Temperature control adjusting circuit of hair drier

Abstract

According to the hair drier (hair dryer) temperature control adjusting circuit, a heating device is divided into two windings of a first heating wire and a second heating wire, the mains supply detection module is used for detecting the change of the voltage value of the mains supply, and the alternating current zero-crossing detection module is used for capturing the zero-crossing point of the alternating current of the mains supply; the MCU module is used for respectively controlling whether the first silicon controlled rectifier control module, the second silicon controlled rectifier control module and the third silicon controlled rectifier control module are conducted or not according to control signals sent by the mains supply detection module and the alternating current zero-crossing detection module, and controlling the conduction time to change the series-parallel connection mode and chopping of two windings of the first heating wire and the second heating wire according to control signals sent by the mains supply detection module and the alternating current zero-crossing detection module; combination of different powers under the condition that mains supplies with different voltages are input is achieved, so that the final power is stable or constant, the application range of the blower is wider, the blower can be compatible with the mains supplies with different input voltages and can be used in countries with different input mains supplies, the cost is effectively saved, and the application range of the blower is widened. And the size of the control circuit is mastered reasonably.

Description

Technical Field

[0001] The present application relates to the technical field of hair dryers, and in particular to a temperature control and regulation circuit for a hair dryer. Background Art

[0002] A hair dryer is composed of a set of heating wires and a high-speed fan. When powered on, the heating wires will generate heat, and the wind blown out by the fan will become hot air after passing through the heating wires. If only the fan rotates but the heating wires are not hot, then the air blown out is just wind without heat.

[0003] However, the mains voltages used in various countries in the world are different. Therefore, if hair dryers are to be sold or used globally, the voltage of household electricity in each country must be considered, and hair dryers with corresponding voltages must be selected. Otherwise, the hair dryer may be burned out or malfunction, which will cause considerable trouble to companies or users. Utility Model Content

[0004] It is very necessary to design a hair dryer control circuit that is universal for different mains voltages around the world. The present application provides a hair dryer temperature control circuit.

[0005] The present application provides a hair dryer temperature control circuit that adopts the following technical solution:

[0006] A hair dryer temperature control and regulation circuit comprises a mains detection module, an MCU module, an alternating current zero-crossing detection module, a first thyristor control module, a second thyristor control module, and a third thyristor control module, wherein the signal output ends of the mains detection module and the alternating current zero-crossing detection module are connected to the signal input end of the MCU module, the signal output end of the MCU module is respectively connected to the signal input ends of the first thyristor control module, the second thyristor control module, and the third thyristor control module, the output end of the first thyristor control module and the first output end of the second thyristor control module are respectively connected to a first heating wire, and the second output end of the second thyristor control module and the output end of the third thyristor control module are respectively connected to a second heating wire.

[0007] In one of the embodiments, the mains power detection module includes a voltage sampling unit.

[0008] In one embodiment, the AC zero-crossing detection module includes a first AC zero-crossing detection unit and a second AC zero-crossing detection unit.

[0009] In one embodiment, the first thyristor control module includes a first control unit and a first thyristor unit, and the first control unit and the first thyristor unit are electrically connected.

[0010] In one embodiment, the second thyristor control module includes a second control unit and a second thyristor unit, and the second control unit and the second thyristor unit are electrically connected.

[0011] In one embodiment, the third thyristor control module includes a third control unit and a third thyristor unit, and the third control unit and the third thyristor unit are electrically connected.

[0012] In summary, this application has the following beneficial technical effects:

[0013] The above-mentioned hair dryer temperature control and regulation circuit is configured by the coordination of a mains detection module, an MCU module, an AC zero-crossing detection module, a first thyristor control module, a second thyristor control module, and a third thyristor control module, so that the heating device is divided into two windings, a first heating wire and a second heating wire. The mains detection module is used to detect the change of the voltage value of the mains, and the AC zero-crossing detection module is used to capture the zero-crossing point of the mains AC. The MCU module controls the first thyristor control module, the second thyristor control module, and the third thyristor control module to change the series-parallel connection mode and chopping of the two windings of the first heating wire and the second heating wire according to the control signals sent by the mains detection module and the AC zero-crossing detection module, so as to realize the combination of different powers when the mains voltage is input, so as to achieve the stability or constant of the final power, so as to make the hair dryer more widely applicable, compatible with mains with different input voltages or frequencies, and can be used in different countries with mains input. There is no need to prepare multiple hair dryers adapted to different input mains voltages, which also effectively saves costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 The invention discloses a circuit diagram of a temperature control circuit of a hair dryer (hair dryer) of the present invention. DETAILED DESCRIPTION

[0015] 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.

[0016] It should be noted that when an element is considered to be "connected" to another element, it may be directly connected to the other element or there may be an intermediate element at the same time. On the contrary, when an element is said to be "directly" connected to another element, there is no intermediate element.

[0017] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art in the technical field of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0018] The following is combined with Figure 1 This application is described in further detail.

[0019] like Figure 1 As shown, a temperature control and regulation circuit of a hair dryer comprises a mains detection module 1, an MCU module, an AC zero-crossing detection module 2, a first thyristor control module 3, a second thyristor control module 4, and a third thyristor control module 5, wherein the signal output ends of the mains detection module 1 and the AC zero-crossing detection module 2 are connected to the signal input end of the MCU module, and the signal output end of the MCU module is respectively connected to the signal input ends of the first thyristor control module 3, the second thyristor control module 4, and the third thyristor control module 5, the output end of the first thyristor control module 3 and the first output end of the second thyristor control module 4 are respectively connected to the first heating wire, and the second output end of the second thyristor control module 4 and the output end of the third thyristor control module 5 are respectively connected to the second heating wire.

[0020] In one of the embodiments, the mains power detection module 1 includes a voltage sampling unit.

[0021] In one embodiment, the AC zero-crossing detection module 2 includes a first AC zero-crossing detection unit and a second AC zero-crossing detection unit.

[0022] In one embodiment, the first thyristor control module 3 includes a first control unit and a first thyristor unit, and the first control unit and the first thyristor unit are electrically connected.

[0023] In one embodiment, the second thyristor control module 4 includes a second control unit and a second thyristor unit, and the second control unit and the second thyristor unit are electrically connected.

[0024] In one embodiment, the third thyristor control module 5 includes a third control unit and a third thyristor unit, and the third control unit and the third thyristor unit are electrically connected.

[0025] The mains detection module 1 includes a voltage sampling unit, which includes a resistor R20, a resistor R21, and a resistor R22, and the resistors R20, R21, and R22 are connected in series. DC_HV is obtained by rectifying the mains (AC80V-AC300V) through a diode, including half-wave rectification or bridge rectification. DC_HV is sampled by the resistor R20, the resistor R21, and the resistor R22 to be sent to the ADC pin of the MCU module, which is used to monitor the change of the mains voltage and thus change the working state of the first thyristor control module 3, the second thyristor control module 4, and the third thyristor control module 5 to control the working mode of the two sets of heating wires to achieve the purpose of constant power or stable power.

[0026] In single-phase AC, AC_L is the live wire of the mains, and AC_N is the neutral wire of the mains. If it is American standard, then both AC_L and AC_N are the live wires of the mains.

[0027] The AC zero-crossing detection module 2 includes a resistor R23, a resistor R24, a resistor R25, a resistor R26, a resistor R27, a capacitor C7, a diode D1B, a diode D1A, and a voltage regulator DV1. The first AC zero-crossing detection unit includes a resistor R23, a resistor R24 ​​for voltage reduction, a diode D1A, a voltage regulator DV1, and a capacitor C7. The AC is reduced in voltage by the resistor R23 and the resistor R24, rectified by the diode D1A, limited by the voltage regulator DV1, filtered by the capacitor C7, and finally sent to the P015 interface of the MCU module.

[0028] The second AC zero-crossing detection unit includes resistors R23, R24, R26, R27, diode D1B, and voltage regulator DV1. The AC can also be stepped down by resistors R23 and R24, limited by voltage regulator DV1, rectified by diode D1B, and limited by resistors R26 and R27, and finally sent to another input IO port of the MCU module. The MCU module detects the change of voltage through these two IO ports to capture the zero-crossing point. The second AC zero-crossing detection unit can also be omitted, because there are only two frequencies of AC power in the market: 50HZ or 60HZ, so its phase can be calculated by detecting one side to get the other side.

[0029] The control circuits of the first thyristor control module 3 , the second thyristor control module 4 , and the third thyristor control module 5 are basically the same, and all of them trigger high-power thyristors through optocoupler thyristors.

[0030] The first thyristor control module 3 includes a first control unit and a first thyristor unit, and the first control unit and the first thyristor unit are electrically connected. The first control unit is an optocoupler thyristor U1, and the first thyristor unit is a thyristor Q1;

[0031] The second thyristor control module 4 includes a second control unit and a second thyristor unit, and the second control unit and the second thyristor unit are electrically connected. The second control unit is an optical coupler thyristor U2, and the second thyristor unit is a thyristor Q2;

[0032] The third thyristor control module 5 includes a third control unit and a third thyristor unit, and the third control unit and the third thyristor unit are electrically connected. The third control unit is an optical coupler thyristor U3, and the third thyristor unit is a thyristor Q3;

[0033] For example: the first thyristor Q1. The MCU module controls the on and off of the built-in light-emitting diode of the optocoupler thyristor U1 to trigger the bidirectional thyristor inside the optocoupler thyristor U1 to turn on. After the bidirectional thyristor inside the optocoupler thyristor U1 turns on, the thyristor Q1 is triggered and the thyristor Q1 turns on. Among them, the capacitor C1 and the resistor R5 are the protection devices of the thyristor Q1, and the actual work does not affect the working logic of the thyristor Q1. The resistor R1 and the resistor R2 are current limiting resistors, and their values ​​are determined according to the selection of the optocoupler thyristor U1, the thyristor Q1 and the load. The resistor R6 and the capacitor C2 are the shutdown circuit of the thyristor.

[0034] The trigger circuits of the other two power thyristors are similar to that of thyristor Q1. They are classic circuits and will not be described in detail here.

[0035] The bidirectional thyristor thyristor Q1, thyristor Q2, and thyristor Q3 are prohibited from being turned on at the same time.

[0036] State 1: When the external voltage is low, the low-resistance heating wire and the high-resistance heating wire are in parallel connection mode.

[0037] State 2: When the external voltage is the second lowest, the low-resistance heating wire works and the high-resistance heating wire is turned off.

[0038] State 3: When the external voltage is the second highest, the low-resistance heating wire is turned off and the high-resistance heating wire is turned on.

[0039] State 4: When the external voltage is high, the low-resistance heating wire and the high-resistance heating wire are connected in series.

[0040] The above four states can be time-divided and reused according to the current input mains power state. That is, under a certain voltage, the above four states can be quickly interchanged according to a certain rule to achieve the purpose of stabilizing the power of the heating device. At the same time, under a certain state, the heating wire can work in chopping mode. For example, in state 1, the heating wire can work in half wave, full wave or 270°. In short, the ultimate goal is to keep the power of the heating device constant as much as possible under a wide voltage condition.

[0041] The resistances of the first heating wire and the second heating wire are preferably one large and one small, but can be equal, and their positions can be interchanged according to different driver programs, but the hardware structure remains unchanged.

[0042] The working states of thyristors Q1, Q2 and Q3 are changed to realize the series-parallel relationship between the first heating wire and the second heating wire:

[0043] When the MCU module pin PTC_1 is high, the optocoupler thyristor U1 is turned on, and the thyristor Q1 is turned on. When the MCU module pin PTC_2 is low, the optocoupler thyristor U2 is turned off, and the thyristor Q2 is turned off. When the MCU module pin PTC_3 is low, the optocoupler thyristor U3 is turned off, and the thyristor Q3 is turned off, the heating wire circuit is: the alternating current goes from AC_N to the thyristor Q1, then to the second heating wire and then to AC_L. At this time, the second heating wire works alone. At the same time, the MCU changes the level change of PTC_C1 through the detection of the zero point to realize the chopping of the thyristor Q1, thereby controlling the power change of the second heating wire.

[0044] When the MCU module pin PTC_1 is low, the optocoupler thyristor U1 is cut off, and the thyristor Q1 is cut off; the MCU module pin PTC_2 is high, the optocoupler thyristor U2 is turned on, and the thyristor Q2 is turned on; the MCU module pin PTC_3 is low, the optocoupler thyristor U3 is cut off, and the thyristor Q3 is cut off. The heating wire circuit is: the alternating current goes from AC_N to the first heating wire, then to the thyristor Q2, then to the second heating wire, and then to AC_L. At this time, the first heating wire and the second heating wire work in series. At the same time, the MCU changes the PTC_C2 level change by the zero-crossing time to realize the chopping of the thyristor Q2, thereby controlling the power change of the first heating wire and the second heating wire.

[0045] When the MCU module pin PTC_1 is low, the optocoupler thyristor U1 is cut off, the thyristor Q1 is cut off, the MCU module pin PTC_2 is low, the optocoupler thyristor U2 is cut off, the thyristor Q2 is cut off, the MCU module pin PTC_3 is high, the optocoupler thyristor U3 is turned on, the thyristor Q3 is turned on, the heating wire circuit is: the alternating current goes from AC_N to the first heating wire, then to the thyristor Q3, and then to AC_L. At this time, the first heating wire works alone. At the same time, the MCU changes the level change of PTC_C3 through the detection of the zero point to realize the chopping of the thyristor Q3, thereby controlling the power change of the first heating wire.

[0046] When the MCU module pin PTC_1 is high, the optocoupler thyristor U1 is turned on, and the thyristor Q1 is turned on. When the MCU module pin PTC_2 is low, the optocoupler thyristor U2 is turned off, and the thyristor Q2 is turned off. When the MCU module pin PTC_3 is high, the optocoupler thyristor U3 is turned on, and the thyristor Q3 is turned on, the heating wire circuit is: the alternating current goes from AC_N to the first heating wire, then to the thyristor Q3, and then to AC_L. Another set of alternating current AC_N goes to the thyristor Q1, then to the second heating wire, and then to AC_L. At this time, the first heating wire and the second heating wire work in parallel. At the same time, the MCU changes the level change of PTC_C1 or PTC_C3 through the detection of the zero point to realize the chopping of the thyristor Q1 or the thyristor Q3, thereby controlling the power change of the first heating wire and the second heating wire.

[0047] In this way, a hair dryer temperature control and regulation circuit is provided by cooperating with a mains detection module 1, an MCU module, an AC zero-crossing detection module 2, a first thyristor control module 3, a second thyristor control module 4, and a third thyristor control module 5 to divide a heating device into two windings, namely, a first heating wire and a second heating wire. The mains detection module 1 is used to detect the change in the voltage value of the mains, and the AC zero-crossing detection module 2 is used to capture the zero-crossing point of the mains AC. The MCU module controls the first thyristor control module 3, the second thyristor control module 4, and the third thyristor control module 5 to change the conduction mode of the series-parallel connection and chopping of the two windings of the first heating wire and the second heating wire according to the control signals sent by the mains detection module and the AC zero-crossing detection module, so as to realize a combination of different powers when the mains voltage is input, so as to achieve the stability or constancy of the final power, so as to make the hair dryer more widely applicable, compatible with mains with different input voltages, and used in different countries with mains input. There is no need to prepare multiple hair dryers adapted to different input mains voltages, and the cost is effectively saved.

[0048] What is described above is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes within the technical scope disclosed by the present invention according to the technical scheme and the utility model concept of the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A hair dryer temperature control circuit, characterized in that: The invention comprises a mains detection module, an MCU module, an AC zero-crossing detection module, a first thyristor control module, a second thyristor control module and a third thyristor control module. The signal output ends of the mains detection module and the AC zero-crossing detection module are connected to the signal input end of the MCU module. The signal output end of the MCU module is respectively connected to the signal input ends of the first thyristor control module, the second thyristor control module and the third thyristor control module. The output end of the first thyristor control module and the first output end of the second thyristor control module are respectively connected to the first heating wire. The second output end of the second thyristor control module and the output end of the third thyristor control module are respectively connected to the second heating wire.

2. A hair dryer temperature control circuit according to claim 1, characterized in that: The mains power detection module includes a voltage sampling unit.

3. A hair dryer temperature control circuit according to claim 1, characterized in that: The AC zero-crossing detection module includes a first AC zero-crossing detection unit and a second AC zero-crossing detection unit.

4. A hair dryer temperature control circuit according to claim 1, characterized in that: The first thyristor control module includes a first control unit and a first thyristor unit, and the first control unit and the first thyristor unit are electrically connected.

5. A hair dryer temperature control circuit according to claim 1, characterized in that: The second thyristor control module includes a second control unit and a second thyristor unit, and the second control unit and the second thyristor unit are electrically connected.

6. A hair dryer temperature control circuit according to claim 1, characterized in that: The third thyristor control module includes a third control unit and a third thyristor unit, and the third control unit and the third thyristor unit are electrically connected.

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