Series-parallel alternate control circuit for double-voltage heating wires of air duct

Abstract

The utility model discloses a series-parallel alternate control circuit for double-voltage heating wires of a hair dryer, and relates to the technical field of hair dryers. According to the circuit provided by the utility model, in actual use, the driving circuit is adopted to respectively control the first heating wire and the second heating wire to be used in a low-voltage 100-125V voltage region when the first heating wire and the second heating wire are connected in parallel to work, and the first heating wire and the second heating wire are controlled to be used in a high-voltage 220-240V voltage region when the first heating wire and the second heating wire are connected in series to work; a three-group heating wire control circuit in a series-parallel connection mode is used in the two groups of three-wire same-resistance-value heating wires, so that external high-voltage heating or external low-voltage heating is controlled, a single-wire control silicon controlled rectifier corresponding voltage opening and closing mode is adopted in a chip, and double current can be shared in a double-circuit silicon controlled rectifier in a parallel connection mode under the same heating wire loading power; double voltages can be used; and a finished product manufacturing process is simple in procedure control, simple in design and low in cost.

Description

Technical Field

[0001] The utility model relates to the technical field of hair dryers, in particular to a hair dryer dual-voltage heating wire series-parallel alternating control circuit. Background Art

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

[0003] In the existing technology, the electronic hair dryer uses voltage to control two voltage circuits separately. The two circuits are controlled separately by thyristors to control different voltage heating wires for heating power, and the step-down wire drives the rectifier voltage to control the motor drive circuit. Figure 16 , its working principle is: the driver chip IC turns on / off, and controls the heating wire conversion by controlling the thyristor; Figure 16 In the process, the driver chip IC needs to set the Triac1 and Triac2 pins to control the on / off state. This solution is limited to certain areas and is not convenient for travel. The design cost increases because the voltages of different countries need to be considered, which also complicates the material control cost of the finished product. Utility Model Content

[0004] The purpose of the present invention is to provide a circuit for controlling the series and parallel alternation of dual-voltage heating wires of a hair dryer, so as to solve the problems raised in the above-mentioned background technology.

[0005] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0006] A hair dryer dual-voltage heating wire series-parallel alternating control circuit includes a power supply circuit and a main control circuit, and also includes multiple groups of heating wire control circuits controlled by the main control circuit and multiple groups of heating wires connected to the heating wire control circuit; the multiple groups of heating wire control circuits include a first heating wire control circuit, a second heating wire control circuit, and a third heating wire control circuit respectively connected in parallel with the main control circuit; the multiple groups of heating wires include a first heating wire and a second heating wire;

[0007] The first heating wire is connected between the first heating wire control circuit and the second heating wire control circuit to form a first heating circuit; the second heating wire is connected between the second heating wire control circuit and the third heating wire control circuit to form a second heating circuit; the first heating wire and the second heating wire are connected in series and connected between the first heating wire control circuit and the third heating wire control circuit to form a third heating circuit.

[0008] Preferably, the multiple groups of heating wire control circuits also include a fourth heating wire control circuit and a fifth heating wire control circuit respectively connected in parallel to the main control circuit; the multiple groups of heating wires also include a third heating wire and a fourth heating wire, and the third heating wire is connected between the power supply circuit and the fourth heating wire control circuit to form a fourth heating loop; the third heating wire and the fourth heating wire are connected in series and connected between the power supply circuit and the fifth heating wire control circuit to form a fifth heating loop.

[0009] Preferably, it also includes a motor control circuit, which includes a motor MD1 and a bridge rectifier circuit; the power supply terminal ACL-1 of the power supply circuit is connected to the bridge rectifier circuit, and the bridge rectifier circuit has two outputs, one is electrically connected to the motor MD1, and the other is electrically connected to the third heating wire. The fourth heating wire control circuit and the fifth heating wire control circuit control the third heating wire and the fourth heating wire to reduce the voltage and supply power to the motor MD1.

[0010] Preferably, the first heating wire control circuit includes an optical coupler U1 and a thyristor T1, the input end of the optical coupler U1 is connected to the main control circuit, and the output end of the optical coupler U1 is connected to the control electrode of the thyristor T1;

[0011] The second heating wire control circuit includes an optical coupler U2 and a thyristor T2, wherein the input end of the optical coupler U2 is connected to the main control circuit, and the output end of the optical coupler U2 is connected to the control electrode of the thyristor T2;

[0012] The third heating wire control circuit includes an optical coupler U3 and a thyristor T3 . The input end of the optical coupler U3 is connected to the main control circuit, and the output end of the optical coupler U3 is connected to the control electrode of the thyristor T3 .

[0013] Preferably, the power supply circuit includes a live wire access terminal AC-L and a neutral wire access terminal AC-N, a power protection circuit, and an AC-DC conversion circuit; the live wire access terminal AC-L is connected to the AC-DC conversion circuit after passing through the power protection circuit to output a 5V DC voltage.

[0014] Preferably, it further includes a key circuit, which is electrically connected to the main control circuit.

[0015] Preferably, it further comprises a voltage detection circuit and a zero-crossing trigger circuit, and the voltage detection circuit and the zero-crossing trigger circuit are electrically connected to the main control circuit respectively.

[0016] Preferably, it also includes a temperature detection circuit; the temperature detection circuit includes a thermistor NTC, one end of the thermistor NTC is externally connected to the 5V terminal, the other end of the thermistor NTC is grounded through a resistor R32, an external resistor R31 is connected between the thermistor NTC and the resistor R32, and the resistor R31 is externally connected to the NTC1 pin of the main control chip IC1 in the main control circuit.

[0017] Preferably, it also includes an indicator light circuit, which is electrically connected to the main control circuit.

[0018] Preferably, the model of the main control chip in the main control circuit is IC / SC8F6780 / 20.

[0019] Compared with the prior art, the beneficial effects achieved by the present invention are:

[0020] In the circuit of the present invention, in different countries, the AC voltage that can be input to the power circuit is between 100-240V. The main control circuit can control the first heating wire control circuit, the second heating wire control circuit, and the third heating wire control circuit according to the different input voltages to control the first heating wire and the second heating wire to heat up. The fourth heating wire control circuit and the fifth heating wire control circuit control the heating wire to reduce the voltage to supply power to the motor. The heating wire is a resistive load, and its power calculation is mainly determined by the voltage and the resistance of the heating wire. Each heating wire heats up individually or in combination under the control of the main control circuit; by controlling different heating wires, the output power of the heating wire in the heating load circuit can be controlled under two different external voltages to meet the practical value; So that dual voltage can be used; it can be used with universal voltage worldwide, the process control of manufacturing finished products is simple, the design is simple and the cost is low; in actual use, the driving circuit of the utility model is used to control the first heating wire and the first heating wire to work in parallel for use in the low voltage 100-125V voltage area, and the first heating wire and the first heating wire to work in series for use in the high voltage 220-240V voltage area, and 3 thyristors are used in series-parallel mode in 2 groups of 3-wire heating wires with the same resistance value. When the thyristor T3 is turned on, the external high voltage is controlled to heat up, and when the thyristor T1 / T2 is turned on, the external low voltage is controlled to heat up. The chip adopts a single-line control thyristor corresponding voltage opening and closing mode. The same heating wire carrying power can be shared by the double current in the dual-way thyristors in parallel. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0022] Figure 1 This is a circuit diagram of the entire utility model;

[0023] Figure 2 It is a schematic diagram of the first heating circuit of the utility model as a whole;

[0024] Figure 3 It is a schematic diagram of the second heating circuit of the utility model as a whole;

[0025] Figure 4 It is a schematic diagram of the third heating circuit of the utility model as a whole;

[0026] Figure 5 It is a schematic diagram of the fourth heating circuit of the utility model as a whole;

[0027] Figure 6 It is a schematic diagram of the fifth heating circuit of the utility model as a whole;

[0028] Figure 7 This is a circuit diagram of the main control circuit of the utility model;

[0029] Figure 8 This is a schematic diagram of the first heating wire control circuit, the second heating wire control circuit, and the third heating wire control circuit of the utility model;

[0030] Figure 9 This is a circuit diagram of the fourth heating wire control circuit, the fifth heating wire control circuit, and the motor control circuit of the present invention;

[0031] Figure 10 It is a circuit diagram of the power supply circuit of the utility model;

[0032] Figure 11 This is a circuit diagram of the key circuit of the utility model;

[0033] Figure 12 This is a circuit diagram of the voltage detection circuit and the zero-crossing trigger circuit of the utility model;

[0034] Figure 13 This is a circuit diagram of the temperature detection circuit of the utility model;

[0035] Figure 14 This is a circuit diagram of the indicator light circuit of the utility model;

[0036] Figure 15 It is a circuit diagram of the entire utility model;

[0037] Figure 16 It is the circuit diagram recorded in the background technology of this utility model;

[0038] In the picture:

[0039] Power supply circuit; 11. Power supply protection circuit; 12. AC / DC conversion circuit; 20. Main control circuit; 30. Multiple heating wire control circuits; 31. First heating wire control circuit; 32. Second heating wire control circuit; 33. Third heating wire control circuit; 34. Fourth heating wire control circuit; 35. Fifth heating wire control circuit; 301. First heating circuit; 302. Second heating circuit; 303. Third heating circuit; 304. Fourth heating circuit; 305. Fifth heating circuit; 40. Multiple heating wires; 41. First heating wire; 42. Second heating wire; 43. Third heating wire; 44. Fourth heating wire; 50. Key circuit; 60. Voltage detection circuit; 70. Zero-crossing trigger circuit; 71. Bridge rectifier circuit; 80. Temperature detection circuit; 90. Motor control circuit; 100. Indicator light circuit. DETAILED DESCRIPTION

[0040] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0041] like Figure 1 As shown, a hair dryer dual-voltage heating wire series-parallel alternating control circuit includes a power supply circuit 10 and a main control circuit 20, and also includes multiple groups of heating wire control circuits 30 controlled by the main control circuit 20 and multiple groups of heating wires 40 connected to the multiple groups of heating wire control circuits.

[0042] The multiple heating wire control circuits include a first heating wire control circuit 31, a second heating wire control circuit 32, and a third heating wire control circuit 33, which are respectively connected in parallel with the main control circuit 20; and also include a fourth heating wire control circuit 34 and a fifth heating wire control circuit 35, which are respectively connected in parallel with the main control circuit 20.

[0043] The plurality of heating wire groups include a first heating wire 41 , a second heating wire 42 , a third heating wire 43 and a fourth heating wire 44 .

[0044] like Figures 1-6As shown, the first heating wire 41 is connected between the first heating wire control circuit 31 and the second heating wire control circuit 32 to form a first heating circuit 301; the second heating wire 42 is connected between the second heating wire control circuit 32 and the third heating wire control circuit 33 to form a second heating circuit 302; the first heating wire 41 and the second heating wire 42 are connected in series between the first heating wire control circuit 31 and the third heating wire control circuit 33 to form a third heating circuit 303. The third heating wire 43 is connected between the power supply circuit 10 and the fourth heating wire control circuit 34 to form a fourth heating circuit 304; the third heating wire 43 and the fourth heating wire 44 are connected in series between the power supply circuit 10 and the fifth heating wire control circuit 35 to form a fifth heating circuit 305.

[0045] Thus forming a variety of heating modes:

[0046] Mode 1: When the switch of the first heating wire control circuit 31 is turned on to make the first heating circuit 301 conductive, the current flows through the first heating wire 41 in the first heating circuit, and only the first heating wire 41 generates heat. Figure 2 shown.

[0047] Mode 2: When the switch of the second heating wire control circuit 32 is turned on to make the second heating circuit 302 conductive, the current flows through the second heating wire 42 in the second heating circuit, and only the second heating wire 42 generates heat. Figure 3 shown.

[0048] Mode 3: When the switches of the first heating wire control circuit 31 and the third heating wire control circuit 33 are turned on respectively to make the third heating circuit 303 conductive, current flows through the first heating wire 41 and the second heating wire 42 connected in series, and the first heating wire 41 and the second heating wire 42 heat up at the same time. Figure 4 shown.

[0049] Mode 4: When the fourth heating wire control circuit 34 is turned on to make the fourth heating circuit 304 conductive, the current flows through the third heating wire 43. At this time, only the third heating wire 43 generates heat. Figure 5 shown.

[0050] Mode 5: When the fifth heating wire control circuit 35 is turned on to make the fifth heating circuit 305 conductive, the current flows through the third heating wire 43 and the fourth heating wire 44 connected in series, and the third heating wire 43 and the fourth heating wire 44 are heated at the same time. Figure 6 shown.

[0051] Mode 6: Equivalent to performing mode 1 + mode 2 simultaneously: Since the first heating wire 41 and the second heating wire 42 of the above-mentioned mode 1 and mode 2 are both heated independently, when mode 1 and mode 2 are heated simultaneously, mode 6 is formed, so that the first heating wire 41 and the second heating wire 42 are connected in parallel and heat independently at the same time.

[0052] Mode 7: Equivalent to performing Mode 1 and Mode 4 simultaneously; at this time, the first heating wire 41 and the third heating wire 43 generate heat independently at the same time.

[0053] Mode 8: Equivalent to performing mode 1 and mode 5 simultaneously; at this time, the first heating wire 41 , the third heating wire 43 and the fourth heating wire 44 generate heat simultaneously.

[0054] Other heating modes include: simultaneous mode 2 + mode 4; simultaneous phase mode 2 and mode 5; simultaneous mode 3 and mode 4; simultaneous mode 3 and mode 5, etc.; in different modes, the heating power is different, dual voltage can be used, and the requirements of the free adjustment mode of heating power are met; it can be used with universal voltage worldwide, the production process of finished products is simple to control, the design is simple and the cost is low.

[0055] The circuit diagram of this utility model is shown in FIG. Figures 7 to 15 As shown, a more specific implementation method can be embodied as a hair dryer dual-voltage heating wire series-parallel alternating control circuit, including a power supply circuit 10, a main control circuit 20, a first heating wire control circuit 31, a second heating wire control circuit 32, a third heating wire control circuit 33, a fourth heating wire control circuit 34, a fifth heating wire control circuit 35, and a motor control circuit 90. The first heating wire control circuit 31, the second heating wire control circuit 32, and the third heating wire control circuit 33 control the first heating wire 41 and the second heating wire 42. The power supply circuit 10, the first heating wire control circuit 31, the second heating wire control circuit 32, the third heating wire control circuit 33, the fourth heating wire control circuit 34, the fifth heating wire control circuit 35, and the motor control circuit 90 are respectively electrically connected to the main control circuit 20.

[0056] The first heating wire control circuit 31 , the second heating wire control circuit 32 , and the third heating wire control circuit 33 are connected in parallel, and the first heating wire 41 and the second heating wire 42 are connected in series.

[0057] like Figure 7 As shown, the main control circuit 20 includes a chip IC1, the VDD pin of the chip IC1, the capacitor C3 and the GND pin of the chip IC1 are connected in series in sequence, an external 5V terminal is connected between the VDD pin of the chip IC1 and the capacitor C3, and the connection between the capacitor C3 and the GND pin of the chip IC1 is grounded; in this embodiment, the model of the main control chip in the main control circuit 20 is IC / SC8F6780 / 20.

[0058] like Figure 8 As shown, the first heating wire control circuit 31 includes an optocoupler U1 and a thyristor T1, the input end of the optocoupler U1 is connected to the main control circuit 20, and the output end of the optocoupler U1 is connected to the control electrode of the thyristor T1; the second heating wire control circuit 32 includes an optocoupler U2 and a thyristor T2, the input end of the optocoupler U2 is connected to the main control circuit 20, and the output end of the optocoupler U2 is connected to the control electrode of the thyristor T2; the third heating wire control circuit 33 includes an optocoupler U3 and a thyristor T3, the input end of the optocoupler U3 is connected to the main control circuit 20, and the output end of the optocoupler U3 is connected to the control electrode of the thyristor T3; each heating wire control circuit is optically isolated by the optocouplers U1, U2, and U3, and the switching of each heating circuit is realized by the thyristors T1, T2, and T3.

[0059] like Figure 8 As shown, as a specific embodiment, the 3rd interface of the optical coupler U1, the resistor R9, the resistor R10, the 2nd interface of the thyristor T1, the 1st interface of the thyristor T1, the resistor R4 and the 4th interface of the optical coupler U1 are sequentially connected in series; the 3rd interface of the thyristor T1 is electrically connected between the resistor R4 and the 4th interface of the optical coupler U1;

[0060] One end of the first heating wire 41 is connected in series with one end of the second heating wire 42, and the other end of the first heating wire is electrically connected between port 1 of the thyristor T1 and the resistor R4. A resistor R5 and a capacitor C1 are connected in parallel to the outside of port 1 of the thyristor T1 and port 2 of the thyristor T1, and the resistor R5 and the capacitor C1 are connected in series. Port 1 of the optocoupler U1 is connected to the Triac3 pin of the external chip IC1 through the resistor R6, and port 2 of the optocoupler U1 is grounded. Port 2 of the optocoupler U1 is electrically connected between port 1 of the optocoupler U1 and the resistor R6 through the resistor R8. A power supply terminal AC-L of the power supply circuit 10 is externally connected between port 1 of the thyristor T1 and the resistor R4.

[0061] The 3rd interface of the optical coupler U2, the resistor R12, the resistor R13, the resistor R18, the 1st interface of the thyristor T2, the 2nd interface of the thyristor T2 and the 4th interface of the optical coupler U2 are connected in series in sequence; the 3rd interface of the thyristor T2 is electrically connected between the resistor R13 and the resistor R18;

[0062] The connection between the 2nd interface of the thyristor T2 and the 4th interface of the optical coupler U2 is electrically connected between the first heating wire 41 and the second heating wire 42. A resistor R17 and a capacitor C5 are connected in parallel to the outside of the thyristor T2 and the 2nd interface of the thyristor T2, and the resistor R17 and the capacitor C5 are connected in series. The 1st interface of the optical coupler U2 is connected to the Triac4 pin of the chip IC1 through the resistor R11. The 2nd interface of the optical coupler U2 is grounded. The 2nd interface of the optical coupler U2 is electrically connected between the 1st interface of the optical coupler U2 and the resistor R11 through the resistor R15. The power supply terminal AC-N of the power supply circuit 10 is externally connected between the 1st interface of the thyristor T2 and the resistor R18.

[0063] The 3rd interface of the optical coupler U3, the 2nd interface of the thyristor T3, the 1st interface of the thyristor T3, the resistor R19, the resistor R23, the resistor R22 and the 4th interface of the optical coupler U3 are connected in series in sequence; the 3rd interface of the thyristor T3 is electrically connected between the resistor R19 and the resistor R23; the resistor R19 and the resistor R18 are connected in series, and the 1st interface of the thyristor T3 is connected in series with the 1st interface of the thyristor T2;

[0064] The connection line between the 2nd interface of the thyristor T3 and the 3rd interface of the optocoupler U3 is connected to the end of the second heating wire 42 away from the first heating wire 41. The resistor R25 and the capacitor C6 are connected in parallel to the outside of the 2nd interface of the thyristor T3 and the 3rd interface of the thyristor T3, and the resistor R25 and the capacitor C6 are connected in series; the 1st interface of the optocoupler U3 is connected to the Triac5 pin of the external chip IC1 through the resistor R20, and the 2nd interface of the optocoupler U3 is grounded. The 2nd interface of the optocoupler U3 is electrically connected between the 1st interface of the optocoupler U3 and the resistor R20 through the resistor R24.

[0065] like Figure 9 As shown, the fourth heating wire control circuit 34 includes a thyristor T4 connected in series, and the fifth heating wire control circuit 35 includes a thyristor T5 connected in series; the third heating wire 43 and the fourth heating wire 44 are connected in series, the thyristor T4 and the thyristor T5 are connected in parallel, and one end of the third heating wire 43 is connected to the bridge rectifier circuit 71 of the motor control circuit 90; one end of the third heating wire 43 is connected to the bridge rectifier circuit 71 of the motor control circuit, and the other end of the third heating wire 43 is connected to the cathode of the thyristor T4, the anode of the thyristor T4 is externally connected to the power supply terminal AC-N of the power supply circuit 10, the control electrode of the thyristor T4 is connected to the Triac1 pin of the external chip IC1 through the resistor R26, and the anode of the thyristor T4 is electrically connected between the control electrode of the thyristor T4 and the resistor R26 through the resistor R28;

[0066] One end of the fourth heating wire 44 is connected to one end of the third heating wire 43, and the other end of the fourth heating wire 44 is connected to the cathode of the thyristor T5. The anode of the thyristor T5 is externally connected to the power supply terminal AC-N of the power supply circuit 10. The control electrode of the thyristor T5 is connected to the Triac2 pin of the external chip IC1 through the resistor R27. The anode of the thyristor T5 is electrically connected between the control electrode of the thyristor T5 and the resistor R27 through the resistor R29.

[0067] Power is supplied to the third heating wire 43 via the power supply terminal ACL-1 through the bridge rectifier circuit. Pin Triac1 of the control chip IC1 controls the on / off switching of the thyristor T4 to enable or disable the third heating wire 43. Power is supplied to the fourth heating wire 44 via the power supply terminal ACL-1 through the bridge rectifier circuit 71 and the third heating wire 43. Pin Triac2 of the control chip IC1 controls the on / off switching of the thyristor T5 to enable or disable the fourth heating wire 44. Because the third and fourth heating wires 43 and 44 are connected in series, when the thyristor T5 is turned on, the third and fourth heating wires 43 and 44 simultaneously generate heat.

[0068] like Figure 9 As shown, the hair dryer dual-voltage heating wire series-parallel alternating control circuit also includes a motor control circuit 90, which includes a motor MD1 and a bridge rectifier circuit 71; the power supply terminal ACL-1 of the power supply circuit 10 is connected to the bridge rectifier circuit 71, and the bridge rectifier circuit has two outputs, one electrically connected to the motor MD1, and the other electrically connected to the third heating wire 43. The fourth heating wire control circuit 34 and the fifth heating wire control circuit 35 control the third heating wire 43 and the fourth heating wire 44 to reduce the voltage and supply power to the motor MD1;

[0069] like Figure 9 As shown, the bridge rectifier circuit includes a diode D01, a diode D02, a diode D03, and a diode D04. The connection point 1 between the diode D01 and the diode D02 is electrically connected to the power supply terminal ACL-1 of the power supply circuit 10, the connection point 4 between the diode D01 and the diode D03 is connected to the negative electrode of the motor MD1, the connection point 3 between the diode D02 and the diode D04 is connected to the positive electrode of the motor MD1, and the connection point 2 between the diode D03 and the diode D04 is connected to the third heating wire 43; the bridge rectifier circuit realizes DC drive of the motor MD1.

[0070] like Figure 10 As shown, the power supply circuit 10 includes a live wire access terminal AC-L and a neutral wire access terminal AC-N, a power protection circuit 11, and an AC-DC conversion circuit 12; the live wire access terminal AC-L is connected to the AC-DC conversion circuit 12 after passing through the power protection circuit 11, and outputs a 5V DC voltage.

[0071] like Figure 10 As shown, in one embodiment, the power supply circuit 10 includes a live wire input terminal AC-L and a neutral wire input terminal AC-N, an on / off switch OFF / NO, a fuse F1, a diode D1, a resistor R1, a chip IC2, a resistor R2, a capacitor C4, a resistor R7, an electrolytic capacitor EC1, an electrolytic capacitor EC2, and an adjustable resistor VAR1; the live wire input terminal AC-L, the fuse F1, the diode D1, the resistor R1, and the Drain pin of the chip IC2 are connected in series in sequence, and the Drain pins of the chip IC2 are connected in parallel with each other;

[0072] The neutral line access terminal AC-N is connected in series with the VOUT pin of the chip IC2 through the capacitor C4, the connection between the neutral line access terminal AC-N and the capacitor C4 is grounded, an external 5V terminal is connected between the capacitor C4 and the VOUT pin of the chip IC2, a resistor R2 and an electrolytic capacitor EC1 are connected in parallel to the outside of the capacitor C4, and the resistor R2 and the electrolytic capacitor EC1 are connected in parallel; the SEL pin of the chip IC2 is electrically connected between the electrolytic capacitor EC1 and the neutral line access terminal AC-N through the resistor R7, and the GND pin of the chip IC2 is electrically connected between the electrolytic capacitor EC1 and the neutral line access terminal AC-N; the VDD pin of the chip IC2 is electrically connected between the electrolytic capacitor EC1 and the neutral line access terminal AC-N through the electrolytic capacitor EC2;

[0073] The connection line between the neutral line access terminal AC-N and the capacitor C4 is externally connected to an adjustable resistor VAR1, a capacitor C2, a resistor R3, and two diodes D2 and D3 connected in reverse series. The adjustable resistor VAR1, the capacitor C2, the resistor R3, and the diode D2 are electrically connected between the fuse F1 and the diode D1 respectively.

[0074] Capacitor C2, resistor R3 and two reverse-connected diodes D2 and D3 form a power protection circuit to prevent lightning strikes, overvoltage, interference, and surge power absorption, thus protecting the circuit.

[0075] The power supply terminal AC-L is electrically connected to the fuse F1 to ensure safe operation of the circuit; the voltage passing through the fuse F1, the adjustable resistor VAR1, the resistor R1, and the diode D1 is used by the AC-DC conversion chip IC2.

[0076] like Figure 11As shown, in one embodiment, the hair dryer dual-voltage heating wire series-parallel alternating control circuit also includes a key circuit 50, and the key circuit 50 is electrically connected to the main control circuit 20; in a more specific embodiment, the key circuit 50 includes a switch key OFF / ON, a control key UP, and a control key DWON, one end of the switch key OFF / ON is grounded, and the other end of the switch key OFF / ON is connected to the COOL pin of the external chip IC1 through the resistor R14; one end of the control key UP is grounded, and the other end of the control key UP is connected to the UP pin of the external chip IC1 through the resistor R16; one end of the control key DOW is grounded, and the other end of the control key DOW is connected to the DOW pin of the external chip IC1 through the resistor R21; the key circuit 50 realizes the control of the hair dryer.

[0077] like Figure 12 As shown, in one embodiment, the hair dryer dual-voltage heating wire series-parallel alternating control circuit further includes a voltage detection circuit 60 and a zero-crossing trigger circuit 70, and the voltage detection circuit 60 and the zero-crossing trigger circuit 70 are respectively electrically connected to the main control circuit 20. In one embodiment, the voltage detection circuit 60 includes a resistor R33, one end of the resistor R33 is externally connected to the power supply terminal AC-L of the power supply circuit 10, the other end of the resistor R33 is externally connected to the Vcheck pin of the chip IC1, and a resistor R34 and a capacitor C7 are externally connected between the resistor R33 and the Vcheck pin of the chip IC1. The resistor R34 and the capacitor C7 are connected in parallel, and the resistor R34 and the capacitor C7 are both externally connected to the 5V terminal; the zero-crossing trigger circuit 70 includes a resistor R35, one end of the resistor R35 is externally connected to the power supply terminal AC-L of the power supply circuit 10, the other end of the resistor R33 is externally connected to the Zero pin of the chip IC1, and a capacitor C8 is externally connected between the resistor R35 and the Zero pin of the chip IC1, and the capacitor C8 is grounded;

[0078] The voltage detection circuit 60 is used to detect the input voltage of the hair dryer in the country used this time, and transmit the input voltage value to the main control circuit 20, and then the main control circuit 20 adjusts the operation of different heating wires according to the set mode; the zero-crossing trigger circuit 70 is used for AC load control when the main control circuit 20 controls the control chip IC1. When the voltage detection circuit 60 detects that the voltage exceeds the set value, an interrupt request is generated. Only by sending a trigger pulse at the corresponding trigger pin in the interrupt service program of the main control circuit 20 control chip IC1 can the bidirectional thyristor be triggered to turn on, so as to achieve the effect of different heating wires working individually and / or in combination.

[0079] like Figure 13As shown, in one embodiment, the hair dryer dual-voltage heating wire series-parallel alternating control circuit also includes a temperature detection circuit 80; the temperature detection circuit 80 includes a thermistor NTC, one end of the thermistor NTC is externally connected to the 5V end, and the other end of the thermistor NTC is grounded through a resistor R32, an external resistor R31 is connected between the thermistor NTC and the resistor R32, and the resistor R31 is externally connected to the NTC1 pin of the chip IC1; the temperature detection circuit 80 is used to detect the blowing temperature of the hair dryer in real time.

[0080] like Figure 14 As shown, the hair dryer dual-voltage heating wire series-parallel alternating control circuit also includes an indicator light circuit 100; the indicator light circuit is electrically connected to the main control circuit 20. In one embodiment, the indicator light circuit 100 includes an indicator light LED1, an indicator light LED2, an indicator light LED3 and a resistor R30; the indicator light LED1, the indicator light LED2 and the indicator light LED3 are connected in parallel, and the indicator light LED1, the indicator light LED2 and the indicator light LED3 are each electrically connected to the resistor R30, the resistor R30 is connected to the SEG6 pin of the external chip IC1, the indicator light LED1 is connected to the SEG4 pin of the external chip IC1, the indicator light LED2 is connected to the SEG3 pin of the external chip IC1, and the indicator light LED3 is connected to the SEG5 pin of the external chip IC1; the LED indicator circuit is used to indicate information such as the switch status, hot and cold air gears, temperature, and air flow rate.

[0081] Specific working principle:

[0082] The circuit of the present invention is used in different countries. The AC voltage that the power supply circuit 10 can input is between 100-240V. The main control circuit 20 can control the first heating wire control circuit 31, the second heating wire control circuit 32, and the third heating wire control circuit 33 according to the different input voltages to control the first heating wire 41 and the second heating wire 42 to heat up. The fourth heating wire control circuit 34 and the fifth heating wire control circuit 35 control the third heating wire 43 and the fourth heating wire 44 to reduce the voltage and supply power to the motor. Each heating wire is a resistive load, and its power calculation is mainly determined by the voltage and the resistance of the heating wire. Each heating wire heats up individually or in combination under the control of the main control circuit 20. By controlling different heating wires, the output power of the heating wires in the heating load circuit is controlled when two different external voltages are reached, so as to meet the practical value. Dual voltage can be used. It can be used with universal voltage worldwide. The process control of the finished product is simple, the design is simple and the cost is low.

[0083] Working principle of the circuit: The power supply supplies power to the driver chip IC1 and the control circuit. The chip adopts a single-line communication method and adopts different external AC power to control the first heating wire and the second heating wire respectively to achieve two external different voltages. The heating wire power in the heating load circuit is controlled by series and parallel alternating control of the heating wire output power. After the utility model adopts the above circuit, it can be used in two different AC voltages of 100-240V in the external AC wide voltage. If necessary, Figure 2 The display shows that in actual use, the driving circuit of the utility model is used to control the first heating wire and the first heating wire to work in parallel for use in the low voltage 10-125V voltage area, and the first heating wire and the first heating wire to work in series for use in the high voltage 220-240V voltage area. Three thyristors are used in series and parallel in two groups of three-wire heating wires with the same resistance value. When the thyristor T3 is turned on, the external high voltage is controlled to heat up. When the thyristor T1 / T2 is turned on, the external low voltage is controlled to heat up. The chip adopts a single-line control thyristor corresponding voltage opening and closing method. The same heating wire carries power. Using a parallel method can share double the current in the dual-way thyristors. The two AC voltages can be calculated by the voltage divider identification of the two voltages of the resistor R33 and the resistor R34, and two AC voltages can be used.

[0084] The utility model is suitable for hairdressing appliances such as high-speed hair dryers, electronic hair dryers, and hair curlers with heating wires.

[0085] Finally, it should be noted that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art will be able to modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein with equivalents. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A hair dryer dual-voltage heating wire series-parallel alternating control circuit, comprising a power supply circuit (10) and a main control circuit (20), characterized in that: The invention also includes a plurality of heating wire control circuits (30) controlled by a main control circuit (20) and a plurality of heating wires (40) connected to the plurality of heating wire control circuits; the plurality of heating wire control circuits include a first heating wire control circuit (31), a second heating wire control circuit (32), and a third heating wire control circuit (33) respectively connected in parallel to the main control circuit (20); the plurality of heating wires include a first heating wire (41) and a second heating wire (42); the first heating wire (41) is connected between the first heating wire control circuit (31) and the second heating wire control circuit (32) to form a first heating circuit (301); the second heating wire (42) is connected between the second heating wire control circuit (32) and the third heating wire control circuit (33) to form a second heating circuit (302); the first heating wire (41) and the second heating wire (42) are connected in series and then connected between the first heating wire control circuit (31) and the third heating wire control circuit (33) to form a third heating circuit (303).

2. The hair dryer dual-voltage heating wire series-parallel alternating control circuit according to claim 1, characterized in that: The plurality of heating wire control circuits (30) further include a fourth heating wire control circuit (34) and a fifth heating wire control circuit (35) respectively connected in parallel to the main control circuit (20); the plurality of heating wires (40) further include a third heating wire (43) and a fourth heating wire (44), wherein the third heating wire (43) is connected between the power supply circuit (10) and the fourth heating wire control circuit (34) to form a fourth heating loop (304); and the third heating wire (43) and the fourth heating wire (44) are connected in series and then connected between the power supply circuit (10) and the fifth heating wire control circuit (35) to form a fifth heating loop (305).

3. The hair dryer dual-voltage heating wire series-parallel alternating control circuit according to claim 2, characterized in that: The invention also includes a motor control circuit (90), wherein the motor control circuit includes a motor MD1 and a bridge rectifier circuit (71); the power supply terminal ACL-1 of the power supply circuit (10) is connected to the bridge rectifier circuit (71); the bridge rectifier circuit has two outputs, one of which is electrically connected to the motor MD1 and the other is electrically connected to the third heating wire (43); the fourth heating wire control circuit (34) and the fifth heating wire control circuit (35) control the third heating wire (43) and the fourth heating wire (44) to reduce the voltage and supply power to the motor MD1.

4. The hair dryer dual-voltage heating wire series-parallel alternating control circuit according to claim 1, characterized in that: The first heating wire control circuit (31) comprises an optical coupler U1 and a thyristor T1, wherein the input end of the optical coupler U1 is connected to the main control circuit (20), and the output end of the optical coupler U1 is connected to the control electrode of the thyristor T1; The second heating wire control circuit (32) comprises an optical coupler U2 and a thyristor T2, wherein the input end of the optical coupler U2 is connected to the main control circuit (20), and the output end of the optical coupler U2 is connected to the control electrode of the thyristor T2; The third heating wire control circuit (33) comprises an optical coupler U3 and a thyristor T3, wherein the input end of the optical coupler U3 is connected to the main control circuit (20), and the output end of the optical coupler U3 is connected to the control electrode of the thyristor T3.

5. The hair dryer dual-voltage heating wire series-parallel alternating control circuit according to claim 1, characterized in that: The power supply circuit (10) comprises a live wire access terminal AC-L and a neutral wire access terminal AC-N, a power protection circuit (11), and an AC / DC conversion circuit (12); the live wire access terminal AC-L is connected to the AC / DC conversion circuit (12) after passing through the power protection circuit (11) to output a 5V DC voltage.

6. The hair dryer dual-voltage heating wire series-parallel alternating control circuit according to claim 1, characterized in that: It also includes a key circuit (50), wherein the key circuit (50) is electrically connected to the main control circuit (20).

7. The hair dryer dual-voltage heating wire series-parallel alternating control circuit according to claim 1, characterized in that: It also includes a voltage detection circuit (60) and a zero-crossing trigger circuit (70), wherein the voltage detection circuit (60) and the zero-crossing trigger circuit (70) are respectively electrically connected to the main control circuit (20).

8. The hair dryer dual-voltage heating wire series-parallel alternating control circuit according to claim 1, characterized in that: It also includes a temperature detection circuit (80); the temperature detection circuit (80) includes a thermistor NTC, one end of the thermistor NTC is externally connected to a 5V terminal, the other end of the thermistor NTC is grounded via a resistor R32, an external resistor R31 is connected between the thermistor NTC and the resistor R32, and the resistor R31 is externally connected to the NTC1 pin of the main control chip IC1 in the main control circuit (20).

9. The hair dryer dual-voltage heating wire series-parallel alternating control circuit according to claim 1, characterized in that: It also includes an indicator light circuit (100), which is electrically connected to the main control circuit (20).

10. The hair dryer dual-voltage heating wire series-parallel alternating control circuit according to claim 1, characterized in that: The model of the main control chip in the main control circuit (20) is IC / SC8F6780 / 20.

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