KR200445460Y1 - Non-Magnetic Thermal Controller of Current Control - Google Patents

Abstract

The present invention relates to a current control type thermostat.

The purpose of the present invention is to adopt a current transformer that detects the output current of the thermal heater and automatically shuts off the thermal function when the output current exceeds the set range of temperature. Is kept constant, and if the heater is short-circuited, it detects a sudden change in current and immediately stops the operation of the thermal controller, eliminating the risk of damage to the electric mat or fire due to overheating and generating no harmful electromagnetic waves. Its purpose is to provide a current-controlled magnetometerless thermostat that can be used safely by essentially eliminating it.

The present invention to achieve the above object is a power switch to turn on / off;

A heater to heat the electric mat;

A heater output current sensing transformer configured to sense and output a heater output current;

A DC power supply for converting a commercial AC voltage into a DC voltage used in a digital circuit;

An input alternating voltage-DC voltage converting circuit unit for converting an input AC voltage into a DC voltage;

An offset voltage stabilization circuit unit for stabilizing offset voltages by the elements;

A current amplifier amplifying the input current from the offset stabilization circuit and the input current from the heater output current sensing transformer;

A sensing alternating current-direct current converting circuit unit converting the alternating current output from the current amplifier into a direct current;

A microcomputer that controls the operation of the entire thermostat as a main control circuit;

A temperature control volume for variably adjusting a temperature of a mat such as an electric mat within a predetermined range; And

It is characterized by providing a current control type magnetic field-free thermostat, characterized in that it comprises a thermostat for controlling the temperature of the thermostat.

Current Control, Electric Mat, Magnetic Fieldless, Temperature Controller

Description

Non-Magnetic Thermal Controller of Current Control

The present invention relates to a current control type magnetic field temperature controller, in particular, adopts a current transformer for detecting the output current of the thermal heater, and automatically shuts off the thermal function by stopping the output function when the output current is exceeded. If it is within the setting range, the temperature is kept constant by operating the heater, and when the short circuit occurs, it detects a sudden change in current and immediately stops the operation of the thermo controller, eliminating the risk of damage to the electric mat or fire due to overheating. The present invention relates to a current-controlled non-magnetic thermostat that can safely use electromagnetic waves by essentially eliminating the generation of harmful electromagnetic waves.

Conventional electric mat control temperature controller is a method of maintaining the temperature control temperature at a set temperature by applying a detection signal to the control unit of the thermostat by winding the sensing line on the heater wire to sense the capacitance of the sensing wire and using a sensor for the silicon heating wire However, if the output part using the triac is destroyed, 220V may be added to the hot wire as it is, and the hot wire may overheat. To prevent this, a mechanically operated bimetal was used. The problem of the bimetal is that the on / off operation reaction speed is slow according to temperature, and the overheat cutoff effect of the protection purpose due to overheating may be reduced.

Since the sensing line has a large variation in capacitance with temperature, the electronic mat has a large variation in set temperature. In addition, due to the spiral winding of the sensing wire on the heater wire, electromagnetic waves (electric field + magnetic field) are generated to be harmful to the human body.

If the mat is covered with a blanket for a long time in a high temperature state, the insulation effect of the sensing line due to overheating will be reduced, and if the insulation breakdown occurs, the sensing line and the heating line, which are components of the electrical mat, may short-circuit. This increases the risk of fire.

In addition, by developing a feedback control circuit that can measure and control the amount of change in heating temperature in real time while heating using a heating wire having a characteristic of a thermal wire, an economical temperature controller is required without a separate temperature sensor. The switching of the current applied to the heating wire is made by detecting the current which is changed by using a thyristor-type heater output part, and in real time by performing voltage control and output control by using a diode in the zero crossing detection part by a microcomputer and a general circuit method. Thermostats are available that can measure and control temperature changes. However, this method also has a disadvantage in that a short is generated inside the hot wire at a high temperature and cannot be used.

The present invention has been made to solve the above problems, the applicant using a constant change of the heating wire to a nickel alloy wire (more than 30% change) when the actual current (220V) flows, the resistance value changes and flows Using the change of the current value, the principle of detecting the amount of current at the output stage and sending a signal to the photocoupler in comparison with the previously input value is used to turn the output on and off at the gate of the SCR.

It adopts a current transformer that detects the output current of the thermal heater and automatically shuts off the heating function when it exceeds the setting range of the output current for each temperature, and stops the heating function when the output current is within the setting range. When the heater is short-circuited, it detects a sudden change in current and immediately stops the operation of the thermal controller, eliminating the risk of damage to the electric mat or fire due to overheating, and eliminating the use of sensing wires, thereby essentially eliminating harmful electromagnetic waves. The objective is to provide a current-controlled magnetometerless thermostat that can be used safely.

In addition, the present invention automatically cuts off at over 60 degrees of the Korea Institute of Standards and Technology for the purpose of hardware protection in case of full-function destruction in simulation, and current control system with overheat cut-off function to automatically connect at below 60 degrees. Another object is to provide a system thermostat.

The present invention to achieve the above object, the power switch to turn on / off;

A heater to heat the electric mat;

A heater output current sensing transformer configured to sense and output a heater output current;

A DC power supply for converting a commercial AC voltage into a DC voltage used in a digital circuit;

An input alternating voltage-DC voltage converting circuit unit for converting an input AC voltage into a DC voltage;

An offset voltage stabilization circuit unit for stabilizing offset voltages by the elements;

A current amplifier amplifying the input current from the offset stabilization cycle and the input current from the heater output current sensing transformer;

A sensing alternating current-direct current converting circuit unit converting the alternating current output from the current amplifier into a direct current;

A microcomputer that controls the operation of the entire thermostat as a main control circuit;

A temperature control volume for variably adjusting a temperature of a mat such as an electric mat within a predetermined range; And

It is characterized by providing a current control type magnetic field-free thermostat, characterized in that it comprises a thermostat for controlling the temperature of the thermostat.

According to the present invention, it adopts a current transformer that detects the output current of the thermal heater and automatically shuts off the thermal function when the output current exceeds the setting range for each temperature, and stops the heating function. The effect of keeping the temperature constant can be obtained. In addition, it detects a sudden change in current when a short circuit occurs in the heater and immediately stops the operation of the thermal controller, eliminating the risk of damage to the mat or overheating due to overheating, and eliminating the use of a sensing wire to generate harmful electromagnetic waves. By eliminating it fundamentally, it is possible to implement a current-controlled magnetic-free thermostat that can be used safely.

Hereinafter, the current controlled magnetic field temperature controller of the present invention will be described in detail with reference to the accompanying drawings.

1 is a block circuit diagram of the current-controlled magnetic-free thermostat of the present invention.

As shown in FIG. 1, the temperature controller of the present invention includes a power switch 10, a heater 20, a heater output current sensing transformer 30, a DC power supply device 40, an input AC voltage-DC voltage conversion circuit unit ( 50, an offset voltage stabilization circuit unit 60, a current amplifier 70, a sensing AC current-DC current conversion circuit unit 80, a microcomputer 90, a temperature control volume 100, and a thermal control unit 110.

The power switch 10 is a switch for turning on / off the power, and is composed of a switch 11 and an LED 12. The heater 20 is a part which heats an electric mat (not limited to an electric mat, and includes an electric yoke, an electric blanket, etc.). The heater output current sensing transformer 30 is a transformer for sensing and outputting a heater output current. The heater output current sensing transformer 30 receives a current from the thermal control unit 110 to be described later and a current from the overheat cutoff switch 120 and outputs the current to the current amplifier 70. All. The DC power supply device 40 is a device for converting a commercial AC voltage into a DC voltage of 5V used in a digital circuit. The input alternating voltage-DC voltage converting circuit unit 50 is a circuit for converting an input AC voltage into a DC voltage, and includes an OP amplifier 51, a DC voltage converting diode 52, a backflow preventing diode 53, and a ripple cancellation capacitor 54 It is composed of In the input AC voltage-DC voltage conversion circuit 50, the resistors R2, R3, and R4 are voltage divider resistors. The offset voltage stabilization circuit unit 60 is a circuit for stabilizing offset voltages by elements, and one of two inputs of the OP amplifier 61 has a feedback input to act as a current buffering function to stabilize the current drift. Stabilize. In this offset voltage stabilization circuit section 60, resistors R5 and R6 are voltage divider resistors, and C1 is a ripple cancellation capacitor.

The current amplifier 70 amplifies the current from the offset voltage stabilization circuit unit 60 and the current from the heater output current sensing transformer. The sensing alternating current-DC current converting circuit unit 80 is a circuit for converting the alternating current output from the current amplifier 70 into a direct current. The OP amplifier 81, the DC current converting diode 82, and the backflow prevention diode 83 ) And a ripple cancellation capacitor 84. R9, R10, and R11 at the front end of the circuit are divided voltage resistances. The microcomputer 90 controls the operation of the entire thermostat as a main control circuit. The temperature control volume 100 includes a volume 101 (VR) and a semi volume 102 (SVR) for variably adjusting the temperature within a predetermined range, such as an electric mat, and the semi volume is auxiliary to the volume 101. Increases the variable width of the volume as a volume. The thermal control unit 110 is a part for controlling the heat of the temperature controller, and is composed of an LED 111, a photo coupler 112, and a silicon-controlled rectifier 113 so that the photo coupler 112 is turned on when the LED 111 is turned on. The gate of the SCR 113 is turned on and output to the heater output current sensing transformer 30. Here, R13 and C2 are resistors and capacitors for preventing malfunction due to an external surge voltage. ZNR 114 is a surge observer that absorbs surge voltages. The poly switch 120 is a switch that operates to automatically shut off when the electrical mat is more than 60 degrees, and automatically connected when less than 60 degrees. The voltage drop unit 130 is composed of R17 and C3 is a kind of transformer to drop the commercial AC voltage.

Then, the operation of the current-controlled magneticless thermostat of the present invention configured as described above will be described.

First, when the switch 10 of the power switch is turned on, the LED 12 of the power switch 10 is turned on, and a low signal is input to the GND terminal (not shown) of the central processing unit 90 and the central processing unit 90 ). After the initialization operation is completed, the central processing unit 90 sends a pulse width modulation (PWM) signal to the heater 20 to turn on the LED 111 of the photo thermal control unit 110 and turn on the SCR 113. Then, the gate of the SCR 113 is controlled by the phase control method so that the output signal of the SCR 113 drives the heater 20 of the electric mat to operate the heating function. The heater output current sensing transformer 30 senses the output current of the heater 20 and sends a sense current to the current amplifier 70. The offset voltage stabilization circuit unit 60 is a circuit for providing a stable reference voltage to the current amplifier 70. After receiving the stable reference voltage from the offset voltage safety circuit unit 60 and the signal input from the heater output current sensing transformer 30, the current amplifier 70 amplifies the sensed small current and then senses the alternating current-DC current converting circuit unit ( 80) to DC current. This DC current value is read by the CURRENT input port of the central processing unit 90, the current flowing through the circuit load is calculated from the ADC value, and converted into a resistance value (circuit load) by Ohm's law (V = IR). It is possible to control the temperature by controlling the temperature by changing the resistance value to temperature from a table value prepared in advance in the microcomputer 90 in the program. Therefore, the temperature control can be performed without the temperature sensor by repeating the above process. In this process, the temperature value can be controlled by turning on the SCR 113 when the temperature value is lower than the set value compared to the table value pre-stored in the microcomputer 90 and turning off the SCR 113 when the temperature value is higher than the set value. have. That is, when the surface temperature of the electric mat or the like is less than the value based on the 60 degrees of the Korea Technical Standard Institute standard temperature, the temperature controller is operated, and when the temperature is more than 60 degrees, the temperature controller is blocked.

When the heater 20 detects a sudden change in current when the heater 20 is short-circuited, the heater current amplifier 70 amplifies the detected inrush AC current, and then senses the alternating current-DC current to the AC current in the current amplifier 80. Convert to current This DC current value is read into the CURRENT input port of the central processing unit 90, and the current flowing through the circuit load is calculated using an ADC (analog digital conversion) value to detect a sudden change in the current to immediately operate the thermal controller 110. You can stop it.

In the input AC voltage-DC voltage converting circuit section 50, if a change in the input AC power occurs, the AC voltage is converted into a DC voltage, and the DC voltage value is read into the VOLT input port of the central processing unit 90 to read the ADC ( Analog-to-digital conversion) can be used to minimize the current conversion error caused by the input alternating voltage variation by calculating the correction value for the variation of the input alternating voltage. When the inrush voltage is detected due to the short of the AC input voltage, the operation of the thermal controller can be stopped immediately.

Therefore, since the thermostat of the present invention does not use a general sensor wire, no magnetic field is generated, and thus it can be used as an electric mat that is harmless to the human body. In addition, in the simulation, the overheat cutoff switch 120, that is, a poly switch is added to protect the hardware in the event of full-function destruction, by using the characteristics of the poly switch 120 to automatically cut off at 60 degrees or more. In addition, the automatic connection at 60 degrees or less improves the problems of mechanical bimetals generally used.

That is, the SCR 113 cannot be controlled due to component failure inside the thermostat (Korea Institute of Standards and Technology), and power is supplied to the hot wire as it is (surface temperature 60 degrees). In this case, the current value was measured and the current flowing below the value was not allowed to pass using the characteristics of the poly switch. Thus, even if an abnormality occurred, the surface temperature of the electric mat and the like was not designed to exceed the current value of 60 degrees or more.

According to the temperature controller of the present invention, it adopts a current transformer that detects the output current of the thermal heater, and automatically shuts off the thermal function when the output current of the temperature exceeds the set range, and stops the heat function. It is possible to obtain the effect of keeping the temperature constant by operating. In addition, it detects a sudden change in current when the heater is shorted or short-circuit, and immediately stops the operation of the thermal controller, eliminating the risk of damage to the mat or overheating due to overheating. By eliminating it fundamentally, it is possible to implement a current-controlled magnetic-free thermostat that can be used safely.

Therefore, according to the present invention may have the following advantages.

By not attaching bimetals and sensors attached to hot wires, cost and work costs can be reduced. There is no worry of shorting inside the heating wire even when using high power with the existing non-magnetic heating wire. In addition, even when there is a blanket, the output stage can be turned off even with a change of ± 3C. Therefore, it is possible to significantly reduce the current mat (electric mat), electric yaw, electric field defects (burning, sticking, local overheating due to heat rise).

Although the present invention has been described with reference to one embodiment, the present invention is not limited thereto, and various modifications and variations may be made by those skilled in the art without departing from the spirit and scope of the appended claims below. Such modifications and variations are intended to be interpreted as being within the scope of the present invention.

1 is a block circuit diagram of a current control type magnetic-free temperature controller of the present invention.

* Description of the symbols for the main parts of the drawings *

10: power switch 20: heater

30: heater output current sensing transformer 40: DC power supply

50: input AC voltage to DC voltage conversion circuit

60: offset voltage stabilization circuit

70: current amplifier

80: sensing alternating current-DC current converting circuit part

90: micom 100: temperature control volume

110: heat control unit 120: overheat cut off switch

Claims (5)

A power switch for powering on / off; A heater to heat the electric mat; A heater output current sensing transformer configured to sense and output a heater output current; A DC power supply for converting a commercial AC voltage into a DC voltage used in a digital circuit; An input alternating voltage-DC voltage converting circuit unit for converting an input AC voltage into a DC voltage; An offset voltage stabilization circuit unit for stabilizing offset voltages by the elements; A current amplifier amplifying the input current from the offset stabilization cycle and the input current from the heater output current sensing transformer; A sensing alternating current-direct current converting circuit unit converting the alternating current output from the current amplifier into a direct current; A microcomputer that controls the operation of the entire thermostat as a main control circuit; A temperature control volume for variably adjusting a temperature of a mat such as an electric mat within a predetermined range; And Current control system magnetic field temperature controller, characterized in that it comprises a thermostat for controlling the temperature of the thermostat. The method of claim 1, The current control system magnetic field temperature controller, characterized in that it further comprises an overheat cutoff switch which operates to automatically cut off the electric mat 60 degrees or more, and automatically connects it when it is 60 degrees or less. The method of claim 1, The thermal control unit includes an LED, a photo coupler, a circuit on / off SCR, a malfunction preventing film caused by an external surge voltage, and a surge removing unit. The method of claim 1, And the input AC voltage to DC voltage conversion circuit part includes an OP amplifier, a DC voltage conversion diode, a non-return diode, and a ripple cancellation capacitor. The method of claim 1, The sensing current alternating current-DC current converting circuit unit is a current control type magnetic field temperature controller, characterized in that it comprises an OP amplifier, a DC current conversion diode, a backflow prevention diode and a ripple cancellation capacitor.

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