Hot water equipment and temperature controller thereof

Abstract

The utility model provides a hot water device and a temperature controller thereof, the temperature controller comprises a switch module, a temperature difference voltage signal generation module, a sawtooth wave signal generation module and a driving signal generation module, the temperature difference voltage signal generation module is used for generating a temperature difference voltage signal based on temperature difference data; the sawtooth wave signal generation module is used for generating a sawtooth wave signal, the driving signal generation module is connected with the temperature difference voltage signal generation module, the sawtooth wave signal generation module and the switch module, and the driving signal generation module is used for comparing the temperature difference voltage signal with the sawtooth wave signal to generate a driving signal for controlling the switch module to work. According to the utility model, the temperature difference data is converted into the voltage signal by using the temperature difference voltage signal generation module, and the voltage signal is compared with the sawtooth wave signal to generate the driving signal for controlling the switch module to work, so that the control precision of the switch module is improved, and the heating power of the heater is accurately adjusted; the cost can be reduced and the efficiency can be increased on the basis of constant-temperature control.

Description

Technical Field

[0001] This utility model relates to the field of hot water equipment technology, and in particular to a hot water equipment and its temperature controller. Background Technology

[0002] An instant water heater is a type of water heater that heats water instantly without waiting, quickly bringing the target temperature to users' lives.

[0003] Most existing instant water heaters use electronic thermostatic technology controlled by a microcontroller to maintain their instant heating and constant temperature characteristics. That is, the main control board of the instant water heater uses a combination of multiple algorithms, such as PID control algorithm and fuzzy algorithm, based on data such as inlet water temperature, outlet water temperature, voltage, and water flow rate, to control the output power of the thyristor and ensure the stability of the outlet water temperature.

[0004] However, the cost of using a microcontroller for electronic temperature control is relatively high, while the effect of mechanical temperature control is not ideal.

[0005] Therefore, how to reduce costs while ensuring constant temperature control is an urgent technical problem to be solved.

[0006] In view of the above, this utility model is hereby proposed. Utility Model Content

[0007] The technical problem this invention aims to solve is to overcome at least some of the shortcomings of existing technologies and provide a temperature controller. This controller converts temperature difference data into a voltage signal using a temperature difference voltage signal generation module, and compares this signal with a sawtooth wave signal to generate a drive signal for controlling the switching module. This improves the control accuracy of the switching module, thereby precisely adjusting the heating power of the heater. Furthermore, using the temperature difference voltage signal generation module to generate the temperature difference voltage signal saves costs compared to electronic temperature control technology using a microcontroller, thus achieving cost reduction and efficiency improvement while maintaining constant temperature control. Moreover, the independent operation of each module in the temperature controller reduces equipment failure rates and maintenance costs.

[0008] To solve the above-mentioned technical problems, the first aspect of this utility model is to provide a temperature controller, comprising:

[0009] Switch module;

[0010] Thermoelectric voltage signal generation module, used to generate thermoelectric voltage signal based on temperature difference data;

[0011] A sawtooth wave signal generation module, used to generate sawtooth wave signals; and

[0012] A drive signal generation module is connected to the temperature difference voltage signal generation module, the sawtooth wave signal generation module, and the switch module, and is used to compare the temperature difference voltage signal with the sawtooth wave signal to generate a drive signal that controls the operation of the switch module.

[0013] In some embodiments, the temperature difference voltage signal generation module includes:

[0014] The actual temperature and voltage signal generation module is used to generate the actual temperature and voltage signal of the medium under test.

[0015] A set temperature and voltage signal generation module is used to generate a set temperature and voltage signal for the medium under test; and

[0016] An error amplification voltage signal generation module is connected to the actual temperature voltage signal generation module and the set temperature voltage signal generation module, and is used to compare the actual temperature voltage signal and the set temperature voltage signal to generate the temperature difference voltage signal.

[0017] In some embodiments, the actual temperature voltage signal generation module includes a first voltage divider circuit and a first terminal connected to the first voltage divider circuit, the first terminal being used to connect a temperature sensor.

[0018] The first voltage divider circuit is used to convert the actual temperature data of the medium under test sensed by the temperature sensor into the actual temperature voltage signal, and the output of the first voltage divider circuit transmits the actual temperature voltage signal to the error amplification voltage signal generation module.

[0019] In some embodiments, the set temperature voltage signal generation module includes a first adjustable positioner and a second voltage divider circuit connected to the first adjustable positioner.

[0020] The second voltage divider circuit is used to convert the set temperature data for the medium under test indicated by the first adjustable positioner into the set temperature voltage signal, and the adjustment terminal of the first adjustable positioner transmits the set temperature voltage signal to the error amplification voltage signal generation module.

[0021] In some embodiments, the error amplification voltage signal generation module includes a first operational amplifier, a second adjustable positioner, and a third adjustable positioner;

[0022] Wherein, the inverting input terminal of the first operational amplifier is connected to the set temperature voltage signal generation module, and the non-inverting input terminal of the first operational amplifier is connected to the actual temperature voltage signal generation module.

[0023] One end of the second adjustable positioner is connected to the inverting input of the first operational amplifier, and the other end of the second adjustable positioner is connected to the adjustment end of the second adjustable positioner and then connected to the output of the first operational amplifier.

[0024] The adjustment terminal of the third adjustable positioner is connected to one end of the third adjustable positioner and then connected to the non-inverting input terminal of the first operational amplifier; the other end of the third adjustable positioner is connected to reference ground.

[0025] The first operational amplifier differentially amplifies the set temperature voltage signal and the actual temperature voltage signal to obtain a temperature difference voltage signal, and transmits the temperature difference voltage signal to the drive signal generation module through the output terminal.

[0026] In some embodiments, the drive signal generation module includes a second operational amplifier, the two input terminals of which are respectively connected to the thermoelectric voltage signal generation module and the sawtooth wave signal generation module;

[0027] The second operational amplifier compares the thermoelectric voltage signal and the sawtooth wave signal to obtain a drive signal, and transmits the drive signal to the switching module through the output terminal.

[0028] In some embodiments, the switching module includes a second terminal block, a silicon controlled rectifier output optocoupler, and a third terminal block connected in sequence.

[0029] The second terminal is used to connect a control switch, and the third terminal is used to connect a heater.

[0030] The second terminal is connected to the output terminal of the second operational amplifier. When the control switch is turned on, the drive signal controls the output power of the thyristor output optocoupler.

[0031] In some embodiments, the sawtooth wave signal generation module includes:

[0032] Power supply circuitry for generating pulsating DC voltage signals; and

[0033] A waveform generation circuit, connected to the power supply circuit, is used to convert the pulsating DC voltage signal into the sawtooth wave signal.

[0034] In some embodiments, the waveform generating circuit includes an inverting circuit, an energy storage circuit, and a discharging circuit;

[0035] The inverting circuit is used to convert the waveform of the DC voltage signal, and the converted DC voltage signal forms the sawtooth wave signal during the charging and discharging process of the energy storage circuit and the discharge circuit.

[0036] A second aspect of this utility model also provides a hot water device, including the temperature controller described above.

[0037] By adopting the above technical solution, this utility model has the following beneficial effects compared with the prior art.

[0038] The temperature controller provided by this invention converts temperature difference data into a voltage signal using a temperature difference voltage signal generation module. This voltage signal is then compared with a sawtooth wave signal to generate a drive signal for controlling the switching module. This allows for precise control of the PWM duty cycle in the drive signal, improving the control accuracy of the switching module and thus accurately adjusting the heater's heating power. Furthermore, using a temperature difference voltage signal generation module to generate the temperature difference voltage signal saves costs compared to electronic temperature control technology using a microcontroller, achieving cost reduction and efficiency improvement while maintaining constant temperature control. Moreover, the independent operation of each module in the temperature controller reduces equipment failure rates and maintenance costs. Attached Figure Description

[0039] The accompanying drawings, as part of this utility model, are used to provide a further understanding of the present utility model. The illustrative embodiments and descriptions of the present utility model are used to explain the present utility model, but do not constitute an undue limitation of the present utility model. Obviously, the drawings described below are merely some embodiments; those skilled in the art can obtain other drawings based on these drawings without creative effort. In the drawings:

[0040] Figure 1 This is a partial structural schematic diagram of a hot water device according to an exemplary embodiment of the present utility model;

[0041] Figure 2 This is a schematic diagram of the structure of a temperature controller according to an exemplary embodiment of the present utility model;

[0042] Figure 3 This is a circuit diagram of a sawtooth wave signal generation module according to an exemplary embodiment of the present utility model;

[0043] Figure 4 This is a circuit diagram of a temperature difference voltage signal generation module according to an exemplary embodiment of the present utility model;

[0044] Figure 5 This is a circuit diagram of the drive signal generation module and the switch module according to an exemplary embodiment of the present utility model;

[0045] Figure 6 This is a schematic diagram of a replaceable chip structure for a drive signal generation module according to an exemplary embodiment of the present invention.

[0046] In the picture: 100, hot water equipment;

[0047] 110. Main body; 120. Inlet pipe; 130. Outlet pipe; 140. Bypass pipe; 150. Outlet water temperature sensor; 160. Temperature controller; 170. Inlet water flow sensor;

[0048] 161. Switch module;

[0049] 162. Temperature difference voltage signal generation module; 1621. Actual temperature voltage signal generation module; 1622. Set temperature voltage signal generation module; 1623. Error amplification voltage signal generation module;

[0050] 163. Sawtooth wave signal generation module; 1631. Power supply circuit; 1632. Waveform generation circuit;

[0051] 164. Drive signal generation module.

[0052] It should be noted that these accompanying drawings and textual descriptions are not intended to limit the scope of the present invention in any way, but rather to illustrate the concept of the present invention to those skilled in the art by referring to specific embodiments. Detailed Implementation

[0053] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions in the embodiments will be clearly and completely described below with reference to the accompanying drawings. The following embodiments are used to illustrate this utility model, but are not intended to limit the scope of this utility model.

[0054] In the description of this utility model, it should be noted that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0055] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0056] As described in the background section, the cost of using a microcontroller for electronic temperature control in existing related technologies is relatively high, while the effect of mechanical temperature control is not ideal. Based on this, this utility model provides a temperature controller, including a switching module, a temperature difference voltage signal generation module, a sawtooth wave signal generation module, and a drive signal generation module. The temperature difference voltage signal generation module generates a temperature difference voltage signal based on temperature difference data. The sawtooth wave signal generation module generates a sawtooth wave signal. The drive signal generation module is connected to the temperature difference voltage signal generation module, the sawtooth wave signal generation module, and the switching module, and is used to compare the temperature difference voltage signal with the sawtooth wave signal to generate a drive signal that controls the operation of the switching module. In the above solution, by using the temperature difference voltage signal generation module to convert temperature difference data into a voltage signal, and comparing it with the sawtooth wave signal to generate a drive signal that controls the operation of the switching module, the PWM duty cycle in the drive signal can be precisely controlled, improving the control accuracy of the switching module, and thus accurately adjusting the heating power of the heater. Furthermore, compared with electronic temperature control technology using a microcontroller, the above solution saves costs, thereby achieving cost reduction and efficiency improvement in temperature control. Moreover, the independent operation of each module in the temperature controller can reduce the failure rate and maintenance costs of the equipment.

[0057] The preferred technical solution of the hot water equipment 100 and its temperature controller 160 provided by this utility model is described below with reference to the accompanying drawings.

[0058] Figure 1 This is a partial structural schematic diagram of a hot water device 100 according to an exemplary embodiment of the present utility model.

[0059] like Figure 1 As shown, the hot water device 100 includes a body 110, which is connected to an inlet pipe 120 for cold water and an outlet pipe 130 for hot water. In some embodiments, a bypass pipe 140 is also connected between the outlet pipe 130 and the inlet pipe 120. Preferably, the hot water device 100 is an instantaneous water heater.

[0060] A heater is installed inside the body 110 to heat the cold water entering the body 110 to a set temperature. An outlet water temperature sensor 150 is installed on the outlet pipe 130 to detect the outlet water temperature. An inlet water flow sensor 170 is installed on the inlet water pipe 120 to detect the inlet water flow rate. The hot water equipment 100 also includes a temperature controller 160 to control the heating power of the heater based on the detected outlet water temperature.

[0061] Figure 2 This is a schematic diagram of the structure of a temperature controller 160 according to an exemplary embodiment of the present utility model;

[0062] like Figure 2As shown, the temperature controller 160 includes a switch module 161, a temperature difference voltage signal generation module 162, a sawtooth wave signal generation module 163, and a drive signal generation module 164. The switch module 161 is connected to the heater and is used to controllably adjust the heater's heating power. The temperature difference voltage signal generation module 162 generates a temperature difference voltage signal based on the temperature difference between the outlet water temperature and the set temperature. The sawtooth wave signal generation module 163 generates a sawtooth wave signal. The drive signal generation module 164 is connected to the temperature difference voltage signal generation module 162, the sawtooth wave signal generation module 163, and the switch module 161, and is used to compare the temperature difference voltage signal with the sawtooth wave signal to generate a drive signal that controls the operation of the switch module 161. The drive signal controls the operating state of the switch module 161, thereby adjusting the heater's heating power to achieve constant temperature control.

[0063] In the above solution, the present invention uses a temperature difference voltage signal generation module 162 to convert temperature difference data into a voltage signal, and compares it with a sawtooth wave signal to generate a drive signal for controlling the operation of the switch module 161. This solves both the problem of high cost of microcontrollers and the problem of unstable mechanical temperature control, and can achieve cost reduction and efficiency improvement on the basis of achieving constant temperature control.

[0064] Figure 3 This is a circuit diagram of the sawtooth wave signal generation module 163 according to an exemplary embodiment of the present utility model.

[0065] like Figure 3 As shown, the sawtooth wave signal generation module 163 includes a power supply circuit 1631 and a waveform generation circuit 1632. The power supply circuit 1631 is used to generate a pulsating DC voltage signal. The waveform generation circuit 1632 is connected to the power supply circuit 1631 and is used to convert the pulsating DC voltage signal into the sawtooth wave signal.

[0066] Furthermore, the waveform generation circuit 1632 includes an inverting circuit, an energy storage circuit, and a discharging circuit; wherein, the inverting circuit is used to convert the waveform of the DC voltage signal, and the converted DC voltage signal forms the sawtooth wave signal during the charging-discharging process of the energy storage circuit and the discharging circuit.

[0067] As an example, the electronic components included in the power supply circuit 1631 are fuse T1, isolation transformer, rectifier bridge BD1, diode D1, energy storage capacitor E1, resistor R1, Zener diode ZD1, transistor N1, and energy storage capacitor E2.

[0068] The electronic components included in the inverting circuit are pull-up resistor R5, current-limiting resistor R8, transistor N4, pull-up resistor R4, and transistor N3.

[0069] The energy storage circuit includes electronic components such as current-limiting resistor R7, PNP transistor P1, current-limiting resistor R9, energy storage capacitor E4, diode D2, and diode D3.

[0070] The electronic components included in the discharge circuit are transistor N5, resistor R12, and fourth adjustable positioner VR1.

[0071] The connection relationships of the electronic components in the sawtooth wave signal generation module 163 are illustrated below as an example.

[0072] The mains live wire L is connected to one end of the primary winding of the isolation transformer, and the other end of the primary winding of the isolation transformer is connected to one end of the fuse T1. The other end of the fuse T1 is connected to the mains neutral wire N.

[0073] One end of the secondary winding of the isolation transformer is connected to one AC input terminal of the rectifier bridge BD1, and the other end of the secondary winding of the isolation transformer is connected to the other AC input terminal of the rectifier bridge BD1.

[0074] The V+ output terminal of rectifier bridge BD1 is connected to the anode of diode D1 and also to one end of resistor R8, transmitting the pulsating DC voltage signal to waveform generator circuit 1632. The cathode of diode D1 is connected to the positive terminal of energy storage capacitor E1, and the negative terminal of energy storage capacitor E1 is connected to the V- terminal of rectifier bridge BD1; this potential is defined as reference ground (GND). The positive terminal of energy storage capacitor E1 (polarized capacitor) is connected to one end of resistor R1, and the other end of resistor R1 is connected to the cathode of Zener diode ZD1. The anode of Zener diode ZD1 is connected to reference ground.

[0075] The junction of resistor R1 and Zener diode ZD1 is connected to the base of transistor N1. The collector of transistor N1 is connected to the positive terminal of energy storage capacitor E1. The emitter of transistor N1 is connected to the positive terminal of energy storage capacitor E2. The negative terminal of energy storage capacitor E2 is connected to reference ground.

[0076] In the above scheme, an isolation transformer is used on the mains power LN to reduce the 220V AC to a low-voltage 10.5V AC. To protect the isolation transformer and the circuit, a fuse T1 is added to the primary winding coil circuit to limit the current. After passing through the rectifier bridge BD1, the low-voltage AC forms a pulsating DC voltage signal (represented by Wave in the diagram), the pulsation frequency of which is twice the input mains frequency. The pulsating DC voltage is rectified and filtered through diode D1 onto the energy storage capacitor E1 to obtain a relatively smooth DC voltage. This energy storage capacitor E1 can be a high-frequency capacitor to reduce losses.

[0077] To further improve the quality of the power supply circuit 1631, a voltage regulator circuit consisting of resistor R1, Zener diode ZD1, and transistor N1 is used to accurately control the power supply voltage within a certain range. This voltage value is determined by the voltage across Zener diode ZD1 and the base-emitter voltage drop of transistor N1. That is, the voltage value of this voltage regulator circuit is equal to the voltage of Zener diode ZD1 minus 0.7V (a typical value of the base-emitter voltage drop of the transistor). The nominal voltage of the Zener diode ZD1 in this invention is 7.5V, therefore the output voltage of the voltage regulator circuit is 6.8V. Energy storage capacitor E2 is used to stabilize the power supply to provide sufficient energy for subsequent circuits.

[0078] It should be noted here that, Figures 3 to 6 The diagram shows that the 6.8V nodes of each circuit are connected to the positive terminal of the energy storage capacitor E2, and the voltage is provided by the power supply circuit 1631.

[0079] In the inverting circuit, one end of the pull-up resistor R5 is connected to the positive terminal of the energy storage capacitor E2, and the other end of the pull-up resistor R5 is connected to the collector of transistor N4. The base of transistor N4 is connected to the current-limiting resistor R8, and the emitter of transistor N4 is connected to reference ground (GND). The base of transistor N3 is connected to the collector of transistor N4, the emitter of transistor N3 is connected to reference ground (GND), the collector of transistor N3 is connected to one end of the pull-up resistor R4, and the other end of the pull-up resistor R4 is connected to the positive terminal of the energy storage capacitor E2.

[0080] The base of transistor P1 is connected to one end of resistor R7, and the other end of resistor R7 is connected to the collector of transistor N3. The collector of transistor P1 is connected to the cathode of diode D3, and the anode of diode D2 is connected to the cathode of diode D2. The anode of diode D2 is connected to the positive terminal of energy storage capacitor E2. The emitter of transistor P1 is connected to one end of current-limiting resistor R9, and the other end of current-limiting resistor R9 is connected to the positive terminal of energy storage capacitor E4 (a polarized capacitor). The negative terminal of energy storage capacitor E4 is connected to reference ground.

[0081] The positive terminal of the energy storage capacitor E4 is connected to the collector of the transistor N5. The emitter of the transistor N5 is connected to one end of the resistor R12, and the other end of the resistor R12 is connected to the reference ground. The base of the transistor N5 is connected to the adjustment terminal of the fourth adjustable positioner VR1. The other two ends of the fourth adjustable positioner VR1 are connected to the two ends of the energy storage capacitor E2, that is, one end is connected to the reference ground, and the other end is connected to the positive terminal of the energy storage capacitor E2.

[0082] In the above scheme, the pulsating DC voltage signal (represented by Wave in the diagram) is amplified by an inverting amplifier circuit consisting of pull-up resistor R5, current-limiting resistor R8, and transistor N4, resulting in a narrow-width spike waveform. This waveform is then amplified by an inverter consisting of pull-up resistor R4 and transistor N3, producing a narrow-width notch signal. This signal controls the switching on and off of PNP transistor P1 via current-limiting resistor R7, thereby controlling the current flowing through transistor P1 and charging energy storage capacitor E4 through current-limiting resistor R9. The forward voltage drop of diodes D2 and D3 is used to reduce the collector voltage of transistor P1, controlling the maximum charging voltage of energy storage capacitor E4 and preventing malfunctions in subsequent circuits due to excessively high voltage.

[0083] Transistor N5, resistor R12, and fourth adjustable positioner VR1 constitute a discharge circuit used to release the energy of energy storage capacitor E4. The fourth adjustable positioner VR1 can control the magnitude of the discharge current, i.e., change the discharge speed, while resistor R12 limits the discharge current limit.

[0084] As mentioned earlier, the current-limiting resistor R9, the energy storage capacitor E4, etc. constitute the charging circuit to charge the energy storage capacitor E4, and the discharge circuit composed of transistor N5, resistor R12, and fourth adjustable positioner VR1 discharges the energy storage capacitor E4, forming a charging-discharging process. A sawtooth wave signal (represented by JUCHI in the figure) is generated on the collector of transistor N5. The frequency of this waveform is related to the mains input frequency.

[0085] Figure 4 This is a circuit diagram of the temperature difference voltage signal generation module 162 according to an exemplary embodiment of the present utility model.

[0086] like Figure 4 As shown, the temperature difference voltage signal generation module 162 includes an actual temperature voltage signal generation module 1621, a set temperature voltage signal generation module 1622, and an error amplification voltage signal generation module 1623. The actual temperature voltage signal generation module 1621 generates the actual temperature voltage signal of the water in the outlet pipe 130; the set temperature voltage signal generation module 1622 generates the set temperature voltage signal set by the user; the error amplification voltage signal generation module 1623 is connected to the actual temperature voltage signal generation module 1621 and the set temperature voltage signal generation module 1622, and is used to compare the actual temperature voltage signal and the set temperature voltage signal to generate the temperature difference voltage signal.

[0087] Specifically, the actual temperature voltage signal generation module 1621 includes a first voltage divider circuit and a first terminal connected to the first voltage divider circuit. The first terminal is used to connect to the outlet water temperature sensor 150. The first voltage divider circuit is used to convert the actual temperature data sensed by the outlet water temperature sensor 150 into the actual temperature voltage signal. The output of the first voltage divider circuit transmits the actual temperature voltage signal to the error amplification voltage signal generation module 1623.

[0088] The set temperature voltage signal generation module 1622 includes a first adjustable positioner and a second voltage divider circuit connected to the first adjustable positioner; wherein, the second voltage divider circuit is used to convert the set temperature data indicated by the first adjustable positioner into the set temperature voltage signal, and the adjustment terminal of the first adjustable positioner transmits the set temperature voltage signal to the error amplification voltage signal generation module 1623.

[0089] The error amplification voltage signal generation module 1623 includes a first operational amplifier, a second adjustable positioner, and a third adjustable positioner. The inverting input of the first operational amplifier is connected to the set temperature voltage signal generation module 1622, and the non-inverting input of the first operational amplifier is connected to the actual temperature voltage signal generation module 1621. One end of the second adjustable positioner is connected to the inverting input of the first operational amplifier, and the other end of the second adjustable positioner is connected to the adjustment terminal of the second adjustable positioner and then to the output terminal of the first operational amplifier. The adjustment terminal of the third adjustable positioner is connected to one end of the third adjustable positioner and then to the non-inverting input of the first operational amplifier, and the other end of the third adjustable positioner is connected to a reference ground. The first operational amplifier differentially amplifies the set temperature voltage signal and the actual temperature voltage signal to obtain a temperature difference voltage signal, and transmits the temperature difference voltage signal to the drive signal generation module 164 through its output terminal.

[0090] As an example, the first voltage divider circuit includes current-limiting resistors R22 and R15 connected in series. The second voltage divider circuit includes resistors R13, R14, R20, and R21 connected in series with the first adjustable positioner.

[0091] The connection relationships of the electronic components in the thermoelectric voltage signal generation module 162 are illustrated below by way of example.

[0092] One end of resistor R13 is connected to the positive terminal of energy storage capacitor E2, the other end of resistor R13 is connected to one end of resistor R14, the other end of resistor R14 is connected to one end of first adjustable positioner VR3, the other end of first adjustable positioner VR3 is connected to one end of resistor R20, the other end of resistor R20 is connected to one end of resistor R21, and the other end of resistor R21 is connected to reference ground.

[0093] One end of the current-limiting resistor R22 is connected to the positive terminal of the energy storage capacitor E2, and the other end of the current-limiting resistor R22 is connected to one end of the current-limiting resistor R15. The other end of the current-limiting resistor R15 is connected to one end of the first terminal CN3, and the other end of the first terminal CN3 is connected to the reference ground. The first terminal CN3 is connected to the outlet water temperature sensor 150 on the outlet water pipe 130. Preferably, the outlet water temperature sensor 150 is an NTC sensor.

[0094] The adjustment terminal of the first adjustable positioner VR3 is connected to one end of the resistor R18, and the other end of the resistor R18 is connected to the inverting input terminal of the first operational amplifier. One end of the second adjustable positioner VR2 is connected to the inverting input terminal of the first operational amplifier, and the other end of the second adjustable positioner VR2 is connected to the adjustment terminal of the second adjustable positioner VR2 and connected to the output terminal of the first operational amplifier.

[0095] The connection point of resistor R15 to the first terminal CN3 is connected to one end of resistor R19. The other end of resistor R19 is connected to the non-inverting input of the first operational amplifier. The non-inverting input of the first operational amplifier is connected to the adjustment terminal of the third adjustable positioner VR4 and to one end of the third adjustable positioner VR4. The other end of the third adjustable positioner VR4 is connected to reference ground.

[0096] In the above scheme, the user sets the target temperature through a first voltage divider circuit consisting of a first adjustable positioner VR3 and resistors R13, R14, R20, and R21. Resistors R13, R14, R20, and R21 are used to limit the user's adjustment range, while the first adjustable positioner VR3 is used to adjust the specific temperature point (corresponding to the voltage value obtained by the first voltage divider circuit).

[0097] The outlet water temperature detection section uses current-limiting resistors R22 and R15 to connect to the first terminal. The other end of the first terminal is connected to ground. When in use, a thermal resistance type temperature sensor can be inserted into this terminal to achieve temperature sampling.

[0098] All the resistors mentioned above are connected in series using two resistors. This makes it easy to find the appropriate resistance value, which helps to reduce the types of components, material costs, and management costs.

[0099] The user-defined temperature and voltage signal (represented by SHEDING in the figure) and the actual temperature and voltage signal detected by the sensor (represented by SHIJI in the figure) are passed through an error amplification circuit consisting of resistors R18 and R19, a second adjustable positioner VR2, a third adjustable positioner VR4, and an operational amplifier to obtain an error amplification signal (represented by Io in the figure). Typically, error amplification circuits are designed using active differential amplifiers. In this invention, to facilitate adjustment of the error amplification factor, the second adjustable positioner VR2 and the third adjustable positioner VR4 are matched. This facilitates adjustment of the amplification factor (i.e., synchronous adjustment of VR2 and VR4, increasing or decreasing simultaneously, VR2 = VR4), and also facilitates adjustment of amplifier deviations (such as the influence of inherent op-amp parameters). This adjustment causes a deviation between the second and third adjustable positioners VR2 and VR4, resulting in linearized output, i.e., easy zeroing. This setup allows the use of a low-cost operational amplifier to achieve the desired result.

[0100] Figure 5 This is a circuit diagram of the drive signal generation module 164 and the switch module 161 according to an exemplary embodiment of the present utility model.

[0101] like Figure 5 As shown, the drive signal generation module 164 includes a second operational amplifier. The two input terminals of the second operational amplifier are respectively connected to the thermo-voltage signal generation module 162 and the sawtooth wave signal generation module 163. The second operational amplifier compares the thermo-voltage signal and the sawtooth wave signal to obtain a drive signal, and transmits the drive signal to the switch module 161 through the output terminal.

[0102] The switch module 161 includes a second terminal block, a thyristor output optocoupler, and a third terminal block connected in sequence; wherein, the second terminal block is used to plug in a control switch, and the third terminal block is used to plug in a heater; the second terminal block is connected to the output terminal of the second operational amplifier, and when the control switch is turned on, the drive signal controls the output power of the thyristor output optocoupler.

[0103] The connection relationship between the electronic components in the drive signal generation module 164 and the switch module 161 is illustrated below by way of example.

[0104] The non-inverting input (+) of the second operational amplifier is connected to the output (Io) of the first operational amplifier, and the inverting input (-) of the second operational amplifier is connected to the collector (JUCHI) of transistor N5, forming a comparator circuit. The output of the second operational amplifier is connected to one end of resistor R3, and the other end of resistor R3 is connected to the anode of diode D4. The cathode of diode D4 is connected to one end of capacitor C1, and the other end of capacitor C1 is connected to reference ground. One end of resistor R6 is connected to the cathode of diode D4, and the other end of resistor R6 is connected to the base of transistor N2. The emitter of transistor N2 is connected to reference ground. The collector of transistor N2 is connected to the cathode of LED1. The anode of LED1 is connected to one end of resistor R2, and the other end of resistor R2 is connected to the positive terminal of energy storage capacitor E2.

[0105] One end of resistor R10 is connected to the output of the second operational amplifier, and the other end of resistor R10 is connected to pin 2 of the second terminal CN2. Pin 1 of the second terminal CN2 is left floating. Pin 3 of the second terminal CN2 is connected to pin 1 of the SCR output optocoupler IC1. Pin 2 of the SCR output optocoupler IC1 is connected to reference ground, and pin 3 of the SCR output optocoupler IC1 is left floating. Pin 4 of the SCR output optocoupler IC1 is connected to pin 4 of the third terminal CN1. Pin 5 of the SCR output optocoupler IC1 is left floating. Pin 6 of the SCR output optocoupler IC1 is connected to one end of resistor R11. The other end of resistor R11 is connected to one end of resistor R23, and the other end of resistor R23 is connected to pin 3 of the third terminal CN1.

[0106] Pin 1 of the third terminal CN1 is connected to the neutral wire N of the mains power supply, pin 2 of the third terminal CN1 is left floating, pin 3 of the third terminal CN1 is connected to the live wire L of the mains power supply, and the third terminal CN1 is connected to the heater.

[0107] In the above scheme, the temperature difference voltage signal (Io) and the sawtooth wave signal (JUCHI) are compared and calculated using a second operational amplifier to obtain a drive signal (represented by QUDONG in the figure). This drive signal passes through a rectifier and filter circuit composed of resistor R3, diode D4, and capacitor C1, and then enters the base of transistor N2 through current-limiting resistor R6. This controls the drive of LED1 connected to the collector of transistor N2 to indicate the current heating status.

[0108] The driving signal (QUDONG) is connected to a second terminal through a current-limiting resistor R10. To prevent problems such as rework caused by incorrect insertion during the production process or maintenance, a 3P connector is used for this terminal. This connector can be connected to a control switch. When the switch is turned on, the driving signal (QUDONG) can drive the thyristor output optocoupler IC1 through the resistor R10, and then control the bidirectional thyristor inside the thyristor output optocoupler IC1, thereby controlling the power supply of the heater and achieving the temperature regulation function.

[0109] In addition, two different terminals are used in the switch module 161, which can prevent incorrect insertion that may lead to unnecessary rework and risks, and the lead serial numbers are reasonably set on the terminals. That is, even when the terminals are inserted reversely, the circuit will not be damaged. At the same time, anti-reverse terminals are used in the selection of terminals, further ensuring the straight-through rate of the product.

[0110] To further reduce costs, a chip with the model number LM358DT that is mass-produced in the market can be used to replace the above-mentioned driving signal generation module 164, as shown in Figure 6 The structure and principle of the chip with the model number LM358DT can be referred to the chip manual, and will not be elaborated here in this utility model.

[0111] Next, refer to Figures 1 to 6 to elaborate the working principle of the temperature controller 160.

[0112] The outlet water temperature sensor 150 uses an NTC thermistor, which is a type of sensor whose resistance value decreases as the temperature increases. When it is used in this utility model for water temperature detection, the actual temperature voltage signal (SHIJI) detected by the sensor will decrease as the water temperature rises.

[0113] The differential voltage signal Io output by the first operational amplifier has the following relationship:

[0114] When VR2 = VR4, the first operational amplifier forms a differential amplifier circuit, Io = (SHIJI - SHEDING) * VR2 / R18, where the Io signal does not exceed the range of the power supply voltage of the first operational amplifier.

[0115] When the actual water temperature is higher than the set temperature, the higher the temperature, the smaller the actual temperature voltage signal, that is, SHIJI < SHEDING. At this time, the calculated value of Io is negative, but since the lowest power supply rail of the op amp with single power supply is 0, so Io = 0 at this time. Since the sawtooth wave signal (JUCHI) is greater than 0, the second operational amplifier (comparator mode) outputs a low level of 0 at this time.

[0116] When the actual water temperature is not higher than the set temperature, SHIJI >= SHEDING, and the calculated value of Io is positive at this time.

[0117] When Io is greater than the maximum value of the sawtooth wave signal (JUCHI), the second operational amplifier (comparator mode) outputs a high-level drive signal (QUDONG). That is, when the water temperature deviation is too large (less than the set temperature), the drive signal causes the switching module to control the heater to heat at full power.

[0118] When Io is less than the maximum value of the sawtooth wave signal (JUCHI), the second operational amplifier (comparator mode) outputs a drive signal (QUDONG) as a PWM signal. That is, when the water temperature approaches the set temperature, the drive signal causes the switching module to control the heater to reduce the heating power to avoid overheating. Moreover, the closer the actual water temperature is to the set temperature, the lower the PWM duty cycle and the lower the heating power, thus achieving precise temperature control.

[0119] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model in any way. Although the present utility model has been disclosed above with reference to a preferred embodiment, it is not intended to limit the present utility model. Any person skilled in the art can make some modifications or alterations to the above-described technical content to create equivalent embodiments without departing from the scope of the present utility model. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present utility model without departing from the scope of the present utility model shall still fall within the scope of the present utility model.

Claims

1. A temperature controller, characterized in that, include: Switch module; Thermoelectric voltage signal generation module, used to generate thermoelectric voltage signal based on temperature difference data; Sawtooth wave signal generation module, used to generate sawtooth wave signals; as well as A drive signal generation module is connected to the temperature difference voltage signal generation module, the sawtooth wave signal generation module, and the switch module, and is used to compare the temperature difference voltage signal with the sawtooth wave signal to generate a drive signal that controls the operation of the switch module.

2. The temperature controller according to claim 1, characterized in that, The temperature difference voltage signal generation module includes: The actual temperature and voltage signal generation module is used to generate the actual temperature and voltage signal of the medium under test. A set temperature and voltage signal generation module is used to generate a set temperature and voltage signal for the medium under test; and An error amplification voltage signal generation module is connected to the actual temperature voltage signal generation module and the set temperature voltage signal generation module, and is used to compare the actual temperature voltage signal and the set temperature voltage signal to generate the temperature difference voltage signal.

3. The temperature controller according to claim 2, characterized in that, The actual temperature voltage signal generation module includes a first voltage divider circuit and a first terminal connected to the first voltage divider circuit. The first terminal is used to connect to a temperature sensor. The first voltage divider circuit is used to convert the actual temperature data of the medium under test sensed by the temperature sensor into the actual temperature voltage signal, and the output of the first voltage divider circuit transmits the actual temperature voltage signal to the error amplification voltage signal generation module.

4. The temperature controller according to claim 2, characterized in that, The set temperature voltage signal generation module includes a first adjustable positioner and a second voltage divider circuit connected to the first adjustable positioner. The second voltage divider circuit is used to convert the set temperature data for the medium under test indicated by the first adjustable positioner into the set temperature voltage signal, and the adjustment terminal of the first adjustable positioner transmits the set temperature voltage signal to the error amplification voltage signal generation module.

5. The temperature controller according to claim 2, characterized in that, The error amplification voltage signal generation module includes a first operational amplifier, a second adjustable positioner, and a third adjustable positioner. Wherein, the inverting input terminal of the first operational amplifier is connected to the set temperature voltage signal generation module, and the non-inverting input terminal of the first operational amplifier is connected to the actual temperature voltage signal generation module. One end of the second adjustable positioner is connected to the inverting input of the first operational amplifier, and the other end of the second adjustable positioner is connected to the adjustment end of the second adjustable positioner and then connected to the output of the first operational amplifier. The adjustment terminal of the third adjustable positioner is connected to one end of the third adjustable positioner and then connected to the non-inverting input terminal of the first operational amplifier; the other end of the third adjustable positioner is connected to reference ground. The first operational amplifier differentially amplifies the set temperature voltage signal and the actual temperature voltage signal to obtain a temperature difference voltage signal, and transmits the temperature difference voltage signal to the drive signal generation module through the output terminal.

6. The temperature controller according to any one of claims 1 to 5, characterized in that, The drive signal generation module includes a second operational amplifier, and the two input terminals of the second operational amplifier are respectively connected to the thermoelectric voltage signal generation module and the sawtooth wave signal generation module; The second operational amplifier compares the thermoelectric voltage signal and the sawtooth wave signal to obtain a drive signal, and transmits the drive signal to the switching module through the output terminal.

7. The temperature controller according to claim 6, characterized in that, The switching module includes a second terminal block, a silicon controlled rectifier output optocoupler, and a third terminal block connected in sequence. The second terminal is used to connect a control switch, and the third terminal is used to connect a heater. The second terminal is connected to the output terminal of the second operational amplifier. When the control switch is turned on, the drive signal controls the output power of the thyristor output optocoupler.

8. The temperature controller according to claim 6, characterized in that, The sawtooth wave signal generation module includes: Power supply circuitry for generating pulsating DC voltage signals; and A waveform generation circuit, connected to the power supply circuit, is used to convert the pulsating DC voltage signal into the sawtooth wave signal.

9. The temperature controller according to claim 8, characterized in that, The waveform generating circuit includes an inverting circuit, an energy storage circuit, and a discharging circuit; The inverting circuit is used to convert the waveform of the DC voltage signal, and the converted DC voltage signal forms the sawtooth wave signal during the charging and discharging process of the energy storage circuit and the discharge circuit.

10. A hot water device, characterized in that, Includes a temperature controller according to any one of claims 1 to 9.

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