JP3177415B2 - Control device for electrical equipment with heater - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for an electric device having a heater such as a refrigerator.

[0002]

2. Description of the Related Art Conventionally, in a low-temperature showcase,
For example, Japanese Utility Model Publication No. 5-5429 (F25D23 / 0)
0) for the purpose of defrosting the cooler, or
Multiple heaters are installed for the purpose of preventing condensation,
Further, a plurality of heaters are attached to the refrigerator to maintain the temperature in the refrigerator at a set value.

[0003]

However, when an abnormality such as a disconnection or a short circuit occurs in the heater, an alarm operation is performed by detecting an abnormal temperature caused by the abnormality. Takes time. In particular,
When a plurality of heaters are provided, it is extremely difficult to detect when one of the heaters is broken or partially short-circuited. Therefore, the operation has been continued without warning. Therefore, the energization rate of other heaters increases,
There is also a problem that temperature unevenness is generated in a storage such as a hot storage, and a normal heater is burdened to shorten its life.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional technical problem, and is a control capable of executing an abnormal alarm operation and a temperature control operation in an electric apparatus having a heater accurately and smoothly. It is intended to provide a device.

[0005]

A control device according to the present invention is used for an electric apparatus having a heater which generates heat by energization, and detects a temperature detecting means and a current supplied to the heater. Current value detection means, alarm means, and control means for controlling energization to the heater based on the output of the temperature detection means and controlling the alarm means based on the output of the current value detection means. The control means activates the alarm means when the current supplied to the heater falls below a predetermined value, and controls the self-holding means for holding the operation of the alarm means.
A step, wherein the heater is provided while the alarm means is operating.
Is prohibited .

A control device according to a second aspect of the present invention is characterized in that, in the above, a plurality of heaters are connected in series, and the current value detecting means detects a current supplied to the series circuit.

According to a third aspect of the present invention, in the above invention, the control means includes a differential amplifying means for generating an output proportional to a difference between the temperature detected by the temperature detecting means and the set temperature, and a sawtooth wave. Sawtooth wave generating means to be generated, comparing means for comparing the outputs of the differential amplifying means and the sawtooth wave generating means, and switching means for ON-OFF controlling the energization of the heater based on the output of the comparing means. In addition to controlling the energization rate to the heater, the operation of the alarm unit is prohibited while the energization to the heater is stopped.

According to a fourth aspect of the present invention, in the control apparatus, the control means includes a first output based on an output of the comparison means,
The apparatus further comprises means for operating the alarm means by a product of the second output generated when the output of the current value detecting means decreases and delaying the rise of the first output to accelerate the fall. I do.

According to a fifth aspect of the present invention, there is provided the control device according to the first aspect,
Alternatively, the control means may be configured such that the temperature detection means detects the temperature.
Generates an output proportional to the difference between the output temperature and the set temperature
Differential amplification means and sawtooth wave generation to generate sawtooth waves
Raw means and sawtooth generated by this sawtooth wave generating means
Crest value changing means for changing the crest value of the wave, and differential amplifying means
Comparing means for comparing the output of the
ON-O based on the output of the comparing means
Switching means for performing FF control.
Sign.

According to a sixth aspect of the present invention, there is provided a control device according to the first aspect.
Alternatively, the control means may be configured such that the temperature detection means detects the temperature.
Generates an output proportional to the difference between the output temperature and the set temperature
Differential amplification means and sawtooth wave generation to generate sawtooth waves
The output of the generating means, the differential amplifying means and the sawtooth wave generating means
Comparing means for comparing and an output based on the output of the comparing means.
Switching means for ON-OFF control of the power supply to the motor
And the temperature detected by the temperature detecting means is a set temperature.
The heater is energized at the specified energization rate even if the temperature reaches
It is characterized by that.

According to a seventh aspect of the present invention, the control device according to
Used for electrical equipment equipped with a heater that generates heat
Temperature detection means and the current supplied to the heater.
The output of the current value detection means, alarm means, and temperature detection means
Controls the power supply to the heater based on the current and detects the current value
Control means for controlling the alarm means based on the output of the means.
The control means includes means for controlling the current supplied to the heater to a predetermined value.
If it exceeds, activate the alarm means and
Self-holding means for holding the operation of
It is characterized in that energization of the heater is prohibited during operation
And

[0012]

Next, an embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram of an electric circuit of the control device 1 of the present invention. The control device 1 of the embodiment is for controlling a refrigerator (not shown), for example. The temperature controller 2 performs a temperature control of a refrigerator (not shown), and executes an alarm and a protection operation. And a protection circuit section 3. The proportional control circuit 4 included in the temperature control section 2 is provided with a thermistor sensor 6 as temperature detecting means for detecting the temperature in the refrigerator (not shown).

The sensor 6 is connected to an amplifier circuit 7 composed of an OP amplifier, and the output of the amplifier circuit 7 is a non-inverting circuit of a differential amplifier circuit 8 also composed of an OP amplifier as a differential amplifier. Connected to input. The output of a setting circuit (setting the temperature in the refrigerator) 11 to which the terminal voltage of a temperature setting volume (variable resistor) 9 is connected is connected to the inverting input of the differential amplifier circuit 8.

The output of the differential amplifying circuit 8 is connected to a non-inverting input of a comparing circuit 12 (comparator) which also comprises an OP amplifier. The inverting input of the comparison circuit 12 includes a PUT,
Further, an output of a sawtooth wave generating circuit 14 as a sawtooth wave generating means including a resistor, a variable resistor 13 and the like is connected. The peak value of the sawtooth wave output from the sawtooth wave generating circuit 14 is changed by the variable resistor 13.

The output of the comparison circuit 12 triggers a solid state relay SSR 16 as a switching means. The SSR 16 is connected in series to a plurality of heaters 17 for heating the inside of the storage room and the commercial AC power supply AC. Further, a transistor 18 is connected between the output of the comparison circuit 12 and the ground.

On the other hand, the protection circuit section 3 includes a disconnection detection circuit 21.
A current-voltage conversion circuit having a current transformer (current transformer) 23 as current value detection means provided in the electric circuit of the heater 17 in the disconnection detection circuit 21. 24 are provided. The current-voltage conversion circuit 24 converts the current supplied to the heater 17 detected by the current transformer 23 into a voltage value and outputs the voltage value. The output of the current-voltage conversion circuit 24 is connected to an inverting input of a comparison circuit (comparator) 26 composed of an OP amplifier. Is done. The terminal voltage of a disconnection alarm current value setting volume (variable resistor) 27 is connected to the non-inverting input of the comparison circuit 26.

The output of the comparison circuit 26 is input to an AND circuit 28, and the output of the comparison circuit 12 is further input to the AND circuit 28 via a permission signal generation circuit 29. The permission signal generation circuit 29 includes a resistor,
The comparison circuit 12 includes a capacitor and a diode.
Is output to the AND circuit 28 by delaying the rise of the output and delaying the fall.

On the other hand, a delay circuit 31 is provided in the overcurrent detection circuit 22, and the output of the current / voltage conversion circuit 24 is supplied to the comparison circuit (comparator) 3 via the delay circuit 31.
2 non-inverting inputs. A terminal voltage of a short-circuit alarm current value setting volume (variable resistor) 33 is connected to an inverting input of the comparison circuit 32.

The output of the comparison circuit 32 and the output of the AND circuit 28 of the disconnection detection circuit 21 are input to an OR circuit 34. The output of the OR circuit 34 is output via a self-holding circuit 36 to an alarm display as alarm means. 37. The output of the self-holding circuit 36 is connected to the base of the transistor 18.

Next, the operation of the control device 1 having the above configuration will be described. The terminal voltage of the sensor 6 changes in inverse proportion to the internal temperature of the not-shown storage, which is amplified by the amplifier 7 and input to the non-inverting input of the differential amplifier 8. The set temperature set by the volume control 9 is input to the inverting input of the differential amplifier circuit 8 via the setting circuit 11, whereby the differential amplifier circuit 8 detects the set temperature and the temperature detected by the sensor 8. Outputs the difference (voltage).

When the internal temperature is sufficiently lower than the set temperature, the output of the amplifying circuit 7 is larger than the output of the setting circuit 11, so that the output V1 of the differential amplifying circuit 8 becomes
As shown in the upper part of FIG. 2, the peak is higher than the peak of the sawtooth wave V2 generated by the sawtooth wave generation circuit 14. Accordingly, the output V3 of the comparison circuit 12 is always at a high potential (hereinafter, referred to as "H") as shown in the lower part of FIG.
Is constantly triggered to conduct, and the heater 17 is always energized, that is, 100% energized.

[0022] With such 100% energization, the internal temperature rises rapidly. As a result, the terminal voltage of the sensor 6 decreases, and the difference from the set temperature decreases.
Output V1 also decreases. Then, when the voltage becomes lower than the peak of the sawtooth wave V2 as shown in the upper part of FIG. 3, the output V3 of the comparison circuit 12 becomes a rectangular pulse which becomes “H” only during the period when V1 is higher than V2 as shown in the lower part of FIG.

That is, the SSR 16 is conductive (ON) only during the period when V3 is "H", and is non-conductive (OFF) during the period of the bottom potential (hereinafter referred to as "L").
7 is reduced (for example, 50%). As a result, the amount of heat generated by the heater 17 decreases, and the degree of increase in the internal temperature becomes slow.

When the internal temperature further rises, the output V1 of the differential amplifier circuit 8 further decreases, whereby the duty ratio of the heater 17 also gradually decreases, but the internal temperature reaches the set temperature. After that, even when the heat leakage of the storage compartment and the calorific value of the heater 17 are balanced, the output V1 of the differential amplifier circuit 8 does not reach the lowest point of the sawtooth wave V2 as shown in the upper part of FIG. Set the settings (amplification rate, etc.) and place. Thereby, even when the internal temperature reaches the set temperature, the energization rate of the heater 17 is not zero and is energized at a predetermined value, so that the time until the set temperature is reached can be shortened. In addition, it is possible to reliably reach the set temperature even when heat leakage from the storage is large.

The peak value of the sawtooth wave output from the sawtooth wave generating circuit 14 (proportional control start) is determined by the variable resistor 1
3 can be easily changed as shown in FIG. 6 or FIG. Therefore, it is possible to freely change the temperature at which the above-described proportional control is started in accordance with the characteristics of the electric device, so that the so-called overshoot and undershoot of the temperature are reduced, and the temperature control accuracy is further improved. Can be.

On the other hand, the value of the current supplied to the heater 17 is detected by the current transformer 23, converted into a voltage value by the current-voltage conversion circuit 24, and input to the inverting input of the comparison circuit 26. At this time, any abnormality in the heater 17 (disconnection / short circuit)
Does not occur, and if the energizing current value is the rated current, the disconnection alarm current value (threshold voltage. Higher than the SSR
As shown in the upper part of FIG. 5, the output VA of the comparison circuit 26 is "L" during the period when the circuit 16 is conducting, and "H" during the non-conducting state, that is, the period when the current is zero.

On the other hand, the output VB of the permission signal generation circuit 29 and the output VA of the comparison circuit 26 are input to the AND circuit 28 and the product thereof is calculated. The output VB of the permission signal generation circuit 29 is as described above. Since the rise of the output V3 of the comparison circuit 12 is delayed and the fall is accelerated (shown in the middle part of FIG. 5), VA and VB simultaneously become "H" while the rated current is flowing through the heater 17. As a result, the output of the AND circuit 28 does not become “H” but always becomes “L” (shown in the lower part of FIG. 5).

Therefore, as long as the output of the comparison circuit 32 is "L", the output of the OR circuit 34 is "L", the self-holding circuit 36 does not generate an output, and the alarm display 37 does not operate. Thus, the occurrence of false reports is avoided. Here, as shown in FIG. 9, if the product of VA and the AND circuit 28 is taken as it is without operating V3 in the self-holding circuit 36, a period during which both are simultaneously switched to "H" is created. , The output of the AND circuit 28 intermittently becomes “H” and an alarm is issued. However, the inconvenience is solved in the present invention.

Next, when a disconnection occurs in a part of the heater 17, the current supplied to the heater 17 detected by the current transformer 17 becomes lower than the disconnection alarm current value set by the potentiometer 27. , The output V3 of the comparison circuit 12
Becomes “H” and the output VA of the comparison circuit 26 becomes “H” during the entire period when the SSR 16 is conducting (ON),
As a result, the output of the AND circuit 28 becomes “H”.
This output is input to the self-holding circuit 36 via the OR circuit 34 and is self-held, so that an alarm is continuously displayed on the alarm display 37, and the transistor 18 is turned on to turn on the comparison circuit 12. Output V3 is forced to zero. As a result, the SSR 16 becomes non-conductive, and the power supply to the heater 17 is cut off.

As described above, according to the present invention, when a disconnection occurs in a portion of the heater 17, the disconnection can be detected quickly and accurately based on a decrease in the current supplied thereby, and an alarm can be issued. Therefore, it is possible to prevent the occurrence of temperature abnormality and the normal deterioration of the heater 17 beforehand. Further, the operation of the alarm display 37 is self-maintained, and while the alarm display 37 is operating, the energization of the heater 17 is prohibited. Therefore, the alarm is stopped for some reason such as a fluctuation in the power supply voltage. In this way, it is possible to reliably prevent the normal heater 17 other than the broken heater 17 from deteriorating. The self-holding of the alarm is canceled when the power supply is stopped.

The output of the current-voltage conversion circuit 24 is delayed by the delay circuit 31 of the overcurrent detection circuit 22 and then input to the non-inverting input of the comparison circuit 32. At this time, if no abnormality (disconnection / short circuit) has occurred in the heater 17 and the supplied current value is the rated current, the short-circuit alarm current value (threshold voltage; here, the threshold value voltage set in the volume 33). , A predetermined value higher than the rated current), the output of the comparison circuit 32 becomes “L”. Therefore, as long as the output of the AND circuit 28 is "L", the output of the OR circuit 34 is "L", the self-holding circuit 36 does not generate an output, and the alarm display 37 does not operate.

Next, when a short circuit occurs in a part of the heater 17, the current value of the heater 17 detected by the current transformer 17 becomes higher than the short-circuit alarm current value set by the volume control 33. , The output of the comparison circuit 32 becomes “H”. This output is input to the self-holding circuit 36 via the OR circuit 34 and is self-held, so that an alarm is continuously displayed on the alarm display 37, and the transistor 18 is turned on to turn on the comparison circuit 12. Output V3 is forced to zero. As a result, the SSR 16 becomes non-conductive, and the power supply to the heater 17 is cut off.

As described above, according to the present invention, the alarm indicator 37 is operated when the current supplied to the heater 17 exceeds a predetermined value. It becomes possible to detect the short circuit quickly and accurately based on the increase of the energizing current and to issue an alarm. Therefore, the occurrence of abnormal temperature and the normal heater 17
Can be avoided beforehand.

Here, in the embodiment, the current-voltage conversion circuit 24
Is output by the delay circuit 31 and input to the comparison circuit 32. Therefore, even if the rise of the terminal voltage (reference voltage) of the variable resistor 33 is delayed when the power is turned on, a short circuit alarm may be issued. Is prevented.

Next, FIG. 8 shows a specific connection example of a plurality of heaters 17A... (Three), 17B. In this case, the capacity of the heater 17A is, for example, 160W, and the capacity of the heater 17B is 230W.
In this case, the heaters 17A and 17B are connected one by one in series, and these series circuits are connected in parallel to the AC power supply AC. The current transformer 23 is provided so as to detect a current of a common power supply line of each series circuit.

With this configuration, for example, even when one heater 17A is disconnected, the current is not supplied to the heater 17B connected to the heater 17A. Becomes larger.
Therefore, the disconnection detection accuracy of the disconnection detection circuit 21 can be improved.

Although the embodiment has been described by taking a warm storage as an example, the present invention is not limited thereto, and the present invention is effective for various electric appliances including a heater, such as a refrigerator and a low-temperature showcase.

[0038]

As described in detail above, according to the first aspect of the present invention, a current value detecting means for detecting a current supplied to the heater is provided, and based on an output of the current value detecting means, a current supplied to the heater is determined. Since the control means activates the alarm means when the value falls below a predetermined value, when a disconnection occurs in a part of the heater, the disconnection is quickly and accurately detected based on a decrease in the energizing current caused by the disconnection. , Will be able to issue an alarm. Therefore, it is possible to prevent the occurrence of temperature abnormality and the normal deterioration of the heater . In particular, control
The means comprises self-holding means for holding the operation of the alarm means
Power supply to the heater is disabled while the alarm is activated.
So that any changes such as power supply voltage fluctuations
Prevent inconvenience that alarm is stopped due to cause, disconnect
To prevent deterioration of normal heaters other than the heater
Is what you can do.

According to the second aspect of the present invention, in addition to the above, a plurality of heaters are connected in series, and the current value detecting means detects the current supplied to the series circuit. Even when the contact capacity is small, the change in the current value due to the disconnection is increased, and the disconnection detection accuracy can be improved.

According to the third aspect of the present invention, in addition to the above inventions, the control means further comprises a differential amplifying means for generating an output proportional to a difference between the temperature detected by the temperature detecting means and the set temperature; , A comparing means for comparing the outputs of the differential amplifying means and the sawtooth wave generating means, and energizing the heater based on the output of the comparing means.
A switching means for N-OFF control is provided to control the duty ratio to the heater, and while the power supply to the heater is stopped, the operation of the alarm means is prohibited. Accurate temperature control can be realized, and the inconvenience that the disconnection alarm is erroneously issued by the alarm unit while the power supply to the heater is stopped by the switching unit can be prevented.

According to the invention of claim 4, in addition to the above, the control means includes a first output based on an output of the comparison means and a second output generated when the output of the current value detection means decreases. And means for delaying the rise of the first output and hastening the descent of the first output, so that the first output and the second output are output when no disconnection abnormality occurs. Can be prevented from occurring at the same time, and the occurrence of an erroneous disconnection alarm can be more reliably prohibited.

According to a fifth aspect of the present invention, in addition to the first or second aspect, the control means further comprises a temperature detecting means.
Generates an output proportional to the difference between the detected temperature and the set temperature
Differential amplifying means and sawtooth generating sawtooth
Wave generating means and saws generated by the sawtooth wave generating means
Crest value changing means for changing the crest value of the Gili wave, and differential amplification
Means for comparing the output of the means and the sawtooth wave generating means
And the power to the heater is set to O based on the output of the comparing means.
Switching means for N-OFF control.
Therefore, high-precision temperature control is performed by the so-called proportional control of the heater.
It can be realized. In particular, sawtooth wave generation means
Value changing method to change the peak value of sawtooth wave
Since the step is provided, the proportional control start temperature can be changed freely.
So-called overshoot of temperature,
Smaller undershoot to further improve temperature control accuracy
It is possible to make it.

According to a sixth aspect of the present invention, in addition to the first or second aspect of the invention, the control means further comprises a temperature detecting means.
Generates an output proportional to the difference between the detected temperature and the set temperature
And differential amplifying means for, saw for generating a sawtooth wave
Output of the wave generation means, the differential amplification means and the sawtooth wave generation means.
Comparing means for comparing forces and based on the output of the comparing means
To control ON-OFF of energization to heater
Means for detecting the temperature detected by the temperature detecting means.
Even when the temperature reaches the constant temperature, the heater
Power, so high-precision temperature control
It is possible to realize degree control. In particular, the temperature detection
If the temperature detected by the stage reaches the set temperature,
The heater is energized at the energization rate.
Can reduce the time it takes to reach
As well as ensuring reliable heat leakage from electrical equipment.
At the set temperature.

According to the seventh aspect of the present invention, power is supplied to the heater.
A current value detecting means for detecting a current is provided.
The current supplied to the heater exceeds a predetermined value based on the output of the
The control means activates the alarm means when it is received
Therefore, if a short circuit occurs in any part of the heater,
Short-circuiting quickly and accurately based on the increase in
It will be able to detect and issue an alarm. Follow
To prevent abnormal temperature and deterioration of normal heater
It is possible to do. In particular, the control means operates the alarm means.
Self-holding means for holding the operation
During the operation, the power to the heater was prohibited.
Alarm stops for some reason such as power supply voltage fluctuation.
To prevent the inconvenience of shutting down
So that the normal deterioration of the heater can be reliably prevented.
It becomes.

[Brief description of the drawings]

FIG. 1 is a block diagram of an electric circuit of a control device for a refrigerator as an embodiment of the present invention.

FIG. 2 is a diagram illustrating outputs of a differential amplifier circuit, a sawtooth wave generation circuit, and a comparison circuit for explaining proportional control of a heater.

FIG. 3 is a diagram illustrating outputs of a differential amplifier circuit, a sawtooth wave generation circuit, and a comparison circuit for explaining another proportional control of a heater.

FIG. 4 is a diagram illustrating outputs of a differential amplifier circuit, a sawtooth wave generation circuit, and a comparison circuit for explaining another proportional control of the heater.

FIG. 5 is a diagram illustrating outputs of a comparison circuit, a permission signal generation circuit, and an AND circuit for explaining a disconnection alarm operation;

FIG. 6 is a diagram illustrating a change in a peak value of the sawtooth wave generation circuit.

FIG. 7 is a diagram illustrating a change in the peak value of another sawtooth wave generation circuit.

FIG. 8 is a block diagram of an electric circuit of the control device of the refrigerator, showing a specific example of the heater connection.

FIG. 9 is a diagram illustrating the output of each element when the permission signal generation circuit is not used in the disconnection alarm operation.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Controller 4 Proportional control circuit 6 Sensor 8 Differential amplifier circuit 12 Comparison circuit 13 Variable resistor 14 Sawtooth wave generation circuit 16 SSR 17 Heater 18 Transistor 21 Disconnection detection circuit 22 Overcurrent detection circuit 23 Current transformer 24 Current-voltage conversion circuit 28 AND circuit 29 Permit signal generation circuit 37 Alarm display

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-55-114120 (JP, A) JP-A-64-8415 (JP, A) JP-A-60-146308 (JP, A) JP-A 61-114 134817 (JP, A) JP-A-3-57180 (JP, A) JP-A-4-28190 (JP, A) JP-A-61-164510 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) F25D 21/08 F25D 23/00 301 H05B 3/00 365

Claims (7)

(57) [Claims] 1. An electric apparatus having a heater which generates heat by energization, comprising: a temperature detection unit; a current value detection unit for detecting a current supplied to the heater; an alarm unit; Control means for controlling energization to the heater and controlling the alarm means based on an output of the current value detection means, wherein the control means is configured to control when the energization current to the heater falls below a predetermined value. Self-holding hand for operating the alarm means and holding the operation of the alarm means
A step, wherein the heater is provided while the alarm means is operating.
A control device for an electric device including a heater, wherein the control unit prohibits energization of the electric device. 2. The control device for an electric device having a heater according to claim 1, wherein a plurality of heaters are connected in series, and the current value detecting means detects a current supplied to the series circuit. . 3. The differential amplification means for generating an output proportional to the difference between the temperature detected by the temperature detection means and the set temperature; the sawtooth wave generating means for generating a sawtooth wave; Means for comparing the output of the means and the sawtooth wave generating means, and switching means for ON-OFF controlling the power supply to the heater based on the output of the comparison means, and controlling the power supply rate to the heater. ,
3. The control device for an electric device having a heater according to claim 1, wherein the operation of the alarm unit is prohibited while the power supply to the heater is stopped. 4. The control means operates the alarm means by a product of a first output based on an output of the comparison means and a second output generated when the output of the current value detection means decreases. 4. The control device for an electric device having a heater according to claim 3, further comprising means for delaying the rise of the first output and hastening the fall. 5. The control means according to claim 1, wherein said control means detects a temperature detected by said temperature detection means.
Differential amplification that produces an output proportional to the difference between the temperature and the set temperature
Means and a sawtooth wave generating means for generating a sawtooth wave
And the sawtooth wave generated by the sawtooth wave generating means
Crest value changing means for changing the high value, and the differential amplification means
And comparison means for comparing the output of the sawtooth generator, this
Turns on the power to the heater based on the output of the comparing means.
Switching means for OFF control.
The heater according to claim 1 or 2 is provided.
Control device for electrical equipment. 6. The control means includes means for detecting the temperature.
Differential that generates an output proportional to the difference between the set temperature and the set temperature
Amplifying means and a sawtooth wave generator for generating a sawtooth wave
And the output of the differential amplifying means and the sawtooth wave generating means.
Based on the output of the comparing means to compare and
Switching for ON-OFF control of energization to the heater
Means, and a temperature detected by the temperature detecting means.
When the temperature reaches the set temperature, the
The method according to claim 1, wherein the heater is energized.
A control device for an electric device comprising the heater according to claim 2. 7. An electric device having a heater which generates heat when energized.
In the device, a temperature detecting means and an electric current for detecting a current supplied to the heater are provided.
Flow value detecting means, alarm means, and output of the temperature detecting means
Controlling the energization of the heater based on
Controlling the alarm means based on the output of the current value detection means;
Control means, and the control means controls the heater.
If the supplied current exceeds a predetermined value, the alarm means is activated.
Self-holding means for holding the operation of the alarm means
While the alarm means is operating, to the heater
Equipped with a heater characterized in that energization of electricity is prohibited
Equipment control device.