JP2003053126A - Electric apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electric apparatus the heating element of which can be prevented preliminarily from exceeding a prescribed temperature. SOLUTION: This electric apparatus is provided with a heating element 1, a blower 2 for sending air to the element 1, a current transformer 9 for detecting an ampere of the blower 2, a relay 7 for switching over the power- supplied state to the element 1 and a microcomputer 3 for controlling a transistor 6 and another transistor 10 so that the power supplied to the element 1 is broken by the relay 7 when it is decided according to the ampere detected by the transformer 9 that the blower 2 or a photo-coupler 5 is abnormal.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric device equipped with a heating element and a blower. In particular, it relates to energization control of the heating element.

[0002]

2. Description of the Related Art FIG. 3 shows the configuration of a control device for controlling energization of a heating element and a blower, which is provided in a conventional electric device having a heating element and a blower. The heating element 1 is connected to an AC power source 8 via a relay 7. Further, the blower 2 is connected to the AC power source 8 via a photo triac which is a light receiving portion of the photo coupler 5. That is, the heating element 1 and the blower 2 are connected in parallel.

The terminal 12 to which the constant voltage V _CC (= 12V) is supplied is connected to the control terminal of the relay 7 and the anode of the light emitting diode which is the light emitting portion of the photocoupler 5. The control terminal of the relay 7 is connected to the collector of the NPN transistor 6, and the emitter of the transistor 6 is grounded.
The cathode of the light emitting diode, which is the light emitting portion of the photocoupler 5, is connected to the collector of the NPN transistor 4 via the resistor R1, and the emitter of the transistor 4 is grounded. The base of the transistor 4 and the base of the transistor 6 are connected to the microcomputer 3, respectively.

The control device having such a configuration operates as follows. When the operation switch of electrical equipment is turned on,
The microcomputer 3 sets the voltage signal sent to the base of the transistor 4 and the voltage signal sent to the base of the transistor 6 to High level, respectively.

The microcomputer 3 is a transistor 4
By setting the voltage signal to be sent to the base of the high level to the high level, the transistor 4 is turned on and the constant voltage V _CC is supplied to the light emitting portion of the photocoupler 5. This allows
The photocoupler 5 is turned on, and the blower 2 is energized and driven. At the same time, the microcomputer 6 sets the voltage signal sent to the base of the transistor 6 to the high level, so that the transistor 6 is turned on. As a result, the relay 7 is turned on and the heating element 1
Energizes and generates heat.

Then, during the operation of the electric equipment, the microcomputer 3 constantly sets the voltage signal sent to the base of the transistor 4 to the high level. As a result, the blower 2 is constantly driven during the operation of the electric device. Further, during the operation of the electric device, the microcomputer 3 switches the level of the voltage signal sent to the base of the transistor 6 between the High level and the Low level according to the operation setting condition stored in advance. As a result, the energization of the heating element 1 is ON / OFF controlled according to the operation setting conditions. That is, the blower 2 and the heating element 1 are independently controlled. The microcomputer 3 includes a memory (not shown), and the operation setting conditions are stored in advance in the memory.

Then, the operation switch of the electric equipment is turned off.
In this state, the microcomputer 3 sets the voltage signal sent to the base of the transistor 4 and the voltage signal output to the base of the transistor 6 to the Low level. Alternatively, even after the operation switch is turned off, only the blower 2 is turned for a certain period of time in order to cool the heating element 1 in a high temperature state and then turned off.

The microcomputer 3 is a transistor 4
By setting the voltage signal to be sent to the base of the low level to the low level, the transistor 4 is turned off and the constant voltage V _CC is not supplied to the light emitting portion of the photocoupler 5. As a result, the photocoupler 5 is turned off, the power supply to the blower 2 is cut off, and the blower 2 stops blowing air. And at the same time,
When the microcomputer 3 sets the voltage signal sent to the base of the transistor 6 to the Low level, the transistor 6 is turned off. As a result, the relay 7 is turned off, the power supply to the heating element 1 is cut off, and the heating element 1 stops generating heat.

In such an electric device, a predetermined amount of air is blown from the blower 2 to the heating element 1, and the blown air becomes high temperature by the heating element 1. However, when an abnormality occurs in the blower 2, or when the microcomputer 3 malfunctions and the base signal of the transistor 4 that is the drive signal of the blower 2 becomes uncontrollable, a predetermined amount of air is not blown to the heating element 1. The temperature of the heating element 1 may become higher than the set temperature, which may cause a failure of electric equipment or a fire. For this reason, in the conventional electric equipment, a thermal fuse or the like is provided, and when the temperature of the heating element 1 exceeds a predetermined temperature, the thermal fuse or the like operates to cut off the energization of the heating element 1.

[0010]

However, when the thermal fuse or the like is activated, it is necessary to replace the parts, and there is a problem that the cost and the labor involved therewith are increased.

In view of the above problems, it is an object of the present invention to provide an electric device capable of preventing the heating element from exceeding a predetermined temperature.

[0012]

In order to achieve the above object, in an electric device according to the present invention, a heating element, a blower for sending air to the heating element, and an abnormality of the blower or a drive element of the blower. An abnormality detecting means for detecting the above, a switching means for switching the energization state to the heating element, and a control means for controlling the switching means so as to cut off the energization of the heating element when the abnormality detecting means detects an abnormality. And prepare for.

The abnormality detecting means includes a current detecting means for detecting a current value of the blower, and a judging means for judging an abnormality when the current value detected by the current detecting means is a predetermined value or less. , May be provided.

A plurality of switching means may be provided.

In addition, an electric device having any one of the above configurations is
A dehumidifier that includes a hygroscopic body and regenerates the hygroscopic body by sending air heated by the heating element to the hygroscopic body by the blower may be used.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows the configuration of a control device that controls energization of a heating element and a blower included in an electric device according to the present invention. The same parts as those of the control device of FIG. 3 are designated by the same reference numerals.

The heating element 1 is connected to an AC power source 8 via a relay 7. Further, the blower 2 is connected to the AC power source 8 via the primary side of the current transformer 9 and a phototriac which is a light receiving portion of the photocoupler 5. That is, the heating element 1
And the blower 2 are connected in parallel.

The terminal 12 to which the constant voltage V _CC (= 12V) is supplied is connected to the emitter of the PNP type transistor 11, and the collector of the transistor 11 is the control terminal of the relay 7 and the anode of the light emitting diode which is the light emitting portion of the photocoupler 5. Connected to. The control terminal of the relay 7 is connected to the collector of the NPN transistor 6, and the emitter of the transistor 6 is grounded. The cathode of the light emitting diode, which is the light emitting portion of the photocoupler 5, is connected to the collector of the NPN transistor 4 via the resistor R1.
The emitter of is grounded. The base of the transistor 4 and the base of the transistor 6 are connected to the microcomputer 3, respectively.

The emitter-base of the transistor 11 is connected via a capacitor C4. The connection point between the base of the transistor 11 and the capacitor C4 is connected to the collector of the NPN transistor 10 via the resistor R7. The emitter of the transistor 10 is grounded, and the base of the transistor 10 is connected to the microcomputer 3 via the capacitor C3. The side of the capacitor C3 which is not connected to the base of the transistor 10 and the emitter of the transistor 10 are connected via the resistor R6.

The anode of the diode D1 and one end of the resistor R2 are connected to one end of the current transformer 9 on the secondary side. One end of the resistor R3 and the anode of the diode D2 are connected to the cathode of the diode D1. The other end of the resistor R3 is connected to one end of the resistor R5, one end of the resistor R4, and the positive side of the capacitor C1. The positive side of the microcomputer 3 and the capacitor C2 is connected to the other end of the resistor R5. Then, the other end of the current transformer 9 on the secondary side, the other end of the resistor R2, the other end of the resistor R4, and the capacitor C1.
And the negative side of the capacitor C2 is grounded. Further, the cathode of the diode D2 has a constant voltage V _CC '
It is connected to a terminal 13 to which (= 5V) is supplied.

The control device having such a configuration operates as follows. When the operation switch of electrical equipment is turned on,
The microcomputer 3 has a transistor 10 High
/ Low pulse signal is transmitted. Since the pulse signal conducts the capacitor C3, the transistor 10 also turns ON / OFF in synchronization with the pulse signal. The resistor R6 is a level-fixing pull-down resistor when the microcomputer 3 is not sending a pulse signal. By repeating ON / OFF of the transistor 10, electric charge is accumulated in the electric field capacitor C4 via the resistor R7, and the transistor 1
A direct current potential difference is generated between the base and the emitter of No. 1, and the transistor 11 is turned on. At the same time, the microcomputer 3 sets the voltage signal sent to the base of the transistor 4 and the voltage signal sent to the base of the transistor 6 to High level. As a result, the transistors 4 and 6 are turned on.

The microcomputer 3 is the transistor 1
By sending the pulse signal to 0 and setting the voltage signal sent to the base of the transistor 4 to the high level, the transistor 4 is turned on and the constant voltage V _CC is supplied to the light emitting portion of the photocoupler 5. As a result, the photocoupler 5 is turned on and the blower 2 is energized and driven. Further, the microcomputer 3 sends a pulse signal to the transistor 10 and sets the voltage signal sent to the transistor 6 to the high level, whereby the transistor 6 is turned on. As a result, the relay 7 is turned on, and the heating element 1 is energized to generate heat.

Then, during the operation of the electric equipment, the microcomputer 3 constantly sends a pulse signal to the transistor 10 and keeps the voltage signal sent to the base of the transistor 4 at a high level. As a result, the blower 2 is constantly driven during the operation of the electric device. However, this does not apply when the blower 2 described later is abnormal.

Further, during the operation of the electric equipment, the microcomputer 3 constantly sends a pulse signal to the transistor 10 and sets the level of the voltage signal sent to the base of the transistor 6 to High according to the operation setting condition stored in advance.
Switch to h level and low level. This allows
The energization of the heating element 1 is ON / OFF controlled according to the operation setting conditions. The microcomputer 3 includes a memory (not shown), and the operation setting conditions are stored in advance in the memory. However, this does not apply when the blower 2 described later is abnormal.

Then, the operation switch of the electric device is turned off.
In this state, the microcomputer 3 sets the voltage signal output to the base of the transistor 6 to the Low level.
Immediately or after a fixed time, the voltage signal output to the base of the transistor 4 is set to the Low level, and the transistor 1
The pulse signal output to 0 is stopped.

The microcomputer 3 is a transistor 6
By setting the voltage signal to be sent to the base of the low level to the low level, the transistor 6 is turned off and the heating element 1
Is cut off and the heating element 1 stops generating heat. After that or after a certain time, the transistor 4 is turned off and the constant voltage V _CC is not supplied to the light emitting portion of the photocoupler 5. As a result, the photocoupler 5 is turned off, the power supply to the blower 2 is cut off, and the blower 2 stops blowing air. At the same time, the microcomputer 3 stops the output of the pulse signal to the transistor 10 so that the transistor 6
Turns off. In addition, when it is desired to cool the heating element 1, the transistor 4 may be set to the OFF state after a predetermined time has passed since the power supply to the heating element 1 was cut off.

Even if the microcomputer 3 fails or runs out of control, it is impossible for the pulse signal to continue to be sent to the transistor 10, and the transistor 11 must be turned off.
It becomes a state. At this time, both the heating element 1 and the blower 2 are stopped.

Further, in the unlikely event that the transistor 4 or the transistor 6 is short-circuited, the microcomputer 3 can stop the output of the pulse signal, so that the heating element 1 and the blower 2 can be de-energized.

Next, the operation when an abnormality occurs in the blower 2 or the photo coupler 5 will be described. The current transformer 9 constantly detects the current value supplied to the blower 2. The current transformer 9 outputs an alternating voltage according to the current value supplied to the blower 2 to the secondary side. The AC voltage output to the secondary side of the current transformer 9 is the resistance R
2 to R5, diodes D1 to D2, capacitors C1 to C
After being converted into a DC voltage by 2, it is input to the microcomputer 3.

The microcomputer 3 operates so as to cut off the energization of the heating element 1 when the input DC voltage value is equal to or lower than the preset value stored in the memory in advance. That is, the microcomputer 3 includes the transistor 10
Stop sending pulse signal to the. As a result, the transistor 10 is turned off, and the transistor 11 is accordingly turned off. At the same time, the microcomputer 3 sets the signal sent to the transistor 6 to the Low level regardless of the above-mentioned operation setting conditions. As a result, the transistor 6 is turned off.

Then, as the transistors 11 and 6 are turned off, the relay 7 is turned off, the energization of the heating element 1 is cut off, and the heating element 1 stops generating heat.

In the unlikely event that the transistor 6 is short-circuited, the transistor 10 and the transistor 1
If 1 and 2 are normal, the heating element 1 can be de-energized. Even if the transistor 10 or the transistor 11 is short-circuited by any chance, if the transistor 6 is normal, the heating element 1 can be de-energized. Further, as described above, even if a DC signal is added to the signal output from the microcomputer port connected to the transistor 10 when the microcomputer 3 runs out of control, the DC signal is cut by the capacitor 3, so the transistor 10 is turned off. , Heating element 1 and blower 2
Can be turned off. In this way the heating element 1
Since a plurality of switching means for controlling the energization are provided, it is possible to more reliably prevent the heating element from exceeding the predetermined temperature.

Further, the microcomputer 3 controls the transistor 10 with a pulse signal to turn on the transistor 6 in Hi.
It is controlled by a binary signal of gh / Low level. Thus, by making the control signals for controlling the switching means different types of signals for the respective switching means, it is possible to prevent the heating element from exceeding a predetermined temperature even if a problem occurs in the microcomputer 3. Will be more likely to be possible.

Next, the case where the present invention is applied to a dehumidifier will be described with reference to FIG. 2 showing the structure of the mechanical portion of the dehumidifier. The same parts as those of the control device of FIG. 1 are designated by the same reference numerals.

Reference numeral 21 is an air filter disposed inside the suction port 20 and removes dust such as dust contained in the air sucked from the suction port 20. Reference numeral 22 is a condenser that cools the air that has passed through the air filter 21, and 23 is a dehumidification rotor that absorbs the moisture contained in the air that has passed through the condenser 22. Reference numeral 24 is a heat exchanger that removes heat from the air that has passed through the dehumidification rotor 23, and 26 is a blower. In the dehumidifier, by operating the blower 26, the suction port 2
The suction of air into the main body from 0 is started, and the air sucked into the main body is filtered by the air filter 21 → the condenser 22 →
A flow of air (hereinafter referred to as dehumidified air) discharged from the outlet 25 to the outside of the main body through the dehumidifying rotor 23 and the heat exchanger 24 in this order occurs. Further, 2 is also a blower, and by operating the blower 2, the air circulating inside the main body (condenser 22 → heat exchanger 24 → heating element 1 → dehumidifying rotor 23 → condenser 22 → ... Flow of air).

Further, 27 is a water receiving tank for temporarily storing the water condensed in the condenser 22, and 28 is a water receiving tank 2.
A water level sensor for detecting the water level of 7 and a water receiving tank 2
A pump for conveying the water accumulated in 7 and a storage tank 30 for accumulating the water conveyed by the pump 29. In addition, 31 is a tube which becomes a flow path of water conveyed to the water storage tank 30 by the pump 29.

The dehumidifying rotor 23 is formed by impregnating a belt-shaped sheet-shaped base material such as cardboard paper with a solvent in which zeolite (hygroscopic material) is dissolved and supporting it on the surface of a belt-shaped flat sheet, and the like. The corrugated corrugated sheet having a height of about 1 to 1.5 mm, which is impregnated with and carried by a solvent in which the hygroscopic material is dissolved, is adhered, and the integrated single wave molded body is wound to form a rotor. . This dehumidifying rotor 23
Are rotatably driven by a motor (not shown).

Next, the operation of the dehumidifier having such a configuration will be described. The dehumidifier starts the dehumidifying operation when a power switch (not shown) arranged in the operation unit is turned on and an operation switch (not shown) is turned on in that state. The dehumidifier operates the blower 2 and the blower 26. By the operation of the blower 26, the dehumidified air is sucked into the main body from the suction port 20. First, the air filter 21 removes dust and dirt contained in the dehumidified air. Next, the dehumidifying rotor 23 absorbs the moisture contained in the dehumidified air. Then, the heat exchanger 24 takes heat from the dehumidified air. The dehumidified air passes through the air filter 21, the dehumidifying rotor 23, and the heat exchanger 24 in this order, and then is discharged from the air outlet 25. Therefore, the dehumidified air discharged from the air outlet 25 is dry and relatively cold air.

The dehumidifying rotor 23 is rotationally driven by the motor (not shown) as described above to change the position where the dehumidified air passes. The dehumidifying rotor 23 stores the moisture absorbed from the dehumidified air at the location where the dehumidified air passes, and the ability to absorb the moisture from the dehumidified air decreases at that location. In order to remove the moisture from the dehumidifying rotor 23 that stores the moisture absorbed from the dehumidified air, the blower 2 causes a flow of regenerated air that regenerates the dehumidified rotor 23. The operation of the regenerated air for removing water from the dehumidifying rotor 23 will be described in detail below.

The operation of the blower 2 causes a flow of regenerated air circulating inside the dehumidifier. After the regenerated air is heated to 200 to 250 ° C. by the heating element 1, the dehumidifying rotor 23
Pass through. At this time, the regenerated air having a relatively high temperature removes water from the dehumidifying rotor 23. The dehumidifying rotor 23, which has been deprived of moisture by the regenerated air, regenerates the ability to absorb moisture from the dehumidified air.

The regenerated air from which the moisture has been removed from the dehumidifying rotor 23 is warm and moist air, which is cooled in the condenser 22 to condense the moisture contained in the regenerated air. The water condensed here is collected in the water receiving tank 27. On the other hand, the regenerated air that has passed through the condenser 22 is dry, dry air that has been dewatered, and receives heat from the heat exchanger 24. After that, the regenerated air is heated again by the heating element 1 and removes water from the dehumidifying rotor 23 as described above.

In this way, the dehumidifying rotor 23 deprives the dehumidified air of moisture, and the regenerated air deprives the dehumidifying rotor 23 of moisture. Then, the condenser 22 removes the moisture of the regenerated air. Therefore, the dehumidifying operation can be continuously performed.

Furthermore, in the dehumidifier, the water level sensor 28 constantly monitors the water level in the water receiving tank 27.
When it detects that 8 has reached a predetermined water level, the pump 29
Is operated to convey the water accumulated in the water receiving tank 27 to the water storage tank 30 and stop the pump 29.

[0044]

According to the present invention, the abnormality detecting means for detecting an abnormality in the blower or the drive element of the blower, the switching means for switching the energization state to the heating element, and the abnormality detecting means when the abnormality is detected. Since the control means for controlling the switching means so as to cut off the energization of the heating element is provided, the energization of the heating element can be cut off when an abnormality occurs in the blower. As a result, it is possible to prevent the heating element from exceeding a predetermined temperature.

Further, according to the present invention, the abnormality detecting means detects the current value of the blower and the abnormality when the current value detected by the current detecting means is below a predetermined value. Since the determination means is provided, the abnormality detection means can be realized with a simple configuration.

Further, according to the present invention, since a plurality of the switching means are provided, even if a problem occurs in which a part of the switching means is short-circuited, it is possible to cut off the electricity supply to the heating element. As a result, it is possible to more reliably prevent the heating element from exceeding a predetermined temperature. The control signal sent to the switch means by the control means is preferably a different type of signal for each switch means.

Further, according to the present invention, the dehumidifier having a hygroscopic body and regenerating the hygroscopic body by sending the air heated by the heating element to the hygroscopic body by the blower has any one of the above-mentioned configurations. As a result, there is no risk of the hygroscopic body being damaged or burned by high heat. As a result, it is possible to realize a dehumidifier that is safe and does not require replacement of components such as a temperature fuse.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of a control device that controls energization of a heating element and a blower included in an electric device according to the present invention.

FIG. 2 is a diagram showing a configuration of a dehumidifier according to the present invention.

FIG. 3 is a diagram illustrating a configuration of a control device that controls energization of a heating element and a blower included in a conventional electric device.

[Explanation of symbols]

1 heating element 2 blower 3 microcomputer 4 transistors 5 Photo coupler 6 transistors 7 relays 8 AC power supply 9 Current transformer 10, 11 transistor

Claims (4)

[Claims] 1. An electric device comprising a heating element and a blower for sending air to the heating element, an abnormality detecting means for detecting an abnormality of the blower or a driving element of the blower, and an energization state to the heating element. An electric device, comprising: a switching unit that switches the switching unit and a control unit that controls the switching unit to cut off the energization of the heating element when the abnormality detecting unit detects an abnormality. 2. The abnormality detecting means includes a current detecting means for detecting a current value of the blower, and a judging means for judging an abnormality when the current value detected by the current detecting means is a predetermined value or less. The electric device according to claim 1, further comprising: 3. The electric device according to claim 1, further comprising a plurality of the switching means. 4. The electric device according to claim 1, further comprising a hygroscopic body, wherein the air heated by the heat generating body is sent to the hygroscopic body by the blower to thereby form the hygroscopic body. Dehumidifier to regenerate.