JPH07105264B2 - Electric heating system - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an electric heating device having a plurality of heaters in an electric carpet or the like and capable of switching heating capacity.

(Background Art) In an electric heating device such as an electric carpet, a heater having a high and low heat generation capacity is provided in order to quickly warm up at the time of starting and to prevent overheating during normal use and to save energy. Depending on the situation, some heaters can be selected.

However, in the conventional electric heating device of this type, the switching of the heating capacity of the heater (watt switching) is currently performed by a manual switch, and the heating capacity can be automatically switched with a simple configuration. The realization of the device was awaited.

(Object of the Invention) The present invention has been proposed in view of the above points, and at the time of startup that requires a quick start-up, heating is performed with a heater having a high heat generation capacity, and then switching to a heater having a low heat generation capacity in an appropriate time. The purpose of the present invention is to provide an electric heating device that performs a comfortable original work by determining the heating capacity when the heat generation capacity is low and switching to the high heat generation capacity when the heat generation capacity is insufficient. I am trying.

DISCLOSURE OF THE INVENTION The present invention will be described in detail below with reference to the drawings illustrating embodiments.

FIG. 1 shows an embodiment corresponding to the first item of the claims. The configuration will be described with reference to FIG. 1. The commercial power source 1 has a first relay after a power switch SW.
The first heater H ₁ or the second heater H 2 of the heating element ₂ is connected via the contact of Ry _{1 and} the contact of the second relay Ry ₂ to form a closed circuit. The first heater H ₁ is a heater having a high heat generation capacity, and the second heater H ₂ is a heater having a low heat generation capacity. The primary winding of the transformer T is connected to the commercial power supply 1 via the power switch SW, and the secondary winding of the transformer T is connected to the input terminal of the power supply circuit 3 which supplies the DC power supply V _CC . .

On the other hand, the heating element 2 has sensor electrodes S ₁ and S ₂ which are arranged close to each other over the entire surface on which the heaters H ₁ and H ₂ are arranged, and a heat-sensitive material such as a plastic semiconductor is provided between the sensor electrodes S ₁ and S _2. Material is provided. Then, the sensor electrode S ₁ AC voltage is applied through the resistor R ₀ from the secondary winding of the transformer T, the voltage generated between the sensor electrode S _1, S ₂ are input to the detection circuit 4, rectified and A signal (temperature detection signal) that is smoothed and changes according to the temperature is input to the switching circuit 5. The switching circuit 5 compares the input temperature detection signal with the temperature setting signal and outputs a signal, which drives the transistor Q ₁ to relay.
It is designed to make Ry ₁ work. The heater H ₁ ,
The contact of the relay Ry ₂ for switching of H ₂ to the second heater of H ₂ normally closed contact NC is low heat capacity, also normally open contact NO is connected to the first heater H ₁ of highly exothermic capacity.

On the other hand, the timing circuit 6 has an oscillation circuit 7, a counter circuit 8, and an inverter A ₁ , and the output of the counter circuit 8 is connected to the base of a transistor Q ₂ which drives a relay Ry ₂ via the inverter A _1. At the same time, it is supplied as part of the power supply of the oscillation circuit 10 of the heating capacity determination circuit 9.
Further, the output of the inverter A ₁ is supplied as the power source of the oscillation circuit 7 in its own clock circuit 6, and the output of the oscillation circuit 7 is input as the clock of the counter circuit 8.

On the other hand, the heating capacity determination circuit 9 includes an oscillation circuit 10 and a time determination circuit 1.
1, which has an energization determination circuit 12, the output of the oscillation circuit 10 is input to the time determination circuit 11, and the oscillation circuit 10 starts / stops the oscillation operation from the output of the switching circuit 5 via the energization determination circuit 12. A control signal is given to the switching circuit 5
Is configured to oscillate only when the output of is at a high level. The output of the time discriminating circuit 11 is input to the reset terminal R of the counter circuit 8 of the time counting circuit 6 and is also fed back to the oscillation circuit 10 to hold the output.

The operations related to the timing circuit 6 and the heating capacity determination circuit 9 will be described later, and the basic temperature control operations will be described below. First, as described above, an AC voltage is applied to the sensor electrode S ₁ from the secondary winding of the transformer T via the resistor R ₀ , the sensor electrode S ₂ is grounded, and the sensor electrode S ₁ is grounded.
Since the heat-sensitive material exhibiting a negative impedance is arranged between S ₁ and S ₂ , an AC voltage divided by the resistance R ₀ and the impedance of the heat-sensitive material is generated at the sensor electrode S ₁ . Since the impedance of the heat sensitive material changes according to the temperature of the heaters H ₁ and H ₂ , the amplitude of the signal generated in the sensor electrode S ₁ follows the heater temperature. Therefore, a DC temperature detection signal can be obtained by rectifying and smoothing this signal by the detection circuit 4.

In the switching circuit 5, the temperature detection signal provided from the detection circuit 4 and a user-adjustable temperature controller (not shown)
When the heater temperature is lower than the set temperature, the selected heater H ₁
Or to turn on the transistor Q ₁ to turn on the relay Ry ₁ to perform power supply to the heater H _2, if the heater temperature conversely higher than the set temperature stops the energization to the heater H ₁ or heater H ₂ Operates to turn off the transistor Q ₁ to turn off the relay Ry ₁ . Therefore, the heaters H ₁ and H ₂ are guided to a predetermined temperature by these operations (ON / OFF control). However, it is only when the heat generation capacity has a sufficient value for the environment that the predetermined temperature can be reached within a practical period of time, and in the present invention, the on / off control is performed as described later. Whether or not sufficient heating can be performed with the heater H ₂ having a low heat generation capacity by monitoring the time of the period (this time depends on the rate of rise of the heater temperature and serves as data for judging the heating capacity) I try to judge.

FIG. 2 shows an embodiment in which FIG. 1 is shown more specifically in correspondence with the second term of the claims, and a concrete example relating to the timing circuit 6 and the heating capacity discrimination circuit 9 will be described below according to this embodiment. The specific configuration and operation will be described.

The oscillating circuit 7 of the clock circuit 6 and the oscillating circuit 10 of the heating capacity discriminating circuit 9 are composed of PUT (programmable unijunction transistor) oscillating circuits, and the power supply terminal of the oscillating circuit 7 is the output of the inverter A ₁ and the oscillating circuit 10 The power supply terminals of the charging / discharging circuit are connected to the output of the counter circuit 8. In addition, the capacitor of the charge / discharge circuit of the oscillator circuit 10
The across C ₂ the collector and the emitter of the transistor Q ₃ of the energizing discrimination circuit 12 is connected, so that the output of the switching circuit 5 is applied to the base of the transistor Q ₃ via the inverter A ₂ . Next, the programmable unijunction transistor PU of the oscillator circuit 7
The gate of T ₁ is connected to the clock terminal of the counter circuit 8. In addition, the gate of the programmable unijunction transistor PUT ₂ of the oscillator circuit 10 is a time determination circuit.
Is connected to the 11-inverting input terminal of the comparator CP ₁ of (one terminal), the base collector and emitter of a transistor connected Q ₄ is connected to the output of the inversion between the input terminal and the ground terminal the comparator CP ₁ . The oscillator circuit
Unlike the oscillation circuit 7, one end of the gate division resistance of 10 is the power supply V
Directly connected to _CC . The output of the comparator CP ₁ is input to the reset terminal of the counter circuit 8.

In operation, since the output of the counter 8 is low level at the time of starting, the output of the inverter A ₁ is high level, the transistor Q ₂ is turned on, and the relay Ry ₂ is turned on.
The heater H ₁ is selected and has a high heat generation capacity. As a result, the temperature of the heater rises quickly at the start, and the feeling of heating is increased. Further, since the output of the inverter A ₁ is at a high level, the oscillation circuit 7 is supplied with power and generates a clock pulse at a predetermined cycle.
Input to the clock terminal of. Then, when the number of clock pulses corresponding to the predetermined time T ₀ is counted, the output of the counter circuit 8 becomes high level, the output of the inverter A ₁ becomes low level, and the transistor Q ₂ turns off → the relay Ry ₂
Is turned off, the heater H ₂ is selected, and the heat generation capacity is low. Further, as a result, the power supply of the oscillation circuit 7 is stopped, the oscillation is stopped, the clock pulse is not input to the clock terminal of the counter circuit 8, the output of the counter circuit 8 is kept in the high level state, and the relay Ry ₂ is turned on. It is kept off and operated with low heat generation capacity by the heater H ₂ . In addition, in parallel with these operations, the above-mentioned temperature control (ON / OFF control) is performed by the detection circuit 4, the switching circuit 5, the relay Ry _{1, and the} like.

On the other hand, when the output of the counter circuit 8 is at a high level (when the heater H ₂ having a low heat generation capacity is operating), power is supplied to the resistor R ₂ and the capacitor C ₂ of the charge / discharge circuit of the oscillator circuit 10, and in this state When the output of the switching circuit 5 enters a high level period (on period of on / off control related to temperature control), the transistor Q ₃ of the energization determination circuit 12 turns off and the capacitor C ₂
Since both ends of are opened, the oscillation circuit 10 becomes operable.

Then, FIG. 3 shows the change of the anode voltage V _A with respect to the time t, but the time until the gate conduction of the programmable unijunction transistor PUT ₂ of the oscillation circuit 10 is shown.
And T _1, when the ON period of time T ₁ within the time T relay Ry ₁ ends are turned off, the oscillation circuit 10 is an oscillation stop until the next on-period, the output of the comparator CP ₁ time determination circuit 11 low There is no change in status as it is at the level. That is, even when the heater H ₂ having a low heat generation capacity is in operation, the on / off control is normally performed, it is determined that the heater has sufficient heating capacity, and the operation is continued.

On the other hand, as shown in FIG. 4, when the ON period does not end within the time T ₁ , the gate of the programmable unijunction transistor PUT ₂ of the oscillation circuit 10 becomes conductive, the gate voltage becomes low level, and the time determination The output of the comparator CP ₁ of circuit 11 is inverted to the high level and transistor Q
_The signal is fed back to the gate of the programmable unijunction transistor PUT ₂ by ₄ to hold the high level state, and the reset signal is given to the reset terminal of the counter circuit 8 to put the counter circuit 8 in the reset state.
Its output inverts to low level and holds its state thereafter. That is, the ON period of the on-off control according to the temperature control of a heater H ₂ of low heat capacity when followed predetermined time above T ₁ is determined to the heater H insufficient _2, heating capacity of the low heat capacity, high fever again The capacity heater H ₁ is selected and then held in that state.

FIG. 5 and FIG. 6 show the above operation,
FIG. 5 shows a case where it is judged that the heater H ₂ having a low heat generation capacity has a sufficient heating capacity, and FIG. 6 shows a case where it is judged that the heating capacity is insufficient. That is, in any case at the time of start-up, the heater H ₁ having a high heat generating capacity is operated, and after a predetermined time T ₀ when the counter circuit 8 reaches the full count, the heater H ₂ having a low heat generating capacity is switched to the heater H ₂ having a low heat generating capacity. When the ON period for ON / OFF control during operation of ₂ is shorter than the predetermined time T _{1, the} state by the heater H ₂ having a low heat generation capacity is maintained as shown in FIG. 5, and conversely the ON period is the predetermined time. When it is longer than T ₁ , it is switched to the heater H ₁ having a high heat generation capacity as shown in FIG. 6, and thereafter, the heater H ₁ having a high heat generation capacity is operated.

FIG. 7 shows an embodiment corresponding to the third aspect of the invention, and the time for determining whether or not the heating ability of the heater H ₂ having a low heat generation capacity is sufficient in the heating ability determination circuit 9. The T ₁ is changed according to the room temperature. That is, the lower the room temperature, the lower the heat generation capacity of the heater H ₂
In this case, the heating capacity tends to be insufficient, so the determination time T ₁ of the ON period is shortened, and when the heating capacity is insufficient, the heater H ₁ with a high heat generation capacity is switched to quickly. Conversely, when the room temperature is high, the determination time T ₁ The heater H ₁ having a long heat generation capacity is not switched unnecessarily. As a configuration,
The configuration of the oscillator circuit 10 in FIG. 2 is partially modified, and a negative characteristic thermistor NTC is connected in parallel with the resistor connected between the gate of the programmable unijunction transistor PUT ₂ and the DC power supply V _CC. .

FIG. 8 shows an embodiment corresponding to the fourth aspect of the claims, and a signal from the heating capacity determination circuit 9 is given to the timing circuit 6 via the heater heat generation capacity recovery circuit 13 so that the heating capacity once becomes insufficient. Even if the low heat generating capacity is switched to the high heat generating capacity, the low heat generating capacity is switched again after a predetermined time. In the operation, an output is output from the heating capacity determination circuit 9 and the heater H ₁ having a high heating capacity is operated again. However, when the heating capacity operation is started, the timing circuit 6 is operated again for a predetermined time T. ₀
After the passage of time, the heater heat generation capacity return circuit 13 operates again so that the low heat generation capacity operation is performed, and the above-described operation is repeated.

FIG. 9 shows another embodiment, which is the second embodiment described above.
Transistor for holding operation of time discrimination circuit 11 in the figure
Remove the Q _4, is obtained by the repeated switching between high heating capacity and low heat capacity to heating capacity is sufficient. In operation, when the ON period in the heater H ₂ having a low heat generation capacity in the oscillation circuit 10 exceeds the set time T ₁ ,
Programmable unijunction transistor PU
T ₂ is conducting, and the gate voltage V _G has a waveform as shown in FIG. At this time, the output of the comparator CP ₁ has a pulse waveform as shown in FIG. 11, and this waveform is input to the reset terminal of the counter circuit 8 of the timing circuit 6. As a result, the counter circuit 8 is cleared, the output of the counter circuit 8 becomes low level, the transistor Q ₂ is turned on, the relay Ry ₂ is turned on, the heater H ₁ having a high heating capacity is operated, and the counter circuit 8 is turned on again. Counting started at
When the predetermined time T ₀ is reached, the output of the counter circuit 8 becomes high level, the low heat generation capacity operation is resumed, and these operations are repeated.

Also, the heater heat capacity recovery circuit 13 in FIG. 8 is provided with a counting means for counting a switching signal for controlling the heater temperature as an oscillation signal, and when the count value reaches a predetermined value, the original low heat capacity is restored. It can also be switched. The oscillator circuit 7 in the clock circuit 6
It is also possible to use a switching signal for controlling the temperature of the heater instead of the oscillation signal of.

(Effects of the Invention) As described above, according to the present invention, in an electric heating device having a plurality of heaters and selectively changing the heaters to have different heating capacities, a high heating capacity is provided at the time of starting. The heater is used to quickly raise the temperature of the heater, and after a lapse of a predetermined time, it automatically switches to a heater with a low heat generation capacity to prevent overheating, and when the heating capacity is insufficient and sufficient heating cannot be performed, the temperature is raised again. Since the heater is switched to one having a heat generation capacity, there is an effect that comfortable and efficient heating can be performed.

[Brief description of drawings]

FIG. 1 is a circuit configuration diagram showing an embodiment of the electric heating apparatus of the present invention, FIG. 2 is a circuit configuration diagram partially showing FIG. 1 in detail, and FIGS. 3 to 6 are FIG. 7 is an explanatory diagram of the operation of FIG. 7, and FIG. 7 to FIG. 9 are circuit configuration diagrams showing other embodiments, respectively.
FIG. 10 and FIG. 11 are explanatory diagrams of the operation of FIG. 1 ... Commercial power source, 2 ... Heating element, 3 ... Power supply circuit, 4 ...
... Detection circuit, 5 ... Switching circuit, 6 ... Timer circuit, 7 ... Oscillation circuit, 8 ... Counter circuit, 9 ... Heating capacity determination circuit, 10 ... Oscillation circuit, 11 ... Time determination circuit,
12 …… energization discrimination circuit, 13 …… heater heat capacity reset circuit

Claims (5)

[Claims] 1. A plurality of heaters, a heat generation capacity switching means for selectively switching these heaters so as to make at least two kinds of heat generation capacities, a temperature detection means for detecting a temperature of the heater, and the heater. Temperature setting means for setting the temperature of the heater, means for comparing the detected temperature of the temperature detecting means and the set temperature of the temperature setting means to control ON / OFF of the heater, and increase the heat generation capacity at the time of starting, and A means for driving the heat generation capacity switching means so as to reduce the heat generation capacity after a lapse of a predetermined time and a heating capacity by monitoring the on time of the on / off control when the heater is operated at a low heat generation capacity. And a heating capacity determination means for switching the heat generation capacity of the heater to high when the heater does not reach a predetermined heater set temperature within a predetermined time. Heating. 2. The heating capacity determination means is preset with an oscillating means which is operable during an ON period of a heater having a low heat generation capacity and whose output increases, and an output value of the oscillating means at the end of the ON period. The electric heating device according to claim 1, further comprising: a determination unit that determines whether the length is short or short by comparing the value with a value according to a predetermined time. 3. The electric heating device according to claim 2, wherein the oscillating cycle of the oscillating means is changed in accordance with the room temperature, and the predetermined time for determining the heating capacity is variable. 4. A heater heating capacity restoring means for switching the heating capacity of the heater from a low heating capacity to a high heating capacity by the heating capacity switching means and then operating the heater to restore the original low heating capacity. The electric heating device according to item 1. 5. The heater heat generation capacity returning means has counting means for counting a switching signal for heater temperature control as an oscillation signal, and switches to the original low heat generation capacity when a predetermined count value is reached. The electric heating device according to claim 4, wherein