Control circuit of wide-voltage hair dryer

Abstract

The utility model discloses a control circuit of a wide-voltage hair dryer, which is characterized by comprising a power input circuit, a main control circuit, a mains supply zero-cross detection circuit, a voltage detection circuit, a heating drive circuit and an inverter drive circuit, the power supply input circuit is respectively connected with the mains supply zero-cross detection circuit and the voltage detection circuit, the mains supply zero-cross detection circuit and the voltage detection circuit are respectively connected with the main control circuit, the main control circuit is connected with the heating driving circuit, the inversion driving circuit is connected with the main control circuit, and the main control circuit is connected with the power supply input circuit. By the adoption of the design, the heating drive circuit is combined with the voltage detection circuit, two control modes are provided so as to meet the use requirements in different voltage environments, the power output in the low-voltage environment is close to the power output in the high-voltage environment, the power output in the high-voltage environment is close to the power output in the high-voltage environment, and the power output in the high-voltage environment is close to the power output in the high-voltage environment. And the use experience in a low-voltage environment is improved, so that the practicability of the product is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of hair dryers, in particular to a control circuit of a wide-voltage hair dryer. Background Art

[0002] At present, the standard voltage of domestic electrical appliances is 220V, so most electrical appliances are designed according to the standard voltage circuit, such as hair dryers. However, in the actual environment, the voltage in each region will be different. For example, in some rural areas, since they are self-built houses, they will install the circuits themselves for cost considerations and the standards for wires will be lowered. At this time, once there are more electrical appliances in the home, it will cause low voltage. In this case, when a hair dryer designed for standard voltage is used, due to the low voltage, the hair dryer may not be used normally or the use effect of the hair dryer will deteriorate, such as reduced air volume, low heating temperature, etc.

[0003] Therefore, it is urgent to design a control circuit for a wide-voltage hair dryer to overcome one or more of the above-mentioned deficiencies of the prior art. Summary of the invention

[0004] The technical solution adopted by the utility model to solve the above technical problems is: a control circuit of a wide-voltage hair dryer, characterized in that it includes: a power input circuit, a main control circuit, a mains zero-crossing detection circuit, a voltage detection circuit, a heating drive circuit, and an inverter drive circuit; the power input circuit is respectively connected to the mains zero-crossing detection circuit and the voltage detection circuit, the mains zero-crossing detection circuit and the voltage detection circuit are respectively connected to the main control circuit, the main control circuit is connected to the heating drive circuit, the inverter drive circuit is connected to the main control circuit, the inverter drive circuit is also connected to an electrical appliance, and the main control circuit is an MCU chip.

[0005] In a preferred embodiment, the voltage detection circuit includes: a resistor R7, a resistor R8, a resistor R12, and a capacitor C8, the resistor R7, the resistor R8, and the resistor R12 are connected in series in sequence, the capacitor C8 is connected in parallel with the resistor R12, and the capacitor C8 is connected to pin 3 of the main control circuit.

[0006] In a preferred embodiment, the AC power zero-crossing detection circuit includes: a resistor R10, a resistor R11, a resistor R30, an optical coupler U3, a capacitor C9, a capacitor C7, and a resistor R9; the resistor R10 is connected to the live wire AC-L, the resistor R30 and the resistor R11 are connected in series, and the resistor R30 is connected to the neutral wire AC-N, the resistor R10 and the resistor R11 are connected to the optical coupler U3, the output end of the optical coupler U3 is connected to the capacitor C9, the capacitor C9 and the resistor R9 are connected to the ZERO pin of the main control circuit, and the resistor R9 is connected in series with the capacitor C7.

[0007] In a preferred embodiment, the heating drive circuit includes: a resistor R32, a resistor R42, an optocoupler U6, an optocoupler U7, an optocoupler isolation drive TR1, an optocoupler isolation drive TR2, a resistor R35, a resistor R43, a resistor R29, and a resistor R40; the resistor R32 is connected to the HEAT1 pin of the main control circuit, the optocoupler U6 is connected to the resistor R32, the resistor R29 is connected to the optocoupler U6, the optocoupler isolation drive TR1 is connected to the optocoupler U6, the resistor R35 is connected to the optocoupler isolation drive TR1, and is connected to the heating device T1; the resistor R42 is connected to the HEAT2 pin of the main control circuit, the optocoupler U7 is connected to the resistor R42, the resistor R40 and the optocoupler isolation drive TR2 are respectively connected to the optocoupler U7, the resistor R43 is connected to the optocoupler isolation drive TR2, and is connected to the heating device T2; the resistor R29, the optocoupler isolation drive TR1, the optocoupler isolation drive TR2 and the resistor R40 are connected to the live wire AC-L in the same line.

[0008] In a preferred embodiment, the power input circuit includes: an electromagnetic interference protection circuit, a rectifier and filter circuit, and a step-down circuit; the battery interference protection circuit is connected to the rectifier and filter circuit, the step-down circuit is connected to the rectifier and filter circuit, the main control circuit is connected to the step-down circuit, the electromagnetic interference protection circuit is also connected to the AC power zero-crossing detection circuit, the heating drive circuit is also connected to the electromagnetic interference protection circuit, the voltage detection circuit is connected to the rectifier and filter circuit, and the rectifier and filter circuit is also connected to the inverter drive circuit.

[0009] In a preferred embodiment, the heating drive circuit is further connected to an NTC temperature measuring circuit, and the NTC temperature measuring circuit is connected to the main control circuit.

[0010] The beneficial effect of the utility model is that two control modes are provided by combining the heating drive circuit with the voltage detection circuit to adapt to the usage requirements in different voltage environments, and the power output in the low voltage environment is close to that in the high voltage environment, thereby improving the user experience in the low voltage environment and thus improving the practicality of the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 This is a principle block diagram of the utility model;

[0012] Figure 2 The circuit diagram of the power input circuit of the utility model;

[0013] Figure 3 It is a circuit diagram of the voltage detection circuit of the utility model;

[0014] Figure 4 It is a circuit diagram of the utility model of the mains zero-crossing detection circuit;

[0015] Figure 5 This is a circuit diagram of the heating drive circuit of the utility model;

[0016] Figure 6 The circuit diagram of the inverter drive circuit of the utility model;

[0017] Figure 7 The circuit diagram of the NTC temperature measuring circuit of the utility model;

[0018] Figure 8 This is a circuit diagram of the main control circuit of the utility model.

[0019] In the figure:

[0020] 10. Power input circuit; 11. Electromagnetic interference protection circuit; 12. Rectification and filtering circuit; 13. Buck circuit; 14. Main control circuit; 15. Mains zero-crossing detection circuit; 16. Voltage detection circuit; 17. Heating drive circuit; 18. Heating device; 19. NTC temperature measurement circuit; 20. Inverter drive circuit. DETAILED DESCRIPTION

[0021] In order to make the above-mentioned purposes, features and advantages of the utility model more obvious and easy to understand, the specific implementation methods of the utility model are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the utility model. However, the utility model can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the utility model, so the utility model is not limited by the specific embodiments disclosed below.

[0022] In the description of the embodiments of the present utility model, it should be noted that, unless otherwise clearly specified and limited, the terms, "connection" and "installation" should be understood in a broad sense. For example, "connection" can be a detachable connection or a non-detachable connection; it can be a direct connection or an indirect connection through an intermediate medium. In addition, "connection" can be a direct connection or an indirect connection through an intermediate medium. Among them, "fixed" means that they are connected to each other and the relative position relationship after connection remains unchanged. The directional terms mentioned in the embodiments of the present utility model, such as "inside", "outside", "top", "bottom", etc., are only reference to the directions of the accompanying drawings. Therefore, the directional terms used are for better and clearer explanation and understanding of the embodiments of the present utility model, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the embodiments of the present utility model.

[0023] In the embodiments of the present invention, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features.

[0024] In the embodiment of the present invention, "and / or" is only a description of the association relationship of the associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0025] References to "one embodiment" or "some embodiments" etc. described in this specification mean that one or more embodiments of the utility model include specific features, structures or characteristics described in conjunction with the embodiment. Therefore, the statements "in one embodiment", "in some embodiments", "in some other embodiments", "in some other embodiments", etc. that appear in different places in this specification do not necessarily refer to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized in other ways. The terms "including", "comprising", "having" and their variations all mean "including but not limited to", unless otherwise specifically emphasized in other ways. Therefore, the utility model is not limited to the specific embodiments disclosed below.

[0026] like Figure 1-Figure 8 As shown, the utility model provides a control circuit of a wide-voltage hair dryer, characterized in that it includes: a power input circuit 10, a main control circuit 14, a mains zero-crossing detection circuit 15, a voltage detection circuit 16, a heating drive circuit 17, and an inverter drive circuit 20; the power input circuit 10 is connected to the mains zero-crossing detection circuit 15 and the voltage detection circuit 16 respectively, the mains zero-crossing detection circuit 15 and the voltage detection circuit 16 are connected to the main control circuit 14 respectively, the main control circuit 14 is connected to the heating drive circuit 17, the inverter drive circuit 20 is connected to the main control circuit 14, the inverter drive circuit 20 is also connected to an electrical appliance, and the main control circuit 14 is an MCU chip;

[0027] Specifically, the power input circuit 10 is connected to the mains power, which is provided to the main control circuit 14 after rectification and voltage reduction to supply power to the main control circuit 14. The mains power zero-crossing detection circuit 15 is used to detect the moment when the voltage changes from positive to negative or from negative to positive, and transmits the detection signal to the main control circuit 14. The voltage detection circuit 16 is used to detect the voltage of the mains power. The heating drive circuit 17 is divided into two paths, which are connected to two heating devices 18. The main control circuit 14 reads the detection signal of the voltage detection circuit 16, and controls the two heating drive circuits 17 to work according to the signal of the mains power zero-crossing detection circuit 15. If the mains voltage is 120V, the main control circuit 14 controls the two heating drive circuits 17 to drive the two heating devices 18 to work at the same time. If the mains voltage is 230V, the main control circuit 14 controls the two heating drive circuits 17 to drive the two heating devices 18 to work in time-sharing manner. This control makes the power of the hair dryer similar under the environment of 120V voltage or 230V voltage.

[0028] Further, the voltage detection circuit 16 includes: a resistor R7, a resistor R8, a resistor R12, and a capacitor C8, wherein the resistor R7, the resistor R8, and the resistor R12 are connected in series in sequence, the capacitor C8 is connected in parallel with the resistor R12, and the capacitor C8 is connected to pin 3 of the main control circuit 14;

[0029] Specifically, the AC input is rectified by the power input circuit 10 to obtain a DC voltage, which is then divided by resistors R7, R8, and R12, then filtered by capacitor C8, and finally output to the ADC detection port of the main control circuit 14 to detect the AC voltage. The main control circuit 14 performs corresponding control based on the detected voltage value.

[0030] Further, in the present embodiment, the mains zero-crossing detection circuit 15 includes: a resistor R10, a resistor R11, a resistor R30, an optical coupler U3, a capacitor C9, a capacitor C7, and a resistor R9; the resistor R10 is connected to the live wire AC-L, the resistor R30 and the resistor R11 are connected in series, and the resistor R30 is connected to the neutral wire AC-N, the resistor R10 and the resistor R11 are connected to the optical coupler U3, the output end of the optical coupler U3 is connected to the capacitor C9, the capacitor C9 and the resistor R9 are connected to the ZERO pin of the main control circuit 14, and the resistor R9 is connected in series with the capacitor C7;

[0031] Specifically, resistors R10, R11, and R30 limit the flow of AC power, which is then isolated by optocoupler U3 and filtered by capacitor C9 to obtain an AC zero-crossing signal that is transmitted to the zero-crossing detection port of the main control circuit 14. The main control circuit 14 controls the operation of the heating device 18 based on the zero-crossing detection signal.

[0032] Further, in the present embodiment, the heating drive circuit 17 includes: a resistor R32, a resistor R42, an optocoupler U6, an optocoupler U7, a bidirectional trigger diode TR1, a bidirectional trigger diode TR2, a resistor R35, a resistor R43, a resistor R29, and a resistor R40; the resistor R32 is connected to the HEAT1 pin of the main control circuit 14, the optocoupler U6 is connected to the resistor R32, the resistor R29 is connected to the optocoupler U6, the bidirectional trigger diode TR1 is connected to the optocoupler U6, the resistor R35 is connected to the bidirectional trigger diode TR1, and is connected to the heating device T1; the resistor R42 is connected to the HEAT2 pin of the main control circuit 14, the optocoupler U7 is connected to the resistor R42, the resistor R40 and the bidirectional trigger diode TR2 are respectively connected to the optocoupler U7, the resistor R43 is connected to the bidirectional trigger diode TR2, and is connected to the heating device T2; the resistor R29, the bidirectional trigger diode TR1, the bidirectional trigger diode TR2 and the resistor R40 are connected to the live wire AC-L in the same line;

[0033] Specifically, the heating drive circuit 17 is divided into two paths, which are respectively connected to the two heating devices 18. The main control circuit 14 outputs a heating signal which is isolated by the optocouplers U6 and U7, and then drives the bidirectional trigger diode to control the two heating devices 18T1 and T2 to work simultaneously or in time-sharing.

[0034] Further, in the present embodiment, the power input circuit 10 includes: an electromagnetic interference prevention circuit 11, a rectifier and filter circuit 12, and a buck circuit 13; the battery interference prevention circuit is connected to the rectifier and filter circuit 12, the buck circuit 13 is connected to the rectifier and filter circuit 12, the main control circuit 14 is connected to the buck circuit 13, the electromagnetic interference prevention circuit 11 is also connected to the mains zero-crossing detection circuit 15, the heating drive circuit 17 is also connected to the electromagnetic interference prevention circuit 11, the voltage detection circuit 16 is connected to the rectifier and filter circuit 12, and the rectifier and filter circuit 12 is also connected to the inverter drive circuit 20;

[0035] Specifically, the electromagnetic interference protection circuit 11 is used to prevent electromagnetic interference, the rectifier and filter circuit 12 is used to rectify and filter the input AC power to obtain direct current, and the step-down circuit 13 is used to reduce the AC power voltage to the operating voltage value of the main control circuit 14. Among them, the electromagnetic interference protection circuit 11, the rectifier and filter circuit 12, and the step-down circuit 13 are the same as the circuits of common single-voltage brushless hair dryers, so they are not elaborated here.

[0036] Furthermore, in this embodiment, the heating drive circuit 17 is also connected to an NTC temperature measuring circuit 19, and the NTC temperature measuring circuit 19 is connected to the main control circuit 14;

[0037] Specifically, the heating drive circuit 17 is also connected to an NTC temperature measuring circuit 19 for detecting the operating temperature of the heating device 18 and also for overheating protection.

[0038] To summarize, the present application provides two control methods by combining the heating drive circuit 17 with the voltage detection circuit 16 to adapt to the usage requirements in different voltage environments, and the power output in the low voltage environment is close to that in the high voltage environment, thereby improving the user experience in the low voltage environment and thus improving the practicality of the product.

[0039] The present invention is not limited to what is described in the specification and implementation modes, and therefore, additional advantages and modifications can be easily realized by those familiar with the art. Therefore, without departing from the spirit and scope of the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details, representative devices, and illustrative examples shown and described herein.

Claims

1. A control circuit for a wide voltage hair dryer. It is characterized in that include: Power input circuit, main control circuit, mains zero-crossing detection circuit, voltage detection circuit, heating drive circuit, inverter drive circuit; The power input circuit is connected to the mains zero-crossing detection circuit and the voltage detection circuit respectively, the mains zero-crossing detection circuit and the voltage detection circuit are connected to the main control circuit respectively, the main control circuit is connected to the heating drive circuit, the inverter drive circuit is connected to the main control circuit, the inverter drive circuit is also connected to the electrical appliance, and the main control circuit is an MCU chip.

2. The control circuit of the wide voltage hair dryer according to claim 1, It is characterized in that The voltage detection circuit includes: a resistor R7, a resistor R8, a resistor R12, and a capacitor C8. The resistor R7, the resistor R8, and the resistor R12 are connected in series in sequence. The capacitor C8 is connected in parallel with the resistor R12. The capacitor C8 is connected to pin 3 of the main control circuit.

3. The control circuit of the wide voltage hair dryer according to claim 1, It is characterized in that The mains zero-crossing detection circuit includes: a resistor R10, a resistor R11, a resistor R30, an optical coupler U3, a capacitor C9, a capacitor C7, and a resistor R9; the resistor R10 is connected to the live wire AC-L, the resistor R30 and the resistor R11 are connected in series, and the resistor R30 is connected to the neutral wire AC-N, the resistor R10 and the resistor R11 are connected to the optical coupler U3, the output end of the optical coupler U3 is connected to the capacitor C9, the capacitor C9 and the resistor R9 are connected to the ZERO pin of the main control circuit, and the resistor R9 is connected in series with the capacitor C7.

4. The control circuit of the wide voltage hair dryer according to claim 1, It is characterized in that The heating drive circuit includes: a resistor R32, a resistor R42, an optocoupler U6, an optocoupler U7, an optocoupler isolation drive TR1, an optocoupler isolation drive TR2, a resistor R35, a resistor R43, a resistor R29, and a resistor R40; the resistor R32 is connected to the HEAT1 pin of the main control circuit, the optocoupler U6 is connected to the resistor R32, the resistor R29 is connected to the optocoupler U6, the optocoupler isolation drive TR1 is connected to the optocoupler U6, the resistor R35 is connected to the optocoupler isolation drive TR1, and is connected to the heating device T1; the resistor R42 is connected to the HEAT2 pin of the main control circuit, the optocoupler U7 is connected to the resistor R42, the resistor R40 and the optocoupler isolation drive TR2 are respectively connected to the optocoupler U7, the resistor R43 is connected to the optocoupler isolation drive TR2, and is connected to the heating device T2; the resistor R29, the optocoupler isolation drive TR1, the optocoupler isolation drive TR2 and the resistor R40 are connected to the live wire AC-L in a common line.

5. The control circuit of the wide voltage hair dryer according to claim 1, It is characterized in that The power input circuit includes: an electromagnetic interference protection circuit, a rectifier and filter circuit, and a step-down circuit; the electromagnetic interference protection circuit is connected to the rectifier and filter circuit, the step-down circuit is connected to the rectifier and filter circuit, the main control circuit is connected to the step-down circuit, the electromagnetic interference protection circuit is also connected to the AC power zero-crossing detection circuit, the heating drive circuit is also connected to the electromagnetic interference protection circuit, the voltage detection circuit is connected to the rectifier and filter circuit, and the rectifier and filter circuit is also connected to the inverter drive circuit.

6. The control circuit of the wide voltage hair dryer according to claim 1, It is characterized in that The heating drive circuit is also connected to an NTC temperature measuring circuit, and the NTC temperature measuring circuit is connected to the main control circuit.

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