A temperature control circuit, control method, and PCR instrument

Abstract

This invention provides a temperature control circuit, a control method, and a PCR instrument. The temperature control circuit includes a controller, a first driver chip, a first switch, a transformer circuit, a second switch, a third switch, a TEC module, and a feedback circuit. The controller controls the on / off state of the first switch; the first switch controls the charging and discharging of the primary coil of the transformer in the transformer circuit; the second switch controls the conduction of the TEC cooler's operating circuit in the TEC module; the third switch controls the operating state of the TEC cooler; and the feedback circuit provides feedback on the operating surface temperature of the TEC cooler. By introducing a transformer, this invention achieves power isolation between the system power supply and the TEC cooler's power supply, reducing the risk of system leakage. Simultaneously, the controller controls the pulse width of the generated PWM signal to control the on-time of the first switch, thereby controlling the energy consumption of the TEC cooler.

Description

Technical Field

[0001] This invention belongs to the field of medical devices and relates to a temperature control circuit, control method, and PCR instrument. Background Technology

[0002] When an N-type semiconductor and a P-type semiconductor are combined to form an electric couple, and a voltage is applied to this couple, causing a current to flow through it, one end of the couple will absorb heat from the outside, while the other end will release heat to the outside. This phenomenon is called the Peltier effect. Thermoelectric coolers (TECs), as devices that utilize the Peltier effect for heating or cooling, are widely used in cooling certain components of electronic and radio communication equipment due to their advantages such as being noiseless, vibration-free, requiring no refrigerant, small size, and light weight.

[0003] The biochemical reaction system of rapid PCR instruments operates at temperatures ranging from 60℃ to 95℃, requiring rapid heating and cooling as well as accurate temperature control. Typically, rapid PCR instruments use a thermoelectric cooler (TEC) for temperature control. The circuitry employs an H-bridge to drive the TEC chip, using pulse width modulation (PWM) to control the TEC's on-time and indirectly adjust its cooling power. However, this method requires the system power supply voltage to match the TEC's operating voltage. Different TEC models require power supply systems with corresponding voltages, and changing the system power supply voltage can affect the operation of other circuit modules, causing inconvenience for system upgrades. Furthermore, the lack of isolation in the TEC power supply poses a potential leakage risk to operators. Additionally, while TEC temperature control generally uses a proportional-integral-differential (PID) algorithm, which is mature, reliable, and highly accurate, it struggles to simultaneously achieve rapid heating / cooling with minimal overshoot and rapid stabilization. Summary of the Invention

[0004] In view of the shortcomings of the prior art described above, the purpose of this invention is to provide a temperature control circuit, control method, and PCR instrument to solve the problems in the prior art where the system power supply voltage is difficult to match with different TEC operating voltages and other circuit modules of the system simultaneously, the TEC power supply is not isolated, and the PID algorithm is difficult to achieve rapid heating / cooling, small overshoot, and rapid stabilization at the same time.

[0005] To achieve the above and other related objectives, the present invention provides a temperature control circuit, comprising: a controller, a first driver chip, a first switch, a transformer circuit, a second switch, a third switch, a TEC module, and a feedback circuit, wherein:

[0006] The controller's first signal output terminal is electrically connected to the first driver chip input terminal of the first driver chip;

[0007] The first electrode of the first switch is electrically connected to the output terminal of the first driver chip of the first driver chip.

[0008] The second electrode of the first switch is electrically connected to the first port of the transformer circuit of the transformer circuit;

[0009] The first port of the transformer secondary coil in the transformer circuit is electrically connected to the second switch input terminal of the second switch, and the second port of the transformer secondary coil in the transformer circuit is electrically connected to the second electrode of the third switch.

[0010] The second switch output terminal of the second switch is electrically connected to the first electrode of the third switch.

[0011] The third contact of the third switch and the first contact of the third switch are electrically connected to the first input terminal and the second input terminal of the TEC module, respectively. The second contact of the third switch is electrically connected to the third contact of the third switch. The fourth contact of the third switch is electrically connected to the first contact of the third switch.

[0012] The first output terminal and the second output terminal of the TEC module are electrically connected to the first input terminal and the second input terminal of the feedback circuit, respectively.

[0013] The feedback circuit output terminal is electrically connected to the input terminal of the controller.

[0014] Optionally, the transformer circuit includes a second port of the transformer circuit, a capacitor, a resistor, and a transformer. The first electrode of the capacitor is electrically connected to the second port of the transformer circuit, the second electrode of the capacitor is electrically connected to the first electrode of the resistor, the second electrode of the resistor, the first port of the transformer primary coil, and the first port of the transformer circuit are electrically connected to each other, and the second port of the transformer primary coil, the second port of the transformer circuit, and the first electrode of the capacitor are electrically connected to each other.

[0015] Optionally, the first switch includes an NMOS transistor, the drain of the NMOS transistor serves as the second electrode of the first switch, the source of the NMOS transistor serves as the third electrode of the first switch, and the source is grounded, and the second port of the transformer circuit is connected to a high potential.

[0016] Optionally, the second switch includes a unidirectional conducting device.

[0017] Optionally, the first switch includes a PMOS transistor, the drain of the PMOS transistor serves as the second electrode of the first switch, the source of the PMOS transistor serves as the third electrode of the first switch, and the source is connected to a high potential, and the second port of the transformer circuit is grounded.

[0018] Optionally, the temperature control circuit further includes a switch control circuit, which includes a second driver chip and a relay. The second driver chip input terminal is electrically connected to the controller second output terminal of the controller, and the second driver chip output terminal is electrically connected to the relay first electrode. The relay second electrode is grounded to form a circuit. The switch control circuit controls the third switch to make electrical contact with the third switch first contact and the third contact, or to make electrical contact with the third switch second contact and the third switch fourth contact.

[0019] Optionally, the TEC module includes a TEC cooler, a temperature sensor, and a PCR reaction working area. The TEC cooler is in contact with the PCR reaction working area. The first input terminal of the TEC module includes a first electrode of the TEC cooler, the second input terminal of the TEC module includes a second electrode of the TEC cooler, the first output terminal of the TEC module includes a first electrode of the temperature sensor, and the second output terminal of the TEC module includes a second electrode of the temperature sensor.

[0020] Optionally, the feedback circuit includes an amplifier, the first output terminal of the TEC module is electrically connected to the first input terminal of the amplifier, the second output terminal of the TEC module is electrically connected to the second input terminal of the amplifier, and the output terminal of the amplifier is electrically connected to the input terminal of the controller.

[0021] Optionally, the controller includes an analog-to-digital conversion unit.

[0022] The present invention also provides a PCR instrument, the PCR instrument including the temperature control circuit.

[0023] The present invention also provides a temperature control method, comprising:

[0024] The target temperature value is set on the controller, the temperature signal is generated by the TEC module, and the temperature signal is amplified and output through the feedback circuit;

[0025] The controller reads the output signal of the feedback circuit and converts the output signal into a temperature value.

[0026] The controller determines the difference between the temperature value and the target temperature value. When the difference is not 0°C, the controller controls the first output terminal of the controller to generate a PWM signal to control the first switch to control the transformer circuit. The controller controls the second output terminal of the controller to generate a switch signal to control the switch circuit to control the third switch. The unidirectional conduction of the second switch is used to make the TEC cooler in the TEC module work.

[0027] Repeat steps S2-S3 at least once until the controller determines that the difference is 0°C. The controller then controls the first output terminal of the controller to stop generating PWM signals and the second output terminal of the controller to stop generating switching signals, so that the TEC cooler stops working.

[0028] Optionally, the temperature control for determining when the difference is not 0°C further includes the following steps:

[0029] When the difference is greater than 0°C, the switch signal generated by the second output terminal of the controller controls the third switch to the first connection state so that the TEC cooler switches to the cooling operation state.

[0030] When the difference is less than 0°C, the switch signal generated by the second output terminal of the controller controls the third switch to be in the second connection state so as to accelerate the heating and cooling rate of the TEC cooler;

[0031] When the absolute value of the difference is greater than a preset difference, the pulse width of the PWM signal generated by the first output terminal of the controller is set to a preset value so as to accelerate the heating and cooling rate of the TEC cooler;

[0032] When the absolute value of the difference is less than or equal to the preset difference, the PID algorithm is used to set the pulse width of the PWM signal to the absolute value of the value calculated from the sampled value, so as to slow down the heating and cooling rate of the TEC cooler.

[0033] Optionally, the PWM signal controls the on and off states of the first switch. The first switch includes an NMOS transistor. When the PWM signal is high, the first switch is on, and the second port of the transformer circuit connected to the high potential, the primary coil of the transformer in the transformer circuit, and the grounded first switch form a loop, converting electrical energy into magnetic energy and storing it in the transformer core. When the PWM signal is low, the first switch is off, and the primary coil of the transformer, the capacitor, and the resistor form a loop to protect the first switch. The second switch is on, and the secondary coil of the transformer generates an induced electromotive force that is automatically adjusted according to the operating voltage of the TEC cooler to power the TEC cooler.

[0034] Optionally, the PWM signal controls the on and off states of the first switch. The first switch includes a PMOS transistor. When the PWM signal is low, the first switch is on, and the grounded second port of the transformer circuit, the primary coil of the transformer in the transformer circuit, and the first switch connected to a high potential form a loop, converting electrical energy into magnetic energy and storing it in the transformer core. When the PWM signal is high, the first switch is off, and the primary coil of the transformer, the capacitor, and the resistor form a loop to protect the first switch. The second switch is on, and the secondary coil of the transformer generates an induced electromotive force that is automatically adjusted according to the operating voltage of the TEC cooler to power the TEC cooler.

[0035] Optionally, the range of the preset difference is 1 to 2°C.

[0036] As described above, the temperature control circuit, control method, and PCR instrument of the present invention incorporate an analog-to-digital converter (ADC) unit in the controller and design the power supply for the TEC cooler as a transformer. The ADC unit converts the potential information transmitted by the feedback circuit into a temperature value, compares it with a set target value, and controls the pulse width of the PWM signal output from the first output terminal of the controller and the output of the switching signal from the second output terminal of the controller based on the comparison result. This controls the operating state of the TEC cooler, enabling it to rapidly heat up / cool down, reduce temperature overshoot, ensure high temperature control accuracy, and reduce costs. Furthermore, the transformer circuit design utilizes the system power supply to charge the primary coil of the transformer. When the transformer circuit is de-energized, the secondary coil of the transformer supplies power to the TEC cooler. The induced electromotive force in the secondary coil of the transformer can automatically adjust according to the different operating voltages of the TEC cooler. This not only allows the system power supply to simultaneously meet the needs of TEC coolers with different operating voltages but also isolates the system power supply from the power supply to the TEC cooler, reducing the risk of system leakage. Utilizing the built-in ADC unit in the controller eliminates the need for an external ADC unit, saving costs and demonstrating high industrial applicability. Attached Figure Description

[0037] Figure 1 The diagram shown is a schematic of a temperature control circuit according to the present invention.

[0038] Figure 2 The diagram shown is a circuit diagram of the transformer circuit in a temperature control circuit according to the present invention.

[0039] Figure 3 The flowchart shown is a temperature control method according to the present invention.

[0040] Component designation explanation

[0041] 1 Controller

[0042] 11 Controller First Output Terminal

[0043] 12 Controller Input Terminals

[0044] 13 Controller Second Output Terminal

[0045] 14 Analog-to-Digital Conversion Unit

[0046] 2 First driver chip

[0047] 21 First driver chip input terminal

[0048] 22 First driver chip input terminal

[0049] 3 First Switch

[0050] 31 First switch, first electrode

[0051] 32 First switch, second electrode

[0052] 33 First switch third electrode

[0053] 4. Transformer circuit

[0054] 41 Transformer

[0055] 411 Transformer primary coil

[0056] 4111 First port of the primary coil of the transformer

[0057] 4112 Second port of the primary coil of the transformer

[0058] 412 Transformer secondary coil

[0059] 4121 Transformer secondary coil first port

[0060] 4122 Transformer secondary coil second port

[0061] 413 Transformer core

[0062] 42 Transformer circuit first port

[0063] 43. Second port of transformer circuit

[0064] 44 Capacitors

[0065] 441 First electrode of capacitor

[0066] 442 Capacitor Second Electrode

[0067] 45 resistor

[0068] 451 Resistor First Electrode

[0069] 452 Resistor Second Electrode

[0070] 5 Second Switch

[0071] 51 Second switch input terminal

[0072] 52 Second switch output terminal

[0073] 6. Third switch

[0074] 61 Third switch first electrode

[0075] 62 Third switch second electrode

[0076] 63 Third switch first contact

[0077] 64 Third switch second contact

[0078] 65 Third contact of the third switch

[0079] 66 Third switch, fourth contact

[0080] 7 TEC Module

[0081] 71TEC Cooler

[0082] 711 TEC module first input terminal

[0083] 712 TEC module second input terminal

[0084] 72 Temperature Sensor

[0085] 721 TEC module first output terminal

[0086] 722 TEC module second output terminal

[0087] 73 PCR

[0088] 8 Feedback Circuit

[0089] 81 amplifier

[0090] 811 amplifier first input terminal

[0091] 812 Amplifier Second Input Terminal

[0092] 813 Amplifier Output Terminal

[0093] 9. Switch control circuit

[0094] 91 Second driver chip

[0095] 911 Second Driver Chip Input Terminal

[0096] 912 Second Driver Chip Output Terminal

[0097] 92 Relay

[0098] 921 Relay First Electrode

[0099] 922 Relay Second Electrode Detailed Implementation

[0100] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0101] Please see Figures 1 to 3 It should be noted that the illustrations provided in this embodiment are only schematic representations of the basic concept of the present invention. Therefore, the drawings only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0102] Example 1

[0103] This embodiment provides a temperature control circuit, such as Figure 1 and Figure 2 The diagram shows the schematic of the temperature control circuit and the circuit diagram of the transformer circuit within the temperature control circuit, including: a controller 1, a first driver chip 2, a first switch 3, a transformer circuit 4, a second switch 5, a third switch 6, a TEC module 7, and a feedback circuit 8. Specifically, the controller's first signal output terminal 11 is electrically connected to the first driver chip input terminal 21 of the first driver chip 2; the first switch's first electrode 31 is electrically connected to the first driver chip output terminal 22 of the first driver chip 2; the first switch's second electrode 32 is electrically connected to the transformer circuit's first port 42; the transformer's secondary coil's first port 4121 in the transformer circuit 4 is electrically connected to the second switch input terminal 51 of the second switch 5; and the transformer's secondary coil's second port 4122 in the transformer circuit 4 is electrically connected to the third switch... The second electrode 62 of the third switch of switch 6 is electrically connected; the second switch output terminal 52 of the second switch 5 is electrically connected to the first electrode 61 of the third switch of the third switch 6; the third contact 65 and the first contact 63 of the third switch 6 are electrically connected to the first input terminal 711 and the second input terminal 712 of the TEC module, respectively; the second contact 64 of the third switch 6 is electrically connected to the third contact 65; the fourth contact 66 of the third switch 6 is electrically connected to the first contact 63; the first output terminal 721 and the second output terminal 722 of the TEC module are electrically connected to the first input terminal 811 and the second input terminal 812 of the feedback circuit 8, respectively; the output terminal 813 of the feedback circuit 8 is electrically connected to the input terminal 12 of the controller.

[0104] Specifically, the first driver chip 2 is used to process the PWM signal output by the controller 1 and convert the output signal into an electrical signal that controls the second switch 3 to turn on and off.

[0105] As an example, the transformer circuit includes a transformer circuit second port 43, a capacitor 44, a resistor 45, and a transformer 41. The capacitor first electrode 441 of the capacitor 44 is electrically connected to the transformer circuit second port 43, the capacitor second electrode 442 of the capacitor 44 is electrically connected to the resistor first electrode 451 of the resistor 45, the resistor second electrode 452 of the resistor 45, the transformer primary coil first port 4111 of the transformer 41, and the transformer circuit first port 42 are electrically connected to each other, and the transformer primary coil second port 4112, the transformer circuit second port 43, and the capacitor first electrode 441 are electrically connected to each other.

[0106] Specifically, the capacitor 44 and the resistor 45 are used to protect the first switch 3 to prevent it from being broken down by the high voltage generated by the primary coil 411 of the transformer when the first switch 3 is opened.

[0107] Specifically, the second port 4112 of the primary coil of the transformer and the second port 4122 of the secondary coil of the transformer are terminals with the same name, that is, the potential polarity of the induced electromotive force of the second port 4112 of the primary coil of the transformer and the second port 4122 of the secondary coil of the transformer is the same.

[0108] As an example, the first switch 3 includes an NMOS transistor, the drain of which serves as the second electrode 32 of the first switch, and the source of which serves as the third electrode 33 of the first switch 3, with the source grounded. The second port 42 of the transformer circuit is connected to a high potential so that when the first switch 3 is turned on, the second port 43 of the transformer circuit, the transformer circuit 4, and the first switch 3 form a loop, charging the primary coil 411 of the transformer and generating an induced electromotive force in the secondary coil 412 of the transformer. The second switch 5 is turned off, and the TEC module 7 is not powered. When the first switch 3 is turned off, the secondary coil 412 of the transformer generates an induced electromotive force opposite to that generated when the primary coil 411 is charging, turning on the second switch 5 and powering the TEC module 7.

[0109] As an example, the second switch 5 includes a unidirectional conducting device or other suitable unidirectional conducting device, and the second switch 5 has a unidirectional conducting threshold. In this embodiment, the second switch 5 includes a diode, and the second switch input terminal 51 includes the positive terminal of the diode, and the second switch output terminal 52 includes the negative terminal of the diode.

[0110] Specifically, the second switch 5 is used to prevent current from being generated in the secondary coil 412 of the transformer when the primary coil 411 of the transformer is initially charged, so as to enable the TEC cooler 71 to operate.

[0111] As an example, in another embodiment, the first switch 3 includes a PMOS transistor (not shown), the drain of which serves as the second electrode 32 of the first switch, and the source of which serves as the third electrode 33 of the first switch 3, with the source connected to a high potential. The second port 43 of the transformer circuit is grounded, so that when the first switch 3 is turned on, the second port 43 of the transformer circuit, the transformer circuit 4, and the first switch 3 form a loop, charging the primary coil 411 of the transformer and generating an induced electromotive force in the secondary coil 412 of the transformer. The second switch 5 is turned off, and the TEC module 7 is not powered. When the first switch 3 is turned off, the secondary coil 412 of the transformer generates an induced electromotive force opposite to that generated when the primary coil 411 is charging. The second switch 5 is turned on, supplying power to the TEC module 7. The input terminal 51 of the second switch includes a negative terminal, and the output terminal 52 of the second switch includes a positive terminal.

[0112] As an example, the temperature control circuit further includes a switch control circuit 9, which includes a second driver chip 91 and a relay 92. The second driver chip input terminal 911 of the second driver chip 91 is electrically connected to the controller second output terminal 13 of the controller 1, and the second driver chip output terminal 912 of the second driver chip 91 is electrically connected to the relay first electrode 921 of the relay 92. The relay second electrode 922 of the relay 92 is grounded to form a circuit. The switch control circuit 9 controls the third switch 6 to make electrical contact with the third switch first contact 63 and the third switch third contact 65 or with the third switch second contact 64 and the third switch fourth contact 66.

[0113] Specifically, the second driver chip 91 processes the switching signal output from the second output terminal 13 of the controller and outputs a signal to control the relay 92, so that the third switch 6 switches to make electrical contact with the first contact 63 and the third contact 65 of the third switch or with the second contact 64 and the fourth contact 66 of the third switch. In this embodiment, when the third switch 6 is in electrical contact with the first contact 63 and the third contact 65 of the third switch, the TEC module 7 is in a cooling state; when the third switch 6 is in electrical contact with the second contact 64 and the fourth contact 66 of the third switch, the TEC module 7 is in a heating state. As an example, the TEC module 7 includes a TEC cooler 71, a temperature sensor 72, and a PCR reaction working area 73. The TEC cooler 71 is in contact with the PCR reaction working area 73. The first input terminal 711 of the TEC module includes the first electrode of the TEC cooler. The second input terminal 712 of the TEC module includes the second electrode of the TEC cooler. The first output terminal 721 of the TEC module includes the first electrode of the temperature sensor. The second output terminal 722 of the TEC module includes the second electrode of the temperature sensor.

[0114] Specifically, the temperature sensor 72 is used to read the temperature of the working surface of the TEC cooler 71 and convert the temperature into a temperature signal.

[0115] As an example, the feedback circuit 8 includes an amplifier 81, the first output terminal 721 of the TEC module is electrically connected to the first input terminal 811 of the amplifier 81, the second output terminal 722 of the TEC module is electrically connected to the second input terminal 812 of the amplifier 81, and the amplifier output terminal 813 of the amplifier 81 is electrically connected to the controller input terminal 12 of the controller 1.

[0116] Specifically, the controller 1 includes an analog-to-digital converter unit 14, the amplifier 81 is used to amplify the temperature signal, the controller 1 reads the output signal of the amplifier 81 through the control input terminal 12, and converts the output signal of the amplifier 81 into a temperature value through the analog-to-digital converter unit 14.

[0117] As an example, in another embodiment, the temperature control circuit 9 and the third switch 6 may be electronic switches, solid-state switches, or other suitable switches.

[0118] In this embodiment, a temperature control circuit designs the power supply of the TEC cooler 71 as the transformer circuit 4. The system power supply charges the primary coil 411 of the transformer. After the transformer circuit 4 is de-energized, the secondary coil 412 of the transformer supplies power to the TEC cooler 71. The induced electromotive force induced by the secondary coil 412 of the transformer can be automatically adjusted according to the different operating voltages of the TEC cooler, realizing the matching of the power supply with TEC coolers with different operating voltages and the isolation of the power supply from the TEC cooler 71. At the same time, through cooperation with the feedback circuit 8, the switch control circuit 9 and the controller 1, the real-time monitoring and adjustment of the operating temperature of the TEC cooler 71 can be realized. In addition, the use of the analog-to-digital conversion unit 14 built into the controller 1 saves costs.

[0119] Example 2

[0120] This embodiment provides a PCR instrument, which includes the temperature control circuit described in Embodiment 1.

[0121] As an example, the PCR instrument is used to maintain the required temperature at each stage of the PCR reaction to ensure that the PCR reaction proceeds quickly and smoothly.

[0122] Specifically, the PCR reaction involves heating the DNA template to be amplified to denature and dissociate under the action of two short nucleotides (primers) and a heat-resistant DNA polymerase. When cooled to a certain temperature, the primers bind to the DNA to be amplified on a single linker. The temperature is then raised to anneal the primers, which are then extended under the action of the DNA polymerase. This denaturation-annealing-extension process is repeated continuously, and the DNA template can be amplified 2n times in just tens of minutes.

[0123] As an example, the temperature control circuit is used to control the working state of the TEC cooler in the PCR instrument, so that the temperature can quickly reach the temperature required for the PCR reaction, while stabilizing the temperature during the PCR reaction.

[0124] In this embodiment, the PCR instrument utilizes the temperature control circuit described in Embodiment 1, enabling the PCR instrument to quickly reach the temperature required for the PCR reaction, reducing temperature overshoot, and ensuring a high-precision PCR reaction temperature.

[0125] Example 3

[0126] This embodiment provides a temperature control method, such as... Figure 3 The flowchart shown below illustrates the temperature control method, which includes the following steps:

[0127] S1: Set the target temperature value on the controller, generate a temperature signal using the TEC module, and amplify and output the temperature signal through the feedback circuit;

[0128] S2: Use the controller to read the output signal of the feedback circuit, and convert the output signal into a temperature value through the controller;

[0129] S3: The controller determines the difference between the temperature value and the target temperature value. When the difference is not 0°C, the controller controls the first output terminal of the controller to generate a PWM signal to control the first switch to control the transformer circuit to work. The controller controls the second output terminal of the controller to generate a switch signal to control the switch circuit to control the third switch. The unidirectional conduction of the second switch is used to make the TEC cooler in the TEC module work.

[0130] S4: Repeat steps S2-S3 at least once until the controller determines that the difference is 0°C. The controller then controls the first output terminal of the controller to stop generating PWM signals and the second output terminal of the controller to stop generating switching signals, so that the TEC cooler stops working.

[0131] As an example, the temperature control method can be implemented using the temperature control circuit described in Embodiment 1. Please refer to... Figure 1 The temperature control circuit shown and Figure 2 The circuit diagram of the transformer circuit shown first executes step S1: set the target temperature value on the controller 1, generate a temperature signal using the TEC module 7, and amplify and output the temperature signal through the feedback circuit 8.

[0132] Specifically, a target temperature value is set on the controller 1 according to the temperature required for the PCR reaction.

[0133] Specifically, the temperature of the working surface of the TEC cooler 71 is converted into a temperature signal using the temperature sensor 72 in the TEC module 7.

[0134] Specifically, the feedback circuit 8 amplifies the temperature signal through the first input terminal 811 and the second input terminal 812 of the amplifier 81 in the feedback circuit 8, and outputs it through the amplifier output terminal 813 of the amplifier 81.

[0135] Then, step S2 is performed: the controller 1 reads the output signal of the feedback circuit 8 and converts the output signal into a temperature value through the controller 1.

[0136] Specifically, the controller 1 reads the output signal of the amplifier output terminal 813 through the controller input terminal 12, and processes it through the analog-to-digital conversion unit 14 in the controller 1 to convert the output signal into a temperature value.

[0137] Then execute steps S3 and S4: The controller 1 determines the difference between the temperature value and the target temperature value. When the difference is not 0°C, the controller 1 controls the first output terminal 11 of the controller to generate a PWM signal to control the first switch 3 to control the transformer circuit 4 to work. The controller 1 controls the second output terminal 13 of the controller to generate a switch signal to control the switch circuit 9 to control the third switch 6. The unidirectional conduction of the second switch 5 is used to make the TEC cooler 71 in the TEC module 7 work. Repeat steps S2-S3 at least once until the controller 1 determines that the difference is 0°C. The controller 1 controls the first output terminal 11 of the controller to stop generating the PWM signal and the second output terminal 13 of the controller to stop generating the switch signal, so that the TEC cooler 71 stops working.

[0138] Specifically, the controller 1 reads the temperature value of the working surface of the TEC cooler obtained by the analog-to-digital conversion unit 14.

[0139] Specifically, the controller 1 processes the temperature value and the target temperature value to obtain the difference between the temperature value and the target temperature value, and the controller 1 determines the relationship between the difference and 0°C. When the difference is not 0°C, the controller 1 generates a PWM signal and a switching signal to control the TEC module 7 to work, thereby achieving temperature control of the working surface of the TEC cooler 71.

[0140] Specifically, the temperature control for determining when the difference is not 0°C further includes the following steps:

[0141] S3-1: When the difference is greater than 0°C, the switch signal generated by the second output terminal 13 of the controller controls the third switch 6 to be in the first connection state so that the TEC cooler 71 switches to the cooling working state.

[0142] S3-2: When the difference is less than 0°C, the switch signal generated by the second output terminal 13 of the controller controls the third switch 6 to be in the second connection state so that the TEC cooler 71 switches to the heating working state.

[0143] S3-3: When the absolute value of the difference is greater than the preset difference, the pulse width of the PWM signal generated by the first output terminal 11 of the controller is set to the preset value so as to accelerate the heating and cooling rate of the TEC cooler 71.

[0144] S3-4: When the absolute value of the difference is less than or equal to the preset difference, the PID algorithm is used to set the pulse width of the PWM signal to the absolute value of the value calculated from the sampled value, so as to slow down the heating and cooling rate of the TEC cooler 71.

[0145] Specifically, the first connection state includes the third switch 6 making electrical contact with the first contact 63 and the third contact 65 of the third switch.

[0146] Specifically, the second connection state includes the third switch 6 making electrical contact with the second contact 64 and the fourth contact 66 of the third switch.

[0147] Specifically, the preset value includes the maximum value of the PWM pulse width allowed by the temperature control circuit system.

[0148] Specifically, the sampled value is located between 0 and the difference. In this embodiment, the PID algorithm is used to select the median value of the difference as the sampled value, calculate the value corresponding to the sampled value, and automatically set the pulse width of the PWM signal in the controller 1 to the absolute value of the sampled value.

[0149] As an example, the PWM signal controls the on and off states of the first switch 3. The first switch 3 includes an NMOS transistor. When the PWM signal is high, the first switch 3 is on, and the high-potential transformer circuit second port 43 of the transformer circuit 4, the primary coil 411 of the transformer in the transformer circuit 4, and the grounded first switch 3 form a loop, converting electrical energy into magnetic energy and storing it in the transformer core 413 of the transformer. When the PWM signal is low, the first switch is off, and the primary coil 411 of the transformer, the capacitor 44, and the resistor 45 form a loop to protect the first switch 3. The second switch 5 is on, and the secondary coil 412 of the transformer generates an induced electromotive force that is automatically adjusted according to the operating voltage of the TEC cooler 71 to power the TEC cooler 71.

[0150] Specifically, when the high-potential transformer circuit second port 43 of the transformer circuit 4, the primary coil 411 of the transformer in the transformer circuit 4, and the grounded first switch 3 form a circuit, the transformer 41 converts electrical energy into magnetic energy and stores it in the transformer core 413. After the first switch 3 is opened, the transformer secondary coil 412 generates a voltage that turns on the second switch 5. When the third switch 6 is in the first connected state, the transformer secondary coil 412, the second switch 5, the third switch 6, and the TEC cooler form a circuit, and the TEC cooler 71 performs cooling. When the third switch 6 is in the second connected state, the transformer secondary coil 412, the second switch 5, the third switch 6, and the TEC cooler form a circuit, and the TEC cooler 71 heats up.

[0151] Specifically, the pulse width of the PWM signal determines the duration of the PWM signal at a high level, and also determines the conduction time of the first switch 3, which in turn determines the power supply of the transformer secondary coil 412 and the power consumption of the TEC cooler 71.

[0152] As an example, the method of setting the pulse width of the PWM signal using the PID algorithm includes calculating an intermediate parameter value of the PID parameters of the PID algorithm based on the difference, and setting the absolute value of the intermediate parameter value as the pulse width value of the PWM signal.

[0153] As an example, in another embodiment, the PWM signal controls the on and off states of the first switch 3. The first switch 3 includes a PMOS transistor (not shown). When the PWM signal is low, the first switch 3 is on, and the grounded second port 43 of the transformer circuit, the primary coil 411 of the transformer in the transformer circuit 4, and the first switch 3 connected to a high potential form a loop, converting electrical energy into magnetic energy and storing it in the transformer core 413 of the transformer 41. When the PWM signal is high, the first switch 3 is off, and the primary coil 411 of the transformer, the capacitor 44, and the resistor 45 form a loop to protect the first switch 3. The second switch 5 is on, and the secondary coil 412 of the transformer generates an induced electromotive force that is automatically adjusted according to the operating voltage of the TEC cooler 71 to power the TEC cooler 71.

[0154] Specifically, at the instant the first switch 3 is opened, the capacitor 44 and the resistor 45 form a circuit with the primary coil 411 of the transformer to prevent the instantaneous high voltage generated by the self-induction of the primary coil 411 of the transformer from damaging the first switch 3. The secondary coil 412 of the transformer generates an induced electromotive force that turns on the second switch 5.

[0155] As an example, the range of the preset difference is 1 to 2°C or other suitable range.

[0156] Specifically, the controller 1 stops outputting the PWM signal, the first switch 3 is turned off, the primary coil 411 of the transformer stops charging, and the induced electromotive force generated by the secondary coil 412 of the transformer is not reached by the second switch 5 conducting threshold, so the second switch 5 remains turned off, and the TEC cooler 71 stops working.

[0157] As an example, in another embodiment, the temperature control circuit 9 and the third switch 6 can be replaced by electronic switches, solid-state switches, or other suitable switches.

[0158] This embodiment of a temperature control method utilizes the controller 1 to convert the temperature signal fed back by the feedback circuit 8 into a temperature value, compares it with the target temperature value, and generates the difference. The controller 1 judges the difference and controls the pulse width of the PWM signal generated by the first output terminal 11 of the controller and the switching signal generated by the second output terminal 13 of the controller according to the difference. The pulse width setting of the PWM signal is controlled in segments according to the difference to control the working state of the TEC cooler 71, so that the working surface temperature of the TEC cooler 71 reaches the target temperature value. The method is simple to operate, has fast temperature rise and fall, small temperature overshoot, and high temperature control accuracy.

[0159] In summary, the temperature control circuit, control method, and PCR instrument of this invention separate the system power supply from the TEC module power supply by incorporating a transformer circuit in the circuit, reducing the risk of system leakage and enabling the system power supply to adapt to TEC coolers with different operating voltages. The controller processes the temperature signal and compares it with the target temperature. By segmenting the pulse width of the output PWM signal based on the comparison result, the TEC cooler can achieve rapid heating / cooling, reduce temperature overshoot, ensure high temperature control accuracy, and reduce costs. Simultaneously, the cooperation between the feedback circuit, the switching control circuit, and the controller enables real-time monitoring and adjustment of the TEC cooler's operating temperature. Therefore, this invention effectively overcomes the various shortcomings of the prior art and has high industrial application value.

[0160] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A temperature control circuit, characterized in that, include: The system comprises a controller, a first driver chip, a first switch, a transformer circuit, a second switch, a third switch, a TEC module, and a feedback circuit, wherein: The controller's first signal output terminal is electrically connected to the first driver chip input terminal of the first driver chip; The first electrode of the first switch is electrically connected to the output terminal of the first driver chip of the first driver chip. The second electrode of the first switch is electrically connected to the first port of the transformer circuit of the transformer circuit; The first port of the transformer secondary coil in the transformer circuit is electrically connected to the second switch input terminal of the second switch, and the second port of the transformer secondary coil in the transformer circuit is electrically connected to the second electrode of the third switch. The second switch output terminal of the second switch is electrically connected to the first electrode of the third switch. The third contact of the third switch and the first contact of the third switch are electrically connected to the first input terminal and the second input terminal of the TEC module, respectively. The second contact of the third switch is electrically connected to the third contact of the third switch. The fourth contact of the third switch is electrically connected to the first contact of the third switch. The first output terminal and the second output terminal of the TEC module are electrically connected to the first input terminal and the second input terminal of the feedback circuit, respectively. The feedback circuit output terminal is electrically connected to the input terminal of the controller. The transformer circuit also includes a transformer circuit second port, a capacitor, a resistor, and a transformer. The first electrode of the capacitor is electrically connected to the transformer circuit second port, and the second electrode of the capacitor is electrically connected to the first electrode of the resistor. The second electrode of the resistor, the first port of the transformer primary coil, and the first port of the transformer circuit are electrically connected to each other. The second port of the transformer primary coil, the second port of the transformer circuit, and the first electrode of the capacitor are electrically connected to each other.

2. The temperature control circuit according to claim 1, characterized in that: The first switch includes an NMOS transistor, the drain of the NMOS transistor serves as the second electrode of the first switch, the source of the NMOS transistor serves as the third electrode of the first switch, and the source is grounded. The second port of the transformer circuit is connected to a high potential.

3. The temperature control circuit according to claim 1, characterized in that: The second switch includes a unidirectional conduction device.

4. The temperature control circuit according to claim 1, characterized in that: The first switch includes a PMOS transistor, the drain of the PMOS transistor serves as the second electrode of the first switch, the source of the PMOS transistor serves as the third electrode of the first switch, and the source is connected to a high potential. The second port of the transformer circuit is grounded.

5. The temperature control circuit according to claim 1, characterized in that: The temperature control circuit further includes a switch control circuit, which includes a second driver chip and a relay. The input terminal of the second driver chip is electrically connected to the second output terminal of the controller, and the output terminal of the second driver chip is electrically connected to the first electrode of the relay. The second electrode of the relay is grounded to form a circuit. The switch control circuit controls the third switch to make electrical contact with the first and third contacts of the third switch or with the second and fourth contacts of the third switch.

6. The temperature control circuit according to claim 1, characterized in that: The TEC module includes a TEC cooler, a temperature sensor, and a PCR reaction working area. The TEC cooler is in contact with the PCR reaction working area. The first input terminal of the TEC module includes the first electrode of the TEC cooler, the second input terminal of the TEC module includes the second electrode of the TEC cooler, the first output terminal of the TEC module includes the first electrode of the temperature sensor, and the second output terminal of the TEC module includes the second electrode of the temperature sensor.

7. The temperature control circuit according to claim 1, characterized in that: The feedback circuit includes an amplifier. The first output terminal of the TEC module is electrically connected to the first input terminal of the amplifier. The second output terminal of the TEC module is electrically connected to the second input terminal of the amplifier. The output terminal of the amplifier is electrically connected to the input terminal of the controller.

8. The temperature control circuit according to claim 1, characterized in that: The controller includes an analog-to-digital converter unit.

9. A PCR instrument, characterized in that: The PCR instrument includes the temperature control circuit as described in any one of claims 1-8.

10. A temperature control method, characterized in that, The temperature control method is implemented using the temperature control circuit described in any one of claims 1 to 8, and includes the following steps: S1: Set the target temperature value on the controller, generate a temperature signal using the TEC module, and amplify and output the temperature signal through the feedback circuit; S2: Use the controller to read the output signal of the feedback circuit, and convert the output signal into a temperature value through the controller; S3: The controller determines the difference between the temperature value and the target temperature value. When the difference is not 0°C, the controller controls the first output terminal of the controller to generate a PWM signal to control the first switch to control the transformer circuit to work. The controller controls the second output terminal of the controller to generate a switch signal to control the switch circuit to control the third switch. The unidirectional conduction of the second switch is used to make the TEC cooler in the TEC module work. S4: Repeat steps S2-S3 at least once until the controller determines that the difference is 0°C. The controller then controls the first output terminal of the controller to stop generating PWM signals and the second output terminal of the controller to stop generating switching signals, so that the TEC cooler stops working.

11. The temperature control method according to claim 10, characterized in that, The temperature control for determining when the difference is not 0°C further includes the following steps: When the difference is greater than 0°C, the switch signal generated by the second output terminal of the controller controls the third switch to the first connection state so that the TEC cooler switches to the cooling operation state. When the difference is less than 0°C, the switch signal generated by the second output terminal of the controller controls the third switch to the second connection state so that the TEC cooler switches to the heating operation state; When the absolute value of the difference is greater than a preset difference, the pulse width of the PWM signal generated by the first output terminal of the controller is set to a preset value so as to accelerate the heating and cooling rate of the TEC cooler; When the absolute value of the difference is less than or equal to the preset difference, the PID algorithm is used to set the pulse width of the PWM signal to the absolute value of the value calculated from the sampled value, so as to slow down the heating and cooling rate of the TEC cooler.

12. The temperature control method according to claim 11, characterized in that: The preset difference ranges from 1 to 2°C.

13. The temperature control method according to claim 10, characterized in that: The PWM signal controls the on and off states of the first switch. The first switch includes an NMOS transistor. When the PWM signal is high, the first switch is on. The second port of the transformer circuit connected to the high potential, the primary coil of the transformer in the transformer circuit, and the grounded first switch form a loop, converting electrical energy into magnetic energy and storing it in the transformer core. When the PWM signal is low, the first switch is off. The primary coil of the transformer, the capacitor, and the resistor form a loop to protect the first switch, and the second switch is on. The secondary coil of the transformer generates an induced electromotive force that is automatically adjusted according to the operating voltage of the TEC cooler to power the TEC cooler.

14. The temperature control method according to claim 10, characterized in that: The PWM signal controls the on and off states of the first switch. The first switch includes a PMOS transistor. When the PWM signal is low, the first switch is on, and the grounded second port of the transformer circuit, the primary coil of the transformer in the transformer circuit, and the first switch connected to a high potential form a loop, converting electrical energy into magnetic energy and storing it in the transformer core. When the PWM signal is high, the first switch is off, and the primary coil of the transformer, the capacitor, and the resistor form a loop to protect the first switch. The second switch is on, and the secondary coil of the transformer generates an induced electromotive force that is automatically adjusted according to the operating voltage of the TEC cooler to power the TEC cooler.

Images