A high-efficiency linear temperature control circuit with controllable multiple and its control method

Abstract

This invention discloses a controllable multiple high-efficiency linear temperature control circuit and its control method. The controllable multiple high-efficiency linear temperature control circuit includes: an adjustable voltage output module, a first PWM signal conversion module, a second PWM signal conversion module, a current amplification drive module, a voltage acquisition module, a processing module, and a temperature acquisition module. The voltage acquisition module is connected between the current amplification drive module and the processing module, and is used to detect the output voltage of the current amplification drive module and transmit it to the processing module. The adjustable voltage output module is connected to the second PWM signal conversion module and the current amplification drive module, and dynamically adjusts the voltage output to the current amplification drive module in real time in response to the analog voltage signal. This invention synchronously adjusts the load voltage and current in real time according to the actual constant temperature control needs, achieving a controllable drive current multiple, extremely low electromagnetic interference, high efficiency, and low power consumption linear constant temperature control.

Description

Technical Field

[0001] This invention relates to the field of constant temperature control technology, and in particular to a high-efficiency linear temperature control circuit with controllable multiples and its control method. Background Technology

[0002] In precision instruments such as high-precision inertial navigation and gravity measurement instruments, core components such as precision inertial elements require high-precision constant-temperature control systems with minimal or no electromagnetic interference. These systems typically need to operate in a highly stable temperature environment to avoid the impact of temperature drift on measurement accuracy. Therefore, efficient, stable, and low-interference constant-temperature control systems are crucial.

[0003] However, most existing constant temperature control systems employ switching control; or simply utilize the linear region of transistors to achieve a near-linear temperature control mode. The former controls heating power through frequent switching, which, while efficient, generates severe switching electromagnetic interference, making it unsuitable for extremely high-precision measurements and impacting precision measurement units, hindering accurate measurement. The latter, in temperature control circuits with variable power loads, suffers from significant heat dissipation, resulting in substantial energy loss, and cannot operate reliably for extended periods in extreme high-temperature environments. Summary of the Invention

[0004] This invention provides a controllable multiplier high-efficiency linear temperature control circuit and its control method. The circuit is simple to construct and easy to implement. It can realize real-time adjustment of voltage and current and feedback control of amplified current, achieving the effect of controllable drive current multiplier, extremely low electromagnetic interference, high efficiency and low power consumption linear constant temperature control.

[0005] According to one aspect of the present invention, a high-efficiency linear temperature control circuit with controllable multiple is provided. The high-efficiency linear temperature control circuit with controllable multiple includes: an adjustable voltage output module, a first PWM signal conversion module, a second PWM signal conversion module, a current amplification drive module, a voltage acquisition module, a processing module, and a temperature acquisition module.

[0006] The voltage acquisition module is connected between the current amplification drive module and the processing module. The voltage acquisition module is used to detect the output voltage of the current amplification drive module and transmit it to the processing module.

[0007] The temperature acquisition module is connected to the processing module. The temperature acquisition module is used to detect the temperature of the heating load in the current amplification drive module and generate a temperature signal that is transmitted to the processing module.

[0008] The processing module is used to generate a first PWM signal and a second PWM signal based on the temperature signal and the output voltage, and transmit them to the first PWM signal conversion module and the second PWM signal conversion module respectively, and control the adjustable voltage output module and the current amplification drive module to work together.

[0009] The first PWM signal conversion module is connected to the processing module and the current amplification and drive module. The first PWM signal conversion module is used to output a controllable current according to the first PWM signal and transmit it to the current amplification and drive module. The current amplification and drive module is used to amplify the controllable current and drive the heating load.

[0010] The second PWM signal conversion module is connected to the processing module, and the second PWM signal conversion module is used to convert the second PWM signal into an analog voltage signal and transmit it to the adjustable voltage output module;

[0011] The adjustable voltage output module is connected to the second PWM signal conversion module and the current amplification drive module. The adjustable voltage output module dynamically adjusts the voltage output to the current amplification drive module in real time in response to the analog voltage signal.

[0012] Optionally, the adjustable voltage output module includes: a second capacitor, a DC / DC voltage conversion manager, an inductor, a first resistor, a second resistor, a first capacitor, a third resistor, and a diode;

[0013] The second capacitor is connected between the input voltage pin and the first ground pin of the DC / DC voltage conversion manager. The first end of the inductor is connected to the adjustable voltage output pin of the DC / DC voltage conversion manager. The second end of the inductor is connected to the first end of the first resistor, the first end of the first capacitor, and the current amplification drive module. The second end of the first resistor is connected to the second end of the first capacitor, the first end of the third resistor, the first end of the second resistor, and the output voltage pin of the DC / DC voltage conversion manager. The second end of the second resistor is grounded. The second end of the third resistor is connected to the cathode of the diode. The anode of the diode is connected to the second PWM signal conversion module.

[0014] Optionally, the first PWM signal conversion module includes: a first PCA converter, which is used to convert the first PWM signal into an analog voltage signal and transmit it to the current amplification drive module;

[0015] The second PWM signal conversion module includes a second PCA converter, which is used to convert the second PWM signal into an analog current signal and transmit it to the adjustable voltage output module.

[0016] Optionally, the high-efficiency linear temperature control circuit with controllable multiple further includes: an optocoupler, wherein the first input terminal and the second input terminal of the optocoupler are respectively connected to the first output terminal and the second output terminal of the processing module, and the first output terminal and the second output terminal of the optocoupler are respectively connected to the first PCA converter and the second PCA converter;

[0017] The optocoupler isolator is used to isolate the received first PWM signal and second PWM signal and output them to the first PCA converter and the second PCA converter, respectively.

[0018] Optionally, the current amplification drive module includes: a Darlington transistor, a current sensing resistor, a heating element, and a current sensing amplifier;

[0019] The base of the Darlington transistor is connected to the current output terminal of the second PCA converter. The collector of the Darlington transistor is connected to the adjustable voltage output module and the voltage acquisition module. The emitter of the Darlington transistor is connected to the first terminal of the current sensing resistor and the first input terminal of the current sensing amplifier. The second terminal of the current sensing resistor is connected to the first terminal of the heating element and the second input terminal of the current sensing amplifier. The second terminal of the heating element is grounded. The output terminal of the current sensing amplifier is connected to the feedback terminal of the first PCA converter. The current sensing amplifier is used to detect the voltage flowing through the current sensing resistor and feed it back to the feedback terminal of the first PCA converter to lock the current amplification factor.

[0020] Optionally, the current sensing amplifier has a gain of K, so that the current output to the heating element is K times the output current of the first PCA converter;

[0021] The value of K ranges from 1 to 1000.

[0022] Optionally, the voltage acquisition module includes: an instrumentation operational amplifier and an A / D converter;

[0023] The first and second input terminals of the instrumentation operational amplifier are respectively connected to the collector and emitter of the Darlington transistor. The instrumentation operational amplifier is used to detect the voltage difference between the collector and emitter of the Darlington transistor in real time and transmit the voltage difference to the A / D converter.

[0024] The A / D converter is connected to the output of the instrument operational amplifier and the processing module. The A / D converter is used to convert the voltage difference into a digital quantity and send it to the processing module.

[0025] Optionally, the temperature acquisition module includes: a precision temperature measurement and A / D sampling circuit and a thermistor;

[0026] The two ends of the thermistor are connected to the precision temperature measurement and A / D sampling circuit. The thermistor is used to measure the temperature data of the heating element and transmit it to the precision temperature measurement and A / D sampling circuit.

[0027] The precision temperature measurement and A / D sampling circuit is connected to the processing module. The precision temperature measurement and A / D sampling circuit is used to convert the temperature data into digital data and send it to the processing module.

[0028] According to another aspect of the present invention, a method for regulating a controllable multiple high-efficiency linear temperature control circuit is provided, applied to the controllable multiple high-efficiency linear temperature control circuit described in any one of the preceding aspects, wherein the method for regulating the controllable multiple high-efficiency linear temperature control circuit includes:

[0029] The current temperature signal and the output voltage of the current amplification and drive module are acquired by the temperature acquisition module and the voltage acquisition module, respectively.

[0030] The processing module generates a first PWM signal and a second PWM signal based on the temperature signal and the output voltage.

[0031] The first PWM signal conversion module adjusts the output controllable current based on the first PWM signal and transmits the controllable current to the current amplification and drive module, which amplifies the controllable current and drives the heating load.

[0032] The second PWM signal is converted into an analog voltage signal by the second PWM signal conversion module and transmitted to the adjustable voltage output module.

[0033] The adjustable voltage output module dynamically adjusts the voltage output to the current amplification drive module in real time in response to the analog voltage signal.

[0034] Optionally, the control method of the high-efficiency linear temperature control circuit with controllable multiple further includes:

[0035] The processing module dynamically adjusts the first PWM signal and the second PWM signal based on the temperature signal and the output voltage of the current amplification drive module, so that the output voltage of the current amplification drive module is kept below a set threshold.

[0036] The technical solution of this invention proposes a highly efficient linear temperature control circuit with controllable multiple that achieves extremely low electromagnetic interference, maintains high efficiency and low power consumption, and can reliably operate over a wide temperature range and under varying load conditions. The entire power regulation process is a purely linear analog regulation, completely avoiding switching actions and the high-frequency electromagnetic interference they bring. It is particularly suitable for precision measuring instruments sensitive to electromagnetic environments. By constructing a dual-path coordinated regulation mechanism for voltage and current, and introducing current multiple amplification and locking functions, while achieving pure linear control to eliminate switching interference, the operating voltage drop of the adjusting device in the current amplification drive module can be optimized in real time to keep it in a low-power state, thereby achieving a constant temperature control effect with high efficiency, low power consumption, and minimal electromagnetic interference. In summary, this invention solves the problems of severe switching electromagnetic interference and high self-loss in constant temperature control systems, achieving a simple and easy-to-implement circuit structure, real-time voltage and current adjustment and amplified current feedback control, and achieving a linear constant temperature control effect with controllable drive current multiple, extremely low electromagnetic interference, and high efficiency and low power consumption.

[0037] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of the present invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0038] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying 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.

[0039] Figure 1 This is a schematic diagram of a high-efficiency linear temperature control circuit with controllable multiple provided by an embodiment of the present invention;

[0040] Figure 2 This is a schematic diagram illustrating the working principle of a high-efficiency linear temperature control circuit with controllable multiple provided by an embodiment of the present invention;

[0041] Figure 3 This is a flowchart of a controllable multiple high-efficiency linear temperature control circuit according to an embodiment of the present invention;

[0042] Figure 4 This is a simplified schematic diagram of the control strategy of a high-efficiency linear temperature control circuit with controllable multiple provided by an embodiment of the present invention. Detailed Implementation

[0043] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0044] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0045] Figure 1 This is a schematic diagram of a high-efficiency linear temperature control circuit with controllable multiple provided by an embodiment of the present invention. (Refer to...) Figure 1 The embodiments of the present invention provide a high-efficiency linear temperature control circuit with controllable multiples. The high-efficiency linear temperature control circuit with controllable multiples includes: an adjustable voltage output module 10, a first PWM signal conversion module 20, a second PWM signal conversion module 30, a current amplification drive module 40, a voltage acquisition module 50, a processing module 60, and a temperature acquisition module 70.

[0046] The voltage acquisition module 50 is connected between the current amplification drive module 40 and the processing module 60. The voltage acquisition module 50 is used to detect the output voltage of the current amplification drive module 40 and transmit it to the processing module 60.

[0047] The temperature acquisition module 70 is connected to the processing module 60. The temperature acquisition module 70 is used to detect the temperature of the heating load in the current amplification drive module 40 and generate a temperature signal to be transmitted to the processing module 60.

[0048] The processing module 60 is used to generate a first PWM signal and a second PWM signal based on the temperature signal and the output voltage, and transmit them to the first PWM signal conversion module 20 and the second PWM signal conversion module 30 respectively, and control the adjustable voltage output module 10 and the current amplification drive module 40 to work together.

[0049] The first PWM signal conversion module 20 is connected to the processing module 60 and the current amplification and drive module 40. The first PWM signal conversion module 20 is used to output a controllable current according to the first PWM signal and transmit it to the current amplification and drive module 40. The current amplification and drive module 40 is used to amplify the controllable current and drive the heating load.

[0050] The second PWM signal conversion module 30 is connected to the processing module 60. The second PWM signal conversion module 30 is used to convert the second PWM signal into an analog voltage signal and transmit it to the adjustable voltage output module 10.

[0051] The adjustable voltage output module 10 is connected to the second PWM signal conversion module 30 and the current amplification drive module 40. The adjustable voltage output module 10 dynamically adjusts the voltage output to the current amplification drive module 40 in real time in response to the analog voltage signal.

[0052] Specifically, the temperature signal of the heating load in the current amplification drive module 40 and the output voltage of the adjustment device (such as a Darlington transistor) in the current amplification drive module 40 are acquired by the temperature acquisition module 70 and the voltage acquisition module 50, respectively. Based on the temperature signal and the output voltage, the processing module 60 generates a first PWM signal and a second PWM signal according to a preset control algorithm. The first PWM signal is mainly used to set the target drive current of the heating load, and the second PWM signal is mainly used to adjust the voltage drop on the adjustment device. The first PWM signal conversion module 20 adjusts the output controllable current based on the first PWM signal, and the current is amplified by K times by the current amplification drive module 40 to drive the heating load. The second PWM signal conversion module 30 converts the second PWM signal into an analog voltage signal and transmits it to the adjustable voltage output module 10 to control the adjustable voltage output module 10 to achieve real-time adjustable power supply voltage output. The adjustable voltage output module 10 responds to the analog voltage signal and dynamically adjusts the voltage output to the current amplification drive module 40 in real time, so that the voltage drop on the adjustment device is dynamically adjusted and maintained near the set low power consumption threshold.

[0053] The adjustable voltage output module 10 employs a DC / DC voltage converter with an adjustable voltage terminal (or similar functionality) to achieve adjustable power supply voltage output (using an ultra-low noise, ultra-low EMI, and high-efficiency voltage converter). The processing module 60 uses an ARM microcontroller or ARM processor to run the control algorithm and generate two PWM signals: a first PWM1 signal and a second PWM2 signal. The second PWM signal conversion module 30 (PWM signal to analog voltage output) converts the real-time second PWM control signal into an analog voltage signal, linearly converting the second PWM signal proportionally to an analog voltage of 0V to 5V, which is then output to the adjustable voltage output module 10 to control the adjustable voltage output module 10 to achieve real-time adjustable power supply voltage output.

[0054] Simultaneously, the first PWM signal conversion module 20 (PWM signal to analog current) converts the real-time first PWM control signal into an analog current signal, which is then amplified and output by the current amplification drive module 40. The first PWM signal conversion module 20 linearly converts the ratio (0%-100%) of the first PWM signal into an analog current output of 0mA to 20mA. The adjustable voltage output module 10, which adjusts the power supply voltage in real time, and the PWM control signal, converted into a real-time variable analog current signal, work together with the fixed-ratio current amplification drive module 40 to achieve a high-efficiency linear adjustment circuit with dual regulation and no frequency interference. Combined with a heating load, this achieves a high-efficiency linear temperature control circuit with dual regulation of voltage and current, free from frequency interference.

[0055] The technical solution of this invention proposes a highly efficient linear temperature control circuit with controllable multiple that achieves extremely low electromagnetic interference, maintains high efficiency and low power consumption, and can reliably operate over a wide temperature range and under varying load conditions. The entire power regulation process is a purely linear analog regulation, completely avoiding switching actions and the high-frequency electromagnetic interference they bring. It is particularly suitable for precision measuring instruments sensitive to electromagnetic environments. By constructing a dual-path coordinated regulation mechanism for voltage and current, and introducing current multiple amplification and locking functions, while achieving pure linear control to eliminate switching interference, the operating voltage drop of the adjusting device in the current amplification drive module can be optimized in real time to keep it in a low-power state, thereby achieving a constant temperature control effect with high efficiency, low power consumption, and minimal electromagnetic interference. In summary, this invention solves the problems of severe switching electromagnetic interference and high self-loss in constant temperature control systems, achieving a simple and easy-to-implement circuit structure, real-time voltage and current adjustment and amplified current feedback control, and achieving a linear constant temperature control effect with controllable drive current multiple, extremely low electromagnetic interference, and high efficiency and low power consumption.

[0056] Figure 2 This is a schematic diagram illustrating the working principle of a high-efficiency linear temperature control circuit with controllable multiple according to an embodiment of the present invention. (Refer to...) Figure 2 Optionally, the adjustable voltage output module 10 includes: a second capacitor C2, a DC / DC voltage conversion manager N1, an inductor L, a first resistor R1, a second resistor R2, a first capacitor C1, a third resistor R3, and a diode V2.

[0057] The second capacitor C2 is connected between the input voltage pin Vin and the first ground pin GND1 of the DC / DC voltage conversion manager N1. The first end of the inductor L is connected to the adjustable voltage output pin SW of the DC / DC voltage conversion manager N1. The second end of the inductor L is connected to the first end of the first resistor R1, the first end of the first capacitor C1, and the current amplification drive module 40. The second end of the first resistor R1 is connected to the second end of the first capacitor C1, the first end of the third resistor R3, the first end of the second resistor R2, and the output voltage pin FB of the DC / DC voltage conversion manager N1. The second end of the second resistor R2 is grounded to GND. The second end of the third resistor R3 is connected to the cathode of the diode V2. The anode of the diode V2 is connected to the second PWM signal conversion module 30.

[0058] Specifically, the core of the adjustable voltage output module 10 is a low-noise DC / DC voltage converter manager N1 with an FB feedback pin. The DC / DC voltage converter manager N1, with an adjustable voltage terminal (or similar functionality), is designed so that a resistive feedback network determines the adjustable power supply voltage output mode.

[0059] The voltage output type second PCA converter N2 converts the second PWM (0%~100%) control signal isolated by the optocoupler isolator 80 into a control voltage (0V~5V), which is then input to the output voltage pin FB of the DC / DC voltage conversion manager N1 via diode V1 and matching resistor.

[0060] The first resistor R1, the second resistor R2, and the third resistor R3 form a feedback network. When Vout and V... DAC The first resistor R1, the second resistor R2, the third resistor R3, and V FB When the power feedback network is operating in equilibrium, assuming the current flowing from the first resistor R1 to the second resistor R2 is I1, the current flowing from the third resistor R3 to the second resistor R2 is I2, and the current flowing through the second resistor R2 is I, then the following theoretical relationships hold:

[0061] (1)

[0062] In equation (1), V FB The feedback voltage of the output voltage pin FB of the DC / DC voltage converter N1 is the dynamic feedback control voltage V. DAC The minimum value is determined by the output of the second PCA converter N2, let it be V. DAC1 The maximum value is V DAC2 Then we have:

[0063] (2)

[0064] According to equation (2), the resistance values ​​of the first resistor R1, the second resistor R2, and the third resistor R3 required for the design can be calculated, and the dynamic feedback control voltage V is then used. DAC The DC / DC voltage conversion manager N1 dynamically adjusts the output power supply voltage Vout.

[0065] Continue to refer to Figure 2 Optionally, the first PWM signal conversion module 20 includes: a first PCA converter N3, which is used to convert the first PWM signal into an analog voltage signal and transmit it to the current amplification drive module 40;

[0066] The second PWM signal conversion module 30 includes a second PCA converter N2, which is used to convert the second PWM signal into an analog current signal and transmit it to the adjustable voltage output module 10.

[0067] Specifically, the first PWM signal conversion module 20 is a first PCA converter N3 (current type), used to convert the first PWM signal into an analog current signal (such as 0-20mA). A current-type PCA converter is used to convert the first PWM digital control signal into an analog current output to the base terminal of the Darlington transistor, and a current sensing resistor is connected in series at the emitter output terminal of the Darlington transistor. The heating element load can be directly connected in series with the current sensing resistor.

[0068] The second PWM signal conversion module 30 is a second PCA converter N2 (voltage type), used to convert the second PWM signal into an analog voltage signal (such as 0-5V). A voltage-type PCA converter is used to convert the second PWM digital control signal into a voltage analog quantity and output it to the adjustment input terminal FB of the DC / DC voltage conversion manager N1.

[0069] The high-efficiency linear temperature control circuit with controllable multiples is mainly composed of mature integrated circuits (DC / DC voltage conversion manager, first PCA converter, second PCA converter, operational amplifier, etc.) and a small number of discrete components. It has a clear structure and is easy to design and debug.

[0070] Continue to refer to Figure 2 Optionally, the high-efficiency linear temperature control circuit with controllable multiple further includes: an optocoupler 80, wherein the first input terminal IN1 and the second input terminal IN2 of the optocoupler 80 are respectively connected to the first output terminal and the second output terminal of the processing module 60, and the first output terminal OUT1 and the second output terminal OUT2 of the optocoupler 80 are respectively connected to the first PCA converter N3 and the second PCA converter N2.

[0071] Optical isolator 80 is used to isolate the received first PWM signal and second PWM signal and output them to the first PCA converter N3 and the second PCA converter N2 respectively.

[0072] Specifically, to enhance anti-interference capabilities, the first PWM signal and the second PWM signal are electrically isolated by optocoupler 80. The input terminal of optocoupler 80 is connected to the two PWM output terminals of processing module 60, and the output terminal of optocoupler 80 is connected to two PWM signal conversion modules respectively, which is used to achieve electrical isolation between the control signal and the power circuit, thereby enhancing the system's anti-interference capability and safety.

[0073] Continue to refer to Figure 2 Optionally, the current amplification drive module includes: Darlington transistor V1, current sensing resistor Rs, heating element Rj, and current sensing amplifier N5;

[0074] The base of Darlington transistor V1 is connected to the current output terminal of the second PCA converter N2. The collector of Darlington transistor V1 is connected to the adjustable voltage output module 10 and the voltage acquisition module 50. The emitter of Darlington transistor V1 is connected to the first terminal of the current sensing resistor Rs and the first input terminal IN+ of the current sensing amplifier N5. The second terminal of the current sensing resistor Rs is connected to the first terminal of the heating element Rj and the second input terminal IN- of the current sensing amplifier N5. The second terminal of the heating element Rj is grounded to GND. The output terminal OUT of the current sensing amplifier N5 is connected to the feedback terminal FB of the first PCA converter N3. The current sensing amplifier N5 is used to detect the voltage flowing through the current sensing resistor Rs and feed it back to the feedback terminal FB of the first PCA converter N3 to lock the current amplification factor.

[0075] Specifically, a suitable current-sensing amplifier N5 is used to detect the voltage across the current-sensing resistor Rs, amplify it by a factor of K, and then feed it to the feedback FB terminal of the first current-type PCA converter N3, thereby amplifying the input current by a factor of K to become the driving current. The current-sensing amplifier N5 detects the voltage across the current-sensing resistor Rs, amplifies it by a factor of K, and feeds it back to the feedback terminal FB of the first PCA converter N3, forming a closed loop. This allows the small input current to be precisely amplified by a factor of K before being output to drive the heating element Rj, thus locking the current factor.

[0076] The first PCA converter N3, a current-output type, converts the first PWM (0%~100%) control signal isolated by the optocoupler 80 into an output control current (0mA~20mA). This control current is amplified by Darlington transistor V1, flows through the current-sensing resistor Rs, and then drives the heating element Rj. The current-sensing amplifier N5 detects the current in the current-sensing resistor Rs, amplifies it by a factor of K, and feeds it back to the feedback terminal FB of the first PCA converter N3, thus amplifying the 0mA~20mA control current by a factor of K to drive the heating element Rj. Let the output current of the first PCA converter N3 be I. dac After being amplified by Darlington transistor V1 and current sense amplifier N5, the current is I. k Then we have:

[0077] (3)

[0078] The current I in equation (3) k The current I is used to drive the heating element Rj. k A detection voltage is generated across the current sensing resistor Rs. The current sensing amplifier N5 feeds this detection voltage back to the feedback terminal FB of the first PCA converter N3, forming a closed-loop feedback control current amplification output circuit. This enables the output current of the first PCA converter N3 to be I. dac The output is amplified by a factor of K by Darlington tube V1.

[0079] The circuit in this embodiment is as follows: Figure 1 As shown, the N4 instrumentation operational amplifier collects the voltage across the collector and emitter of the Darlington transistor, converts it to a digital value via an A / D converter, and sends it to the ARM processor. Simultaneously, the ARM processor collects the temperature data from the thermistor Rt via an independent A / D converter. The ARM processor combines the voltage across the collector and emitter of the Darlington transistor with the temperature data to determine PWM1 (control current output) and PWM2 (control voltage output), ensuring proper operation of the heating element and minimizing losses in the Darlington transistor. Let the resistance of the heating element be Rj, and the voltage across the collector and emitter of the Darlington transistor be Vt, then:

[0080] (4)

[0081] Through a dual-path coordinated adjustment mechanism, the processing module 60 dynamically and collaboratively adjusts the load current and the voltage applied to the Darlington transistor V1 based on temperature requirements and real-time detection of the voltage drop between the emitter and collector of the Darlington transistor V1. Its core strategy is to ensure that the Darlington transistor V1 always operates near a preset, low, optimal voltage drop value, thereby significantly reducing its conduction losses and substantially improving overall energy efficiency.

[0082] By constructing a control circuit that achieves real-time positive correlation adjustment between the driving voltage and load current, and applying the current to the heating element, a constant temperature control effect with low power consumption, high efficiency, and minimal interference is achieved. The operating point can be automatically optimized in real time based on changes in the heating element resistance and ambient temperature, ensuring that the Darlington transistor remains in a low-power, low-thermal-stress state, thus improving the reliability of the circuit under long-term operation over a wide temperature range and variable load conditions.

[0083] Optionally, the current sense amplifier has a gain of K, so that the current output to the heating element is K times the output current of the first PCA converter;

[0084] The value of K ranges from 1 to 1000.

[0085] Specifically, through a closed-loop feedback circuit composed of a current-sensing amplifier, the small current output from the first PCA converter is precisely amplified by a factor of K to drive the load. The factor K can be flexibly set by designing the gain of the current-sensing amplifier, enabling a small-power control signal to drive a high-power load, thus enhancing the design flexibility and applicability. By constructing a real-time output current feedback control circuit, the output current amplification lock function is achieved, meeting the flexible design needs of various applications.

[0086] Continue to refer to Figure 2 Optionally, the voltage acquisition module 50 includes: an instrumentation operational amplifier N4 and an A / D converter;

[0087] The first input terminal IN+ and the second input terminal IN- of the instrumentation operational amplifier N4 are connected to the collector and emitter of the Darlington transistor V1, respectively. The instrumentation operational amplifier N4 is used to detect the voltage difference Vt between the collector and emitter of the Darlington transistor N1 in real time and transmit the voltage difference Vt to the A / D converter.

[0088] The A / D converter is connected to the output terminal OUT of the instrumentation operational amplifier N4 and the processing module 60. The A / D converter is used to convert the voltage difference Vt into a digital quantity and send it to the processing module 60.

[0089] Specifically, the instrumentation operational amplifier N4 is connected between the collector and emitter of the Darlington transistor V1 to accurately detect the voltage difference Vt across it. The A / D converter converts this analog voltage difference Vt into a digital value for the processing module 60 to read. The voltage difference Vt across the two ends is controlled by the ARM microcontroller to achieve real-time voltage acquisition by the A / D converter; the acquired temperature data and the voltage data between the collector and emitter of the Darlington transistor are used to adjust the voltage output of the DC / DC voltage conversion manager N1 and the output current of the Darlington transistor V1 in real time according to the designed control algorithm.

[0090] Continue to refer to Figure 2Optionally, the temperature acquisition module 70 includes: a precision temperature measurement and A / D sampling circuit and a thermistor Rt;

[0091] The two ends of the thermistor Rt are connected to the precision temperature measurement and A / D sampling circuit. The thermistor Rt is used to measure the temperature data of the heating element Rj and transmit it to the precision temperature measurement and A / D sampling circuit.

[0092] The precision temperature measurement and A / D sampling circuit is connected to the processing module 60. The precision temperature measurement and A / D sampling circuit is used to convert temperature data into digital data and send it to the processing module 60.

[0093] Specifically, the temperature acquisition module 70 consists of a thermistor Rt, a precision temperature measurement circuit (usually a Wheatstone bridge or constant current source circuit), and an A / D sampling circuit. The thermistor Rt is used to accurately measure the temperature of the heating element Rj.

[0094] Embodiments of the present invention also provide a method for regulating a controllable multiple high-efficiency linear temperature control circuit, applicable to any embodiment of the present invention. Figure 3 This is a flowchart illustrating a controllable multiple high-efficiency linear temperature control circuit regulation method according to an embodiment of the present invention. (Refer to...) Figure 3 The control methods for highly efficient linear temperature control circuits with controllable multiples include:

[0095] S110: The current temperature signal and the output voltage of the current amplification drive module are obtained through the temperature acquisition module and the voltage acquisition module, respectively.

[0096] Specifically, in combination Figure 1 The temperature signal of the heating load in the current amplification drive module 40 and the output voltage of the adjustment device (such as a Darlington tube) in the current amplification drive module 40 are obtained by the temperature acquisition module 70 and the voltage acquisition module 50, respectively.

[0097] S120: The processing module generates a first PWM signal and a second PWM signal based on the temperature signal and the output voltage.

[0098] Specifically, in combination Figure 1 The processing module 60 generates a first PWM signal and a second PWM signal based on the temperature signal and the output voltage, according to a preset control algorithm. The processing module 60 continuously adjusts the first PWM signal (controlling the heating current) according to the temperature signal, and at the same time adjusts the second PWM2 signal (optimizing the operating voltage) according to the output voltage of the current amplification drive module 40. The two work together to enable the system to quickly and stably reach and maintain the target temperature, and the power adjustment device is always in a high-efficiency and low-power operating state throughout the process.

[0099] S130. The first PWM signal conversion module adjusts the output controllable current based on the first PWM signal and transmits the controllable current to the current amplification drive module. The current amplification drive module amplifies the controllable current and drives the heating load.

[0100] Specifically, in combination Figure 1 The first PWM signal is mainly used to set the target drive current of the heating load. The first PWM signal conversion module 20 adjusts the output controllable current based on the first PWM signal, and drives the heating load after being amplified by K times by the current amplification drive module 40.

[0101] S140. The second PWM signal is converted into an analog voltage signal by the second PWM signal conversion module and transmitted to the adjustable voltage output module.

[0102] Specifically, in combination Figure 1 The second PWM signal is mainly used to adjust the voltage drop on the regulating device; the second PWM signal conversion module 30 converts the second PWM signal into an analog voltage signal and transmits it to the adjustable voltage output module 10 to control the adjustable voltage output module 10 to achieve real-time adjustable power supply voltage output.

[0103] S150: The adjustable voltage output module dynamically adjusts the voltage output to the current amplification drive module in real time in response to the analog voltage signal.

[0104] Specifically, in combination Figure 1 The adjustable voltage output module 10 responds to the analog voltage signal and dynamically adjusts the voltage output to the current amplification drive module 40 in real time, so that the voltage drop on the adjustment device is dynamically adjusted and maintained near the set low power consumption threshold.

[0105] The embodiments of the present invention achieve highly efficient and extremely low-interference linear constant temperature control through the combination of the aforementioned hardware circuit and control algorithm. The control method for the controllable multiple high-efficiency linear temperature control circuit provided in the embodiments of the present invention is used to control the controllable multiple high-efficiency linear temperature control circuit provided in any embodiment of the present invention. Therefore, the control method for the controllable multiple high-efficiency linear temperature control circuit provided in the embodiments of the present invention also possesses the beneficial effects described in the above embodiments, and will not be repeated here.

[0106] Optionally, the control method of the efficient linear temperature control circuit with controllable multiple also includes:

[0107] The processing module dynamically adjusts the first PWM signal and the second PWM signal based on the temperature signal and the output voltage of the current amplification drive module, so that the output voltage of the current amplification drive module is kept below a set threshold.

[0108] Specifically, the output voltage of the current amplification drive module is kept below the set threshold to ensure low power consumption on the Darlington tube. The Darlington tube is always in a high-efficiency, low-power operating state, achieving low loss and high efficiency in heating control.

[0109] Figure 4 This is a simplified schematic diagram of the control strategy of a high-efficiency linear temperature control circuit with controllable multiple provided by an embodiment of the present invention. (Refer to...) Figure 4 Set a suitable fixed constant value During operation, ensure the voltage across the collector and emitter of the Darlington transistor is maintained. This ensures that the Darlington transistor operates with low power consumption under any load condition. The first PWM1 signal determines the operating current applied to the heating element, and the second PWM2 signal controls the operating voltage applied to the Darlington transistor. When the voltage... At the same time, while maintaining the normal output of the first PWM1 signal, the output of the second PWM2 signal is adjusted to regulate the control output voltage. To achieve voltage .

[0110] By designing an algorithm that relates PWM duty cycle to output voltage and current, and using the real-time detection of the voltage across the collector and emitter of the Darlington transistor as a reference, the power consumption on the Darlington transistor is kept low, thus achieving low loss and high efficiency in heating control.

[0111] The present invention proposes a high-efficiency linear temperature control circuit and control algorithm with controllable multiple. The circuit is simple and flexible, realizes real-time adjustment of voltage and current with positive correlation, and controllable current amplification multiple, with high efficiency and minimal interference constant temperature control effect.

[0112] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A high-efficiency linear temperature control circuit with controllable multiple, characterized in that, include: Adjustable voltage output module, first PWM signal conversion module, second PWM signal conversion module, current amplification drive module, voltage acquisition module, processing module, and temperature acquisition module; The voltage acquisition module is connected between the current amplification drive module and the processing module. The voltage acquisition module is used to detect the output voltage of the current amplification drive module and transmit it to the processing module. The temperature acquisition module is connected to the processing module. The temperature acquisition module is used to detect the temperature of the heating load in the current amplification drive module and generate a temperature signal that is transmitted to the processing module. The processing module is used to generate a first PWM signal and a second PWM signal based on the temperature signal and the output voltage, and transmit them to the first PWM signal conversion module and the second PWM signal conversion module respectively, and control the adjustable voltage output module and the current amplification drive module to work together. The first PWM signal conversion module is connected to the processing module and the current amplification and drive module. The first PWM signal conversion module is used to output a controllable current according to the first PWM signal and transmit it to the current amplification and drive module. The current amplification and drive module is used to amplify the controllable current and drive the heating load. The second PWM signal conversion module is connected to the processing module, and the second PWM signal conversion module is used to convert the second PWM signal into an analog voltage signal and transmit it to the adjustable voltage output module; The adjustable voltage output module is connected to the second PWM signal conversion module and the current amplification drive module. The adjustable voltage output module dynamically adjusts the voltage output to the current amplification drive module in real time in response to the analog voltage signal.

2. The high-efficiency linear temperature control circuit with controllable multiple according to claim 1, characterized in that, The adjustable voltage output module includes: a second capacitor, a DC / DC voltage conversion manager, an inductor, a first resistor, a second resistor, a first capacitor, a third resistor, and a diode; The second capacitor is connected between the input voltage pin and the first ground pin of the DC / DC voltage conversion manager. The first end of the inductor is connected to the adjustable voltage output pin of the DC / DC voltage conversion manager. The second end of the inductor is connected to the first end of the first resistor, the first end of the first capacitor, and the current amplification drive module. The second end of the first resistor is connected to the second end of the first capacitor, the first end of the third resistor, the first end of the second resistor, and the output voltage pin of the DC / DC voltage conversion manager. The second end of the second resistor is grounded. The second end of the third resistor is connected to the cathode of the diode. The anode of the diode is connected to the second PWM signal conversion module.

3. The high-efficiency linear temperature control circuit with controllable multiple according to claim 1, characterized in that, The first PWM signal conversion module includes: a first PCA converter, which is used to convert the first PWM signal into an analog voltage signal and transmit it to the current amplification drive module; The second PWM signal conversion module includes a second PCA converter, which is used to convert the second PWM signal into an analog current signal and transmit it to the adjustable voltage output module.

4. The high-efficiency linear temperature control circuit with controllable multiple according to claim 3, characterized in that, Also includes: An optocoupler isolator, wherein the first input terminal and the second input terminal of the optocoupler are respectively connected to the first output terminal and the second output terminal of the processing module, and the first output terminal and the second output terminal of the optocoupler are respectively connected to the first PCA converter and the second PCA converter; The optocoupler isolator is used to isolate the received first PWM signal and second PWM signal and output them to the first PCA converter and the second PCA converter, respectively.

5. The high-efficiency linear temperature control circuit with controllable multiple according to claim 3, characterized in that, The current amplification drive module includes: a Darlington transistor, a current sensing resistor, a heating element, and a current sensing amplifier; The base of the Darlington transistor is connected to the current output terminal of the second PCA converter. The collector of the Darlington transistor is connected to the adjustable voltage output module and the voltage acquisition module. The emitter of the Darlington transistor is connected to the first terminal of the current sensing resistor and the first input terminal of the current sensing amplifier. The second terminal of the current sensing resistor is connected to the first terminal of the heating element and the second input terminal of the current sensing amplifier. The second terminal of the heating element is grounded. The output terminal of the current sensing amplifier is connected to the feedback terminal of the first PCA converter. The current sensing amplifier is used to detect the voltage flowing through the current sensing resistor and feed it back to the feedback terminal of the first PCA converter to lock the current amplification factor.

6. The high-efficiency linear temperature control circuit with controllable multiple according to claim 5, characterized in that, The current sensing amplifier has a gain of K, so that the current output to the heating element is K times the output current of the first PCA converter; The value of K ranges from 1 to 1000.

7. The high-efficiency linear temperature control circuit with controllable multiple according to claim 5, characterized in that, The voltage acquisition module includes: an instrumentation operational amplifier and an A / D converter; The first and second input terminals of the instrumentation operational amplifier are respectively connected to the collector and emitter of the Darlington transistor. The instrumentation operational amplifier is used to detect the voltage difference between the collector and emitter of the Darlington transistor in real time and transmit the voltage difference to the A / D converter. The A / D converter is connected to the output of the instrument operational amplifier and the processing module. The A / D converter is used to convert the voltage difference into a digital quantity and send it to the processing module.

8. The high-efficiency linear temperature control circuit with controllable multiple according to claim 5, characterized in that, The temperature acquisition module includes: a precision temperature measurement and A / D sampling circuit and a thermistor; The two ends of the thermistor are connected to the precision temperature measurement and A / D sampling circuit. The thermistor is used to measure the temperature data of the heating element and transmit it to the precision temperature measurement and A / D sampling circuit. The precision temperature measurement and A / D sampling circuit is connected to the processing module. The precision temperature measurement and A / D sampling circuit is used to convert the temperature data into digital data and send it to the processing module.

9. A method for regulating a controllable multiple high-efficiency linear temperature control circuit, applied to the controllable multiple high-efficiency linear temperature control circuit according to any one of claims 1-8, characterized in that, include: The current temperature signal and the output voltage of the current amplification and drive module are acquired by the temperature acquisition module and the voltage acquisition module, respectively. The processing module generates a first PWM signal and a second PWM signal based on the temperature signal and the output voltage. The first PWM signal conversion module adjusts the output controllable current based on the first PWM signal and transmits the controllable current to the current amplification and drive module, which amplifies the controllable current and drives the heating load. The second PWM signal is converted into an analog voltage signal by the second PWM signal conversion module and transmitted to the adjustable voltage output module. The adjustable voltage output module dynamically adjusts the voltage output to the current amplification drive module in real time in response to the analog voltage signal.

10. The control method of the high-efficiency linear temperature control circuit with controllable multiple according to claim 9, characterized in that, Also includes: The processing module dynamically adjusts the first PWM signal and the second PWM signal based on the temperature signal and the output voltage of the current amplification drive module, so that the output voltage of the current amplification drive module is kept below a set threshold.

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