JPH01216414A - Temperature controller - Google Patents

Abstract

PURPOSE:To perform stable temperature control extending over a long period by providing a timer means, performing the temperature detection of a temperature element accurately during the stoppage of a driving means within a prescribed time, and maintaining energizing to a heating wire for a constant time. CONSTITUTION:A microcomputer 8 counts the number of pulses of a pulse generating means 77 by a timer counter 95 after turning OFF a transistor 41 in the driving means, and generates a certain constant cycle. And since the contact of a relay 39 is opened while the transistor 41 is turned OFF, the temperature of the whole of the heater wire 52 can be detected accurately by a transistor 62. The voltage of the temperature signal of the heater wire 52 is compared with the temperature setting voltage of a variable resistor 74 by a comparator 76, and the ON request signal of the relay 39 is inputted to the microcomputer 78, then, the microcomputer 78 drives the transistor 41. In such a way, since detecting capacity for local insulation can be heightened, it is possible to prevent specified deterioration in a macromolecule heating element 6 from being generated, and to perform the stable temperature control of an electric heater, etc., extending over the long period.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a temperature control device for electric heating appliances such as electric carpets and floor heaters.

2. Description of the Related Art An example of the main structure of a conventional electric heating appliance of this type, such as an electric car vent, is shown in FIG. 1 is an electric carpet body, and inside the body 1 there is a temperature detection line 5 for detecting the surface temperature.
This shows an example of a so-called two-wire electric carpet in which a heating wire 9 and a heating wire 9 contributing to heat collection are wired separately. 2 is a controller box that controls the surface temperature of the electric carpet body 1. FIG. 5 is a perspective view of a portion of the temperature detection line 5. FIG. A pair of first electrode wires 3
．． A polymer thermosensitive body 6, which is filled between the two spaces 4 and 4 and whose impedance changes depending on the temperature, is integrally constructed. In addition, 7 is a core thread, 8 is an outer skin, and the electrode wire 3 is spirally wound around the core thread 7, and the polymer temperature sensitive body 6 is filled around it, and the outside is similarly spirally wound. There is a wound Wl polar wire 4, which is covered with an outer skin 8. FIG. 6 is a diagram showing changes in impedance temperature characteristics of the polymer thermosensitive body 6, which has a characteristic that the impedance decreases as the temperature rises.

FIG. 7 is a perspective view of a part of the heating wire 9 that contributes to heating the electric carpet body 1, in which the second electrode wire 13, the heating wire 9, and the insulating resin 10 are integrally constructed. 11 is a core yarn, 12 is an outer sheath, a second electrode wire 13 is spirally wound around the core yarn 11, an insulating resin 10 is filled around the second electrode wire 13, and the outside of the second electrode wire 13 is similarly spirally wound. There is a heated heating wire 9 which is covered with an outer skin 12.

FIG. 8 is a conventional temperature control circuit diagram. 14 is an AC power supply, and 15 is a power switch.

16, 17, 18, 19 are resistors, 20.21 are diodes, and 22.23 are capacitors. The resistor 19, the pair of first electrode wires 3 and 4, the impedance of the polymer temperature sensitive body 6 (assumed to be 2), the resistor 16, the diode 21,
A smoothed temperature signal voltage of the positive cycle of the AC power source 14 is selected by the capacitor 23 . The relational expression of the detected temperature signal voltage is roughly expressed as equation (1), assuming that the voltage of the AC power supply 14 is VAC.

1/(1+resistance 19/Z) X VAC-...-=
- (1) That is, as the temperature rises, the impedance of the polymer thermosensitive element 6 decreases, so the smoothed temperature signal voltage decreases. In addition, even in the negative cycle of the AC power supply 14, the diode 20, resistor 17, and capacitor 22
A voltage symmetrical to the positive cycle is applied to the polymer temperature sensitive body 6.

This is because the polymer thermosensitive body 6 is made of a chemical resin such as vinyl chloride or nylon, and is intended to prevent polarization deterioration and stabilize impedance. 24 is a diode, 25.26.
27, 28, and 29 are resistors, 30 is a variable resistor serving as a temperature setting means for setting a desired temperature, and 31 is a capacitor, which smoothes the voltage to provide a temperature setting voltage.

A2 is a control means that compares and controls the temperature signal voltage of the polymer temperature sensitive body 6 and the temperature setting voltage of the temperature setting means 30. 33 is a diode, a4.35 is a resistor,
36 and 37 are capacitors, 3B is a constant voltage diode, 39 is a relay which is a power control means, and 40 is a diode for surge absorption of the relay 39. diode 3
3. The driving power for the control means 32 and the relay 39 is obtained from the resistor 34, 35, the capacitor 36, 37, and the constant voltage diode 38. Reference numeral 41 indicates a transistor for driving means of the relay 39, reference numerals 42 and 43 indicate a resistor, and reference numeral 44 indicates a diode. The transistor 41 is turned on and off by the control means 32 signal, controls the relay 39, and generates heat Ivj19.
Controls the on/off of energization. Note that the resistor 42 and diode 44 prevent the relay 39 from chattering.

45.46 is a diode, 47.48 is a resistor with a small resistance value, 49 is a safety circuit, and in this example, the resistor is 47.4B.
It is a temperature fuse that is thermally coupled to the When the control means 32 malfunctions and the relay 39 remains on, the temperature of the heating wire 9 of the electric carpet 1 body rises abnormally, the insulating resin 10 melts, and the second electrode wire 13 and the heating wire 9 come into contact. As a result, a large current flows through the resistors 47 and 48, and the resulting Joule heat operates the safety circuit 49 to cut off the alternating current 11[$14]. Note that normally, the impedance of the insulating resin 10 is very large (therefore, only a minute current flows through the resistors 47 and 48, so the safety circuit 49 does not operate).

Next, as another example of the conventional technology, as shown in FIGS. 9 to 11, there is a so-called An example of a one-line blanket will be explained. Note that some of the same components as in the conventional example are given the same reference numerals. FIG. 9 is a block diagram of an electric blanket. 50 is the electric blanket main body, 51 is a controller box, and the electric blanket 5
A single thermal heater wire 52 in which the polymer temperature sensitive body 6 and the heat generating wire 9 are integrated is wired inside the wire. Figure 10 shows
This is a partial structural perspective view of the heat-sensitive heater wire. A polymer temperature-sensitive member 6 whose impedance changes depending on the temperature is filled between the heat-generating wire 9 and the electrode wire 53, and its temperature characteristics are the same as in FIG. 6. In addition, 54 is a core thread, and 55 is an outer skin. FIG. 11 is a control circuit diagram of a single-line blanket, which is another conventional example. 14 is an AC power supply, and 15 is a power switch. 6 is a polymer temperature sensitive body whose impedance changes depending on temperature, 9 is a heating wire, and 5a is an electrode wire. 56 is a diode, 57.58 is a capacitor, 59.
60 is a resistor, and 61 is a constant voltage diode, which constitute a constant voltage circuit. 62 is a base-grounded transistor for temperature detection, 63, 64, and 65 are diodes for protecting the transistor 62, and 66 is a heat generating resistor connected to the electrode wire 53. The temperature detection method is
A transistor 62 whose base is grounded turns on in the negative half cycle of the AC power supply 14 and transmits a temperature signal current flowing through the diodes 63, 64, the resistor 66, the electrode wire 53, the polymer thermosensitive element 6, and the heating wire 9 to the collector side. It is converted into a temperature signal voltage by a resistor 60 and a capacitor 57 connected to the temperature signal. Reference numeral 67 is a thyristor which is a power control means and controls the on/off of energization of the heating wire 9. Reference numeral 68 is a resistor, and reference numeral 69 is a capacitor, which prevents malfunction due to noise. In addition, for temperature detection, the thyristor is non-conductive during the negative half cycle, and a uniform electric field is applied between the polymer temperature sensing element 6 and the electrode wire 53 at any part, so that the accurate temperature of the entire heating edge 9 can be determined. It is something that can be detected. 70 is a diode, 71, 72, 73 are resistors, 74 is a variable resistor which is a setting means for setting a desired temperature, and 76 is a capacitor. These configurations create a smoothed temperature setting voltage. 76 is a comparator which is a comparison means for comparing the temperature signal voltage and the temperature setting voltage, and 77 is the AC power supply 1.
78 is a control means that triggers the thyristor 67 in synchronization with the pulse of the zero volt pulse generating means 77 based on the output signal of the comparator 76 so as to reach a desired temperature. It is intended to be controlled. 79 is a diode, 80
is a resistor, 81 is a capacitor, and 82 is a constant voltage diode, and these components create a power source for the control means 78 and the comparator 76.

49 is a safety means, which in this example is a temperature fuse thermally coupled to a resistor 66.83. 84 is a diode, 85
is a thyristor, 86 is a resistor, 87 is a capacitor,
These control means trigger the thyristor 85 from the control means 78 to cause a large current to flow through the resistor 83 when the thyristor 67, which is the power control means, fails in the reverse direction or when the temperature rises abnormally.
The safety means 49 is operated by the Joule heat, and the AC power supply 1 is
4 is blocked. Further, even when the polymer temperature sensitive body 6 melts due to abnormal temperature, the electrode wire 53 and the heating wire 9 are in direct contact with each other, and the diodes 63, 64, the resistor 66, the electrode wire 53, the polymer temperature sensitive body 6, and the heating wire 9 are connected. A large current flows, and the safety means 49 is activated by the Joule heat of the resistor 66 to cut off the AC power supply 14.

Problems to be Solved by the Invention However, the above configuration has the following problems.

(1) For example, in an electric carpet with a high power consumption of 300 watts or more, if a heat insulator is placed on the heating wire 9 without touching the temperature detection wire 5 locally, the temperature detection wire 5 will detect an abnormal temperature rise in the heating wire 9. This means that it cannot be detected at all. This is because the temperature detection wire 5 and the heat generating wire 9 are wired separately, and an abnormal temperature rise in the heat generating wire 9 may cause discoloration of the underside of the heat insulating material and may even reach the melting temperature of the insulating resin 10. was there. Furthermore, since the temperature detection wire 5 and the heat generation wire 9 are wired in pairs, there are limitations in terms of productivity and cost reduction.

? ) Polymer temperature sensitive body 6 and heating wire 9 shown in other conventional examples
When using the temperature-sensitive heater wire 52 with integrated
Although the drawback (1) is solved, it is limited to electric blankets that consume relatively little power. Additionally, when controlling several hundred watts of power using a thyristor, the number of heat dissipation fins increases and noise increases.

(3) In other conventional examples, the non-conducting region of the thyristor (the negative half cycle of the AC power supply 14) is used for temperature detection, which makes it possible to accurately detect the temperature of the heating wire 9. , for bidirectional power control means such as relays,
Since the heating wire 9 is energized even in the negative half cycle, an equal electric field is not applied to the polymer temperature sensitive body 6 between the heating wire 9 and the electrode wire 53, and the temperature of the heating wire 9 cannot be accurately detected. This is something that cannot be done. Therefore, although the relay was periodically de-energized by the control means to accurately detect the temperature of the polymer thermosensor 6, the temperature exceeded the heat resistance limit of the polymer thermosensor 6 when keeping local areas such as cushions warm. Therefore, the impedance characteristics may change.

The present invention solves the above problems, and provides a temperature control device that uses a heat-sensitive heater wire in which a heat-sensitive wire and a heat-generating wire are integrated, and is capable of stable temperature control over a long period of time.

Means for Solving the Problems In order to solve the above problems, the temperature control device of the present invention includes:
A thermal heater wire having a polymer temperature sensitive body interposed between the heating wire and the electrode wire, a power control means for controlling energization to the heating wire, and a temperature signal current flowing through the polymer temperature sensitive body. a temperature detection circuit for detecting via an electrode wire, a setting means for setting the temperature of the thermosensitive heater wire to a desired temperature, a comparison means for comparing a signal of the temperature detection circuit and a signal of the setting means; a driving means for driving the power distribution control means; a first timer means for maintaining the driving of the driving means for at least a certain period of time; If the driving means is forcibly stopped and restarted at a certain fixed period, and the driving time of the driving means reaches the certain fixed period within the time set by the first timer means, the first When the time set by the timer means is reached, the driving means is forcibly stopped and restarted, and if the heating wire is not energized within the previous cycle, the driving means is restarted from the second timer means. It is composed of a third timer means that forcibly stops and restarts at a time set by the timer means, and a control means that controls the driving means using a signal from the comparing means while the driving means is stopped.

Function: With the above configuration, the control means stops the driving means and restarts the third timer means at a certain regular period.
It is possible to accurately detect the temperature of the single molecule thermosensitive element whose driving means is stopped within at least a certain period of time, and after the power to the heating wire is maintained for at least a certain period of time, the driving means is stopped and the third timer means is restarted. Furthermore, if the heating wire is not energized within the previous regular cycle, the driving means is stopped for a certain period of time and the ninth timer means is restarted, so that the heating wire is not energized once in a row. The energization time is longer than the set time of at least the shorter of the first timer means and the second timer means, and the heating wire was energized for a longer time than the time set by the first timer means within the previous cycle. The time during which the heating wire is energized within a certain period is the remaining time from the time when the driving means stops until the driving means starts to be driven by the signal from the comparison means, and there may be cases where the heating wire is not energized during the previous cycle. The time during which the heating wire is energized within the fixed period has the effect of being the time set by the second timer means.

EXAMPLE Hereinafter, an example of the present invention will be described with reference to the accompanying drawings.

FIG. 1 is a temperature control circuit diagram showing an embodiment of the present invention. Components that are the same as those of the conventional example are given the same reference numerals. The polymer thermosensitive body 6, the heat generating wire 9, and the electrode wire 53 together constitute a thermosensitive heater wire 52, which is wired inside the electric carpet body.

14 is an AC power supply, and 15 is a power switch.

33 is a diode, 35 is a resistor, 39 is a relay which is a power control means, 40 is a diode for absorbing surge of the relay 39, and 41 is a transistor which is a driving means for driving the relay 39. 47.48 is resistance, 4
9 is a safety circuit.

56 is a diode, 59 and 60 are resistors, 58 is a capacitor, and 61 is a constant voltage diode, which constitute a constant voltage circuit. 62 is a base-grounded transistor for temperature detection; 63.64.65.97.98
is a diode, and 96 is a resistor. The temperature detection method uses a transistor 62 whose base is grounded as in other conventional examples.
is turned on in the negative half cycle of the AC power supply 14, and the temperature signal current flowing through the diode 98, the resistor 47, the electrode wire 53, the polymer thermosensitive element 6, and the heating wire 9 is transferred to the resistor 60 and the capacitor connected to the collector side. 57, it is converted into a temperature signal voltage. 70 is a diode, 71, 72, 73 is a resistor, 74 is a variable resistor which is a setting means for setting a desired temperature, and 75 is a capacitor, and a smoothed temperature setting voltage is created by these. 76 is a temperature signal voltage;
A comparator that is a comparison means for comparing temperature setting voltages,
77 is a zero volt pulse generating means that generates pulses synchronized with the AC power supply, 78 is a microcomputer (hereinafter referred to as microcomputer) which is a control means, and the comparator 7
In response to the output signal of 6, the transistor 41, which is a driving means, is turned on, and the relay 39 is controlled.
Controls the energization of the 79.8B is a diode, 80 is a resistor, 81 is a capacitor, and 82 is a constant IF! , a pressure diode, and these configurations create a power source for the comparator 76. Further, 89 is a constant voltage diode, 90 is a diode, 91 is a resistor, and 92 is a capacitor, and these configurations create a driving power source for the microcomputer. 9
3 is a reset circuit for the microcomputer 78, and 94 is a clock circuit for ending the microcomputer. 99, 100, and 95 are timer counters that are first, second, and third timer means, respectively, and create each fixed time and a certain fixed period time by counting the pulses of the zero volt pulse generation means 77. There is. Note that if the microcomputer 78 malfunctions and the relay 39 remains on, the temperature of the heat-sensitive heater wire 52 inside the electric carpet body rises abnormally and the polymer temperature-sensitive body 6 melts, the electrode wire 53 and the heat-generating wire 9 Upon contact, a large current flows through the heating resistors 47 and 48 due to the contact portion, and the safety circuit 49 is activated to cut off the AC power supply 14.

However, since the impedance of the polymer thermosensitive element 6 is usually very large, only a small current flows through the heating resistors 47 and 48, so the safety circuit 49 does not operate.

Further, 96 is a resistance.

Based on the above configuration, the temperature control method according to the embodiment of the present invention can be explained as follows.
This will be explained using FIGS. 3-1 and 4.

The microcomputer 78 turns off the transistor 41 of the driving means, and then counts the number of pulses from the zero-volt pulse generating means 77 using the timer counter 95, thereby creating a certain fixed period. (For example, 5 minutes.) Then, while the transistor 41 is off, the relay 39 is off, and the relay 39 is off.
Since the contacts are open, a uniform electric field is applied to any part of the polymer thermosensitive body 6 between the electrode wire 53 and the heating wire 9, and the temperature of the entire thermosensitive heater wire 52 can be detected by using the AC power supply. In the negative half cycle of 14, accurate temperature detection can be performed by the transistor 62 whose base is grounded. A comparator 76 compares the temperature signal voltage of the thermosensitive heater wire 52 with the temperature setting voltage of a variable resistor 74 serving as a setting means, generates a signal requesting turning on of the relay 39, and inputs the signal to the microcomputer 78. Microcomputer 7
8 immediately drives transistor 41, relay 3
9 is turned on, and the heating wire 9 is energized. Here, the time (Ton) during which the heating wire 9 is energized is within a certain fixed period (TTOTAL), as shown in FIG. 2A.
The ON request signal from the comparator 76 comes (TO
FF).

For temperature control, changing the setting means 74 changes the TOFF time, and the TON within a certain fixed period (TTOTAL) changes.
The desired temperature can be obtained by changing the time and therefore changing the energization rate of the heating wire 9.

Moreover, the day in FIG. 2 shows a case where no current is applied to the heating wire 9 within the previous fixed cycle and a case where a certain fixed cycle time is reached within the set time of the first timer means 99.

The area of energization to the heating wire 9 is a 1 b + ' + d
+. After the heat region ends, if the time TOFF during which the heating wire 9 is not energized exceeds a certain periodic time Ttota47 (TOFF > TTOTAL), the time TAN set by the first timer means energizes the heating wire 9 (area b). Then, from the end of the area, a timer (third timer means 95) with the next regular cycle is activated.
Start AL. Time To (To = TTOTAL - TOFF) obtained by subtracting the time from TTOTAL to the start of energizing area d to the heating wire 9 after the end of zone 0.
If TO≦%N, at least the second timer means 100
The current is maintained for ``'cxv'' set in , and the next η''0TAL is started from the end of the d area. This makes it possible to prevent excessive heat from being supplied, especially when the amount of heat radiated from the electric carpet is small, and to reduce the temperature differential.

In addition, timer counter 95.99.100 is microcomputer 7.
8 and the timer counter 99 is TOFF>
The timer counter 100 starts counting with a signal requesting ON of the relay 39 from the comparator 76 at the time of TOTAL, and is reset when the set time is reached. The timer counter 95 starts counting when the relay 39 turns on request signal, and resets when the set time is reached.The timer counter 95 is reset when the microcomputer 78 turns off the transistor 41, and the timer counter 95 starts counting when the microcomputer 78 turns off the transistor 41. It is a fresh start.

FIG. 3 shows the pattern of energization rate when the electric carpet is kept locally warm with a cushion or the like. This is because the polymer thermosensitive element 6 is filled between the heating wire 9 and the electrode wire 5.3, so from an electrical circuit perspective, it becomes a parallel circuit, and when local heat is kept warm, the heating wire 9 is still hot. In this case, it becomes difficult for the comparator 76 to generate a request signal for turning on the relay 37, and therefore the TOFF time increases and the overall energization rate decreases. Since the energization rate is reduced in this way, it is possible to suppress the temperature rise of the heating wire 9 under the cushion when the cushion is kept locally warm.

Note that the control means 78 is composed of a microcomputer,
By configuring the timer counters ss, 99, and too in the microcomputer 78, the comparison means 76 can also be internally configured if the microcomputer 78 has an analog-to-digital converter, so that the circuit configuration can be extremely simplified. effective.

Further, by using a bidirectional control element as the power control means, there is an effect that the heating wire 9 can be used effectively.

Note that in one embodiment of the present invention, the timer counter 95
．． 99.100 counts the pulses of the zero volt pulse generating means 77, but the clock circuit 94 may also be counted and the present invention is not limited to this embodiment.

Further, in one embodiment of the present invention, a relay 39 is used as the power control means, but a triac may also be used, and the present invention is not limited to this embodiment.

Effects of the Invention As described above, the temperature control device of the present invention provides the following effects.

(1) Accurately detect the temperature when the heating wire is not energized (TOFF) within a certain period (TTOTAL), and determine the energization time (TON) to the heating wire based on the difference between them.
Since the control determines the temperature, it has a high ability to detect local heat retention, suppresses the temperature rise under the cushion, prevents deterioration of the impedance characteristics of the polymer thermosensor in that area, and stabilizes electric heaters etc. over a long period of time. temperature control.

@) Turn off the energization time to the heating wire > T7゜TAL
In the case of , the constant time (T'ON) is independent of the TOFF time.
In addition, when TO≦certain time ("am"), by setting the constant time ("oh") regardless of TO, excessive heat supply can be prevented even when the amount of heat dissipated from the electric carpet is small, and the temperature differential can be made smaller and enable stable temperature control of electric heaters.

0) Extremely safe as the polymer thermosensitive body monitors the temperature of the heating wire.

(Since the 4-polymer temperature sensitive body and the heater wire are integrated, the wiring process inside the electric carpet is simplified and productivity is improved.

[Brief explanation of the drawing]

Figure 1 is a temperature control circuit diagram of one embodiment of the present invention, Figure 2 A1
Figure 2 is a diagram showing the same temperature control method, Figure 4 is a plan view of the main body structure of the conventional electric carpet, Figure 5 is a partial configuration perspective view of the same temperature detection line, and Figure 6 is a diagram showing the same temperature control method. The figure shows an impedance change temperature characteristic diagram of a polymer thermosensitive element, Fig. 7 is a perspective view of a partial configuration of the heating wire, Fig. 8 is a conventional temperature control circuit diagram, and Fig. 9 is another example of a conventional electric blanket. 1st overall view of
079 is a partial structural perspective view of a thermal heater wire, and FIG. 11 is a diagram of another conventional temperature control circuit. 6...Polymer thermosensitive body, 9...Heating wire, 3
9...Power control means, 41...Driving means, 52...Thermosensitive heater wire, 53...
Electrode wire, 62...Temperature detection circuit, 74...
...Setting means, 76...Comparison means, 78...
. . . control means, 95 . . . third timer means,
99...First timer means, 100...
- Second timer means. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 4
Figure 5 Figure 6 Body table Pregnant hawk Figure 7 Section V Figure 9 Figure 10

Claims (4)

[Claims] (1) A thermal heater wire having a polymer thermosensitive material interposed between the heating wire and the electrode wire, a power control means for controlling energization to the heating wire, and a temperature signal flowing to the polymer thermosensitive material. a temperature detection circuit for detecting current through the electrode wire; a setting means for setting the thermosensitive heater wire to a desired temperature; a comparison means for comparing a signal from the temperature detection circuit and a signal from the setting means; a driving means for driving the power control means; a first timer means for maintaining the driving of the driving means for at least a certain period of time; When the driving means is forcibly stopped and restarted at a certain fixed period, and the driving time of the driving means reaches the certain fixed period within the time set by the first timer means, the first When the time set by the timer means is reached, the driving means is forcibly stopped and restarted, and if the heating wire is not energized within the previous cycle, the driving means is stopped by a second timer. A temperature control device comprising: third timer means for forcibly stopping and restarting at a time set by the means; and control means controlling the driving means using a signal from the comparing means during the stopping of the driving means. (2) The temperature control device according to claim 1, wherein the control means is constituted by a microcomputer. (3) The temperature control device according to claim 1 or 2, wherein the first timer means, the second timer means, the third timer means, and the comparison means are configured within the control means. (4) The temperature control device according to claim 1, wherein the power control means is constituted by a bidirectional control element.