifier, a positive input end of the second operational amplifier being connected with the reference voltage, and an inverting input end receiving a difference signal output by the first operational amplifier; The second operational amplifier performs amplification processing on the difference signal. The first amplification circuit further comprises a first resistor and a second resistor; 3. The circuit for implementing temperature precision control according to claim 2, wherein, One end of the first resistor is connected with the reference voltage, and the other end is connected with the positive input end of the first operational amplifier; One end of the second resistor is connected with the external temperature signal and the inverting input end of the first operational amplifier respectively, and the other end is connected with a capacitor in series. The second amplification circuit further comprises a third resistor; 4. The circuit for implementing temperature precision control according to claim 2, wherein, One end of the third resistor is connected with the output end of the first operational amplifier, and the other end is connected with the inverting input end of the second operational amplifier and a fourth resistor respectively.

5. The circuit for realizing temperature accurate control according to claim 2, wherein: The negative electrode of the first diode and the positive electrode of the second diode are connected with the output end of the second amplification circuit through a fifth resistor; The negative electrode of the third diode and the positive electrode of the fourth diode are connected with the output end of the first amplification circuit through a sixth resistor.

6. The circuit for realizing temperature accurate control according to claim 5, wherein: The positive electrode of the first diode is connected with one end of a seventh resistor and the gate electrode of the first MOS tube respectively, the other end of the seventh resistor is connected with an external voltage source, the source electrode of the first MOS tube is connected with the external voltage source, and the drain electrode is connected with a first port of a thermoelectric refrigerator; The negative electrode of the second diode is connected with the gate electrode of the second MOS tube, the source electrode of the second MOS tube is grounded, and the drain electrode is connected with the first port of the thermoelectric refrigerator. The negative electrode of the third diode and the positive electrode of the fourth diode are connected with the sixth resistor.

7. The circuit for implementing temperature precise control according to claim 6, wherein, 8. The circuit for realizing temperature accurate control according to claim 7, wherein: ​ The positive pole of the third diode is connected with one end of an eighth resistor and the gate of the third MOS tube, the other end of the eighth resistor is connected with an external voltage source, the source of the third MOS tube is connected with the external voltage source, and the drain is connected with the second port of the thermoelectric refrigerator. The negative pole of the fourth diode is connected with the gate of the fourth MOS tube, the source of the fourth MOS tube is grounded, and the drain is connected with the second port of the thermoelectric refrigerator.

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