Heating control system and oven

Abstract

Heating control system, characterized in that it comprises: a first heating unit (1), a zero-point detection switching unit (2) for detecting the voltage signal of the supply terminal (100), several burst-firing control driver units (3), a control unit (4), an input unit (5) for setting the heating mode, and a voltage converter unit (6), wherein the first heating unit (1) comprises at least two first heating elements (7) and the first heating elements (7) are assigned one-to-one to a burst-firing control driver unit (3); wherein the input terminal of the burst-firing control driver unit (3), the output terminal of the zero-point detection switching unit (2), the output terminal of the voltage converter unit (6), and the input unit (5) are each electrically connected to the control unit (4); the input terminal of the voltage converter unit (6) and the input terminal of the zero-point detection switching unit (2) are electrically connected to the supply terminal (100); the output terminal of the burst-firing control driver unit (3) and one end of the supply terminal (100) are each connected to the two ends of the corresponding first heating element (7); the zero-point detection switching unit (2), the burst-firing control driver unit (3), and the input unit (5) are each electrically connected to the output terminal of the voltage converter unit (6); wherein The burst-firing control driver unit (3) comprises an optocoupler driver module (31) and a zero-point release module (32); wherein the input terminal of the optocoupler driver module (31) is electrically connected to the control unit (4) and the output terminal of the voltage converter unit (6), respectively; the output terminal of the optocoupler driver module (31) is electrically connected to the control terminal of the zero-point release module (32); the input terminal of the zero-point release module (32) is electrically connected to the output terminal of the voltage converter unit (6); the output terminal of the zero-point release module (32) is connected in series with one end of the supply terminal (100) via the corresponding first heating element (7);wherein the control unit (4) outputs a control signal based on the set heating mode and the detected voltage signal of the supply terminal (100) and controls the operating state of the zero-point release module (32) via the optocoupler driver module (31).

Description

TECHNICAL AREA

[0001] The present utility model relates to the technical field of heating control technology for ovens and in particular to a heating control system and an oven. TECHNICAL BACKGROUND

[0002] With some conventional ovens on the market, where the resistance of the heating wire in the internal heating elements and the supplied mains voltage are relatively fixed, the oven's output power is generally fixed. This significantly limits the oven's functionality and the user experience, preventing the user from fine-tuning the power according to different cooking requirements and adjusting the output power.

[0003] Conventional heating control methods generally use phase-angle control, whereby stepless power regulation from 0% to 100% can be achieved by controlling the firing angle of the thyristor within each half-cycle of the alternating current and by delaying the firing of the thyristor after the voltage reaches zero. This meets the user's requirements for various cooking modes and results in relatively smooth output current and voltage. However, this control method is susceptible to signal interference, does not meet certification standards, and can impair the normal operation of the oven.

[0004] Therefore, it is very important to obtain a heating control system and an oven that can overcome the aforementioned shortcomings. DETAILED DESCRIPTION

[0005] To solve the aforementioned technical problems, the present utility model provides a heating control system comprising a first heating unit, a zero-point detection switching unit for detecting the voltage signal of the supply terminal, several burst-firing control driver units, a control unit, an input unit for setting the heating mode, and a voltage converter unit, wherein the first heating unit comprises at least two first heating elements and the first heating elements of a burst-firing control driver unit are assigned one-to-one.

[0006] The input terminal of the burst-firing control driver unit, the output terminal of the zero-point detection switching unit, the output terminal of the voltage converter unit, and the input unit are each electrically connected to the control unit. The input terminal of the voltage converter unit and the input terminal of the zero-point detection switching unit are electrically connected to the power supply terminal. The output terminal of the burst-firing control driver unit and one end of the power supply terminal are each connected to the two ends of the corresponding first heating element. The zero-point detection switching unit, the burst-firing control driver unit, and the input unit are each electrically connected to the output terminal of the voltage converter unit.

[0007] The burst-firing control driver unit comprises an optocoupler driver module and a zero-point trip module. The input terminal of the optocoupler driver module is electrically connected to both the control unit and the output terminal of the voltage converter unit. The output terminal of the optocoupler driver module is electrically connected to the control terminal of the zero-point trip module. The input terminal of the zero-point trip module is electrically connected to the output terminal of the voltage converter unit. The output terminal of the zero-point trip module is connected in series with one end of the supply terminal via the corresponding first heating element. The control unit outputs a control signal based on the set heating mode and the detected voltage signal from the supply terminal and controls the operating state of the zero-point trip module via the optocoupler driver module.

[0008] Furthermore, the zero point detection switching unit includes a zero point detection module and a signal shaping module.

[0009] The input terminal of the zero-point detection module is electrically connected to the power supply terminal and serves to detect the voltage signal from the power supply terminal. The output terminal of the zero-point detection module is electrically connected to both the input terminal of the signal shaping module and the output terminal of the voltage converter unit. The signal shaping module is electrically connected to the output terminal of the voltage converter unit. The output terminal of the signal shaping module is electrically connected to the control unit and serves to convert the input waveform of the power supply terminal into a square wave for detection by the control unit.

[0010] The heating control system further comprises a second heating unit and several relay driver units, the second heating unit including at least one second heating element. Each relay driver unit is electrically connected to the control unit and the output terminal of the voltage converter unit. The two ends of the second heating element are each electrically connected to one end of the power supply terminal and the corresponding relay driver unit.

[0011] Furthermore, the heating control system includes a current sensing unit. The zero-point trip module has a first current sensing point, and the relay driver unit has a second current sensing point. The current sensing unit is electrically connected to the control unit, the output terminal of the voltage converter unit, the first current sensing point, and the second current sensing point.

[0012] Furthermore, the heating control system includes a communication unit, the communication unit being electrically connected to the control unit and the output terminal of the voltage converter unit.

[0013] Furthermore, the zero-point detection module comprises a first optocoupler, a first diode, a second diode, a third diode, a first resistor, a second resistor and a third resistor, wherein the signal shaping module comprises a first switching transistor, a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor and a first capacitor.

[0014] One end of the emitter terminal of the first optocoupler is electrically connected to one end of the supply terminal via the first resistor. The other end of the emitter terminal of the first optocoupler is connected in series with the second resistor and the first diode, and electrically connected to the other end of the supply terminal. The emitter and collector terminals of the first optocoupler are each connected in parallel with the second and third diodes, respectively. One end of the collector terminal of the first optocoupler is electrically connected to the output terminal of the voltage converter unit via the third resistor. The other end of the collector terminal of the first optocoupler is electrically connected to the control terminal of the first switching transistor via the fourth resistor. The fifth resistor is connected in series between the control terminal and the first terminal of the first switching transistor.The first terminal of the first switching transistor is connected to ground. The second terminal of the first switching transistor is connected in series with the sixth and seventh resistors, and then electrically connected to the control unit. The eighth resistor is connected in series between the junction of the sixth and seventh resistors and the output terminal of the voltage converter unit. The first capacitor is connected in series between the junction of the sixth and seventh resistors and the ground terminal.

[0015] Furthermore, the optocoupler driver module includes a second optocoupler, a ninth resistor, a tenth resistor and an eleventh resistor, with the zero-point trip module comprising a triac.

[0016] One end of the emitter terminal of the second optocoupler is electrically connected to the control unit via the ninth resistor. The other end of the emitter terminal of the second optocoupler is electrically connected to the output terminal of the voltage converter unit and to one end of the tenth resistor. The other end of the tenth resistor is electrically connected to one end of the ninth resistor. One end of the collector terminal of the second optocoupler is electrically connected to the control terminal of the triac via the eleventh resistor. One end of the collector terminal of the second optocoupler is electrically connected to the output terminal of the voltage converter unit. The other end of the collector terminal of the second optocoupler is connected to ground. One terminal of the triac is connected in series with one end of the supply terminal via the corresponding first heating element.

[0017] A filter module is provided between the two ends of the triac, between one end of the collector connection of the second optocoupler and the output connection of the voltage converter unit, and between one end of the collector connection of the second optocoupler and the ground connection.

[0018] Furthermore, the current sensing unit includes a step-down converter module, a twelfth resistor, a second capacitor, a third capacitor, a fourth capacitor and a fifth capacitor.

[0019] The input terminal of the buck converter module is electrically connected to the first current measurement point of the zero-point trip module and the second current measurement point of the relay driver unit. The output terminal of the buck converter module is electrically connected to the control unit via the twelfth resistor. The second capacitor is connected in series between one end of the twelfth resistor and the ground terminal. The output terminal of the buck converter module is electrically connected to the output terminal of the voltage converter unit. The third, fourth, and fifth capacitors are connected in series between the output terminal of the buck converter module and the ground terminal. Furthermore, a carbon fiber heating element is used for the first heating element. The surface of the carbon fiber heating element has an aluminum oxide coating.

[0020] The present utility model further provides an oven comprising a main body and the described heating control system.

[0021] The heating control system and oven provided by this utility model enable the control unit to determine, based on the set heating mode and the voltage signal from the supply connection (sensed by the zero-point detection switching unit), whether the first heating element should be subjected to burst-firing control via the burst-firing control driver unit, thereby controlling the operating state of the zero-point trigger module. Electromagnetic interference is minimal with burst-firing control, a rapid response is possible, and fine-tuned power control of multiple first heating elements can be achieved to enable different heating modes, thus enhancing the grilling experience.

[0022] By using a relay driver circuit to control the switching on or off of the second heating element in the second heating unit, a complement to the finely tuned power control of the first heating unit is created, so that several power levels can be combined.

[0023] The first heating element uses a carbon fiber heating element and features an aluminum oxide coating, which increases thermal efficiency and reduces heat loss. This heating element interacts with the reflective part on the oven's main body to generate heat, resulting in more even heat distribution and effective energy savings. DESCRIPTION OF THE DRAWINGS Fig. Figure 1 shows a schematic block diagram of a heating control system provided by an embodiment of the present utility model. Fig. Figure 2 shows a basic circuit diagram of the voltage converter unit in Fig. 1. Fig. Figure 3 shows a schematic diagram of the input unit, the communication unit, and the control unit in Fig. 1. Fig. Figure 4 shows a schematic diagram of the relay driver unit and the burst-firing control driver unit in Fig. 1. Fig. Figure 5 shows a schematic diagram of the zero-point detection switching unit and the current detection unit in Fig. 1. Fig. Figure 6 shows a schematic diagram of the structure of an oven.

[0024] Reference numeral list: first heating unit 1; zero point detection switching unit 2; zero point detection module 21; signal shaping module 22; burst-firing control driver unit 3; optocoupler driver module 31; zero point release module 32; filter module 33; control unit 4; input unit 5; voltage converter unit 6; first heating element 7; second heating unit 8; relay driver unit 9; second heating element 10; current detection unit 11; communication unit 12; first temperature detection unit 13; second temperature detection unit 14; silicone sleeve 15; protective mesh cover 16; power supply connection 100; main body 200. SPECIFIC EXECUTION FORMS

[0025] To enable the person skilled in the art to better understand the present utility model and thus define its scope of protection more clearly, the present utility model is described in detail below using some specific embodiments. It should be noted that the following specific embodiments represent only a portion of the embodiments of the present utility model, and the concrete and direct description of the corresponding structures serves only to improve the understanding of the present utility model. The specific features do not necessarily and directly limit the scope of protection of the present utility model. Example 1

[0026] With reference to Fig. 1. The present utility model employs the following technical solution: a heating control system comprising a first heating unit 1, a zero-point detection switching unit 2 for detecting the voltage signal of the supply terminal 100, several burst-firing control driver units 3, a control unit 4, an input unit 5 for setting the heating mode, and a voltage converter unit 6, wherein the first heating unit 1 comprises at least two first heating elements 7, and the first heating element 7 of the burst-firing control driver unit 3 is assigned one-to-one. In this embodiment, four first heating elements 7 are provided, the number of which can be adjusted according to actual requirements.

[0027] The input terminal of the burst-firing control driver unit 3, the output terminal of the zero-point detection switching unit 2, the output terminal of the voltage converter unit 6, and the input unit 5 are each electrically connected to the control unit 4. The input terminal of the voltage converter unit 6 and the input terminal of the zero-point detection switching unit 2 are electrically connected to the supply terminal 100. The output terminal of the burst-firing control driver unit 3 and one end of the supply terminal 100 are each connected to the two ends of the corresponding first heating element 7. The zero-point detection switching unit 2, the burst-firing control driver unit 3, and the input unit 5 are each electrically connected to the output terminal of the voltage converter unit 6.

[0028] The burst-firing control driver unit 3 comprises an optocoupler driver module 31 and a zero-point trip module 32. The input terminal of the optocoupler driver module 31 is electrically connected to the control unit 4 and the output terminal of the voltage converter unit 6. The output terminal of the optocoupler driver module 31 is electrically connected to the control terminal of the zero-point trip module 32. The input terminal of the zero-point trip module 32 is electrically connected to the output terminal of the voltage converter unit 6. The output terminal of the zero-point trip module 32 is connected in series with one end of the supply terminal 100 via the corresponding first heating element 7. The zero-point trip module 32 has a first current sensing point L.The control unit 4 outputs a control signal based on the set heating mode and the detected voltage signal of the supply terminal 100 and controls the operating state of the zero-point release module 32 via the optocoupler driver module 31.

[0029] As in Fig. As shown in Figure 4, the optocoupler driver module 31 comprises a second optocoupler U1, a ninth resistor R20, a tenth resistor R17, and an eleventh resistor R18, with the zero-point trip module 32 comprising a triac Q3. One end of the emitter terminal of the second optocoupler U1 is electrically connected to the control unit 4 via the ninth resistor R20. The other end of the emitter terminal of the second optocoupler U1 is electrically connected to the output terminal of the voltage converter unit 6 and to one end of the tenth resistor R17. The other end of the tenth resistor R17 is electrically connected to one end of the ninth resistor R20. One end of the collector terminal of the second optocoupler U1 is electrically connected to the control terminal of the triac Q3 via the eleventh resistor R18. One end of the collector terminal of the second optocoupler U1 is electrically connected to the output terminal of the voltage converter unit 6.The other end of the collector terminal of the second optocoupler U1 is connected to ground. One terminal of triac Q3 is connected in series with one end of the supply terminal 100 via the corresponding first heating element 7. The other terminal of triac Q3 is the first current measuring point L of the zero-point trip module 32.

[0030] A filter module 33 is provided between the two ends of the triac Q3, between one end of the collector connection of the second optocoupler U1 and the output connection of the voltage converter unit 6, and between one end of the collector connection of the second optocoupler U1 and the ground connection.

[0031] As in Fig. As shown in Figure 5, the zero-point detection switching unit 2 comprises a zero-point detection module 21 and a signal shaping module 22. The input terminal of the zero-point detection module 21 is electrically connected to both ends of the supply terminal 100 and serves to detect the voltage signal of the supply terminal 100. The output terminal of the zero-point detection module 21 is electrically connected to both the input terminal of the signal shaping module 22 and the output terminal of the voltage converter unit 6. The signal shaping module 22 is electrically connected to the output terminal of the voltage converter unit 6. The output terminal of the signal shaping module 22 is electrically connected to the control unit 4. The supply terminal 100 is an AC power supply whose corresponding input waveform is a sine wave.

[0032] The zero-point detection module 21 provides the synchronization clock to enable the burst-firing control driver unit 3 to complete the switching operation at the zero point. The signal shaping module 22 converts the input waveform of the supply terminal 100 into a clean and stable square wave to ensure signal quality. The filter module 33 filters out interference and suppresses voltage spikes to prevent false tripping of the zero-point trip module 32, thus comprehensively improving the system's noise immunity, facilitating accurate detection and processing by the control unit 4, and increasing circuit stability.

[0033] As in Fig. As shown in Figure 5, the zero-point detection module 21 comprises a first optocoupler U2, a first diode D10, a second diode D9, a third diode D15, a first resistor R30, a second resistor R39 and a third resistor R31, wherein the signal shaping module 22 comprises a first switching transistor Q6, a fourth resistor R34, a fifth resistor R35, a sixth resistor R27, a seventh resistor R28, an eighth resistor R25 and a first capacitor C14.

[0034] One end of the emitter terminal of the first optocoupler U2 is electrically connected to one end of the supply terminal 100 via the first resistor R30. The other end of the emitter terminal of the first optocoupler U2 is connected in series with the second resistor R39 and the first diode D10, and is also electrically connected to the other end of the supply terminal 100. The emitter and collector terminals of the first optocoupler U2 are each connected in parallel with the second diode D9 and the third diode D15, respectively. One end of the collector terminal of the first optocoupler U2 is electrically connected to the output terminal of the voltage converter unit 6 via the third resistor R31. The other end of the collector terminal of the first optocoupler U2 is electrically connected to the control terminal of the first switching transistor Q6 via the fourth resistor R34.The fifth resistor, R35, is connected in series between the control terminal and the first terminal of the first switching transistor, Q6. The first terminal of the first switching transistor, Q6, is connected to ground. The second terminal of the first switching transistor, Q6, is connected in series with the sixth resistor, R27, and the seventh resistor, R28, and then electrically connected to the control unit 4. The eighth resistor, R25, is connected in series between the junction of the sixth resistor, R27, and the seventh resistor, R28, and the output terminal of the voltage converter unit 6. The first capacitor, C14, is connected in series between the junction of the sixth resistor, R27, and the seventh resistor, R28, and the ground terminal.The signal output by the first optocoupler U2 is inverted and shaped by the signal shaping module 22 and serves to convert the input waveform of the supply terminal 100 into a pure and steep square wave for detection by the control unit 4. The heating control system further comprises a second heating unit 8 and several relay driver units 9, wherein the second heating unit 8 includes at least one second heating element 10. The relay driver unit 9 is electrically connected to the control unit 4 and the output terminal of the voltage converter unit 6. The two ends of the second heating element 10 are each electrically connected to one end of the supply terminal 100 and to the corresponding relay driver unit 9. The relay driver unit 9 has a second current sensing point L1.

[0035] As in Fig. As shown in Figure 4, the relay driver unit 9 comprises a second switching transistor Q1, a relay J1, a fourth diode D3, a thirteenth resistor R9, and a fourteenth resistor R12. The control terminal of the second switching transistor Q1 is electrically connected to the control unit 4 via the thirteenth resistor R9. The fourteenth resistor R12 is connected in series between the control terminal and the first terminal of the second switching transistor Q1. The first terminal of the second switching transistor Q1 is connected to ground. The coil of relay J1 is connected in series between the second terminal of the second switching transistor Q1 and the output terminal of the voltage converter unit 6. The two ends of the coil of relay J1 are connected in parallel with the fourth diode D3. The normally open contact of relay J1 is the second current sensing point L1 of the relay driver unit 9.One of the normally closed contacts of relay J1 is electrically connected to one end of the corresponding second heating element 10. This is suitable for load scenarios requiring high current control and high safety insulation requirements.

[0036] The input unit 5 can be implemented using a keypad, a touchscreen, or other methods. The user selects different heating modes via keys or touchscreen buttons. These heating modes include full-zone heating, zone heating, and regular heating. The control unit 4 detects the heating mode based on the address assigned to each key.

[0037] When the control unit 4 detects that the input unit 5 is set to full-zone heating mode, the control unit 4 reads the voltage signal sent by the zero-point detection module 21. When the voltage zero point is detected, the control unit 4 outputs an initial control signal to all burst-firing control driver units 3 to cause the zero-point trigger module 32 to switch on at the voltage zero point, remain on for several complete waveforms, and then switch off at the voltage zero point, remaining off for several complete waveforms. The output power can be adjusted by controlling the ratio of the switch-on time to the switch-off time. In the present application, the switch-on time and the switch-off time are equal. For example, the rated output power of the first heating element 7 is 1200 W.Following the burst-firing control, the first four heating elements 7 operate at 600 W within the control cycle. The total output power is 2,400 W.

[0038] When the control unit 4 detects that the input unit 5 is set to zone heating mode, the control unit 4 outputs a second control signal to a specified number of burst-firing control driver units 3 to ensure that the corresponding zero-point trigger module 32 remains permanently switched on. For example, after zone control, only two first heating elements 7 operate at 1,200 W. The total output power is 2,400 W. Compared to operating the four first heating elements 7 simultaneously at half power, this effectively reduces heating time, increases thermal efficiency, improves the grilling experience, and results in lower output power during full-zone heating. This also reduces the power cord requirements, making it adaptable to the usage requirements of different regions.

[0039] When the control unit 4 detects that the input unit 5 is set to the regular heating mode, the control unit 4 outputs a third control signal to the control terminal of the second switching transistor Q1 in the relay driver unit 9 to cause it to switch on in a saturation-controlled manner, thereby energizing the relay J1 and operating the second heating element 10 at the rated output power.

[0040] The heating control system also includes a current sensing unit 11. The current sensing unit 11 is electrically connected to the control unit 4, the output terminal of the voltage converter unit 6, the first current measuring point L of the zero-point trip module 32 and the second current measuring point L1 of the relay driver unit 9.

[0041] As in Fig. As shown in Figure 5, the current sensing unit 11 comprises a buck converter module U9, a twelfth resistor R92, a second capacitor C43, a third capacitor C40, a fourth capacitor C41, and a fifth capacitor C42. The input terminal of the buck converter module U9 is electrically connected to the first current sensing point L of the zero-point trip module 32 and to the second current sensing point L1 of the relay driver unit 9. The output terminal of the buck converter module U9 is electrically connected to the control unit 4 via the twelfth resistor R92. The second capacitor C43 is connected in series between one end of the twelfth resistor R92 and the ground terminal. The output terminal of the buck converter module U9 is electrically connected to the output terminal of the voltage converter unit 6.Between the output terminal of the buck converter module U9 and the ground terminal, the third capacitor C40, fourth capacitor C41 and fifth capacitor C42 are connected in series and in parallel.

[0042] By detecting the current signal flowing through relay J1 and triac Q3, the buck converter module U9 proportionally reduces the high-current signal and serves for open-circuit detection and overcurrent protection to increase system safety. Several capacitors form a filter network to filter ripple and high-frequency interference, thus improving sampling accuracy.

[0043] In another embodiment, the heating control system further includes a current sensing module for sensing the system input current.

[0044] The heating control system also includes a communication unit 12. The communication unit 12 is electrically connected to the control unit 4 and the output terminal of the voltage converter unit 6. As in Fig. As shown in Figure 3, the communication unit 12 is implemented using a Bluetooth module and serves to exchange information with external devices (such as a mobile app, a cloud platform, etc.). External devices issue control commands to remotely control the heating mode of the heating control system. In another embodiment, the communication unit 12 can also be implemented using Wi-Fi.

[0045] The heating control system further comprises a first temperature sensing unit 13 and a second temperature sensing unit 14. The first temperature sensing unit 13 and the second temperature sensing unit 14 are each electrically connected to the control unit 4 and the output terminal of the voltage converter unit 6. The first temperature sensing unit 13 and the second temperature sensing unit 14 use temperature probes and serve to detect the temperature of the food and the interior of the oven body in order to implement temperature protection.

[0046] As in Fig. 2 to Fig. As shown in Figure 5, the input terminal of the voltage converter unit 6 is electrically connected to the two ends of the supply terminal 100. The voltage converter unit 6 comprises a first voltage terminal (12 VDC), a second voltage terminal (5 VDC), a third voltage terminal (3.3 VDC), and a fourth voltage terminal (5 VDC).

[0047] The first voltage connection (12 VDC) of the voltage converter unit 6 supplies power to the relay driver unit 9. The second voltage connection (5 VDC) of the voltage converter unit 6 supplies power to the optocoupler driver module 31, the current sensing unit 11, the zero-point sensing module 21, the signal shaping module 22, the input unit 5, the communication unit 12, the first temperature sensing unit 13, the second temperature sensing unit 14, and the control unit 4. The third voltage connection (3.3 VDC) supplies power to the communication unit 12. The fourth voltage connection (5 VDC) supplies power to the optocoupler driver module 31, the zero-point trip module 32, and the filter module 33.

[0048] As in Fig.As shown in Figure 6, the present utility model further provides an oven comprising a main body 200 and the described heating control system. The first heating element 7 uses a carbon fiber heating element. The surface of the carbon fiber heating element has an aluminum oxide coating. The aluminum oxide coating serves to protect and improve infrared radiation, and the use of the carbon fiber heating element, in combination with the heating control system of the present application, enables more precise temperature control.

[0049] In the present embodiment, silicone sleeves 15 are installed at both ends of the first heating element 7. During installation, a protective mesh cover 16 is installed outside the first heating element 7 to reduce impacts during transport and prevent damage.

[0050] The above description does not constitute a limitation of the present utility model, and the present utility model is not limited to the examples mentioned above. Changes, modifications, additions, or replacements made by a person skilled in the art within the essential content of the present utility model should also be included in the scope of protection of the present utility model.

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