Air duct double-voltage heating wire control circuit

Abstract

The utility model discloses a double-voltage heating wire control circuit of an air duct. The double-voltage heating wire control circuit comprises a power supply circuit, a main control circuit, a first heating wire control circuit, a second heating wire control circuit, a third heating wire control circuit, a fourth heating wire control circuit and a motor control circuit. And the first, second, third and fourth heating wire control circuits and the motor control circuit are electrically connected to the main control circuit. In different countries, the alternating voltage which can be input by the power supply circuit ranges from 100 V to 240 V, the main control circuit controls the first heating wire, the second heating wire, the third heating wire and the fourth heating wire to heat according to different input voltages, the heating wires are resistive loads, and power calculation is mainly determined according to the voltages and the resistance of the heating wires. The heating wires are controlled by the main control circuit to independently heat or heat in a combined manner; by controlling different heating wires, the output power of the heating wires in the heating load circuit is controlled under the condition of two different external voltages, so that the practical value is met.

Description

Technical Field

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

[0002] With the improvement of people's living standards, hair dryers have become widely used. After washing hair, people can use hair dryers to quickly dry their hair, which can reduce the time it takes for hair to dry. Hair dryers are also used to assist in hair styling. As a household appliance, hair dryers have greatly facilitated people's lives.

[0003] However, the hair dryer in the related art can only be used with a single voltage. If it is used in other countries, the power of the heating part of the hair dryer will vary greatly due to changes in the mains voltage, and normal heating cannot be guaranteed. Therefore, the hair dryer in the related art has low applicability. Utility Model Content

[0004] In view of this, the present invention aims to address the deficiencies in the prior art, and its main purpose is to provide a hair dryer dual-voltage heating wire control circuit, which ensures normal heating while meeting global voltage applicability, thereby overcoming the shortcomings of the prior art.

[0005] In order to achieve the above purpose, the present invention adopts the following technical solutions:

[0006] A hair dryer dual-voltage heating wire control circuit, comprising a power supply circuit, a main control circuit, a first heating wire control circuit, a second heating wire control circuit, a third heating wire control circuit, a fourth heating wire control circuit, and a motor control circuit;

[0007] The power supply circuit is connected to one end of the first heating wire control circuit, the second heating wire control circuit, the third heating wire control circuit, the fourth heating wire control circuit, and the motor control circuit, and the other ends of the first heating wire control circuit, the second heating wire control circuit, the third heating wire control circuit, the fourth heating wire control circuit, and the motor control circuit are electrically connected to the main control circuit; at the same time, the third heating wire control circuit and the fourth heating wire control circuit are electrically connected to each other, and the third heating wire control circuit and / or the fourth heating wire control circuit are connected to the motor control circuit.

[0008] Compared with the prior art, the present invention has obvious advantages and beneficial effects. Specifically, it can be seen from the above technical solution that the power supply circuit is used to supply power to the hair dryer, which not only supplies power to each heating wire and motor, but also supplies power to each control circuit. In different countries, the AC voltage that can be input to the power supply circuit is between 100-240V. The main control circuit controls the heating of the first heating wire, the second heating wire, the third heating wire, and the fourth heating wire according to the different input voltages. The heating wire is a resistive load, and its power calculation is mainly determined by the voltage and the resistance of the heating wire. The resistance of the first heating wire, the second heating wire, the third heating wire, and the fourth heating wire is the same or different, and each heating wire generates heat individually or in combination under the control of the main control circuit;

[0009] Individual heating means that only one of the first heating wire, the second heating wire, the third heating wire, and the fourth heating wire heats up at a time;

[0010] Combined heating means that two, three or four of the first heating wire, the second heating wire, the third heating wire and the fourth heating wire share heating each time, and the combination types include (A) the first heating wire and the second heating wire heat up; (B) the first heating wire and the third heating wire heat up; (C) the first heating wire and the fourth heating wire heat up; (D) the second heating wire and the third heating wire heat up; (E) the second heating wire and the fourth heating wire heat up; (F) the third heating wire and the fourth heating wire heat up; (G) the first heating wire, the second heating wire and the third heating wire heat up at the same time; (H) the first heating wire, the second heating wire and the fourth heating wire heat up at the same time; (I) the second heating wire, the third heating wire and the fourth heating wire heat up at the same time; (J) the first heating wire, the second heating wire, the third heating wire and the fourth heating wire heat up at the same time, etc., and the combined heating types are no longer listed one by one. In short, the control circuit of the utility model controls the output power of the heating wires in the heating load circuit under two different external voltages by controlling different heating wires, so as to meet the practical value. The chip of the main control circuit adopts a single-line control method and can use two AC voltages.

[0011] In order to more clearly illustrate the structural features and effects of the present invention, the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 This is a block diagram of the entire circuit structure of an embodiment of the present utility model.

[0013] Figure 2 It is a power supply circuit diagram of an embodiment of the present utility model.

[0014] Figure 3 It is a main control circuit diagram of an embodiment of the present utility model.

[0015] Figure 4 This is a diagram of the first heating wire control circuit and the second heating wire control circuit of an embodiment of the present utility model.

[0016] Figure 5 This is a diagram of the third heating wire control circuit, the fourth heating wire control circuit, and the motor control circuit of an embodiment of the present utility model.

[0017] Figure 6 This is a diagram of a voltage detection circuit and a zero-crossing trigger circuit according to an embodiment of the present utility model.

[0018] Figure 7 It is a key circuit diagram of an embodiment of the utility model.

[0019] Figure 8 This is an LED indication circuit diagram of an embodiment of the present utility model.

[0020] Figure 9 This is a temperature detection circuit diagram of an embodiment of the present utility model.

[0021] Figure 10 This is a circuit diagram of an external control device according to an embodiment of the present utility model.

[0022] Description of the accompanying drawings:

[0023] 101. Power supply circuit 1011. 100-240V AC input circuit

[0024] 1012. Rectification and filtering circuit 1013. AC to DC circuit

[0025] 1014, 5V output circuit 102, main control circuit

[0026] 103, first heating wire control circuit 104, second heating wire control circuit

[0027] 105, third heating wire control circuit 106, fourth heating wire control circuit

[0028] 107. Motor control circuit 108. Voltage detection circuit

[0029] 109. Zero-crossing trigger circuit 110. Key circuit

[0030] 111. LED indication circuit 112. Temperature detection circuit. DETAILED DESCRIPTION

[0031] In order to make the technical problems, technical solutions and beneficial effects to be solved by this application more clearly understood, this application is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0032] It should be noted that when an element is referred to as being “fixed on” or “disposed on” another element, it may be directly on the other element or indirectly on the other element. When an element is referred to as being “connected to” another element, it may be directly connected to the other element or indirectly connected to the other element.

[0033] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply 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 this application.

[0034] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. Throughout the description of this application, "plurality" means two or more, unless otherwise specifically defined.

[0035] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention is further described in detail below with reference to the accompanying drawings and embodiments.

[0036] Please refer to Figures 1 to 10 As shown, it shows the specific structure of the preferred embodiment of the present utility model, which is a hair dryer dual-voltage heating wire control circuit, including a power supply circuit 101, a main control circuit 102, a first heating wire control circuit 103, a second heating wire control circuit 104, a third heating wire control circuit 105, a fourth heating wire control circuit 106, and a motor control circuit 107; it also includes a voltage detection circuit 108 and a zero-crossing trigger circuit 109, a button circuit 110, an LED indication circuit 111, and a temperature detection circuit 112.

[0037] Among them, such as Figure 2 As shown, the power supply circuit 101 is used to power the hair dryer, not only for the heating coils and motors, but also for the control circuits. The power supply circuit 101 includes a 100-240V AC input circuit 1011, a rectifier and filter circuit 1012, an AC-to-DC converter 1013, and a 5V output circuit 1014. The 100-240V AC input circuit 1011 is electrically connected to the rectifier and filter circuit 1012, which is electrically connected to the AC-to-DC converter 1013, which is electrically connected to the 5V output circuit 1014.

[0038] The 100-240V AC input circuit 1011 can adapt to input voltages between 100 and 240V when used in different countries, essentially meeting the voltage requirements of all countries. The rectifier and filter circuit 1012 improves electromagnetic compatibility, preventing the power supply circuit 101 from experiencing performance degradation or even damage due to external electromagnetic environments. The AC-to-DC converter 1013 converts the direct current (DC) into DC power suitable for normal use by the circuit board, ultimately generating a stable 5V voltage, which is supplied to the control circuits and other DC loads via the 5V output circuit 1014.

[0039] like Figure 2 As shown, the 100-240V AC input circuit 1011 includes a live wire input terminal AC-L and a neutral wire input terminal AC-N. After the live wire input terminal AC-L and the neutral wire input terminal AC-N input 100-240V AC power from different countries, a power protection circuit is formed by a capacitor C1 connected in parallel between the live wire input terminal AC-L and the neutral wire input terminal AC-N, two diodes D4 and D5 connected in reverse series, and resistors R1 and R2 connected in series. This circuit prevents lightning strikes, overvoltage, interference, and absorbs surge power, thereby protecting the circuit.

[0040] The power supply terminals ACL-1 and ACL-0 are connected to the OFF / ON switch, which controls the power supply on and off. The power supply terminal ACL-1 is located on the live wire input terminal AC-L.

[0041] The rectifier and filter circuit 1012 includes a fuse F1, an adjustable resistor VAR1, a resistor R3, a diode D1, an inductor L1, and an electrolytic capacitor EC2. The power supply terminal ACL-0 is electrically connected to the fuse F1 to ensure safe circuit operation. The other end of the fuse F1 is divided into two paths: one path electrically connected to the adjustable resistor VAR1 and then to the neutral line input terminal AC-N; the other path is connected in series with the resistor R3, the diode D1, and the inductor L1 and then to the AC-DC converter chip pin SW of the AC-DC circuit. The AC-DC converter chip IC1 pin SW is also electrically connected to the electrolytic capacitor EC2 connected to the neutral line input terminal AC-N. The operating principle is that the voltage is rectified and filtered by the fuse F1, adjustable resistor VAR1, resistor R3, diode D1, inductor L1, and electrolytic capacitor EC2 to be used by the AC-DC converter chip IC1.

[0042] The AC-to-DC circuit 1013 includes an AC / DC converter chip IC1. Model number IC / AP8003D, this non-isolated AC / DC converter chip has a fixed 5V output. The AP8003D integrates a PFM controller and a 500V high-reliability MOSFET, making it suitable for low-power, non-isolated switching power supplies with minimal peripheral components. The AP8003D has a built-in 500V high-voltage startup function, enabling rapid system startup and ultra-low standby operation. This AC / DC converter chip IC1 provides comprehensive intelligent protection features, including overload, undervoltage, and overtemperature protection. Furthermore, the AP8003D exhibits excellent EMI characteristics.

[0043] The 5V output circuit 1014 includes a capacitor C3, a diode D2, an inductor L2, an electrolytic capacitor EC1, a resistor R4, and a capacitor C2. Pin VDD of the AC / DC converter chip IC1 is electrically connected to the diode D2 to output a 5V voltage, and pin GND of the AC / DC converter chip IC1 is grounded. The electrolytic capacitor EC1, resistor R4, and capacitor C2 are connected in parallel between pins VDD and GND of the AC / DC converter chip IC1 to form a filter circuit at the 5V output end to output a stable 5V voltage for use by various loads.

[0044] The two pins IGND of the AC-DC converter chip IC1 are electrically connected to one end of the capacitor C3 and the inductor L2 in two ways. The other ends of the capacitor C3 and the inductor L2 are respectively connected to the diode D2, thereby protecting the DC converter chip IC1 and achieving its overload protection, overtemperature protection, and undervoltage protection.

[0045] like Figure 3 As shown, the main control circuit 102 is used to control the hair dryer to achieve various functions. The main control circuit 102 controls different heating wires to heat up individually or simultaneously according to different input voltages detected, and also controls the wind speed of the motor.

[0046] like Figure 3 As shown, the main control circuit 102 includes a control chip U1, a resistor R29, and a capacitor C9. The model of the control chip U1 is BS84C12A, and it has 20 pins, namely: pin CM, pin COM4, ​​pin COM3, pin COM2, pin COM1, pin SEG2, pin SEG1, pin SEG6, pin VSS, pin VDD, pin Triac4, pin NTC, pin Vcheck, pin Triac3, pin Triac2, pin Zero, pin Triac1, pin PA2 SEG5, pin SEG3, pin PA0 SEG4, among which pin PB0 / Key1 is connected in series with resistor R29, pin VSS is grounded, pin VDD is connected to 5V DC, and capacitor C9 is electrically connected between pin VSS and pin VDD to achieve a filtering effect.

[0047] The control chip U1 is BS84C12A, which has an operating voltage of 2.2V to 5.5V and provides up to 12 touch buttons. It can resist interference from various noises, such as power supply noise, RF interference, power supply fluctuations, etc., and has passed the CS dynamic 10V test.

[0048] like Figure 4 As shown, the power supply circuit 101 is connected to one end of the first heating wire control circuit 103, and the other end of the first heating wire control circuit 103 is electrically connected to the main control circuit 102. In addition, the power supply circuit 101 is connected to one end of the second heating wire control circuit 104, and the other end of the second heating wire control circuit 104 is electrically connected to the main control circuit 102.

[0049] like Figure 5 As shown, the power supply circuit 101 is electrically connected to one end of the third heating wire control circuit 105, the fourth heating wire control circuit 106, and the motor control circuit 107, and the other ends of the third heating wire control circuit 105 and the fourth heating wire control circuit 106 are electrically connected to the main control circuit 102 respectively; at the same time, the third heating wire control circuit 105 and the fourth heating wire control circuit 106 are electrically connected to each other, and connected to the motor control circuit 107.

[0050] During operation, the power supply circuit 101 supplies power to the first heating wire control circuit 103, the second heating wire control circuit 104, the third heating wire control circuit 105, the fourth heating wire control circuit 106, and the motor control circuit 107. The main control circuit 102 controls the thyristors of the first heating wire control circuit 103, the second heating wire control circuit 104, and the third heating wire control circuit 105, either individually or simultaneously, depending on the voltage input from the power supply circuit 101, thereby enabling each heating wire to operate individually or simultaneously.

[0051] In one embodiment, if Figure 4 As shown, the first heating wire control circuit 103 includes a first heating wire H1, a first thyristor T1, a resistor R16, and a resistor R17. One end of the first heating wire H1 is connected to the power supply terminal ACL-1 of the power circuit 101 through the terminal J1, the other end of the first heating wire H1 is connected to the cathode of the first thyristor T1, the anode of the first thyristor T1 is connected to a 5V DC power supply, the control electrode of the first thyristor T1 is connected in series with the resistor R16 and then connected to the pin Triac1 of the control chip U1, and the resistor R17 is connected between the anode and the control electrode of the first thyristor T1. The first heating wire H1 is powered by the power supply terminal ACL-1, and the pin Triac1 of the control chip U1 controls the on and off of the first thyristor T1 to ensure that the first heating wire H1 is in operation.

[0052] The second heating wire control circuit 104 includes a second heating wire H2, a second thyristor T2, a resistor R18, and a resistor R19. One end of the second heating wire H2 is connected to the power supply terminal ACL-1 of the power circuit 101 via terminal J2. The other end of the second heating wire H2 is connected to the cathode of the second thyristor T2. The anode of the second thyristor T2 is connected to a 5V DC power source. The control electrode of the second thyristor T2 is connected in series with a resistor R18 and then to the pin Triac2 of the control chip U1. The resistor R19 is connected between the anode and control electrode of the second thyristor T2. Power is supplied to the second heating wire H2 via the power supply terminal ACL-1, and the pin Triac2 of the control chip U1 controls the on / off state of the second thyristor T2, thereby ensuring that the second heating wire H2 is operational.

[0053] In one embodiment, if Figure 5 As shown, the third heating wire control circuit 105 includes a third heating wire H3, a third thyristor T3, a resistor R20, and a resistor R21. One end of the third heating wire H3 is connected to a bridge rectifier circuit, the other end is connected to the cathode of the third thyristor T3, the anode of the third thyristor T3 is connected to a 5V DC power supply, the control electrode of the third thyristor T3 is connected in series with the resistor R20 and then connected to the pin Triac3 of the control chip U1, and the resistor R21 is connected between the anode and the control electrode of the third thyristor T3. The third heating wire H3 is powered by the power supply terminal ACL-1 through the bridge rectifier circuit, and the pin Triac3 of the control chip U1 controls the on / off of the second thyristor T3 to ensure that the third heating wire H3 is in operation.

[0054] The fourth heating wire control circuit 106 includes a fourth heating wire H4, a fourth thyristor T4, a resistor R22, and a resistor R23; one end of the fourth heating wire H4 is connected to the third heating wire H3, the other end is connected to the cathode of the fourth thyristor T4, the anode of the fourth thyristor T4 is connected to a 5V DC power supply, the control electrode of the fourth thyristor T4 is connected in series with the resistor R22 and then connected to the pin Triac4 of the control chip U1, and the resistor R23 is connected between the anode and the control electrode of the fourth thyristor T4.

[0055] Power is supplied to the fourth heating wire H4 via the power supply terminal ACL-1, the bridge rectifier circuit, and the third heating wire H3. Pin Triac4 of the control chip U1 controls the on / off switching of the fourth thyristor T4 to activate or deactivate the fourth heating wire H4. In this embodiment, since the third and fourth heating wires H3 and H4 are connected in series, when the fourth thyristor T4 is turned on, the third and fourth heating wires H3 and H4 generate heat simultaneously.

[0056] In one embodiment, if Figure 5As shown, the motor control circuit 107 includes a motor MD1, a bridge rectifier circuit, and an anemometer ION1. The bridge rectifier circuit is composed of diodes D01, D02, D03, and D04. The connection point 1 between diodes D01 and D02 is electrically connected to the power supply terminal ACL-1 of the power supply circuit 101. The connection point 4 between diodes D01 and D03 is connected to the cathode of motor MD1. The connection point 3 between diodes D02 and D04 is connected to the anode of motor MD1. The connection point 2 between diodes D03 and D04 is connected to the third heating wire H3. The bridge rectifier circuit provides DC drive for motor MD1. The anemometer ION1 is used to detect the airflow from motor MD1 and thus determine the air volume of the air duct.

[0057] In one embodiment, if Figure 6 As shown, the power supply circuit 101 is connected to one end of the voltage detection circuit 108 and the zero-crossing trigger circuit 109, and the other ends of the voltage detection circuit 108 and the zero-crossing trigger circuit 109 are electrically connected to the main control circuit 102; the voltage detection circuit 108 is used to detect the input voltage of the country in which the hair dryer is used, and transmit the input voltage value to the main control circuit 102, and then the main control circuit 102 adjusts the operation of different heating wires according to the set mode. The zero-crossing trigger circuit 109 is used to control the AC load when the main control circuit 102 controls the control chip U1. When the voltage detection circuit 108 detects that the voltage exceeds the set value, an interrupt request is generated. Only when the corresponding trigger pin in the interrupt service routine of the main control circuit 102 control chip U1 sends a trigger pulse can the bidirectional thyristor be triggered to turn on, so as to achieve the effect of different heating wires working separately and / or in combination.

[0058] The voltage detection circuit 108 includes a resistor R5, a resistor R6, and a capacitor C6. One end of the resistor R5 is electrically connected to the power supply terminal AC-L of the power supply circuit 101, and the other end is connected to the pin Vcheck of the main control circuit 102. After the 5V DC power is input, the resistor R6 and the capacitor C6 are connected in parallel to the other end of the resistor R5.

[0059] The zero-crossing trigger circuit 109 includes a resistor R7 and a capacitor C7. One end of the resistor R7 is electrically connected to the power supply terminal AC-L of the power circuit 101, the other end is connected to the pin Zero of the main control circuit 102, and the other end is connected to the capacitor C7 and then grounded.

[0060] In one embodiment, if Figure 7 As shown, a key circuit 110 is further provided, and the key circuit 110 is electrically connected to the main control circuit 102; the key circuit 110 realizes the control of the hair dryer, including switch control, wind speed control and heat control.

[0061] The key circuit 110 includes an OFF / ON switch, an UP / DWON control key, and a COLD key. The OFF / ON switch has one end connected to ground, the other end connected in series with a resistor R24, and then connected to pin SEG2 of the control chip U1. The UP / DWON control key has one end connected to ground, the other end connected in series with a resistor R25, and then connected to pin SEG1 of the control chip U1. The COLD key has one end connected to ground, the other end connected in series with a resistor R26, and then connected to pin SEG3 of the control chip U1. These keys transmit control signals to the main control circuit 102, which then sends control instructions to the heating wires and motors to control the fan speed and heat output.

[0062] In one embodiment, if Figure 8 As shown, the LED indicator circuit 111 is electrically connected to the main control circuit 102; the LED indicator circuit 111 is used to indicate information such as switch status, hot and cold air gears, temperature, and air flow rate.

[0063] The LED indicator circuit 111 includes an indicator light chip U2, which has 10 pins, of which 6 pins are respectively connected in series with resistors R8, R9, R10, R11, R12, and R13, and then correspondingly connected to pins SEG1, SEG2, SEG3, PA0 SEG4, PA2 SEG5, and SEG6 of the main control circuit 102. The remaining 4 pins of the indicator light chip U2 are respectively connected to pins COM1, COM2, COM3, and COM4 of the main control circuit 102.

[0064] In one embodiment, if Figure 9 As shown, a temperature detection circuit 112 is further provided, the power supply circuit 101 is connected to one end of the temperature detection circuit 112, and the other end of the temperature detection circuit 112 is electrically connected to the main control circuit 102; the temperature detection circuit 112 is used to detect the blowing temperature of the hair dryer in real time.

[0065] The temperature detection circuit 112 includes a thermistor NTC, resistors R27, resistor R28, and capacitor C10. One end of the thermistor NTC is connected to a 5V DC power supply, and the other end is electrically connected to resistor R28 and then to ground. The other end of the thermistor NTC is also electrically connected to resistor R27 and then to pin NTC of the main control circuit 102. Capacitor C10 is connected in series between pin NTC and the ground terminal of resistor R28.

[0066] Working principle of the present invention:

[0067] The power supply circuit 101 supplies power to the main control circuit 102 and other control circuits and loads. One end of the main control circuit 102 is electrically connected to the power supply circuit 101, and the other end is electrically connected to each control circuit. The control chip U1 of the main control circuit 102 adopts a single-line communication method. When the power supply circuit 101 inputs external AC power with different voltage values ​​in different countries, it controls the first heating wire, the second heating wire, the third heating wire, and the fourth heating wire to heat up respectively. The heating wire is a resistive load, and its power calculation is mainly determined by the voltage and the resistance of the heating wire. The resistance of the first heating wire, the second heating wire, the third heating wire, and the fourth heating wire are all different. As one specific embodiment, the resistance value of the first heating wire and the second heating wire is 20 ohms, the resistance value of the third heating wire is 50 ohms, and the resistance value of the third heating wire is 70 ohms. According to the calculation formula of power = voltage squared / resistance (ohms),

[0068] (1) When the power circuit 101 inputs a voltage of 220V and only the first heating wire is heating, the heating power of the hair dryer is 220*220 / 20=2420W.

[0069] (2) When the power circuit 101 inputs a voltage of 220V and only the second heating wire is heating, the heating power of the hair dryer is 220*220 / 70=2420W.

[0070] (3) When the power circuit 101 inputs a voltage of 220V and only the third heating wire is heating, the heating power of the hair dryer is 220*220 / 70=968W.

[0071] (4) When the power circuit 101 inputs a voltage of 220V and only the fourth heating wire is heating, the heating power of the hair dryer is 220*220 / 70=691W.

[0072] (5) When the power circuit 101 inputs a voltage of 110V and only the first heating wire is heating, the heating power of the hair dryer is 110*110 / 20=605W.

[0073] (6) When the power circuit 101 inputs a voltage of 110V and only the second heating wire is heating, the heating power of the hair dryer is 110*110 / 20=605W.

[0074] (7) When the power circuit 101 inputs a voltage of 110V and only the third heating wire is heating, the heating power of the hair dryer is 110*110 / 50=242W.

[0075] (8) When the power circuit 101 inputs a voltage of 110V and only the fourth heating wire is heating, the heating power of the hair dryer is 110*110 / 70=173W.

[0076] Obviously, in different countries, when the input voltage is reduced from 220V to 110V, the heating power is greatly reduced, resulting in insufficient heat. In this case, the problem can be solved by controlling the first heating wire, the second heating wire, the third heating wire, and the fourth heating wire to heat simultaneously. For example:

[0077] (9) When the power circuit 101 inputs a voltage of 110V and the first heating wire and the second heating wire generate heat together, the heating power of the hair dryer is 605W+605W=1210W.

[0078] (10) When the power circuit 101 inputs a voltage of 110V and the third heating wire and the fourth heating wire both heat up, the heating power of the hair dryer is 242W+173W=415W.

[0079] (11) When the power circuit 101 inputs a voltage of 110V and the first heating wire, the second heating wire, the third heating wire and the fourth heating wire generate heat together, the heating power of the hair dryer is 605W+605W+242W+173W=1625W.

[0080] It should be noted that there are many combined heating methods, which are not listed here one by one. The control circuit of the utility model controls the output power of the heating wires in the heating load circuit by controlling different heating wires to achieve two different external voltages, so as to meet the practical value.

[0081] To sum up, the design focus of the present invention is that it provides a new type of group of heating wires that can be divided into two voltages to control the same group of heating wires to perform work in an effective space, thereby achieving external alternating current with different voltages, controlling the triggering of the heating triggering load circuit, and performing two-way triggering thyristor control with two different voltages. While being able to be used in different countries and regions, it can control the triggering of the AC control load circuit with different input AC voltages, and can achieve the effect of using two voltages in the same space size. The circuit connected to the driver chip IC1 is simple, so it takes up little PCB space and can achieve dual voltage use; it can be used with universal voltage worldwide, the production process of the finished product is simple to control, and the design is simple and the cost is low.

[0082] The above description is merely a preferred embodiment of the present invention and does not limit the technical scope of the present invention. Therefore, any minor modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A dual-voltage heating wire control circuit for a hair dryer, characterized by: It comprises a power supply circuit (101), a main control circuit (102), a first heating wire control circuit (103), a second heating wire control circuit (104), a third heating wire control circuit (105), a fourth heating wire control circuit (106), and a motor control circuit (107); The power supply circuit (101) is connected to one end of the first heating wire control circuit (103), the second heating wire control circuit (104), the third heating wire control circuit (105), the fourth heating wire control circuit (106), and the motor control circuit (107); the other ends of the first heating wire control circuit (103), the second heating wire control circuit (104), the third heating wire control circuit (105), the fourth heating wire control circuit (106), and the motor control circuit (107) are electrically connected to the main control circuit (102); at the same time, the third heating wire control circuit (105) and the fourth heating wire control circuit (106) are electrically connected to each other, and the third heating wire control circuit (105) and / or the fourth heating wire control circuit (106) are connected to the motor control circuit (107).

2. The hair dryer dual-voltage heating wire control circuit according to claim 1, characterized in that: The power supply circuit (101) comprises a 100-240V AC input circuit, a rectifier and filter circuit, an AC-to-DC circuit, and a 5V output circuit; the 100-240V AC input circuit is electrically connected to the rectifier and filter circuit, the rectifier and filter circuit is electrically connected to the AC-to-DC circuit, and the AC-to-DC circuit is electrically connected to the 5V output circuit.

3. The hair dryer dual-voltage heating wire control circuit according to claim 1, characterized in that: The main control circuit (102) includes a control chip U1, a resistor R29, and a capacitor C9. The control chip U1 is of model BS84C12A and has 20 pins, namely: pin CM, pin COM4, ​​pin COM3, pin COM2, pin COM1, pin SEG2, pin SEG1, pin SEG6, pin VSS, pin VDD, pin Triac4, pin NTC, pin Vcheck, pin Triac3, pin Triac2, pin Zero, pin Triac1, pin PA2 SEG5, pin SEG3, pin PA0 SEG4, wherein pin PB0 / Key1 is connected in series with resistor R29, pin VSS is grounded, pin VDD is connected to 5V DC, and capacitor C9 is electrically connected between pin VSS and pin VDD.

4. The hair dryer dual-voltage heating wire control circuit according to claim 1, characterized in that: The first heating wire control circuit (103) comprises a first heating wire H1, a first thyristor T1, a resistor R16, and a resistor R17; one end of the first heating wire H1 is connected to the power supply terminal ACL-1 of the power circuit (101) through the terminal J1, the other end of the first heating wire H1 is connected to the cathode of the first thyristor T1, the anode of the first thyristor T1 is connected to a 5V direct current, the control electrode of the first thyristor T1 is connected in series with the resistor R16 and then connected to the pin Triac1 of the control chip U1, and the resistor R17 is connected between the anode and the control electrode of the first thyristor T1; The second heating wire control circuit (104) comprises a second heating wire H2, a second thyristor T2, a resistor R18, and a resistor R19; one end of the second heating wire H2 is connected to the power supply terminal ACL-1 of the power supply circuit (101) through the terminal J2, the other end of the second heating wire H2 is connected to the cathode of the second thyristor T2, the anode of the second thyristor T2 is connected to a 5V direct current, the control electrode of the second thyristor T2 is connected in series with the resistor R18 and then connected to the pin Triac2 of the control chip U1, and the resistor R19 is connected between the anode and the control electrode of the second thyristor T2.

5. The hair dryer dual-voltage heating wire control circuit according to claim 1, characterized in that: The third heating wire control circuit (105) comprises a third heating wire H3, a third thyristor T3, a resistor R20, and a resistor R21; one end of the third heating wire H3 is connected to a bridge rectifier circuit, the other end is connected to the cathode of the third thyristor T3, the anode of the third thyristor T3 is connected to a 5V direct current, the control electrode of the third thyristor T3 is connected in series with the resistor R20 and then connected to the pin Triac3 of the control chip U1, and the resistor R21 is connected between the anode and the control electrode of the third thyristor T3; The fourth heating wire control circuit (106) comprises a fourth heating wire H4, a fourth thyristor T4, a resistor R22, and a resistor R23; One end of the fourth heating wire H4 is connected to the third heating wire H3, the other end is connected to the cathode of the fourth thyristor T4, the anode of the fourth thyristor T4 is connected to a 5V DC power supply, the control electrode of the fourth thyristor T4 is connected in series with a resistor R22 and then connected to the pin Triac4 of the control chip U1, and the resistor R23 is connected between the anode and the control electrode of the fourth thyristor T4.

6. The hair dryer dual-voltage heating wire control circuit according to claim 1, characterized in that: The motor control circuit (107) includes a motor MD1, a bridge rectifier circuit, and an anemometer ION1; the bridge rectifier circuit is composed of a diode D01, a diode D02, a diode D03, and a diode D04; a connection point 1 between the diode D01 and the diode D02 is electrically connected to a power supply terminal ACL-1 of the power supply circuit (101); a connection point 4 between the diode D01 and the diode D03 is connected to the cathode of the motor MD1; a connection point 3 between the diode D02 and the diode D04 is connected to the anode of the motor MD1; and a connection point 2 between the diode D03 and the diode D04 is connected to a third heating wire H3.

7. The hair dryer dual-voltage heating wire control circuit according to claim 1, characterized in that: A voltage detection circuit (108) and a zero-crossing trigger circuit (109) are further provided, the power supply circuit (101) is connected to one end of the voltage detection circuit (108) and the zero-crossing trigger circuit (109), and the other end of the voltage detection circuit (108) and the zero-crossing trigger circuit (109) is electrically connected to the main control circuit (102); The voltage detection circuit (108) includes a resistor R5, a resistor R6, and a capacitor C6. One end of the resistor R5 is electrically connected to the power supply terminal AC-L of the power supply circuit (101), and the other end is connected to the pin Vcheck of the main control circuit (102). After 5V DC power is input, the resistor R6 and the capacitor C6 are connected in parallel to the other end of the resistor R5. The zero-crossing trigger circuit (109) comprises a resistor R7 and a capacitor C7, wherein one end of the resistor R7 is electrically connected to the power supply terminal AC-L of the power supply circuit (101), the other end is connected to the pin Zero of the main control circuit (102), and the other end is connected to the capacitor C7 and then grounded.

8. The hair dryer dual-voltage heating wire control circuit according to claim 1, characterized in that: A key circuit (110) is further provided, and the key circuit (110) is electrically connected to the main control circuit (102); The key circuit (110) comprises an on / off key OFF / ON, a control key UP / DWON, and a cold air key COLD. One end of the on / off key OFF / ON is grounded, and the other end is connected in series with a resistor R24 ​​and then connected to a pin SEG2 of the control chip U1; one end of the control key UP / DWON is grounded, and the other end is connected in series with a resistor R25 and then connected to a pin SEG1 of the control chip U1; one end of the cold air key COLD is grounded, and the other end is connected in series with a resistor R26 and then connected to a pin SEG3 of the control chip U1.

9. The hair dryer dual-voltage heating wire control circuit according to claim 1, characterized in that: An LED indication circuit (111) is further provided, and the LED indication circuit (111) is electrically connected to the main control circuit (102); The LED indicator circuit (111) includes an indicator light chip U2, and the indicator light chip U2 has 10 pins, of which 6 pins are respectively connected in series with resistors R8, R9, R10, R11, R12, and R13, and then correspondingly connected to pins SEG1, SEG2, SEG3, PA0 SEG4, PA2 SEG5, and SEG6 of the main control circuit (102), and the remaining 4 pins of the indicator light chip U2 are respectively connected to pins COM1, COM2, COM3, and COM4 of the main control circuit (102).

10. The hair dryer dual-voltage heating wire control circuit according to claim 1, characterized in that: A temperature detection circuit (112) is further provided, the power supply circuit (101) is connected to one end of the temperature detection circuit (112), and the other end of the temperature detection circuit (112) is electrically connected to the main control circuit (102); The temperature detection circuit (112) includes a thermistor NTC, a resistor R27, a resistor R28, and a capacitor C10. One end of the thermistor NTC is connected to a 5V DC power supply, and the other end is electrically connected to the resistor R28 and then grounded. The other end of the thermistor NTC is also electrically connected to the resistor R27 and then to the pin NTC of the main control circuit (102). The capacitor C10 is connected in series between the pin NTC and the ground end of the resistor R28.

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