JPS587300A - Temperature display apparatus of heater - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a display device for a heating appliance such as an iron or an oven.

Generally, this type of appliance has a wide temperature control range, e.g.
It is necessary to be designed with dimensions ranging from 0°C to 260°C, and to be able to set the temperature anywhere between them according to preference. Conventionally, there has been no display that simply indicates that the set temperature has been reached. Furthermore, when a display body is provided, its temperature fluctuates up and down depending on the weight and weight of the load and the mounting status of each component. On the other hand, in the case of ironing, there is an appropriate temperature fluctuation range depending on the type of cloth.

The present invention provides a device that can easily change the lighting temperature range of the display for displaying temperature fluctuations under such various conditions as appropriate.

Embodiments of the present invention will be described below with reference to the accompanying drawings. In FIG. 1, voltages from AC power sources 1 and 2 are applied to a heater 4 via a bidirectional three-terminal controlled rectifier 3. In FIG. In addition, these AC power supplies 1 and 2 are used to obtain DC power for electronic circuits.
It is rectified by a diode 5, dropped in voltage by a resistor 6, and smoothed by a smoothing capacitor 7 to become a DC power source. The temperature adjustment volume 8 has its output terminal 9 so that voltages corresponding to each temperature click point on the left can be obtained, and the current value is 140.
℃, that voltage is applied to one three terminals of the comparison amplifier of the zero-volt switching circuit 10 made up of an IC. A voltage is applied to the other four terminals of the comparison amplifier, which is correlated with the temperature determined by the resistance change of the thermistor 11 for temperature measurement and the ratio to the resistance 11'. When the temperature is low, the resistance of Mister 11 is high, so the voltage at the 4 terminals is low. Therefore, the circuit 10 outputs the gate pulse from the 6th terminal and the element 3
is turned on by zero-volt switching to flow current to the heater 4. Then, it is heated and the temperature rises, causing the thermistor 11
When the resistance of the long terminal becomes smaller and the voltage of the long terminal of the circuit 10 becomes the same as that of the third terminal, the gate pulse from the sixth terminal disappears and the second element 3 turns OFF.

The temperature is controlled as described above, but the temperature is displayed using the light emitting diode only during temperature fluctuations corresponding to the voltage drop of the two Zener diodes 12 and 13 connected to the output terminal 9 of the volume control 8. (hereinafter referred to as LED)
16 lights up, and if the temperature changes above or below this, the LED 14 or LEDle lights up. This means that a voltage higher than the set voltage of the volume 8 by the voltage drop of the Zener diode 12 is detected by the comparison amplification means 1, which is υ, using the IC.
A voltage higher than this voltage is applied to one terminal of the means 17. When the temperature reaches such a high temperature that the resistance of the cap thermistor 11 becomes low, the output of the means 1a becomes L, and the LED 14 lights up. A voltage lower than the set voltage by the voltage drop of the other Zener diode 13 is applied to the + terminal of the means 18, and a voltage lower than this voltage is applied to one terminal of the means 18. That is, when the temperature of the thermistor 11 becomes low and its resistance becomes high, the output of the means 18 becomes H, and the LEDle lights up. At this time, the LED
Since the cathode of e is L, it lights up. This L
The reason why the output of the cathode of the EDz 6 and the means 19 is L is that one terminal of the means 19 has a voltage of 60°C, whereas one terminal corresponds to a high temperature of 140°C. This is because a high value voltage is applied. If this voltage falls below the voltage equivalent to 60° C. at the + terminal of the means 19, the output of the means 19 becomes H, and the LED 23 lights up.

Each LED lights up in this way, but if we set the voltage drop for one constant voltage element, that is, the Zener diode 12.13, to a voltage equivalent to about 20 degrees Celsius,
The lighting range is the temperature within ±2Q°C of the set value. Moreover, it can also be set to +IO°C or -2o°C. In order to make this voltage variable, if you connect a variable resistor in parallel to the Zener diode 12 and 13 using a potentiometer, the voltage will rise above the set value.

The bottom can also be individually set to a variable temperature range.

It is also possible to set the temperature to 10°C or -20°C by placing only the lower side.

FIG. 2 shows another embodiment, in which the load heater 4 is switched on and off by a relay. Connect the voltage from the thermistor 11 to a child terminal of the set voltage means 24 from the output terminal 9 of the volume 8, and compare the power from both. If the temperature is low and the voltage from the thermistor 11 is low, the voltage from the thermistor 11 is The output of 24 becomes H, turns on 5CR26 through resistor 25, causes current to flow through relay coil 2, closes contact 3, and causes heater current to flow. When the temperature is increased, the resistance of the thermistor decreases, the voltage at one terminal of the means 24 decreases, and the output of the means 25 becomes L. Therefore, 5CR26, I) Sheet 2F, and relay contact 3 each become ○FF, and heating stops. On the other hand, for temperature display, the output terminal 9 of the variable resistor is connected to the Zener diode 12.
13, etc., to each comparison and amplification means 17, 18, 19, and the output thereof causes LED 14. 15. 1e
, 23 lights up. And LED1 to display the set temperature
5 lights up when the temperature is within the temperature range defined by the Zener diode 12 and 13, and when the temperature exceeds it, the LED 14 lights up, and when the temperature is insufficient, the LED le lights up. Show that.

Third. FIG. 4 shows yet another embodiment. In the case of Figures 1 and 2, a special LED 23 was added and turned on to notify when the temperature has cooled to about 50°C, which does not cause burns. Third. FIG. 4 shows a circuit that attempts to notify that the temperature has cooled down to about 50°C by blinking an LED to indicate that the temperature has fallen below the appropriate range.

To explain only the main points, in FIG. 3, the output of the means 17 is H and the output of the means 18 is L during the appropriate temperature range, so the LED 15 lights up. As described above, this lighting temperature range is determined by the voltage drop across the Zener diode 12 and 13.

When the temperature falls below that range, the output of the means 18 becomes H.

Means 19ij: Until the temperature reaches around 50'C, the one terminal to which the output from the thermistor 11 is connected is H compared to the ten terminals, so the output is L. Therefore, since the terminal of the means 20 to which the output of this means 19 is connected is L, its output is L.
It is. Therefore, since the anode of LED16 is H and the cand is L, it lights up. As the temperature gradually cools down to about 50°C, the voltage from the thermistor 9 connected to one terminal of the means 19 drops below the 10th terminal, the output of the means 19 becomes H, and the + terminal of the means 20 becomes H, and the means 20 enters an oscillation state as a multivibrator. In other words, the output of the means 20 changes from H to L at a constant cycle, and L E D
1' 6 flashes. Therefore, while the LED does not flash, the temperature is above 50°C, which is still below the appropriate temperature range, and when it flashes, it indicates that the temperature is below 50°C, meaning that one LED serves as two displays.

Figure 4 shows the means 2o for blinking this LEDl6.
6 and is connected in parallel. In Figure 3, there is a loss because the lighting current for LED 16 is always flowing in series, but in Figure 4, the output is H because the oscillation stops if it is not blinked at 50°C or higher, and it is unrelated to the LED 16 circuit.
There is no extra loss in the D circuit. Measure 1 when the temperature drops below 50℃
9, the output changes to H, and the output of the means 19, which had been held at L, is no longer held at one terminal of the means 20, and the means 20 oscillates as a multivibrator, and the output changes to H,
L and changes at a constant period, and the LED 1 6 blinks by bypassing or not bypassing the current of the LED 1 6. Note that means 1 including Zener diodes 12 and 13
7,18. The LEDs 14 and 15 operate in the same manner as in Figures 3 and 1, and are controlled by Zener diodes at -
can be changed. In addition, in Figures 3 and 4, 21
, 22.26 are resistors, 26 are capacitors, and 27.28 are diodes.

In general, when ironing natural fibers such as cotton and linen, even if the temperature is a little high, the fluctuation range may be slightly larger than the appropriate temperature for ironing, but in the case of chemical fibers, the fluctuation range can be reduced. Otherwise, if it crosses the melting point, it will fuse and be bad. Therefore, since a narrow display is required during temperature fluctuations, it is better to use a low Zener diode.

Even for irons with the same performance, the temperature fluctuation varies depending on where the thermistor is installed. In other words, the range of fluctuation is small near the heater, and becomes larger when it is placed near the fabric load and further away from the knitting heater. Since the temperature is set as close to the cloth as possible, the range of fluctuation becomes large. Therefore, it is better to use a Zener diode with a high voltage in this case.

Furthermore, when a load is applied from no load, the temperature fluctuation tends to spread downwards, so if you want to match the actual situation of the iron, the higher side of the center of the set temperature may be +5℃, but the lower side is -16℃. It is also necessary to have a difference of 1 - below, in which case Zener diodes with higher and lower voltages will be used.

In this way, if constant voltage elements with different voltages are required,
A volume may also be used. Alternatively, the volume may be changed as needed.

Q: The temperature level of the water is decided by comprehensively considering each of the above conditions, but as mentioned above, the present invention can satisfy various conditions, such as reducing fabric damage, Furthermore, it is possible to provide an easy-to-use device with good temperature display performance, such as the display not blinking due to slight temperature fluctuations.

[Brief explanation of the drawing]

Figure 1 is an electric circuit diagram showing one embodiment of the present invention, Figures 2-
FIG. 4 is a circuit diagram showing other embodiments. 1.2...AC power supply, 4...Heater, 14°15.16.23...Display body.

Claims (1)

[Claims] It has a display body that notifies that the temperature is at the set temperature, and a means for adding or subtracting a voltage corresponding to the expanded lighting range temperature to the variable set voltage corresponding to the variable set temperature in order to widen the lighting range of this display body. A temperature display device for a heating appliance characterized by the following.