A multi-voltage input compatible home appliance control circuit and control method

Abstract

The application relates to a multi-voltage input compatible household appliance control circuit, which comprises a voltage detection module, a zero-crossing detection module and a control module; the voltage detection module comprises a rectifier circuit, a voltage dividing circuit and an analog-digital conversion circuit connected in sequence, and is used for converting input commercial alternating voltage into a digital AD value; the zero-crossing detection module comprises an optical coupling isolator and a comparator, and is used for detecting a commercial zero-crossing point and obtaining a power supply frequency; the control module is a single-chip microcomputer or a special integrated circuit, and is electrically connected with the voltage detection module and the zero-crossing detection module; and the switching device is connected with a PWM output port of the control module, and is used for adjusting load power.

Description

Technical Field

[0001] This application relates to the field of home appliance control technology, specifically to a home appliance control circuit and control method compatible with multiple voltage inputs. Background Technology

[0002] With the increasing global demand for home appliances, control circuits that are compatible with different input voltages (such as 110V / 220V) have become a key technology.

[0003] In existing solutions, mechanical voltage switching relies on physical switching, which has problems such as large size and low reliability; while wide voltage rectifier circuits can adapt to a wider range of voltages, but because they do not incorporate dynamic power regulation, the load power fluctuates with the voltage, affecting the performance of home appliances. Summary of the Invention

[0004] To address the aforementioned problems, this application provides a home appliance control circuit compatible with multiple voltage inputs, comprising:

[0005] The voltage detection module includes a rectifier circuit, a voltage divider circuit, and an analog-to-digital converter circuit connected in sequence, which are used to convert the input AC mains voltage into a digital AD value;

[0006] The zero-crossing detection module, including an optocoupler and a comparator, is used to detect the zero-crossing point of the mains power and obtain the power supply frequency;

[0007] The control module, which is a microcontroller or a dedicated integrated circuit, is electrically connected to the voltage detection module and the zero-crossing detection module;

[0008] A switching device, connected to the PWM output port of the control module, is used to regulate the load power.

[0009] Optionally, the control module is configured to:

[0010] Calculate the voltage coefficient i based on the AD value corresponding to the standard voltage and the AD value of the actual detected voltage;

[0011] Based on the voltage coefficient i and the preset duty cycle D, the corrected duty cycle Dcon = D × i + D1 is generated, where D1 is the compensation coefficient;

[0012] By controlling the on-time of the switching device through the modified duty cycle, the load can maintain the same power output under different input voltages.

[0013] Optionally, the calculation formula for the voltage coefficient i is executed by the arithmetic unit of the control module: i = (Urea) 2 / Ustd 2 ), where Ustd is the standard voltage and Urea is the actual detection voltage.

[0014] Optionally, the switching device is a thyristor or IGBT, and the control module adjusts the conduction time by the duty cycle of the PWM signal. In the drop-out or chopping mode, the conduction time per cycle is proportional to the corrected duty cycle.

[0015] On the other hand, this application also provides a home appliance control method applicable to multi-voltage mains power supply, suitable for the home appliance control circuit of the above embodiments, including the following steps:

[0016] (a) Obtain the AD value (Vad_rea) of the current mains power supply voltage through the voltage detection circuit and obtain the frequency value F1 through the zero-crossing detection circuit;

[0017] (b) Calculate the voltage coefficient i based on the preset standard voltage value (Ustd) and its corresponding AD value (Vad_std) and standard power (Pstd), where i = (Vad_std²) / (Vad_rea²);

[0018] (c) Based on the voltage coefficient i and the preset load duty cycle D, dynamically adjust the actual load duty cycle to D×i+D1, where D1 is the compensation coefficient determined according to the frequency F1.

[0019] (d) The load is switched on and off by a switch with an adjusted duty cycle to achieve matching of output power with standard power Pstd.

[0020] Optionally, in step (a), the zero-crossing point of the mains power is detected by the zero-crossing detection circuit, the voltage AD value Vad_rea is obtained by the AD sampling circuit, and the frequency F1 is calculated by the frequency detection algorithm.

[0021] Optionally, in step (c), the compensation coefficient D1 is dynamically adjusted according to the deviation between frequency F1 and the preset standard frequency to compensate for the differences in load response at different frequencies.

[0022] Optionally, the switch is a thyristor or IGBT, and the duty cycle is adjusted by a drop-out control or a chopping control method.

[0023] Optionally, the standard voltage Ustd is 110V. When the mains voltage is detected to be 220V, the voltage coefficient i = 1 / 4 and the load duty cycle is adjusted to D / 4 to keep the output power consistent with the 110V standard voltage.

[0024] Optionally, the compensation coefficient D1 is pre-stored in the control unit to adapt to the load characteristics at different frequencies.

[0025] By employing the above-mentioned technical means, it achieves the following beneficial effects:

[0026] This invention significantly improves the power stability of home appliances under different input voltages by integrating a control circuit for voltage detection, frequency compensation, and duty cycle correction. It achieves this by real-time acquisition of the mains voltage and calculation of the voltage coefficient (i=Ustd). 2 / Urea 2 This technology combines a preset duty cycle to generate a corrected duty cycle (Dcon=D×i+D1), dynamically adjusting the load power and solving the problem of significant power reduction caused by voltage fluctuations in traditional solutions (such as the defect of only 25% power at 110V AC). This technology eliminates the need for mechanical switching or independent adjustment modules, reducing hardware complexity and cost. Simultaneously, it achieves electrical isolation between the high-voltage and low-voltage sides through optocoupler isolators, improving system safety.

[0027] Furthermore, this invention combines a zero-crossing detection module to obtain the power supply frequency and determines the compensation coefficient D1 using a lookup table method or linear interpolation method, further optimizing the duty cycle correction accuracy and adapting to fluctuations in power grid frequencies (50Hz / 60Hz) in different regions. This solution not only supports wide voltage input (e.g., 90V-260V AC) but also enables intelligent control via a microcontroller or ASIC, reducing the need for manual intervention. In practical applications, this circuit can be widely used in home appliances with high power stability requirements, such as rice cookers and electric water heaters, extending equipment lifespan and improving user experience, providing reliable technical support for the intelligent development of home appliances. Attached Figure Description

[0028] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0029] Figure 1 A schematic diagram of a home appliance control circuit structure compatible with multiple voltage inputs is provided as an exemplary embodiment of the present invention;

[0030] Figure 2 A schematic diagram of the voltage detection module circuit connection provided in an exemplary embodiment of the present invention;

[0031] Figure 3 A schematic diagram of the circuit connection of the zero-crossing detection module provided in an exemplary embodiment of the present invention;

[0032] Figure 4 A schematic diagram of the circuit connection of the control module and the switching device provided for an exemplary embodiment of the present invention;

[0033] Figure 5 A schematic diagram of wave dropping and chopping provided for an exemplary embodiment of the present invention;

[0034] Figure 6 A flowchart illustrating a home appliance control method applicable to multi-voltage mains power supply, provided as an exemplary embodiment of the present invention. Detailed Implementation

[0035] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0036] like Figure 1 As shown, this embodiment provides a home appliance control circuit compatible with multiple voltage inputs, including: a voltage detection module, a zero-crossing detection module, a control module, and a switching device. The voltage detection module includes a rectifier circuit, a voltage divider circuit, and an analog-to-digital converter circuit connected in sequence, used to convert the input AC mains voltage into a digital AD value; the zero-crossing detection module includes an optocoupler and a comparator, used to detect the zero-crossing point of the mains voltage and obtain the power supply frequency; the control module is a microcontroller or a dedicated integrated circuit, electrically connected to the voltage detection module and the zero-crossing detection module; the switching device is connected to the PWM output port of the control module, used to adjust the load power.

[0037] Among them, such as Figure 2 The diagram shows a schematic of the voltage detection module circuit connection provided in an exemplary embodiment of this application. AC mains power is supplied from the AC input terminal. Diodes D1 and D2 are connected in reverse parallel to the AC input terminal for bidirectional rectification of the mains power. The rectified current flows through resistor R1 for current limiting, and then sequentially through resistors R2 and R3 for voltage division, reducing the voltage to a range suitable for AD sampling. After R3, the current splits into two paths: one path passes through resistor R4 to ground, and the other path connects to capacitor C1 to ground, forming an RC filter circuit to filter out high-frequency interference. The filtered signal is output as a sampling voltage Vad through resistor R5. This achieves the functions of rectifying, dividing, filtering, and sampling the mains voltage.

[0038] like Figure 3 The diagram shown is a schematic of the zero-crossing detection module circuit connection provided in an exemplary embodiment of this application. AC mains power is input from the ACL terminal and flows sequentially through resistors R6, R7, R9, and R8. Resistor R8 and capacitor C1 are connected in parallel to ground. Resistor R8, after voltage division, is connected in series with R10 in the circuit and connected to the ZERO_IN terminal. Resistors R6, R7, R9, R8, and capacitor C1 form a voltage divider and filter network used to extract the AC mains zero-crossing signal. Resistors R8 and R10 are used to match the impedance of subsequent circuits. The ZERO_IN terminal outputs the zero-crossing detection signal, thus realizing the function of AC mains zero-crossing detection and signal output.

[0039] like Figure 4The diagram shown is a schematic diagram of the circuit connection between the control module and the switching device provided in an exemplary embodiment of this application. AC mains power is connected from the AC terminal, passes through the load, and is connected to the switch. The other end of the switch is connected to a PWM signal. The PWM signal regulates the power of the load by controlling the on-time of the switch.

[0040] The voltage detection module acquires the sampled value of the mains voltage, and the zero-crossing detection module outputs the zero-crossing detection signal. The two signals are fed back to the control module. The control module calculates the voltage coefficient i and the corrected duty cycle Dcon based on this information, and then adjusts the conduction time of the switch through the PWM signal to achieve precise control of the load power, so that the load maintains the same power output under different input voltages.

[0041] For example, the switching device is a thyristor or IGBT, the control module is a microcontroller or a dedicated integrated circuit, the control module adjusts the conduction time by the duty cycle of the PWM signal, and in the drop-out or chopping mode, the conduction time per cycle is proportional to the corrected duty cycle.

[0042] like Figure 5 and Figure 6 As shown, this application also provides a home appliance control method suitable for multi-voltage mains power supply, applicable to the home appliance control circuit of the above embodiments, including the following steps:

[0043] Step (a): After the product is powered on, the voltage detection circuit starts to work, converting the AC mains power into a digital AD value (Vad_rea). At the same time, the zero-crossing detection circuit detects the zero-crossing point of the mains power, and obtains the voltage AD value Vad_rea by combining with the AD sampling circuit, and calculates the frequency F1 by the frequency detection algorithm.

[0044] Step (b): The control module calculates the voltage coefficient i based on the preset standard voltage value (Ustd) and its corresponding AD value (Vad_std) and standard power (Pstd), where i = (Vad_std) / (Ustd) / (Vad_std) / (Pstd). 2 ) / (Vad_rea 2 This coefficient is used to determine the degree of difference between the actual mains voltage and the standard voltage.

[0045] Step (c): The control module dynamically adjusts the actual load duty cycle to D×i + D1 based on the voltage coefficient i and the preset load duty cycle D. Here, D1 is a compensation coefficient, dynamically adjusted according to the deviation between frequency F1 and the preset standard frequency to compensate for differences in load response at different frequencies and ensure the stability of load power.

[0046] Step (d): The control module uses a PWM signal to control the conduction time of the switching device with an adjusted duty cycle, ensuring that the load maintains the same power output under different input voltages, thus matching the output power with the standard power Pstd. For example, the switch is a thyristor or IGBT, and duty cycle adjustment is achieved using drop-out control or chopping control.

[0047] For example, this application's solution will be further explained in detail using a household appliance compatible with both 110V and 220V AC mains power. The product's standard voltage is 110V / 50Hz, it operates with a 100% duty cycle, its standard power is P1, and its load resistance is R. When the input AC mains voltage is detected to be 220V / 50Hz, the voltage detection circuit converts it into the corresponding AD value Vad_rea. The control module calculates the voltage coefficient i = (110V / 50Hz / 220V ... 2 ) / (220 2 The duty cycle is set to D / 4, meaning it operates with a 1 / 4 duty cycle to ensure the load power matches the standard 110V voltage. Under the control of the PWM signal from the control module, the switching devices conduct with the adjusted duty cycle, achieving precise control of the load power.

[0048] Through the above control circuit and method, this application realizes stable power output of home appliances under different mains voltages, reduces hardware costs, improves the market competitiveness of products, and enhances the safety and reliability of the system.

[0049] Other embodiments of this application will readily conceive of by those skilled in the art upon consideration of the specification and practice of the technical solutions disclosed herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein. The specification and embodiments are to be considered exemplary only, and the true scope and spirit of this application are indicated by the following claims.

[0050] It should be understood that this application is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this application is limited only by the appended claims.

Claims

1. A home appliance control circuit compatible with multiple voltage inputs, characterized in that, include: The voltage detection module includes a rectifier circuit, a voltage divider circuit, and an analog-to-digital converter circuit connected in sequence, which are used to convert the input AC mains voltage into a digital AD value; The zero-crossing detection module, including an optocoupler and a comparator, is used to detect the zero-crossing point of the mains power and obtain the power supply frequency; The control module is electrically connected to the voltage detection module and the zero-crossing detection module; A switching device, connected to the PWM output port of the control module, is used to regulate the load power.

2. The control circuit according to claim 1, characterized in that, The control module is configured as follows: Calculate the voltage coefficient i based on the AD value corresponding to the standard voltage and the AD value of the actual detected voltage; Based on the voltage coefficient i and the preset duty cycle D, the corrected duty cycle Dcon = D × i + D1 is generated, where D1 is the compensation coefficient; By controlling the on-time of the switching device through the modified duty cycle, the load can maintain the same power output under different input voltages.

3. The control circuit according to claim 2, characterized in that, The formula for calculating the voltage coefficient i is executed by the arithmetic unit of the control module: i = (Urea) 2 / Ustd 2 ), where Ustd is the standard voltage and Urea is the actual detection voltage.

4. The control circuit according to claim 3, characterized in that, The switching device is a thyristor or IGBT, and the control module is a microcontroller or a dedicated integrated circuit. The conduction time is adjusted by the duty cycle of the PWM signal, and in the drop-out or chopping mode, the conduction time per cycle is proportional to the corrected duty cycle.

5. A method for controlling household appliances suitable for multi-voltage mains power supply, characterized in that, Includes the following steps: (a) Obtain the AD value (Vad_rea) of the current mains power supply voltage through the voltage detection circuit and obtain the frequency value F1 through the zero-crossing detection circuit; (b) Calculate the voltage coefficient i based on the preset standard voltage value (Ustd) and its corresponding AD value (Vad_std) and standard power (Pstd), where i = (Vad_std²) / (Vad_rea²); (c) Based on the voltage coefficient i and the preset load duty cycle D, the actual load duty cycle is dynamically adjusted to D×i +D1, where D1 is the compensation coefficient determined according to the frequency F1; (d) The load is switched on and off by a switch with an adjusted duty cycle to achieve matching of output power with standard power Pstd.

6. The method according to claim 5, characterized in that, In step (a), the zero-crossing point of the mains power is detected by the zero-crossing detection circuit, the voltage AD value Vad_rea is obtained by the AD sampling circuit, and the frequency F1 is calculated by the frequency detection algorithm.

7. The method according to claim 5, characterized in that, In step (c), the compensation coefficient D1 is dynamically adjusted according to the deviation between frequency F1 and the preset standard frequency in order to compensate for the difference in load response at different frequencies.

8. The method according to claim 5, characterized in that, The switch is a thyristor or IGBT, and the duty cycle is adjusted by wave dropping control or chopping control.

9. The method according to claim 5, characterized in that, The standard voltage Ustd is 110V. When the mains voltage is detected to be 220V, the voltage coefficient i = 1 / 4 and the load duty cycle is adjusted to D / 4 to keep the output power consistent with the 110V standard voltage.

10. The method according to claim 5, characterized in that, The compensation coefficient D1 is pre-stored in the control unit to adapt to the load characteristics at different frequencies.

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