KR950009883Y1 - Auto temperature control device of electrical heater - Google Patents

Abstract

No content.

Description

Thermostat of electric field

1 is a schematic diagram showing a thermostat of an electric field plate of the prior art

2 is a circuit diagram of a thermostat of an electric field plate according to the present invention

3 (a) and 3 (b) are procharts for explaining the operation of the present invention.

* Explanation of symbols for main parts of the drawings

1: DC power supply circuit 2: Power supply voltage detection circuit

3: power supply voltage zero cross detection circuit 4: protection circuit

5: power control circuit 6: first temperature detecting means

7 second temperature detecting means 8 display device

9: alarm circuit 10: switching device

11: microprocessor

The present invention relates to an automatic temperature control device for an electric blanket, and in particular, it is possible not only to precisely control the temperature of the electric blanket to the actual temperature, but also to automatically control the heating temperature of the electric blanket. It relates to a temperature control device.

The thermostat of a conventional electric sheet or electric yoke (hereinafter collectively referred to as electric sheet) does not set the temperature of the electric sheet in accordance with the actual temperature to be used, but instead of setting the temperature by the amount of power required to generate the required temperature of the electric sheet. It is configured to set, so it is not suitable when the difference between the caution temperature and the actual temperature is severe.

In addition, the heating element used in the electric field is configured to apply an insulating nylon thermistor on the fixed hot wire wound by winding the rolled copper wire to the fiber, and then wound it with a rolled copper wire to use it as a temperature detection wire, and then to coat the PVC again. The structure of a conventional electric field plate using such a heating element is, for example, in the heating element of the electric field plate formed of a hot wire (HL), a nylon thermistor (NS) and a temperature detection line (DL) as shown in FIG. A variable resistor (VR) used as a capacitor and a capacitor (C) are connected to both ends of the detection line (DL), an SCR is connected to one end of the heating wire (HL), and the gate of the SCR is connected to the charging voltage of the capacitor (C). The resistance of the thin thermistor (NS) is changed according to the temperature increase and decrease, and the SCR is caused by the current flowing through the nylon thermistor to the capacitor. Heating the ever by adjusting the triggering time and temperature to maintain a constant temperature.

However, since the resistance value of the nylon thermistor does not vary linearly with temperature change, the heating temperature of the heating element can not be precisely controlled by the current detection only by the temperature detection line, so that the internal temperature of the electric field plate can be precisely and accurately controlled. none. Therefore, the temperature setting range is set to low temperature, medium temperature, high temperature, or 1st stage, 2nd stage ..... 5th stage, but if the difference between setting temperature and ambient temperature is severe, setting temperature Since the actual temperature is very different from the actual temperature, the internal temperature of the electric blanket does not rise to the setting temperature even though the electric blanket operates normally. Therefore, the actual user sets the setting temperature higher than the temperature actually displayed on the temperature control device, or misidentifies the product as defective. There have been a lot of cases that require replacement of the product, and the manufacturer may set the display temperature higher than the actual use degree and cause it to be fired, and it may cause a fire. There was an inconvenience that you can not see what it is.

In addition, the protection device accompanying incidental temperature control is insufficient, and the electric power control method of the electric field is also a half-phase control method using SCR, which takes a considerable time to rise to the setting temperature. There was an inconvenience in that the electric blanket had to be turned on well before it was used.

The present invention has been devised in view of such a conventional problem, and an object of the present invention is to provide an automatic temperature control device for an electric blanket that can precisely and quickly and safely control the temperature of the electric blanket at an actual temperature.

In order to achieve the above object, the present invention controls the power introduced into a common electric heating element heating element corresponding to a 100V / 220V power source to maintain the heating at a predetermined setting temperature to automatically adjust the temperature of the electric heating plate In the regulating device,

First temperature detecting means for detecting a set upper limit temperature and a lower limit temperature of the heating element by converting a voltage detected by the temperature detecting line of the heating element;

Second temperature detecting means installed on one surface of the heating element to accurately detect the temperature of the heating element at an actual temperature within the set upper limit and lower limit temperatures;

And a microprocessor which receives the output of the first temperature detecting means and the second temperature detecting means and controls the power of the triac connected to the heating element so that the temperature of the heating element is controlled to the actual temperature.

In addition, the display device for displaying the actual temperature of the heating element and the occurrence of an abnormal temperature of the heating element is detected by a microprocessor to install a protective circuit for quickly shutting off the power supply to the heating element is more desirable the object of the present invention. Can be achieved.

According to the present invention configured as described above, the temperature of the heating element can be controlled quickly and safely through the first temperature detecting means, and the temperature of the heating element can be precisely controlled to the actual temperature through the second temperature detecting means, thereby providing quickness, safety and precision. In the case of cooperating with the protection circuit in this circuit, it is possible to control the temperature more quickly and to completely eliminate the risk due to the triac, and to display the actual temperature through the display circuit. It can be displayed to set the temperature more precisely without errors.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. A preferred embodiment of the present invention is a power supply voltage detection circuit 2 and a bridge diode (T1), a bridge diode (D7), a smoothing capacitor (C8) and a voltage circuit as shown in FIG. A first blocking circuit and a resistor (R42) connected to the output terminal of the circuit (D7) and composed of a power supply voltage zero cross detection circuit (3) comprising a diode (D4) and a capacitor (C7), and a current fuse (Fl) and a varistor (V1). A protection circuit 4 formed of a second blocking circuit composed of R44 and R45, a transistor Q10, a triac T11, and a temperature fuse F2, a heating wire HL, a nylon thermistor NS, and a temperature detecting line; A power control circuit 5 formed of a triac T10, a transistor Q6, and resistors R28, R29, and R31 for controlling the power supply of the heating element BLK formed by DL, and the heating element BLK. The set upper limit temperature of the heating element which is connected to the temperature detection line DL of and formed of the diode D1, the resistors R25, R26, R27 and the capacitor C5. The first temperature detecting means 6 for detecting the lower limit temperature, and the ordinary temperature sensor dummyster TH and the resistor R24 attached to the outside of the heating element BLK on the clean part of the electric field plate are formed. Second temperature detection means (7) for measuring the surface temperature of the BLK) to an actual temperature, a display device (8) for digitally displaying the actual temperature and the reservation time, and an alarm circuit (9) for generating an alarm signal. ) And a switch wrench (10) consisting of a reservation setting switch (K1), a temperature setting switch (K2), an alarm setting switch (K3), a cancellation switch (K4), and a power switch (K5). It is composed of a microprocessor 11 for receiving and controlling the output. Other reference numeral 12 denotes an oscillation circuit for driving the microprocessor 11 and 13 is a reset circuit of the microprocessor 11.

The operation of the electric plate thermostat of the present invention configured as described above will be described with reference to FIGS. 2, 3 (a) and (b).

First, through the switching device 10, it is set for the reservation, temperature setting, alarm setting for the operation of the electric blanket.

When AC power is supplied with the power switch SW1 turned on, a DC voltage Vcc is applied to each circuit device. Touch the switch (K5) and then touch the temperature setting switch (K2) to display the current temperature.If you keep pressing the switch (K2), it will count down and the display number will increase rapidly and the temperature will be displayed. When the hand is raised when is raised, the setting temperature is displayed and this number is stored in the memory of the microprocessor 11.

On the other hand, the reservation is divided into an on reservation for operating the electric blanket after a predetermined time and an off reservation for stopping the operation of the electric blanket after a predetermined time, and are operated by a switch (K5) and a reservation setting switch (K1). The off-reservation time is queried and stored in the corresponding memory column of the microprocessor 11. After touching the switch K1 and pressing the switch K5, the corresponding remaining time is displayed. On the other hand, when waking up with an alarm after a predetermined elapsed time, when the corresponding time is set by touching the alarm setting switch K3, an alarm signal is generated through the alarm circuit 9 at 2 hours. In addition, if you want to cancel the settings of the reservation, the temperature and the alarm, and the like, if you touch the mode switch and the cancellation switch (K4) is programmed to cancel only the corresponding mode.

After the reservation, the temperature and the alarm are set in this manner, when the reservation time has elapsed, the operation proceeds according to the programs shown in the charts of FIGS. 3A and 3B.

That is, the pin P21 to which the output of the first temperature detecting means 6 is applied by checking the state of the switches K1-K5 and the former P21, P22, P23 of the microprocessor 11 with the microprocessor 11. Check that the value of 1) (the numbers 1-40 on both sides of the microprocessor are the pin numbers) is less than the safe operating voltage (Ts) set to maintain the stability of the electric field. If it is not small, the pin P30 is set to the high level state H, the triac T11 of the protection circuit 4 is operated so that a large current flows in the resistor R45, thereby melting the temperature fuse F2. At the same time, the power supply is cut off and the error message (M) is sent out. Therefore, it is possible to completely protect the device by cutting off the AC power immediately upon abnormal overheating of the heating element BLK or short circuit of the heating element due to a failure.

When the applied voltage of the pin P21 is smaller than the safe operating voltage Ts, the value of the pin P23 to which the output value of the power supply voltage detection circuit 2 of 100 / 220V is applied is the reference value Vs for 100V discrimination. If it is smaller than it is checked, if it is large, it proceeds to the 220V program routine. That is, it is checked whether or not the high level H of the DC power switch K5 is set, and if it is not set to the high level, the routine proceeds to the routine 1 and repeats the above-described routine.

In the case of the high level, the next step is performed to determine whether the input value of the pin p22 to which the output value of the first temperature detecting means 6 is applied is smaller than the upper limit voltage V _A value for the voltage detection line voltage control for 100V. If the voltage is higher than the upper limit voltage V _A , the low level L signal is output to the pin P29 to cut off the power of the triac T10 connected to the heating element BLK, and then In the step, when the value of the pin P22 is 100V, it is checked whether or not the voltage Vx detected when the heating wire HL and the temperature detection line DL are shorted.

If it is checked with a short voltage, it sends an error message (M) and stops the operation of the electric field. When it is checked that it is not a short voltage, it is lower than the lower limit voltage (V _B ) for voltage control of the temperature detection line at 100V. If less is checked whether or not jakeunga, continues the check of the pin (P ₂₂₎ is less, and a small case, continuing with the above-described process, through the process of ①.

On the other hand, when the value of the pin P ₂₂ is smaller than the upper limit voltage value V _A by the voltage control of the temperature detection line at 100 V, the output value of the second temperature detection means 7 by the temperature sensor TH is checked. Whether the value of the pin (P ₂₁ ) is smaller than the setting pin temperature value (TC) by the temperature setting switch value (K ₂ ), and if it is not small, carry out the above-described process through the routine of ① again until it is small. If small, the pin P29 is output at a high level H to cause the triac T10 connected to the heating element BLK to conduct, thereby heating the heating element BLK to increase the temperature. In the next step, check the pin P21 again to see if it is greater than the set temperature value TC, and if it is not large, repeat the routine process until it is large through the routine of ①. When the output is set low, the operation of the triac T10 is stopped to stop the heating of the heating element BLK, and at the same time, when the value of the pin P21 is smaller than the set temperature value TC through the routine of ①. Repeat the above routine process until. Therefore, it is kept heated to the set temperature of the improvement constant.

On the other hand, when the value of the pin (P23) is larger than 100V determination value (VS) is performs the routine of FIG. 3 (b), this process is a temperature detection lines at the time of the check the reference value at the pin (P ₂₂₎ 220V Only the upper limit voltage (V _A ) for voltage control, the lower limit voltage (V _B ) for the voltage control line at 220 V, and the short detection voltage (Vx) at the heating line (HL) and temperature detection line (DL) at 220 V are different. In addition, the program process is performed in the same manner as the 100V process.

According to the present invention configured as described above, the upper limit set temperature and the lower limit set temperature are set in accordance with the voltage detected by the temperature detection line DL of the heating element BLK by the first temperature detecting means 6 to operate only within the range. It is possible to control the triac, which is a power control element of the heating element, stably and quickly in response to the temperature, and to control the actual temperature of the heating element BLK in the upper and lower temperature ranges through the second temperature detecting means 7. Based on this measurement, the microprocessor precisely controls the triac, the power control element, at the actual temperature.

Therefore, even if the setting temperature is severe when the temperature difference from the surroundings is severe, the temperature control device has fastness, safety and precision, so that the triac, which is a radio wave power control element, can be used as a power control element of the heating element. The heating rate of the electric field plate can be doubled. In addition, when the display device is attached, the reservation time and operating temperature can be precisely set, and the actual temperature can be precisely displayed. When the overheating of the heating element BLK occurs, the microprocessor 11 causes the short circuit to occur. After detecting through the temperature detection line (DL), the protection circuit (4) installed on the inlet side of the AC power supply is activated to automatically cut off the AC power supply automatically. It has a great effect.

Claims (3)

In the automatic temperature control device of the electric sheet to adjust the temperature automatically by controlling the power flowing into the heating element of the normal electric sheet corresponding to the 100V / 220V power source to maintain the heating to a predetermined setting temperature, First temperature detecting means for converting a voltage detected by the temperature detecting line of the heating element to detect a set upper limit temperature and a lower limit temperature of the heating element; Second temperature detecting means installed on one side of the surface of the heating element to precisely detect the heating temperature of the heating element to the actual temperature within the set temperature; A microprocessor for controlling the power of the triac connected to the heating element by receiving the output of the first temperature detecting means and the second temperature detecting means to control the temperature of the heating element to the actual temperature within the set temperature range, Thermostat The apparatus of claim 1, further comprising a display device for displaying and setting an operating temperature of the heating element to an actual temperature. [3] The protection circuit according to claim 1 or 2, further comprising a protection circuit which detects the occurrence of an abnormal voltage in the first temperature detecting means due to a short circuit or abnormal temperature of the heating element, and promptly cuts off the power supply to the heating element. Thermostat of electric field