Apparatus and method for temperature control using differential resistance magnetostrictive heating wire

Abstract

The present invention relates to a temperature control device using a non-magnetic heating wire, and more specifically, to a temperature control device and method using a differential resistance non-magnetic heating wire, wherein a first heating wire and a second heating wire configured to cancel out a magnetic field generated from a heating wire are composed of a first metal and a second metal with a large difference in resistance values ​​to increase heat generation efficiency and form a non-magnetic field, and furthermore, a temperature detection means using an operational amplifier (OPAMP) including a DC and a parallel bridge circuit is used to perform precise temperature control.

Description

Technology Field

[0001] The present invention relates to a temperature control device using a non-magnetic heating wire, and more specifically, to a temperature control device and method using a differential resistance non-magnetic heating wire, wherein a first heating wire and a second heating wire configured to cancel out a magnetic field generated from a heating wire are composed of a first metal and a second metal with a large difference in resistance values ​​to increase heat generation efficiency and form a non-magnetic field, and furthermore, a temperature detection means using an operational amplifier (OPAMP) including a DC and a parallel bridge circuit is used to perform precise temperature control. Background Technology

[0003] Generally, heating mats such as electric mats, hot water mats, and electric blankets include a heating wire that generates heat by receiving an electric current, and a temperature control device that regulates the temperature generated by the heating wire by adjusting the current supplied to the heating wire.

[0004] Typically, heating wires and temperature controllers generate heat by supplying household AC power directly to the wires; therefore, they feature simple and inexpensive circuit structures and are advantageous for high-output operation. Due to these advantages, AC-type heating wires and temperature controllers that heat the wires using AC are widely used.

[0005] However, AC heating wires have a problem in that changes in the magnetic field caused by variable alternating current can induce an electric current in the human body when a person sits or lies on the wire, which can be harmful to the human body. To solve this problem, conventional AC heating wires mainly use two-strand non-magnetic heating wires that cancel out the electric field generated by the alternating current by configuring two heating wires internally and configuring the direction of the alternating current flowing through each heating wire to be opposite.

[0006] Conventional temperature control devices using heating wires measure the temperature generated by the heating wire through an NTC thermistor configured around or inside the heating wire, and control the temperature generated by the heating wire by comparing the measured temperature with a set temperature.

[0007] Conventional temperature control devices have problems such as unstable temperature characteristics and reduced precision when using a standard NTC thermistor as a temperature detection sensor, and unstable temperature characteristics at low temperatures (below 40 degrees) and very high production costs for the heating wire when using an expensive synthetic resin (nylon) NTC thermistor to wrap the upper part of the first heating wire, which is the central heating wire. Prior art literature

[0009] Republic of Korea Registered Patent No. 10-1560123 (Published on Oct. 26, 2015) The problem to be solved

[0010] Accordingly, the objective of the present invention is to provide a temperature control device and method using a differential resistance non-magnetic field heating wire, wherein the first heating wire and the second heating wire, configured to cancel out the magnetic field generated from the heating wire, are composed of a first metal and a second metal with a large difference in resistance values ​​to form a non-magnetic field, as well as to increase heat generation efficiency and perform precise temperature control through a temperature detection means utilizing an operational amplifier (OPAMP) including a DC and a parallel bridge circuit.

[0011] In addition, the objective of the present invention is to provide a temperature control device and method using a differential resistance non-magnetic heating wire that performs precise temperature control by measuring the temperature of the heating wire using two different methods: a temperature detection means using an OPAMP and direct current, and an NTC thermistor and alternating current. means of solving the problem

[0013] A temperature control device using a differential resistance non-magnetic field heating wire according to the present invention, according to a first embodiment for achieving the above-mentioned purpose, comprises: a ventricle constituting a central part; a first heating wire having a fifth resistance, which is a primary resistance component of the primary winding, and a first outer sheath covering the upper part of the first heating wire; a second heating wire having a fourth resistance, which is a secondary winding internal resistance having a temperature characteristic that is smaller than the resistance value of the fifth resistance and changes according to temperature, and having one end connected to the other end of the first heating wire; and a first switching unit having one end connected to the live line of an AC power supply and the other end connected to one end of the first heating wire of the differential resistance non-magnetic field heating wire, which turns on or off according to an input gate trigger signal, and supplies the AC power to the first heating wire of the differential resistance non-magnetic field heating wire when turned on. The invention is characterized by comprising: a parallel bridge temperature detection unit that forms a parallel bridge circuit reflecting the fourth resistance of the second heating wire connected to one end and the other end of the second heating wire, is connected to a DC power source to receive DC, and outputs a temperature detection signal according to the temperature of the differential resistance non-magnetic heating wire when the first switching unit is turned off; and a microcomputer that generates a gate trigger signal according to the temperature difference obtained by comparing the temperature corresponding to the temperature detection signal input from the parallel bridge temperature detection unit and the set temperature, and outputs the signal to the first switching unit.

[0014] The above device is characterized by further including a second switching unit connected between the other end of the first heating wire and one end of the second heating wire, which is turned on or off by receiving the gate trigger signal.

[0015] The parallel bridge temperature detection unit comprises: a first resistor, one end of which is connected to the DC power source and the other end of which is connected to the other end of the first heating wire; a second resistor, one end of which is connected to the DC power source; a third resistor, one end of which is connected to the other end of the second resistor and the other end of which is connected to the neutral line of the AC power source and the other end of the second heating wire; and an OPAMP, wherein a non-inverting terminal (+) is connected to the other end of the first resistor and an inverting terminal (-) is connected to the other end of the second resistor and one end of the third resistor, and the first resistor, the second resistor, the third resistor, and the fourth resistor, which is a resistance component of the second heating wire having a fourth resistance value, form a parallel bridge circuit to amplify the change in the fourth resistance value according to the temperature of the differential resistance non-magnetic field heating wire and output a temperature detection signal.

[0016] The above parallel bridge temperature detection unit is characterized by further including a negative feedback resistor, one end of which is connected to the inverting terminal and the other end of which is connected to the output terminal of the OPAMP, for determining the amplification rate of the OPAMP when the parallel bridge circuit is in a parallel condition.

[0017] The first outer sheath of the differential resistance non-magnetic field heating wire is an NTC thermistor, and the device further comprises: a current limiting resistor, one end of which is connected to the live line of the AC power supply unit to limit the current of the AC power supply unit; and a second temperature detection unit, one end of which is connected to the other end of the current limiting resistor, and the other end of which is connected to the other end of the sixth resistor and the other end of which is connected to the neutral line of the AC power supply unit, and which outputs a second temperature detection signal to the microcomputer that reflects the impedance value according to the temperature of the NTC thermistor of the differential resistance non-magnetic field heating wire according to the AC signal supplied to the differential resistance non-magnetic field heating wire when the first switching unit is turned on.

[0018] The microcomputer is characterized by calculating a second temperature corresponding to the second temperature detection signal output from the second temperature detection unit when the first switching unit is turned on, and calculating a first temperature corresponding to the temperature detection signal output from the parallel bridge temperature detection unit when the first switching unit is turned off.

[0019] The above microcomputer is characterized by averaging and displaying the difference between the first temperature and the second temperature if the difference is within a preset range, and displaying the first temperature if it is outside the preset range.

[0020] The voltage ratio between the terminals by the above-mentioned fifth resistor and fourth resistor is characterized as being 20:1 or greater.

[0021] A temperature control device using a differential resistance non-magnetic heating wire according to the present invention, according to a second embodiment for achieving the above-mentioned purpose, comprises: a ventricle constituting a central part; a first heating wire wound on the outer surface of the ventricle and having a fifth resistance component, a first outer sheath covering the upper part of the first heating wire; a second heating wire wound on the outer surface of the first outer sheath and having a fourth resistance that is smaller than the resistance value of the fifth resistance and has a temperature characteristic that changes with temperature, and having one end connected to the other end of the first heating wire; and a first switching unit having one end connected to the live wire of an AC power supply and the other end connected to the other end of the first heating wire, which repeatedly turns on and off according to an input gate trigger signal, and supplies the AC power to the first heating wire when turned on. The invention is characterized by comprising: a parallel bridge temperature detection unit that forms a parallel bridge circuit connected to one end and the other end of the second heating wire and reflects the fourth resistance value of the second heating wire, and is connected to a DC power source to receive DC and output a temperature detection signal according to the temperature of the differential resistance non-magnetic field heating wire; and a microcomputer that generates a gate trigger signal according to the temperature difference obtained by comparing the temperature corresponding to the set temperature and the temperature detection signal input from the parallel bridge temperature detection unit with the set temperature, and outputs the signal to the first switching unit.

[0022] A temperature control method using a differential resistance non-magnetic field heating wire according to the present invention for achieving the above-mentioned purpose comprises: a differential resistance non-magnetic field heating wire comprising a ventricle constituting a central part, a first heating wire wound on the outer surface of the ventricle and having a fifth resistance which is a resistive component, a first outer sheath which is an NTC thermistor covering the upper part of the first heating wire, and a second heating wire wound on the outer surface of the first outer sheath and having a fourth resistance which is smaller than the resistance value of the fifth resistance and has a temperature characteristic that changes with temperature, and having one end connected to the other end of the first heating wire; and a first switching unit having one end connected to the live wire of an AC power supply unit and the other end connected to one end of the first heating wire of the differential resistance non-magnetic field heating wire, which is turned on or off according to an input gate trigger signal, and when turned on, supplies the AC power to the first heating wire of the differential resistance non-magnetic field heating wire. A temperature control device comprising: a parallel bridge temperature detection unit that forms a parallel bridge circuit reflecting a fourth resistance value of the second heating wire connected to one end and the other end of the second heating wire, is connected to a DC power source to receive DC, and outputs a temperature detection signal according to the temperature of the differential resistance non-magnetic heating wire when the first switching unit is turned off; a current limiting resistor, one end of which is connected to the live wire of the AC power source to limit the current of the AC power source; and a microcomputer, wherein when AC power is supplied, the microcomputer acquires temperature setting information, generates a gate trigger signal according to the acquired temperature setting information and outputs it to the first switching unit to supply AC power to the differential resistance non-magnetic heating wire to generate heat; a second temperature measurement process in which the microcomputer receives a second temperature detection signal from the second temperature detection unit and measures a second temperature when the first switching unit is turned on; and a first temperature measurement process in which the microcomputer receives a temperature detection signal from the parallel bridge temperature detection unit and measures a first temperature when the first switching unit is turned off. and is characterized by including a temperature output process in which the microcomputer outputs one or more of the first temperature and the second temperature through an input / output unit.

[0023] In the above temperature output process, the microcomputer is characterized by averaging and outputting the difference between the first temperature and the second temperature if the difference is within a preset range, and outputting the first temperature if it is outside the preset range. Effects of the invention

[0025] The present invention configures the metal materials of the first and second heating wires constituting a non-magnetic heating wire differently so that the difference in resistance values ​​between the first heating wire, which has a high resistance value, and the second heating wire, which has a low resistance value and good temperature characteristics, becomes large. By configuring the current direction flowing through the first heating wire and the current direction flowing through the second heating wire to be opposite to each other, the invention has the effect of controlling the temperature of the heating wire through the first heating wire and measuring the temperature more accurately through the second heating wire while maintaining a non-magnetic field.

[0026] In addition, the present invention measures the temperature through a second heating wire, but measures the temperature of the heating wire using direct current through a differential amplifier using an OPAMP while the AC input to the heating wire is blocked, thereby having the effect of safely protecting the OPAMP while measuring the temperature of the heating wire more precisely.

[0027] In addition, since the present invention allows temperature measurement using a second heating wire and an OPAMP, the configuration wrapping the upper part of the first heating wire can be configured with a general sheath instead of an NTC thermistor, thereby having the effect of lowering the production cost of the non-magnetic heating wire.

[0028] In addition, the present invention has the effect of enabling more precise and stable control by allowing temperature control to be performed using both the first temperature measured by the general AC and NTC thermistor and the second temperature measured by the DC and OPAMP from the second heating wire when the configuration for monitoring the first heating wire is configured with an NTC thermistor. Brief explanation of the drawing

[0030] FIG. 1 is a drawing for explaining the structure of a differential resistance non-magnetic heating wire according to the present invention. FIG. 2 is a block diagram showing a temperature control device using a differential resistance non-magnetic heating wire according to the present invention. FIG. 3 is a circuit diagram of a temperature control device using a differential resistance non-magnetic heating wire according to the first embodiment of the present invention. FIG. 4 is a diagram showing an equivalent circuit diagram of a temperature control device using a differential resistance non-magnetic heating wire according to the first embodiment of the present invention. FIG. 5 is a diagram showing an equivalent circuit diagram of a temperature control device using a differential resistance non-magnetic heating wire according to a second embodiment of the present invention. FIG. 6 is a diagram showing the circuit of the heating wire and the parallel bridge temperature detection unit when the AC power is cut off, according to an embodiment of the present invention. FIG. 7 is a diagram showing an equivalent circuit diagram of a heating wire and a parallel bridge temperature detection unit when the AC power is cut off, according to an embodiment of the present invention. FIG. 8 is a diagram showing an equivalent circuit diagram of a temperature control device using a differential resistance non-magnetic heating wire according to a third embodiment of the present invention. FIG. 9 is a flowchart illustrating a temperature control method using a differential resistance non-magnetic heating wire according to an embodiment of the present invention. Specific details for implementing the invention

[0031] The configuration and operation of a differential resistance non-magnetic field heating wire and a temperature control device using the same according to the present invention will be described below with reference to the attached drawings, and a temperature control method using a differential resistance non-magnetic field heating wire according to an embodiment will be described in detail.

[0032] FIG. 1 is a drawing for explaining the structure of a differential resistance non-magnetic heating wire according to the present invention.

[0033] Referring to FIG. 1, reference numeral 10 in the drawing is a differential resistance non-magnetic heating wire.

[0034] The differential resistance non-magnetic heating wire (10) according to the present invention comprises a core wire (or “Core”, 11) constituting a central part, a first heating wire (12) wound on the outer surface of the core wire (11), a first outer sheath (13) covering the upper part of the first heating wire (12), a second heating wire (14) wound on the outer surface of the first outer part (13), and a covering (15) covering the upper part of the second heating wire (14).

[0035] The first heating wire (12) and the second heating wire (14) of the differential resistance non-magnetic heating wire (10) of the present invention are made of a first metal and a second metal, respectively, having different resistance values.

[0036] The first metal mentioned above may be an alloy heating element or other metal conductor, and the second metal is preferably a metal with a high temperature coefficient, such as copper, iron, or nickel.

[0037] The resistance component of the first heating wire (12) is referred to as the fifth resistor, and the resistance component of the second heating wire (14) is referred to as the fourth resistor. The ratio of the resistance values ​​of the fifth resistor and the fourth resistor (= the ratio of the voltage across the fifth resistor and the fourth resistor) is preferably 20:1 or greater to protect the parallel bridge circuit configuration of the parallel bridge temperature detection unit (100) described later in FIG. 2 and the parallel bridge temperature detection unit (100). For example, if the fifth resistor is 200 kΩ, it is preferable that the fourth resistor is 2 kΩ or less, and if the fourth resistor is 2 kΩ, it is preferable that the fifth resistor is 200 kΩ or more.

[0038] The first outer sheath (13) covering the upper part of the first heating wire (12) may be a general coating such as silicone rubber, fluoropolymer, or PVC, or, depending on the embodiment, may be an NTC thermistor whose resistance value varies with temperature. It is preferable to use polyamide 12 / 11 (nylon series) as the NTC thermistor.

[0040] FIG. 2 is a block diagram showing a temperature control device using a differential resistance non-magnetic field heating wire according to the present invention; FIG. 3 is a circuit diagram showing a temperature control device using a differential resistance non-magnetic field heating wire according to a first embodiment of the present invention; FIG. 4 is an equivalent circuit diagram showing a temperature control device using a differential resistance non-magnetic field heating wire according to a first embodiment of the present invention; FIG. 5 is an equivalent circuit diagram showing a temperature control device using a differential resistance non-magnetic field heating wire according to a second embodiment of the present invention; FIG. 6 is a circuit diagram showing a heating wire and a parallel bridge temperature detection unit when the AC power supply is cut off according to an embodiment of the present invention; and FIG. 7 is an equivalent circuit diagram showing a heating wire and a parallel bridge temperature detection unit when the AC power supply is cut off according to an embodiment of the present invention. The following description will be explained with reference to FIG. 2 to 7.

[0041] A temperature control device using a differential resistance non-magnetic field heating wire comprises a differential resistance non-magnetic field heating wire (10), an AC power source (or referred to as an “AC power source unit”) (20), a DC power source unit (30), an input / output unit (40), a microcomputer (50), a current limiting unit (60), a first switching unit (70), and a parallel bridge temperature detection unit (100), and may further include a second switching unit (80), a second temperature detection unit (90), and a heater current detection unit (110) according to an embodiment.

[0042] The AC power supply unit (20) includes an active wire (Live, L) and a neutral wire (N) and supplies AC power (voltage, current) through the active wire.

[0043] The DC power supply unit (30) receives AC power from the AC power supply unit (20) and generates a driving voltage, which is a DC voltage required for the device, and provides it to a configuration such as a microcomputer (50) that requires the driving voltage. The driving voltage may be one or more of 12V, 5V, 3.3V, etc. According to the embodiment, the DC power supply unit (30) may also provide the driving voltage to the parallel bridge temperature detection unit (100).

[0044] The input / output unit (40) may include an input means including one or more buttons, switches, etc., and a display means for displaying one or more of the operating status of the temperature control device, a measured leakage current, a first temperature of the heating wire, a second temperature of the heating wire, an average temperature of the heating wire, a set temperature, and temperature detection error information.

[0045] The current limiting unit (60) is composed of a current limiting resistor and limits the current of the AC power source to a value below a certain value.

[0046] The first switching unit (70) receives AC power from the AC power unit (20) and receives a switching signal, a gate trigger signal (GATE_TRIGGER_out), from the microcomputer (50). When turned on by the gate trigger signal, the AC power is supplied to the first heating wire (12) of the differential resistance non-magnetic heating wire (10), and when turned off, the AC power supplied to the first heating wire (12) is cut off.

[0047] The parallel bridge temperature detection unit (100) operates by receiving a DC power supply and forms a parallel bridge circuit with the fourth resistor (R4) of the second heating wire (14) of the differential resistance non-magnetic heating wire (10). When the first switching unit (70) is turned off, it detects the temperature of the differential resistance non-magnetic heating wire (10) based on the fourth resistance value of the fourth resistor (R4), which changes according to the temperature of the differential resistance non-magnetic heating wire (10), and outputs a temperature detection signal (or "first temperature detection signal") corresponding to the detected temperature to the microcomputer (50). The DC power supply (120) may be a DC power supply unit (30) or may be configured separately including a battery, etc.

[0048] Referring to FIGS. 7 and 8, the parallel bridge temperature detector (100) includes a first resistor (R1, 101), a second resistor (R2, 102), a third resistor (R3, 103), and an operational amplifier (OPAMP) (104).

[0049] One end of the first resistor (101) and the second resistor (102) is connected to a DC power source (120) to receive DC power. The other end of the first resistor (101) is connected to one end of the second heating wire (14), the other end of the second heating wire (12), and the non-inverting terminal (+) of the OPAMP (104). The other end of the second resistor (102) is connected to one end of the third resistor and the inverting terminal (-) of the OPAMP (104). The other end of the third resistor (103) is connected to the other end of the second heating wire (14) and the neutral line of the AC power supply unit (20).

[0050] The first resistor (101), second resistor (102), third resistor (103), and the fourth resistor, which is a resistance component of the second heating wire (14), form a parallel bridge circuit, and the parallel condition is satisfied when R1=R2 and R4=R3.

[0051] The above OPAMP (104) amplifies the positive change value of R4 and outputs it to the microcomputer (50) as a temperature detection signal.

[0052] A parallel bridge temperature detector (100) has one end connected to the inverting terminal (-) of the OPAMP (104) and the other end connected to the output terminal (OUT) of the OPAMP (104), and has a negative feedback (NF) resistor (or referred to as “nf feedback resistor”) (R nf It may include )(105) more.

[0053] nf feedback resistor (R nf )(105) may be a variable resistor, and when in a parallel condition, the resistance value can be adjusted to control the amplification rate of the OPAMP (104).

[0054] The second switching unit (80) is configured according to the embodiment, and one end is connected to the other end of the first heating wire (12), and the other end is connected to one end of the second heating wire (14), the other end of the first resistor (R1, 104), and the non-inverting terminal (+) of the OPAMP (104), and receives the gate trigger signal from the microcomputer (50) and turns it on or off to connect or disconnect the first heating wire (12) and the second heating wire (14).

[0055] The first switching unit (70) and the second switching unit (80) can be equivalently represented as in FIG. 4.

[0056] In the case of the second embodiment in which the second switching unit (80) is not configured, the other end of the first heating wire (12) and one end of the second heating wire (14) are directly connected as shown in FIG. 5 and connected to the other end of the first resistor (R1, 101) and the non-inverting terminal (+).

[0057] The second temperature detection unit (90) is connected to the other end of the current limiting resistor (60) and the first heating wire (12), and the other end is connected to the neutral wire of the AC power supply unit (20). When the first switching unit (70) is turned on, it detects a second temperature reflecting the resistance value of the NTC thermistor (13) according to the temperature of the differential resistance non-magnetic heating wire (10), and outputs a second temperature detection signal according to the detected second temperature to the microcomputer (50).

[0058] The heater current detection unit (110) is composed of a heater current detection resistor, one end of which is connected to the other end of the second heating wire (14) and the other end of which is connected to the neutral line of the AC power supply unit (20), so that a heater current detection signal corresponding to the heater current flowing through the first heating wire (12) and the second heating wire (14) is output to the microcomputer (50).

[0059] The microcomputer (50) controls the overall operation of the temperature control device using differential resistance non-magnetic heating wire according to the present invention.

[0060] Specifically, the microcomputer (50) receives a temperature control input signal from the input / output unit (40) and receives a temperature detection signal and a second temperature detection signal from the parallel bridge temperature detection unit (100) and the second temperature detection unit (90). It then supplies a gate trigger signal corresponding to the temperature control input signal and the temperature detection signal to the first switching unit (60) to control the amount of heater current supplied to the differential resistance non-magnetic field heating wire (10), thereby controlling the temperature of the heat generated in the differential resistance non-magnetic field heating wire (10). In accordance with the embodiment, it receives a heater current detection signal corresponding to the amount of heater current supplied to the differential resistance non-magnetic field heating wire (10) from the heater current detection unit (1100) and controls the temperature of the heat generated in the radio field heating wire (10) to be maintained at a set temperature.

[0061] Additionally, according to the embodiment, when a temperature detection signal is input from the parallel bridge temperature detection unit (100) and a second temperature detection signal is input from the second temperature detection unit (90), the microcomputer (50) calculates a first temperature for the temperature detection signal and a second temperature for the second temperature detection signal, and outputs either of the calculated first temperature and second temperature through the input / output unit (40).

[0062] Additionally, the microcomputer (50) may be configured to calculate the average temperature of the first and second temperatures and output it through the input / output unit (40) when the difference between the first and second temperatures is less than or equal to a preset threshold, and to output the first temperature through the input / output unit (40) when the difference exceeds the threshold.

[0064] FIG. 8 is a diagram showing an equivalent circuit diagram of a temperature control device using a differential resistance non-magnetic heating wire according to a third embodiment of the present invention.

[0065] The differential resistance non-magnetic heating wire (10) of the temperature control device according to the third embodiment does not operate in a non-magnetic field.

[0066] To explain in detail, one end of the first heating wire (12) of the differential resistance non-magnetic heating wire (10) is connected to the neutral wire of the AC power supply unit (20), and the other end is connected to the live wire of the AC power supply unit (20) through the first switching unit (70), so that when the first switching unit (70) is turned on, it is heated by directly receiving AC power.

[0067] In addition, one end of the second heating wire (14) of the differential resistance non-magnetic field stranded wire (10) is connected to the other end of the first resistor (R1, 101), the second resistor (R2, 102) and the inverting terminal of the OPAMP (104), and the other end is connected to the other end of the third resistor (R3, 103).

[0068] Accordingly, the parallel bridge temperature detection unit (100) according to the third embodiment operates by the DC power supply (120) regardless of the on / off status of the first switching unit (70) and outputs a temperature detection signal to the microcomputer (50) corresponding to the resistance value of the fourth resistor (R4), a resistance component of the second heating wire (14), which varies according to the temperature of the differential resistance non-magnetic heating wire (10) that rises due to the heating of the first heating wire (12) of the differential resistance non-magnetic heating wire (10).

[0069] That is, since only one-way alternating current flows through the first heating wire (12), the magnetic field generated by the first heating wire (12) is not canceled out, but the temperature generated in the differential resistance non-magnetic heating wire (10) can be measured through the second heating wire (14), so it is not necessary to configure an NTC thermistor in the differential resistance non-magnetic heating wire (10). Therefore, the present invention can lower the production cost of the non-magnetic heating wire (10), and can also be configured to form a non-magnetic field as in the first and second embodiments described above depending on the circuit configuration, thereby increasing the usability of the differential resistance non-magnetic heating wire.

[0071] FIG. 9 is a flowchart illustrating a temperature control method using a differential resistance non-magnetic heating wire according to an embodiment of the present invention.

[0072] Referring to FIG. 9, when AC power is supplied to the microcomputer (50) (S111), it obtains temperature setting information that is stored in advance or through the input / output unit (40) (S113).

[0073] When temperature setting information is obtained, the microcomputer (50) outputs a gate trigger signal (GATE_TRIGGER_out), which is a switching signal according to the obtained temperature setting information, to the first switching unit (70) (S115).

[0074] When the gate trigger signal starts to be output, the microcomputer (50) monitors whether both the first temperature and the second temperature are detected (S117), whether only one temperature is detected (S119), or whether neither is detected (S121) through the parallel bridge temperature detector (100) and the second temperature detector (90).

[0075] If the temperature of the differential resistance non-magnetic heating wire (10) is not detected, the microcomputer (50) displays an error message to the input / output unit (40) indicating that the temperature is not detected from the two temperature detection units (90, 100) (S123).

[0076] On the other hand, if only one is detected, the microcomputer (50) outputs the detected temperature through the input / output unit (40) and outputs an error message for the temperature detection unit where no temperature was detected through the input / output unit (40) (S125).

[0077] When the first temperature and the second temperature are detected normally, the microcomputer (50) calculates the temperature difference between the first temperature and the second temperature (S127) and determines whether the calculated temperature difference exceeds a preset reference value (S129).

[0078] If the temperature difference exceeds a reference value, the microcomputer (50) outputs the second temperature through the input / output unit (40) (S131), and if the temperature difference is less than or equal to the reference value, it calculates the average temperature of the first temperature and the second temperature and outputs it through the input / output unit (40) (S133).

[0079] Additionally, since the temperature measurement accuracy of the parallel bridge temperature detection unit (100) is high, the microcomputer (50) may be configured to calculate a weighted average temperature by applying weights to one or more of the first temperature and the second temperature measured by the parallel bridge temperature detection unit (100) and then averaging them, and output the result through the input / output unit (40). The weights may be positive weights or negative weights depending on the type of temperature applied.

[0080] Meanwhile, it will be readily understood by those skilled in the art that the present invention is not limited to the typical preferred embodiments described above, but can be implemented with various improvements, modifications, substitutions, or additions within the scope of the essence of the invention. If such implementation through improvements, modifications, substitutions, or additions falls within the scope of the appended claims below, the technical concept thereof should also be considered to belong to the present invention. Explanation of the symbols

[0082] 10: Differential resistance non-magnetic heating wire 11: Core 12: First heating wire 13: Insulation sheath (or NTC thermistor) 14: Second heating element 15: Outer shell 20: AC power supply 30: DC power supply 40: Input / Output Section 50: Microcomputer 60: Current limiting section (or current limiting resistor) 70: 1st switching unit 80: 2nd switching unit 90: Second temperature detector 100: Parallel bridge temperature detector 101: First resistor (R1) 102: Second resistor (R2) 103: Third resistor (R3) 104: OPAMP 110: Heater current detection unit (or heater current detection resistor)

Claims

Claim 1 A differential resistance non-magnetic heating wire comprising: a ventricle constituting a central part; a first heating wire wound on the outer surface of the ventricle and having a fifth resistance as an internal resistance component; a first outer sheath covering the upper part of the first heating wire; and a second heating wire wound on the outer surface of the first outer sheath and having a fourth resistance as an internal resistance component that is smaller than the resistance value of the fifth resistance and has a temperature characteristic that changes with temperature, and having one end connected to the other end of the first heating wire; a first switching unit having one end connected to the live line of an AC power supply and the other end connected to one end of the first heating wire of the differential resistance non-magnetic heating wire, which turns on or off according to an input gate trigger signal, and supplies the AC power to the first heating wire of the differential resistance non-magnetic heating wire when on; and a parallel bridge circuit formed by connecting one end and the other end of the second heating wire to reflect the fourth resistance of the second heating wire, and connected to a DC power supply to receive DC, wherein the A temperature control device using a differential resistance non-magnetic heating wire, characterized by comprising: a parallel bridge temperature detection unit that outputs a temperature detection signal according to the temperature of the differential resistance non-magnetic heating wire when the first switching unit is turned off; a microcomputer that generates a gate trigger signal according to the temperature difference obtained by comparing the temperature corresponding to the temperature detection signal input from the parallel bridge temperature detection unit and the set temperature, and outputs the gate trigger signal to the first switching unit; and a second switching unit connected between the other end of the first heating wire and one end of the second heating wire, which receives the gate trigger signal and turns on or off. Claim 2 delete Claim 3 A differential resistance non-magnetic heating wire comprising: a ventricle constituting a central part; a first heating wire wound on the outer surface of the ventricle and having a fifth resistance as an internal resistance component; a first outer sheath covering the upper part of the first heating wire; and a second heating wire wound on the outer surface of the first outer sheath and having a fourth resistance as an internal resistance component that is smaller than the resistance value of the fifth resistance and has a temperature characteristic that changes with temperature, and having one end connected to the other end of the first heating wire; a first switching unit having one end connected to the live line of an AC power supply and the other end connected to one end of the first heating wire of the differential resistance non-magnetic heating wire, which turns on or off according to an input gate trigger signal, and supplies the AC power to the first heating wire of the differential resistance non-magnetic heating wire when on; and a parallel bridge circuit formed by connecting one end and the other end of the second heating wire to reflect the fourth resistance of the second heating wire, and connected to a DC power supply to receive DC, wherein the A parallel bridge temperature detection unit that outputs a temperature detection signal according to the temperature of the differential resistance non-magnetic heating wire when the first switching unit is turned off; and a microcomputer that generates a gate trigger signal according to the temperature difference obtained by comparing the temperature corresponding to the temperature detection signal input from the parallel bridge temperature detection unit and the set temperature, and outputs the signal to the first switching unit, wherein the parallel bridge temperature detection unit comprises: a first resistor, one end of which is connected to the DC power source and the other end of which is connected to the other end of the first heating wire; a second resistor, one end of which is connected to the DC power source; and a third resistor, one end of which is connected to the other end of the second resistor and the other end of which is connected to the neutral line of the AC power source and the other end of the second heating wire. A temperature control device using a differential resistance non-magnetic field heating wire, characterized by including an OPAMP in which a change in the value of the fourth resistance according to the temperature of the differential resistance non-magnetic field heating wire is amplified and a temperature detection signal is output, wherein a non-inverting terminal (+) is connected to the other end of the first resistor and an inverting terminal (-) is connected to the other end of the second resistor and one end of the third resistor, and the fourth resistor, which is a resistance component of the second heating wire having the first resistor, second resistor, third resistor, and fourth resistance values, forms a parallel bridge circuit. Claim 4 A temperature control device using a differential resistance non-magnetic heating wire, characterized in that, in paragraph 3, the parallel bridge temperature detection unit further includes a negative feedback resistor, one end of which is connected to the inversion terminal and the other end of which is connected to the output terminal of the OPAMP, and which determines the amplification rate of the OPAMP when the parallel bridge circuit is in a parallel condition. Claim 5 A differential resistance non-magnetic heating wire comprising: a ventricle constituting a central part; a first heating wire wound on the outer surface of the ventricle and having a fifth resistance as an internal resistance component; a first outer sheath covering the upper part of the first heating wire; and a second heating wire wound on the outer surface of the first outer sheath and having a fourth resistance as an internal resistance component that is smaller than the resistance value of the fifth resistance and has a temperature characteristic that changes with temperature, and having one end connected to the other end of the first heating wire; a first switching unit having one end connected to the live line of an AC power supply and the other end connected to one end of the first heating wire of the differential resistance non-magnetic heating wire, which turns on or off according to an input gate trigger signal, and supplies the AC power to the first heating wire of the differential resistance non-magnetic heating wire when on; and a parallel bridge circuit formed by connecting one end and the other end of the second heating wire to reflect the fourth resistance of the second heating wire, and connected to a DC power supply to receive DC, wherein the A parallel bridge temperature detection unit that outputs a temperature detection signal according to the temperature of the differential resistance non-magnetic heating wire when the first switching unit is turned off; and a microcomputer that generates a gate trigger signal according to the temperature difference obtained by comparing the temperature corresponding to the temperature detection signal input from the parallel bridge temperature detection unit and the set temperature, and outputs the signal to the first switching unit, wherein the first outer sheath of the differential resistance non-magnetic heating wire is an NTC thermistor, and a current limiting resistor having one end connected to the live wire of the AC power supply unit to limit the current of the AC power supply; A temperature control device using a differential resistance non-magnetic field heating wire, further comprising a sixth resistor having one end connected to the other end of the current limiting resistor, and a second temperature detection unit having one end connected to the other end of the sixth resistor and the other end connected to the neutral line of the AC power supply unit, wherein when the first switching unit is turned on, the second temperature detection unit outputs a second temperature detection signal to the microcomputer that reflects the resistance value according to the temperature of the NTC thermistor of the differential resistance non-magnetic field heating wire according to the AC signal supplied to the differential resistance non-magnetic field heating wire. Claim 6 A temperature control device using a differential resistance non-magnetic heating wire, characterized in that, in claim 5, the microcomputer calculates a second temperature corresponding to the second temperature detection signal output from the second temperature detection unit when the first switching unit is turned on, and calculates a first temperature corresponding to the temperature detection signal output from the parallel bridge temperature detection unit when the first switching unit is turned off. Claim 7 A temperature control device using a differential resistance non-magnetic heating wire according to claim 6, wherein the microcomputer displays the average when the difference between the first temperature and the second temperature is within a preset range, and displays the first temperature when it is outside the preset range. Claim 8 A differential resistance non-magnetic heating wire comprising: a ventricle constituting a central part; a first heating wire wound on the outer surface of the ventricle and having a fifth resistance as an internal resistance component; a first outer sheath covering the upper part of the first heating wire; and a second heating wire wound on the outer surface of the first outer sheath and having a fourth resistance as an internal resistance component that is smaller than the resistance value of the fifth resistance and has a temperature characteristic that changes with temperature, and having one end connected to the other end of the first heating wire; a first switching unit having one end connected to the live line of an AC power supply and the other end connected to one end of the first heating wire of the differential resistance non-magnetic heating wire, which turns on or off according to an input gate trigger signal, and supplies the AC power to the first heating wire of the differential resistance non-magnetic heating wire when on; and a parallel bridge circuit formed by connecting one end and the other end of the second heating wire to reflect the fourth resistance of the second heating wire, and connected to a DC power supply to receive DC, wherein the A temperature control device using a differential resistance non-magnetic heating wire, comprising: a parallel bridge temperature detection unit that outputs a temperature detection signal according to the temperature of the differential resistance non-magnetic heating wire when the first switching unit is turned off; and a microcomputer that generates a gate trigger signal according to the temperature difference obtained by comparing the temperature corresponding to the temperature detection signal input from the parallel bridge temperature detection unit and the set temperature, and outputs the signal to the first switching unit, wherein the voltage ratio between the terminals by the fifth resistor and the fourth resistor is 20:1 or greater. Claim 9 A differential resistance non-magnetic field heating wire comprising: a ventricle constituting a central part; a first heating wire wound on the outer surface of the ventricle and having a fifth resistance component as a resistive component; a first outer sheath covering the upper part of the first heating wire; and a second heating wire wound on the outer surface of the first outer sheath, having a fourth resistance smaller than the resistance value of the fifth resistance and having a temperature characteristic that changes with temperature, and having one end connected to the other end of the first heating wire; a first switching unit having one end connected to the live wire of an AC power supply and the other end connected to the other end of the first heating wire, which repeatedly turns on and off according to an input gate trigger signal, and supplies the AC power to the first heating wire when turned on; and a parallel bridge temperature detection unit connected to one end and the other end of the second heating wire to form a parallel bridge circuit reflecting the fourth resistance value of the second heating wire, and connected to a DC power supply to receive DC and output a temperature detection signal according to the temperature of the differential resistance non-magnetic field heating wire. The system includes a microcomputer that generates a gate trigger signal based on the temperature difference obtained by comparing the temperature corresponding to the set temperature and the temperature detection signal input from the parallel bridge temperature detection unit with the set temperature, and outputs the signal to the first switching unit, wherein the parallel bridge temperature detection unit comprises: a first resistor, one end of which is connected to the DC power source and the other end of which is connected to the other end of the first heating wire; a second resistor, one end of which is connected to the DC power source; and a third resistor, one end of which is connected to the other end of the second resistor and the other end of which is connected to the neutral line of the AC power source and the other end of the second heating wire. A temperature control device using a differential resistance non-magnetic field heating wire, characterized by including an OPAMP in which a change in the value of the fourth resistance according to the temperature of the differential resistance non-magnetic field heating wire is amplified and a temperature detection signal is output, wherein a non-inverting terminal (+) is connected to the other end of the first resistor and an inverting terminal (-) is connected to the other end of the second resistor and one end of the third resistor, and the first resistor, second resistor, third resistor, and the fourth resistor, which is a resistance component of the second heating wire having the fourth resistance value, form a parallel bridge circuit. Claim 10 delete Claim 11 A differential resistance non-magnetic field heating wire comprising: a ventricle constituting a central part; a first heating wire wound on the outer surface of the ventricle and having a fifth resistance component as a resistive component; a first outer sheath covering the upper part of the first heating wire; and a second heating wire wound on the outer surface of the first outer sheath, having a fourth resistance smaller than the resistance value of the fifth resistance and having a temperature characteristic that changes with temperature, and having one end connected to the other end of the first heating wire; a first switching unit having one end connected to the live wire of an AC power supply and the other end connected to the other end of the first heating wire, which repeatedly turns on and off according to an input gate trigger signal, and supplies the AC power to the first heating wire when turned on; and a parallel bridge temperature detection unit connected to one end and the other end of the second heating wire to form a parallel bridge circuit reflecting the fourth resistance value of the second heating wire, and connected to a DC power supply to receive DC and output a temperature detection signal according to the temperature of the differential resistance non-magnetic field heating wire. A temperature control device using a differential resistance non-magnetic heating wire, comprising a microcomputer that generates a gate trigger signal based on the temperature difference obtained by comparing the temperature corresponding to the set temperature and the temperature detection signal input from the parallel bridge temperature detection unit with the set temperature, and outputs the signal to the first switching unit, wherein the voltage ratio between the terminals by the fifth resistor and the fourth resistor is 20:1 or greater. Claim 12 A differential resistance non-magnetic field heating wire comprising: a ventricle constituting a central part; a first heating wire wound on the outer surface of the ventricle and having a fifth resistance which is a resistive component; a first outer sheath which is an NTC thermistor covering the upper part of the first heating wire; a second heating wire wound on the outer surface of the first outer sheath and having a fourth resistance which is smaller than the resistance value of the fifth resistance and has a temperature characteristic that changes with temperature, and having one end connected to the other end of the first heating wire; and a first switching unit having one end connected to the live wire of an AC power supply and the other end connected to one end of the first heating wire of the differential resistance non-magnetic field heating wire, which turns on or off according to an input gate trigger signal, and supplies the AC power to the first heating wire of the differential resistance non-magnetic field heating wire when turned on. A temperature control device comprising: a parallel bridge temperature detection unit that forms a parallel bridge circuit reflecting a fourth resistance value of the second heating wire connected to one end and the other end of the second heating wire, is connected to a DC power source to receive DC, and outputs a temperature detection signal according to the temperature of the differential resistance non-magnetic heating wire when the first switching unit is turned off; a current limiting resistor, one end of which is connected to the live wire of the AC power source to limit the current of the AC power source; and a microcomputer, wherein when AC power is supplied, the microcomputer acquires temperature setting information, generates a gate trigger signal according to the acquired temperature setting information and outputs it to the first switching unit to supply AC power to the differential resistance non-magnetic heating wire to generate heat; a second temperature measurement process in which the microcomputer receives a second temperature detection signal from the second temperature detection unit and measures a second temperature when the first switching unit is turned on; and a first temperature measurement process in which the microcomputer receives a temperature detection signal from the parallel bridge temperature detection unit and measures a first temperature when the first switching unit is turned off. A temperature control method using a differential resistance non-magnetic heating wire, characterized in that the microcomputer outputs at least one of the first temperature and the second temperature through an input / output unit. Claim 13 A temperature control method using a differential resistance non-magnetic heating wire, characterized in that, in the above temperature output process, the microcomputer averages and outputs the difference between the first temperature and the second temperature if the difference is within a preset range, and outputs the first temperature if it is outside the preset range.

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