JPS6123224A - Temperature controller - Google Patents

Abstract

PURPOSE:To attain the satisfactory control of temperatures by securing the even effect of the ambient temperature change over the set temperatures. CONSTITUTION:When the ambient temperature of a thermistor 27 rises up, the impedance of the thermistor 27 has a drop. Thus the voltage divided by the thermistor 27 and a resistance 28 increases. Then a transistor TR33 is turned on more easily; while a thyristor 13 is turned off more easily respectively. As a result, the temperature is corrected toward a lower level. When the ambient temperature of the thermistor 27 drops, the resistance level of the thermistor 27 rises up. Therefore the TR33 and the thyristor 13 are turned off and on more easily respectively. Thus the temperature is corrected toward a higher level. The both-terminal voltge of resistances 25 and 26 can be divided in a fixed ratio since a series circuit of the resistance 28 and the thermistor 27 is connected in parallel to a series circuit of a variable resistance 25 and a resistance 26. Thus an even correction is secured by the thermistor 27 regardless of the value of the resistance 25.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention relates to a temperature control device used in electric blankets, electric sheets, electric carpets, etc.

<Prior art> This type of conventional temperature control device includes a heat sensitive body whose impedance changes by sensing the heat of a heating element controlled by a switching element, and controls the switching element by changing the impedance of the heat sensitive body. A variable resistor is provided to set the temperature at which the switching element operates by changing the impedance of the heat sensitive element, and the temperature of the heating element is set to a predetermined temperature by adjusting the variable resistor.

As mentioned above, the temperature control device formed by Vcfj& is such that when the temperature of the heating element is set to a predetermined temperature by adjusting the variable resistor, the temperature is kept constant at that set temperature. The temperature of the heating element is controlled to be set at a predetermined temperature even if the environmental (surrounding) temperature changes.

With a temperature control device configured as described above, the temperature of the heating element remains constant even when the ambient temperature, for example, the room temperature in which an electric heater equipped with this temperature control device is used falls. , the user often feels cold, and in the case of electric bed heaters such as electric blankets, the disadvantage is that when it gets cold in the morning, constant temperature control can cause the user to feel cold and wake up. was there.

OBJECT OF THE INVENTION The object of the Kibatsu 8A is to obtain a temperature control device that eliminates the above-mentioned drawbacks.

<Embodiment of the Invention> An embodiment of the temperature control device of the present invention will be described below with reference to the drawings.

The temperature control device of the present invention includes an AC power source 1, a power switch 2.
A first connector 5° consisting of connecting terminals 3 and 4; a heating wire 7 and a shorting wire 8 wound through a heat-sensitive layer 6 made of nylon or the like that melts and short-circuits when the temperature reaches a predetermined temperature (for example, approximately 180°C); heating element 90 heating wire 7. A second connector 12 consisting of a connecting terminal lO.11. Thyristor 13 as a switching element, temperature fuse 14. A current fuse 15 is directly connected to -JIJ to form a main circuit, and a temperature sensitive layer 17 having a negative impedance characteristic whose impedance decreases as the temperature rises is attached to the connection terminal 4 of the first connector 5 of the main circuit.
The first heat-sensitive wire 18 and the second heat-sensitive wire 1 are wound through the
9 is connected to the first heat-sensitive wire 18 of the heat-sensitive body 20, and the second heat-sensitive wire Ill of the heat-sensitive body 20 is connected to the third connector 23 consisting of connection terminals 21 and 22, and the resistor 24. The thyristor 130 is connected to the thyristor 130 through a variable resistor 25 and a resistor 26 in series for temperature setting.
A series circuit of a thermistor 27 and a resistor 28, which detects the ambient temperature (for example, room temperature) and changes its resistance value, is connected in parallel to the series circuit of the variable resistor 25 and the resistor 26. A resistor 29 is connected in parallel, and a series circuit of a diode 30 and a capacitor 31 is connected in parallel to the resistor 28, and the base of a switching transistor 33 is connected to the connection point of the diode 30 and capacitor 31 via a resistor 32. and the transistor 33
The collector of the transistor 33 is connected to the gate of the thyristor 13, the emitter of the transistor 33 is connected to the cathode of the thyristor 13, a diode 34 is connected between the collector and the emitter of the transistor 33, and a resistor 35 is connected. A capacitor 36 and a resistor 37 are connected to the collector of the transistor 33. A diode 38 is connected in series to the connecting terminal 3 of the above-mentioned connector 5, and a resistor 39. Connection terminal 4
A fourth connector 42 consisting of 0-41. Short-circuit wire 8 of the heating element 9. A fifth connector 45 consisting of connection terminals 43 and 44. A heating resistor 46 is connected in series to the cathode of the thyristor 13 for heating and fusing the temperature heater 14 with the short-circuit current of the short-circuit wire 8 of the heating element 9, and a diode 47 is connected to the heating wire 7 of the heating element 9. The power switch 2 and the diode 47 are connected in parallel, and connected to the cathode of the cyrisk 13 via a capacitor 48 at the connection point between the power switch 2 and the diode 47, and a series circuit of a resistor 49 and a neon lamp 50 for operation indication is connected in parallel to the capacitor 48. It is configured by connecting.

In the above configuration, the heat sensitive body 20 connects the first heat sensitive wire 18 with the second heat sensitive wire 19 via the heat sensitive layer 17, as shown in FIG.
As shown in FIG. 3, the heat-sensitive layer 17 has a negative impedance which increases when the VC temperature is low and decreases as the temperature rises. changes the impedance characteristics (coefficients) of

Furthermore, if the thermistor (ambient temperature sensor) 27 is used alone, the impedance will be A in FIG.
When connected in parallel with the resistor 29, the impedance exhibits a characteristic with a negative coefficient as shown in FIG. 4B with respect to ambient temperature. Here, the resistor 29 prevents the apparent impedance of the thermistor 27 from becoming larger than a certain resistance value, and prevents it from being affected by the ambient temperature when the ambient temperature (room temperature) falls below a certain temperature. Then, a heat sensitive element 20 is arranged to sense the heat of the heating element 9, and the heating element 9 and the heat sensitive element 20 are arranged in the heater body (for example, in the blanket body if the heater is a blanket), and other The parts are arranged in a control box, and the parts of the control box and the heating element 9 and heat sensitive element 20 of the heater body are connected through the first connector 5.
Second connector 12. Third connector 23. Fourth connector 42. The fifth connector 45 connects the connectors so that they can be disconnected.

Next, the operating state of the temperature control device of the present invention configured as described above will be explained.

Now, when the power switch 2 is turned on, when the power supply voltage of the AC power supply 1 is a negative power supply voltage (in the opposite direction with respect to the thyristor 13), the power supply voltage of the chain member is changed to the AC power supply 1. current fuse 1
5. Temperature fuse 14. Diode 34. capacitor 3
6. Resistance 37. Diode 38. The capacitor 36 is charged in the closed circuit formed by the power switch 2, and the power supply voltage of the AC power supply 1 in the next half cycle is positive (the thyristor 13
When the capacitor 36 is in the forward direction), the capacitor 36 is charged with nine charges. Gate and cathode of thyristor 13, resistor 46. Fifth connector 45, short-circuit wire 8 of heating element 9. Fourth connector 42. A closed circuit formed by a resistor 39 discharges through the gate and cathode of the thyristor 13 to turn on the thyristor 13.
The above positive power supply voltage is applied to the ON operation of the AC power supply 1. Power switch 2. First connector 51 Heat generating wire 7° of heating element 9 Second
Connector 12. Thyristor 13. A closed circuit formed by a temperature fuse 14 and a current fuse 15 is applied to the heating wire 7 of the heat generating element 9, and current is passed through the heating wire 7 to generate heat. At this time, the resistance value of the heat sensitive layer 17 of the heat sensitive body 20 of the transistor 33 is large because the temperature of the heat sensitive layer 17 of the heat sensitive body 20 is low (the temperature sensed by the heat sensitive body 2o of the heat generated by the heat generating wire 7 of the heat generating body 90 is low). No voltage is generated between the first heat-sensitive wire 18 and the second heat-sensitive wire 19 of the heat-sensitive body 20, which is an OFF operation. When the temperature reaches a predetermined set temperature due to the heat generated by the heat generating line 7 of the heat generating element 8, the sensitivity of the heat sensitive body 20 and the resistance value of the heat layer 17 become smaller. heat ray 1
A voltage is generated across resistor 24 . Variable resistance 25, resistance 26. Thermistor 27. Resistance 28. The voltage is divided by a resistor 29, rectified and smoothed by a diode 30 and a capacitor 31, and the rectified and smoothed voltage is applied to the base of a transistor 33 via a resistor 32, which turns on the transistor 33.
3, the gate of the thyristor 13 is short-circuited, and the thyristor 13 is turned off. Thereafter, such operations are repeated to control the temperature at the temperature set by the variable resistor 25 and/or thermistor 27. In this case, by varying the resistance value of the variable resistor 25, the voltage generated across the variable resistor 25 and the resistor 26 can be varied, thereby making it possible to adjust the temperature. Further, the resistance value of the thermistor 27 changes in response to the ambient temperature (room temperature), and temperature adjustment is performed in response to the ambient temperature.

That is, as the ambient temperature around the thermistor 27 increases, the impedance of the thermistor 27 decreases and the thermistor 27
The voltage divided by the resistor 28 is corrected to become larger, the transistor 33 is more easily turned on and the thyristor 13 is more easily turned off, the temperature is corrected to a lower value, and the ambient temperature of the thermistor 27 is When the voltage decreases, the resistance value of the thermistor 27 increases, the impedance of the thermistor 27 increases, and the voltage divided by the thermistor 27 and the resistor 28 is corrected to become smaller.
3 (L-) makes it easier to turn off the thyristor 13, and corrects the temperature to a higher target.In this way, when the ambient temperature rises due to the thermistor 27, the heating wire 7 of the heating element 9 is controlled. Since the temperature is lowered and the control temperature of the heating wire 7 of the heating element 9 is corrected to be raised when the ambient temperature falls, comfortable heating can be obtained without feeling cold when the morning cools down. in this case,
Since the series circuit of the thermistor 27 and resistor 28 is connected in parallel to the series circuit of variable resistor 25 and resistor 26, the voltage generated across the variable resistor 25 and resistor 26 can be divided at a constant ratio. , correction by the thermistor 27 can be performed relatively evenly even when the value of the variable resistor 25 is large or small. However, when connecting variable resistance thermistors in series as in the past, or when connecting thermistors in parallel to a variable resistance circuit, the temperature setting using the variable resistance is only effective for either "strong" or "weak". For example, when a thermistor is connected in series with a variable resistor, when the resistance value of the variable resistor is decreased and the temperature setting is set to "strong", the change in the resistance value of the thermistor directly affects the temperature setting. On the other hand, when the resistance value of the variable resistor is increased and the temperature setting is set to "weak", the rate of change relative to the change in the resistance value of the thermistor is small. In addition, when the thermistor is connected in parallel to the variable resistance circuit (when connected, the resistance value of the variable resistor is increased and the temperature setting is set to "weak", the change in the resistance value of the thermistor directly affects the resistance value of the variable resistor. When the temperature setting is set to ``Strong'' by decreasing the value, the proportion of change in the resistance value of the thermistor is small, and the disadvantage is that the change in the thermistor only affects either the ``Strong'' or ``Weak'' temperature setting. There is.

The resistor 29 determines the lower limit of the ambient temperature (room temperature) to be corrected, and if this resistor 24 is not present, if the ambient temperature drops extremely and the thermistor 27 becomes too large compared to the resistor 28, The base voltage of the transistor 33 becomes too small and the thyristor 13 continues to be turned on, making it impossible to adjust the temperature using the variable resistor 25.

Also, thyristor 13. becomes uncontrollable and current continues to flow through the heating wire 7 of the heating element 90, and when the heating wire 7 of the heating element 9 overheats, the heat sensitive layer 6 of the heating element 9 melts and the heating wire 7 and the shorting wire 8 are short-circuited. , an AC power source 1. is connected to the heating resistor 46. Current fuse 15. Temperature fuse 14, heating resistor 46. Fifth connector 459 Short circuit line 89 of heating element 9 Heat generating line 7 of heating element 9. The first connector 5, the heating resistor 46 in the closed circuit of the power switch 2
The heating resistor 46 generates heat by applying alternating current from the AC power source 1 to the heating resistor 46, thereby heating and blowing out the temperature fuse 14, thereby cutting off current to the heating wire 7 of the heating element 9, thereby ensuring safety.

<Effects of the Invention> Since the temperature control device of the present invention has the above configuration,
With a simple configuration, changes in ambient temperature can be reflected in the set temperature, and it is possible to automatically set the temperature for comfortable use, such as when it gets cold in the morning. The change in ambient temperature can be reflected uniformly throughout the entire area, and changes in the ambient temperature can be more reliably reflected in the set temperature.Furthermore, the temperature can be adjusted using a variable resistor reliably over the entire change in ambient temperature. can be done.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing an embodiment of the temperature control device of the present invention, FIG. 2 is a configuration diagram of the heat sensitive body shown in FIG. 1, and FIG. 3 is a temperature-impedance characteristic diagram of the heat sensitive body shown in FIG. 2. FIG. 4 is a temperature-impedance characteristic diagram of the thermistor shown in FIG. 1. In the drawing, 9 is a heating element, 13 is a thyristor, 20 is a heat sensitive element, 25 is a variable resistor, 27 is a thermistor, 28.291-
shows resistance. Agent Patent attorney Aihiko Fukushi (and 2 others) - Ba Yan
Third

Claims (1)

[Claims] 1. A temperature control device comprising a heat sensitive body whose impedance changes by sensing the heat of a heat generating body controlled by a switching element, and controlling the switching element by the change in impedance of the heat sensitive body. A series circuit of a thermistor and a resistor for sensing ambient temperature is connected in parallel to a variable resistor that sets the temperature at which the switching element operates, and a resistor is connected in parallel to the thermistor. A temperature control device characterized in that the switching element is controlled by a control signal from a connection point between a thermistor and a resistor.