KR100893297B1 - Apparatus for driving heater of electric hair curler, and method for the same - Google Patents

Abstract

When driving the electric curler's heater, using a thermocouple as a temperature sensor and forming a heater driving circuit with an operational amplifier, the electric drive of the electric curler can detect and control the heater's temperature inexpensively and accurately without using a CPU. An apparatus and a method thereof are provided. The heater driving apparatus of the electric iron, the thermocouple for outputting an electric signal corresponding to the temperature detected from the heater of the electric iron; An amplifier for amplifying the electrical signal output from the thermocouple; A comparison voltage setting unit for setting a comparison voltage in the form of a triangle wave; A discriminating unit for comparing the voltage amplified by the amplifying unit with the voltage set in the comparing voltage setting unit and outputting a discrimination value; And a driving unit for outputting a driving signal for driving the heater in response to the determination value output from the determining unit.

Electric curler, heater, drive circuit, thermocouple, operational amplifier, proportional control, triangle wave

Description

Apparatus for driving heater of electric hair curler, and method for the same}

The present invention relates to a heater driving device and a method of the electric iron, and more particularly, to a driving device and a method for driving the heater during the heating of the heater of the electric iron.

The electric curler generates heat from a heater installed therein, and the generated heat is used to straighten hair or form a wave by bringing the hair into contact with the hair through a heating plate with a built-in heater.

Electric curling irons can be easily connected to a commercial power source at home, and are a beauty device that enables various hair designs to be produced. The demand for products related to curling irons is created, and thus the market demand is gradually increasing.

1 is a perspective view of a general electric iron.

Referring to FIG. 1, a general electric iron 10 includes a pair of main bodies 11 and 12, a hinge 15, a heating plate 13 and 14 with a heater, a power cable 16, and a driving circuit 17. 18).

The general electric iron 10 has a pair of main bodies 11 and 12 coupled to the hinge 15, and the heating plates 13 and 14 having heaters built in the main bodies 11 and 12 face each other. do. The heater is a part that generates heat by receiving power through the power cable 16.

In addition, the general electric curler 10 has a control unit in which the driving circuits 17 and 18 are built in the main bodies 11 and 12, and the main plates 11 and 12 have an upper plate having one side coupled to the hinge 15. 11) and the lower plate 12, the upper plate 11 and the lower plate 12 is provided with a heating plate (13, 14) each having a heater.

With the user holding the iron 10 by hand, the user places a predetermined number of hairs between the main bodies 11 and 12 of the iron 10. Then, when the user grabs the main body (11, 12), the main body (11, 12) is rotated about the hinge (15), approaching each other. Then, the heaters come in contact with both sides of the hair, and the heat of the heating plates 13 and 14 in which the heater is built is transferred to the hair. In this state, when the user pulls the curling iron 10 in the lengthwise direction of the hair, the hair may be straightened while continuously contacting the heating plates 13 and 14 with the heater built therein, or a wave may be formed.

Hair curlers currently use two types of heaters: PTC (Thermistor) heaters and Ceramic heaters. 2a and 2b is a schematic configuration diagram of a heater driving device of the electric iron according to the prior art.

As shown in FIG. 2A, the PTC heater does not use a temperature control circuit, but simply adjusts the temperature to the resistance value of the heater 13 through the heater driving circuit 17, that is, measures the resistance Rs. Thus, when the resistance Rs rises above a certain value, the resistance Rs can be used as a method for adjusting the resistance value so that the resistance does not rise anymore.

Ceramic heaters typically use a temperature control circuit, are usually used for beauty salons, and have the advantage of being very efficient due to the short preheating time. Ceramic heater iron is divided into analog and digital type, and the analog type has a large variation in resistance change according to the temperature rise of the ceramic heater.

In addition, as shown in FIG. 2B, since the digital heater driving circuit 17 performs temperature control using the CPU 17a, a circuit using a PTC (Thermistor) sensor 17b is usually used. This digital type heater driving circuit 17 can be used regardless of resistance change.

Since the heater according to the prior art has a small amount of resistance change, it is difficult to use a conventional analog circuit. Because the change in resistance is minute, it is difficult to control the temperature by accurately measuring the change in resistance, and it takes a long time to detect the change in resistance and control the temperature of the heater based on the change in temperature. Can be a condition. Accordingly, the temperature of the heater must be controlled by using the above-described digital method, but the cost of the heater driving circuit may increase, and an error may occur when the temperature of the PTC (Thermistor) is recognized.

The technical problem to be solved by the present invention is to use a thermocouple as a temperature sensor and to form a heater driving circuit with an operational amplifier when driving a heater of an electric iron, inexpensive and accurate without using a CPU It is an object of the present invention to provide a heater driving device for an electric iron and a method for detecting and controlling the temperature of a heater.

As a means for achieving the above-described technical problem, the heater driving apparatus of the electric iron according to the present invention, the thermocouple for outputting an electric signal corresponding to the temperature detected from the heater of the electric iron; An amplifier for amplifying an electric signal output from the thermocouple; A comparison voltage setting unit for setting a comparison voltage in the form of a triangle wave; A discriminating unit for comparing the voltage amplified by the amplifying unit with a voltage set by the comparing voltage setting unit and outputting a discrimination value; And a driving unit for outputting a driving signal for driving the heater in response to the determination value output from the determination unit.

Here, the heater driving apparatus of the electric iron according to the present invention compares the voltage amplified by the amplifier with a preset voltage, and when the voltage amplified from the amplifier is greater than a predetermined voltage, the driving output from the driver. It may further include a thermocouple protection to block the signal.

Here, the discriminating unit compares the comparison voltage set in the triangular wave form with the amplification voltage output from the amplifying unit, and controls the PID in a proportional differential control (PID) format. Low is characterized by increasing the output.

Here, the thermocouple may be any one selected from among a K-type thermocouple, an N-type thermocouple, an E-type thermocouple, a J-type thermocouple, and a T-type thermocouple according to an operating temperature and an environment of element wires.

The amplifying unit, the comparison voltage setting unit, and the determining unit may be configured using an operational amplifier (OP-AMP) capable of differential operation to control the temperature of the heater in a PID (proportional integral derivative) control format. .

In addition, as a means for achieving the above technical problem, the electric iron according to the present invention, a pair of hinged body; A heater that generates heat by receiving power and is installed to face each of the pair of bodies; And a heater driving circuit for driving the heater, wherein the heater driving circuit comprises: a thermocouple outputting an electric signal corresponding to a temperature detected from the heater; An amplifier for amplifying an electric signal output from the thermocouple; A comparison voltage setting unit for setting a comparison voltage in the form of a triangle wave; A discriminating unit for comparing the voltage amplified by the amplifying unit with a voltage set by the comparing voltage setting unit and outputting a discrimination value; And a driving unit for outputting a driving signal for driving the heater in response to the determination value output from the determination unit.

Here, the electric iron according to the present invention compares the voltage amplified by the amplification unit with a predetermined voltage, and when the voltage amplified by the amplification unit is greater than a predetermined voltage, the driving signal output from the driving unit is cut off. Thermocouple protection may further comprise.

In addition, as a means for achieving the above-mentioned technical problem, the heater driving method of the electric iron according to the present invention, a) when power is applied to the electric iron, the thermocouple detects the temperature of the heater of the electric iron and outputs it as an electric signal Making; b) amplifying the electric signal corresponding to the detected temperature by a predetermined multiple and outputting the amplified voltage; c) calculating a discrimination value by comparing the amplified voltage with a preset comparison voltage; And d) converting and outputting the heater driving signal corresponding to the determination value.

Here, the heater driving method of the electric iron according to the present invention, e) comparing the voltage amplified from the amplification unit with a predetermined voltage, if the voltage amplified from the amplification unit is greater than the predetermined voltage, output from the driving unit The method may further include blocking the driving signal.

In the step c), the preset comparison voltage is set in the form of a triangular wave, and the output voltage is PID controllable by comparing the amplified voltage with the comparison voltage in the form of a triangular wave.

According to the present invention, when a heater of an electric iron is driven, a thermocouple is used as a temperature sensor and a heater driving circuit is formed by an operational amplifier, so that the temperature of the heater can be detected and controlled inexpensively and accurately without using a CPU. .

Hereinafter, with reference to the accompanying drawings, it will be described in detail the heater driving apparatus and method of the electric iron according to an embodiment of the present invention.

As an embodiment of the present invention, there is provided a heater driving apparatus and method of an electric iron that uses a K type thermocouple instead of a thermistor as a temperature sensor and can adjust the temperature of the heater detected from the thermocouple without using a CPU. .

3 is a block diagram of a heater driving device of the electric iron according to an embodiment of the present invention.

Referring to FIG. 3, the heater driving circuit 100 of the electric iron according to the embodiment of the present invention includes a thermocouple 110, an amplifier 120, a comparison voltage setting unit 140, a determination unit 130, and a driving unit. 150, and may further include a thermocouple protection unit 160 and a power supply unit 170.

The thermocouple 110 outputs an electric signal corresponding to the temperature detected from the heater 200 of the electric curler. The driving principle of the thermocouple is that when the ends of different dissimilar metals are bonded to each other and heat is applied thereto, minute electromotive force is generated at both ends of the thermocouple corresponding to the temperature. Thermocouple 110 according to an embodiment of the present invention, for example, K type, the positive electrode (+) is an alloy of nickel and chromium (Ni-Cr; Chromel) and the negative electrode (-) is nickel and aluminum It consists of an alloy of aluminum (Ni-Al; Alumell), the operating temperature can be detected from 0 ℃ to 1200 ℃. The K type thermocouple 110 is widely used because it is cheaper and has a wider temperature measurement range than other types of thermocouples.

In addition, according to the thermocouple 110 according to the embodiment of the present invention, each anode (+) is an alloy of nickel, chromium and silicon (Nicrosil), the cathode (-) is an alloy of nickel and silicon, depending on the use temperature and environment N type thermocouple (Nisil), anode (+) is an alloy of nickel and chromium (Chromel), cathode (-) is an E type thermocouple of an alloy of copper and nickel (Constantan), and anode (+) is iron (Iron) The negative electrode (-) may be a J type thermocouple of a copper and nickel alloy (Constantan), the positive electrode (+) is a copper (Copper), and the negative electrode (-) may be a T type thermocouple which is an alloy of copper and nickel. have.

The amplifier 120 amplifies the electric signal output from the thermocouple 110.

The comparison voltage setting unit 140 sets the comparison voltage in the form of a triangular wave.

The determination unit 130 compares the voltage amplified by the amplifier 120 with a voltage set by the comparison voltage setting unit 140 and outputs a determination value. Specifically, the determination unit 130 compares the comparison voltage set in the triangular wave form with the amplification voltage output from the amplification unit 120, and controls in a PID (proportional integral differential control) form, the detection temperature is Higher outputs lower the outputs, while lower detection temperatures increase the outputs.

The driver 150 outputs a driving signal for driving the heater 200 in response to the determination value output from the determination unit 130.

The thermocouple protector 160 compares the voltage amplified by the amplifier 120 with a preset voltage, and outputs the voltage from the driver 150 when the voltage amplified by the amplifier 120 is greater than a preset voltage. It serves to block the driving signal. Accordingly, when the detection temperature of the heater 200 is greater than or equal to a predetermined temperature, the thermocouple 110 may not operate by blocking the driving signal input to the heater 200, thereby protecting the thermocouple 110. .

The power supply unit 170 may be either an AC power source or a DC power source. For example, the AC power source may be converted into Vcc by converting the AC power source into DC, and then converted into Vcc input to various semiconductor devices, or the heater 200 may be used. DC power for driving) is supplied.

In addition, in the heater driving circuit of the electric iron according to the embodiment of the present invention, the amplifier 120, the comparison voltage setting unit 140 and the determination unit 130 is PID (proportional integral of the temperature of the heater 200) Differential) can be configured by using OP-AMP which can be differentially operated to control in the form of control.

On the other hand, the heater driving circuit of the electric iron according to the embodiment of the present invention is a circuit using an amplification and a comparator by using an operational amplifier (OP-AMP), K-type thermocouple (Thermocouple) by utilizing the characteristics of the operational amplifier Amplify the electromotive force relative to the temperature generated by the maximum, detect the abnormality such as disconnection of the thermocouple 110, and also the PID (proportional control) type of the temperature of the heater 200 by utilizing the differential operation (difference) of the operational amplifier To control.

Here, PID control (proportional integral derivative control) is a kind of feedback control to maintain the output voltage of the system based on the error between the control variable and the reference input, Proportional control and Proportional-Integral. ) A combination of control and proportional-derivative control. At this time, the P control (proportional) multiplies the error signal between the reference signal and the current signal by a proper proportional constant gain to generate a control signal. In addition, I control (proportional integration) uses integral control in parallel to proportional control, which integrates an error signal to produce a control signal. D control (proportional derivative) uses derivative control in parallel to proportional control to differentiate the error signal to form a control signal.

4 is a circuit diagram of a heater driving apparatus of the electric iron according to the embodiment of the present invention.

Referring to FIG. 4, the heater driving circuit 100 of the electric iron according to the embodiment of the present invention includes a thermocouple 110, an amplifier 120, a comparison voltage setting unit 140, a determination unit 130, and a driving unit. And a thermocouple protection unit 160 and a power supply unit 170. Here, if the heater driving circuit 100 of the electric iron according to the embodiment of the present invention can implement the same function, it is apparent to those skilled in the art that the present invention is not limited to the circuit configuration shown in FIG.

First, the amplifier 120 is composed of OP-AMP ((U3; 121) and resistors R7 and R9), and a small amount of electromotive force generated corresponding to the temperature detected from the thermocouple 110 is converted into R7 / R9. Amplification is about 1000 times or more, because a low amplification rate may cause a malfunction of the heater driving circuit.

The comparison voltage setting unit 140 is composed of a plurality of resistors (R5, R6, R8, R11, R12, R14, R16) OP-AMP (U2; 141), and sets the comparison voltage in the form of a triangular wave, The comparison voltage set as described above is input to one input terminal of the determination unit 130.

The determination unit 130 is composed of an OP-AMP (U4) 131 and resistors R13 and R15, and the OP-AMP (U4) 131 receives an electrical signal amplified by an electric quantity corresponding to the detected temperature of the heater. The determination value is output by comparing the set temperature set by the comparison voltage setting unit 140, that is, the comparison voltage set in the form of a triangular wave. The determination unit 130 is to control the temperature of the heater 200 in the PID format. If the detection temperature of the heater is high, the output is lowered. If the detection temperature of the heater is low, the determination unit 130 increases and outputs the output.

The driver 150 includes a switching transistor Q2, a triac T1, and a plurality of resistors R4, R17, and R18, and corresponds to the heater output from the determination unit 130. A driving signal for driving 200 is output. Here, the triac T1 is a power semiconductor device that controls switching of a power source for driving the heater 200 in response to the output of the switching transistor Q2.

The thermocouple protection unit 160 includes an OP-AMP (U1) 161, resistors R1, R2, and R3, and a switching transistor Q1, and the voltage amplified from the amplifier 120 is a preset voltage. In comparison, when the voltage amplified by the amplifier 120 is greater than a predetermined voltage, the driving signal output from the driver 150 is blocked. That is, the output signal output through the switching transistor Q1 blocks the signal output from the determination unit 130 from being input to the switching transistor Q2 of the driver 150. In other words, when the detection temperature of the heater 200 is greater than or equal to a predetermined temperature, the thermocouple 110 may not operate by blocking the driving signal input to the heater 200, thereby protecting the thermocouple 110. For example, when the thermocouple 110 is disconnected due to overheating, the thermocouple 110 may be prevented from detecting a temperature of the heater 200 in advance, and may also prevent hair damage and fire due to overheating. Can be prevented.

The power supply unit 170 includes diodes D1 and D2, a zener diode D3, and a capacitor C3, and may be either an AC power source or a DC power source, for example, an AC power source. Rectify and convert it to Vcc input to the semiconductor element, or supply DC power DC for driving the heater 200.

Meanwhile, FIGS. 5A to 5D are diagrams illustrating driving waveforms for driving a heater of an electric iron according to an embodiment of the present invention.

FIG. 5A illustrates a comparison voltage V_ref set in a triangular wave form, a voltage detected and amplified from a thermocouple in response to a temperature T_sense of a heater, and a driving voltage V_drive output from a driving unit, respectively.

5B illustrates a case where the temperature detected from the heater is low, and the comparison voltage V_ref is set in the form of a triangular wave, and since the temperature T_sense of the heater is low, the voltage detected and amplified from the thermocouple is higher than the comparison voltage V_ref. It indicates low, and corresponds to outputting the driving voltage (V_drive) from the drive correspondingly.

5C illustrates a case where the temperature detected from the heater is medium, and the comparison voltage V_ref is set in the form of a triangular wave, and since the temperature T_sense of the heater is medium, the voltage detected and amplified from the thermocouple is the comparison voltage V_ref. It indicates that it is medium compared to), and correspondingly, the driving unit outputs the driving voltage V_drive.

5D illustrates a case where the temperature detected from the heater is high, and the comparison voltage V_ref is set in the form of a triangular wave, and since the temperature T_sense of the heater is high, the voltage detected and amplified from the thermocouple is greater than the comparison voltage V_ref. High indicates that the driving unit outputs the driving voltage V_drive.

5B to 5D, the waveform of the driving voltage V_drive output from the driver may be found to decrease in the width of the high section as the temperature detected from the heater increases.

On the other hand, Figure 6 is an operation flowchart of a heater driving method of the electric iron according to an embodiment of the present invention.

Referring to FIG. 6, in the heater driving method of the electric iron according to the embodiment of the present invention, first, when power is applied to the electric iron (S610), the thermocouple detects the temperature of the heater of the electric iron and outputs it as an electric signal. (S620).

Next, an amplified electric signal corresponding to the detection temperature is amplified by a predetermined multiple to output the amplified voltage (S630).

Next, a determination value is calculated by comparing the amplified voltage with a predetermined comparison voltage (S640). At this time, the predetermined comparison voltage is set in the form of a triangular wave, and outputs an PID controllable output signal by comparing the amplified voltage with the comparison voltage in the form of a triangular wave.

Next, after converting the heater driving signal corresponding to the determination value (S650), the heater is driven by the heater driving signal (S660).

7 is a flowchart illustrating a method of driving a heater of an electric iron according to a specific embodiment of the present invention.

Referring to FIG. 7, in the method of driving a heater of an electric iron according to a specific embodiment of the present invention, first, when power is applied to the electric iron (S701), the thermocouple detects the temperature of the heater of the electric iron and outputs it as an electric signal. It is made (S702). In this case, the thermocouple may be selected from a K type thermocouple, an N type thermocouple, an E type thermocouple, a J type thermocouple, and a T type thermocouple according to a use temperature and an environment.

Next, the electric signal corresponding to the detected temperature is amplified by a predetermined multiple and the amplified voltage is output (S703). That is, the electric signal corresponding to the minute electromotive force generated from the K type thermocouple is amplified by about 1000 times or more.

Next, a determination value is calculated by comparing the amplified voltage with a predetermined comparison voltage (S704). At this time, the predetermined comparison voltage is set in the form of a triangular wave, and outputs an PID controllable output signal by comparing the amplified voltage with the comparison voltage in the form of a triangular wave.

Next, it is determined whether the determination value is smaller than the low temperature value T_low (S705), or whether the determination value is larger than the low temperature value T_low and smaller than the high temperature value T_high (S706), or It is determined whether the determination value is larger than the high temperature value T_high and smaller than the threshold temperature value T_critical (S707).

Next, when the determination value is smaller than the high temperature value T_high, the heater is driven with the heater driving signal after conversion to the heater driving signal corresponding to each determination value (S708).

If the determination value is greater than the high temperature value T_high and smaller than the threshold temperature value T_critical, the thermocouple protection circuit is operated to protect the thermocouple (S710).

As a result, according to an embodiment of the present invention, by using a thermocouple instead of a conventional PTC (Thermistor) sensor and configuring a heater driving circuit with an operational amplifier, it is possible to reduce the temperature of the heater accurately and inexpensively without using a CPU. Detection and control. The heater driving circuit is a circuit resistant to rapid temperature detection and control and can be used for temperature control in all fields.

The present invention described above is not limited to the above-described embodiments and the accompanying drawings, and it is common in the art that various substitutions, modifications, and changes can be made without departing from the technical spirit of the present invention. It will be evident to those who have knowledge of.

1 is a perspective view of a general electric iron.

2a and 2b is a schematic configuration diagram of a heater driving device of the electric iron according to the prior art.

3 is a block diagram of a heater driving device of the electric iron according to an embodiment of the present invention.

4 is a circuit diagram of a heater driving apparatus of the electric iron according to the embodiment of the present invention.

5A to 5D are diagrams illustrating driving waveforms for driving a heater of an electric iron according to an embodiment of the present invention, respectively.

6 is a flowchart illustrating a method of driving a heater of an electric iron according to an embodiment of the present invention.

7 is a flowchart illustrating a method of driving a heater of an electric iron according to a specific embodiment of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

100: heater drive device 110: thermocouple

120: amplifier 130: discrimination unit

140: comparison voltage setting unit 150: driving unit

160: thermocouple protection unit 170: power supply

200: heater

Claims (10)

A thermocouple outputting an electric signal corresponding to the temperature detected from the heater of the electric curler; An amplifier for amplifying an electric signal output from the thermocouple 1000 times; A comparison voltage setting unit for setting a comparison voltage in the form of a triangle wave; A discriminating unit for comparing a voltage amplified by the amplifying unit with a magnitude of a triangular wave type voltage set by the comparing voltage setting unit and outputting a discrimination value; And A driving unit for outputting a driving signal for driving the heater in response to the discriminating value output from the determining unit Including, As the temperature detected from the heater increases, the driving voltage output from the driving unit is narrowed so that an output section of the driving voltage output from the driving unit becomes narrower, and the amplified voltage is output only in a section in which the amplified voltage is lower than the comparison voltage of the triangular wave form. The thermocouple is a positive electrode (+) is a chromel alloy of nickel and chromium, the cathode (-) is a heater type device of electric iron, characterized in that the K-type thermocouple is an alloy of nickel and aluminum. The method of claim 1, Comparing the voltage amplified from the amplifier with a predetermined voltage, and if the voltage amplified from the amplifier is greater than a predetermined voltage, the thermocouple protection unit further comprises a thermocouple protection unit for blocking the drive signal output from the drive unit Heater drive unit. The method of claim 1, The determining unit compares the comparison voltage set in the triangular wave form with the amplification voltage output from the amplifying unit, and controls the PID in a proportional integral differential control (PID) format. When the detection temperature is high, the output is lowered and the detection temperature is low. The heater drive device of the electric iron, characterized in that to increase the output power. delete The method of claim 1, The amplifying unit, the comparison voltage setting unit and the discriminating unit includes an electric amplifier (OP-AMP) that can be differentially operated in order to control the temperature of the heater in a PID (proportional integral derivative) control type drive. A pair of bodies hinged; A heater that generates heat by receiving power and is installed to face each of the pair of bodies; And Heater drive circuit for driving the heater To include, the heater driving circuit, A thermocouple outputting an electrical signal corresponding to the temperature detected from the heater; An amplifier for amplifying an electric signal output from the thermocouple; A comparison voltage setting unit for setting a comparison voltage in the form of a triangle wave; A discriminating unit for comparing the voltage amplified by the amplifying unit with a voltage set by the comparing voltage setting unit and outputting a discrimination value; And A driving unit for outputting a driving signal for driving the heater in response to the determination value output from the determination unit, As the temperature detected from the heater increases, the driving voltage output from the driving unit is narrowed so that an output section of the driving voltage output from the driving unit becomes narrower, and the amplified voltage is output only in a section in which the amplified voltage is lower than the comparison voltage of the triangular wave form. The thermocouple is an electric iron, characterized in that the positive electrode (+) is an alloy of nickel and chromium, the negative electrode (-) is a K-type thermocouple is an alloy of nickel and aluminum. The method of claim 6, The heater driving circuit, A thermocouple protection unit which compares the voltage amplified by the amplification unit with a preset voltage and cuts off a driving signal output from the driving unit when the voltage amplified by the amplifying unit is greater than a predetermined voltage. Electric curling iron further comprising. delete delete delete

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