JPS5840630A - Temperature control circuit of electric heater - Google Patents

Abstract

PURPOSE:To shorten the time of a temperature rise up to a desired set point without re-setting a temperature setting dial in the middle, by putting a timer in operation for a prescribed time by the 1st output of a switching circuit which controls a heat source driving circuit. CONSTITUTION:The 1st output L for turning off a transistor 11 among output signals of a switching circuit 10 is received to output an output H from a timer 13 for a prescribed time. Then, a reference value inputted to the switching circuit 10 by the output H of the timer 13 is corrected to a value made lower by a prescribed correction value than a value which corresponds to set temperature. While the timer 13 is in counting operation, temperature higher than the desired temperature is regarded as target temperature and a temperature control circuit is operated to shorten the time of a temperature rise.

Description

[Detailed Description of the Invention] This product is an electric IIk product such as an electric carpet! An example of a conventional electric carpet temperature control circuit is shown in Figure 1, which is related to the temperature control circuit of the device.
Connect the heater 3 to the power supply 2 via the e
On the other hand, a heat-sensitive electrode 5 made of flunium foil or the like is attached to a 40 piece aUW of a sensitive l&resistor made of a polyand resin having negative temperature-impedance characteristics, and a resistor is attached to this sensitive I#. The heater 3Vr was installed at 40°C, and both Il were covered with an insulating film (I
(not shown) to form a heat-sensitive element, and input a predetermined AC voltage signal to the oscillation circuit (7), and this AC voltage signal is connected to an impedance element that is connected to the input/output circuit (80). By dividing the voltage between the heat-sensitive element and the heat-sensitive element 6, a partial pressure corresponding to the impedance shown by the heat-sensitive resistor 4tIK of the heat-sensitive element 6 is applied to the thermo-sensitive electric @SK, and changes in impedance of the heat-sensitive resistor 4 due to temperature changes are applied. This output voltage is generated as an output voltage change, is detected by the temperature detection circuit 9 through the output part of the input/output circuit 8, and the detected value is made to correspond to a predetermined set temperature in the next stage switching circuit 10. Compare it with a given reference value, and use the comparison judgment output to drive the next stage transistor 11t-ON Φ OFF, control the drive of the relay excitation coil l connected in series to this transistor 11, and control the relay contact 1m + 1m. This temperature control circuit is designed to control the temperature by connecting and disconnecting the power supply path of the heater circuit through on/off operation. Now, the reference value t- input to the switching circuit IO is
It is configured such that the resistance ffi of the variable resistor in the voltage divider circuit is set to a value corresponding to a desired temperature by operating a temperature setting dial. Even if a predetermined temperature is set by operating the temperature setting dial, the temperature rise is slow in the initial stage of energization, so it takes a long time for the target source gK to be reached.The temperature rise characteristics are shown in Fig. In order to avoid such a delay t- in the rise of τ and reach the target temperature early, conventionally the temperature setting dial is set to a scale I+/& that is larger than the target temperature at the initial stage of energization. This method involves forcibly accelerating the temperature setting and then readjusting the temperature setting dial to the target temperature scale after a predetermined period of time has elapsed. In this electric heating device, the heater is covered with a surface material, a back material, nylon, etc., and has a nine-layer structure, and due to the heat capacity of these materials, the heat distribution is not uniform. ! Therefore, the purpose of this invention is to turn the power supply line of the heater circuit on and off several to tens of times during the process, and the temperature rise time tends to be longer. To provide a temperature control circuit for an electric heating device that is easy to use and can increase the temperature rise time to a desired set temperature by as much as 111 times without requiring any troublesome operations when changing settings. .

An embodiment of this invention is shown in FIGS. 3 and 4. That is, the temperature control circuit of this electric heating device is set upon receiving the first L output that turns off the transistor 11 among the output signals of the switching circuit 10 in the conventional example, and is set for a predetermined period of time.

A timer 13 that continues to output H output is added, and this timer 1
The reference value inputted to the switching circuit IO by the H output of No. 3 is adjusted by a predetermined correction value ΔV from the value corresponding to the set temperature.
(The higher the detected temperature, the smaller the detected temperature value input to switching circuit 1G becomes.)
3, the temperature control circuit operates with a temperature higher than the desired temperature as the target temperature, thereby shortening the rise time by 1 degree.

FIG. 4 shows its specific circuit configuration. In the figure, a voltage dividing circuit M14 which inputs a reference value to one reference value input terminal e of a comparator constituting the switching circuit IO is connected in series between a DC voltage power supply +V and ground, and a running constant resistor 15. Variable resistor a16 and DC voltage power supply +v
DD = Identification resistor 17.18 connected in series between the variable resistor 160 and the sliding head 116a, a reference voltage is obtained from the connection midpoint N of the fixed resistor 17.18, and this voltage dividing circuit 14 Separately, a transistor 19 and a fixed resistor 20 are connected in series to form a nine-base ratio correction circuit 21.

The transistor 19 of the reference value correction circuit 21 is turned on in response to the H output of the timer 3, and the on operation of the transistor 19 turns on the variable resistor 1.
60 For the divided resistance from the 18m position of the sliding tap to the ground terminal position fP, the identification resistance 2 of the reference value correction circuit N21
The timer 13 is connected in parallel to the switching circuit 1 as described above.
Of the output of 0, transistor 11 is turned off (and the relay excitation coil 1 connected in series with transistor 11 stops driving, and the relay contacts 1m and la of the power supply path are turned off). A voltage dividing circuit consisting of a single operation history that continues to output an H output that turns on the transistor 19 of the reference value correction circuit 21 by counting single operations for a predetermined set time, and thereafter maintains the L output state. The variable resistor 16, which constitutes a part of the variable resistor 14, has its sliding tap 16a interlocked with a temperature setting dial (#A not shown), and by changing the position of the sliding tap 16a, the connection midpoint of the p voltage dividing circuit 14 can be adjusted. The voltage of N, that is, the reference value is changed. The operation of the temperature control circuit of this electric heating device is as follows.

When the temperature setting dial is turned and energized f:M#i according to the desired set temperature scale, the reference voltage obtained from the connection midpoint N of the voltage dividing circuit 14 and the temperature obtained from the heat sensitive element 6 are obtained. The switching circuit 10 compares the detected value with the H and LK outputs of the comparison judgment of the switching circuit 1o, and the transistor 11f is turned on and off to perform temperature control.
At this time, the temperature setting dial is set to "low" K, and in the next case, in other words, the sliding tab 16a of the variable resistor 16 is shifted to the power supply side terminal position P2, and the voltage at the connection midpoint N in the next case, that is, the reference The values are the respective values t-R, eRb, and R0 of the identified resistor 15, 17, and 18° variable resistor IIILO.
If tVR is set, then conversely, if the temperature setting dial is set to "temperature 1", then in other words, the sliding tap 16- of the variable resistor 16 is
The standard value of the pigeon house with the ground side terminal shifted to position P is Tonashi.In line with the tendency for the temperature detection value to decrease as the temperature of the sensor M* child 6 increases, the standard value is at a low level at high temperature settings. IIK shift.

J(f:/f The first L output of the circuit 1o is
3, the timer 13 continues to output an H output for a predetermined period of time and turns on the transistor 19 of the reference value correction circuit 21. Therefore, the fixed resistor 20 is inserted in a row from the sliding tap 1611 position of the variable resistor 16 of the voltage dividing circuit 14 to the dividing resistor from the ground side terminal position P, and the I#!
The partial pressure, that is, the reference value obtained from the continuous midpoint N, decreases by the corrected value of 47 minutes, and temperature control is performed at a target temperature higher than the temperature set with the temperature setting dial, and after the time set on timer 3 has elapsed. becomes the output #: tL of timer 3, transistor 19 is turned off, it is separated from fixed resistor 2o and variable resistor FCa 116, temperature control is performed based on the normal reference value, and timer 130 output is turned off. During operation, the temperature rise time is reduced.

At this time, set the temperature setting dial to "weak", that is, shift the sliding tap 16a of the variable resistor 16 to the position P of the power supply side terminal. If the value of Rd is the value of In this case, the decrease in the reference value due to the insertion pressure in the reference value correction cycle N21 is large, and conversely, (2) and (2)'
As can be seen from the comparison, when the temperature is set to "strong", there is almost no decrease in the reference value due to the insertion of the reference value correction circuit 21 (tX) (there is no decrease in the reference value when the temperature is set to "strong"), as shown in FIG. As shown in the diagram, turn the temperature setting dial from "low" to l1II.
As the adjustment is made to t "strong", the reference value correction circuit 21
By inserting the correction value ΔVFi for the normal reference value (indicated by A in the figure) K, the normal reference value AK becomes less than 1. The correction value ΔV increases, and the temperature rise characteristic is efficiently improved. ◎ In order to achieve fcIII in this way, from the beginning of 1 energization, the reference value is The value #i will be automatically corrected to be lower than the value corresponding to the set temperature, and the temperature will be controlled toward the target temperature higher than the set 11 degrees, making it possible to significantly shorten the time it takes to rise the temperature. When the time set in the timer 13 has elapsed, the temperature automatically returns to the reference value corresponding to the original set temperature.
The temperature rise time can be automatically shortened without requiring the user to perform troublesome operations such as readjusting the temperature setting dial.

Additionally, the lower the reference value is automatically corrected so that it becomes larger as the set temperature is lower, so the correction value ΔV is If the setting is on the weak J side, which is a small temperature with poor temperature rise characteristics, the correction value ΔV will become large, and the improvement in temperature rise characteristics can be automatically changed according to the temperature setting conditions, resulting in an effective temperature increase. In order to improve the start-up characteristics, the temperature control circuit of the electric heating device of the present invention includes a heat-sensitive element that detects the heat source temperature and outputs a detected value corresponding to the detected wet ash; A switching circuit that compares the detected value with a predetermined reference value and controls the heat source drive circuit on and off using the comparison judgment output, and a variable resistor as a part, and adjusts the value of the variable resistor to adjust the reference value. a reference value correction circuit that partially includes a switching element and is connected to a 111Km column of variable resistors of the voltage divider circuit and corrects the reference value by the on/off operation of the switching element; A timer receives the first heat source drive circuit off control output among the outputs of the switching circuit and holds the switching element of the reference correction circuit in a predetermined operating state for a predetermined period of time, and the reference value correction circuit adjusts the reference value to the reference value. Since the value is automatically corrected to 5 to correspond to the value above the target temperature and the temperature rise time is accelerated, the temperature rise time is 9 hours earlier, and moreover, the temperature rise time is shorter on the low temperature side with poor temperature rise %. The correction ratio of the reference value for temperature setting becomes larger, and the temperature rise characteristic can be efficiently improved. It has the advantage of being easy to use and does not require any special operations.

[Brief explanation of drawings]

Fig. 1 is a circuit diagram of a conventional example, Fig. 2 is a diagram showing its temperature rise characteristics, JIE 3 is a schematic circuit diagram showing a second embodiment of the present invention, Fig. 114 is a TlI section circuit diagram showing its specific configuration, The fifth panel is an explanatory diagram showing the relationship between the set temperature and the reference value. l...Relay excitation coil, 1a...Relay contact, 2
...power supply, 3...heater, 6...thermal element, 7.
...Oscillation circuit, 9...Temperature detection circuit, 1o...Switching circuit, 11...Transistor, 12...DC power supply circuit, 13...Timer, 14...Voltage divider circuit,
15, 17.18...Fixed resistance % 16...Variable resistor, 16[...Sliding tap, 19...Transistor, 2o...Fixed resistance, 21...Reference value correction circuit 1st Figure 1 Hour Figure 2 2 Tiles

Claims (1)

[Claims] A heat sensitive element that detects a heat source temperature and outputs a detected value corresponding to the detected temperature, and a switching circuit that compares the detected value with a predetermined reference value and controls the heat source drive circuit on and off using the comparison judgment output. a voltage divider circuit that includes a KIJ transformer and allows the reference value to be changed by changing the value of the variable resistor -14; and a voltage divider circuit that includes a switching element at -11 and is connected in parallel to the variable resistor of the voltage divider circuit. a reference value correction circuit that corrects the reference value by the on/off operation of the switching element; and a timer for maintaining a switching element of the correction circuit in a predetermined operating state, and the reference value correction circuit automatically corrects the reference value so as to correspond to a value of 100 degrees or more, thereby speeding up the temperature rise time. Nine electric heating device temperature control circuit ports