JPH11198492A - Apparatus and method for temperature rising control of electronic machinery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the temp. rising control device of an electronic machinery capable of sufficiently ensuring the margin of internal temp. rising in a low cost at the time of a constant load and capable of accurately controlling the rotation of a fan. SOLUTION: An ECU 10 and a power supply unit 20 are allowed to be adjacent to each other and a heat sink 6 having an FET 5 fixed thereto is arranged in contact with the leading end of a thermistor 2. Then, the heating temp. of the FET 5 is sensed and the internal atmospheric temp. in an apparatus is estimated from this data to perform the rank division of the rising intermediate temp. of the FET 5 up to the fusion of a temp. fuse and these data are discriminated by a CPU 8 to control the rotation of a fan.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a temperature rise control device for an electronic device for controlling a rise in the internal temperature of an electronic device such as an image forming apparatus, and a temperature rise control method for the electronic device.

[0002]

2. Description of the Related Art Conventionally, there has been provided a switching power supply circuit for intermittently transmitting DC power on a primary side of a transformer by a switching transistor to a secondary side, and performing a predetermined image forming operation using an output of the switching power supply circuit as a power supply. The image forming apparatus to be used is well known.

In this image forming apparatus, in order to control the rise in the internal temperature of the apparatus, the rise in the internal temperature of the apparatus and the rise in the temperature of the heat-generating components in the switching power supply circuit are monitored.
In many cases, a temperature rise control device that controls the rotation operation of a fan that sucks in outside air or discharges air to the outside of the device is incorporated in the device.

As the means for detecting the internal temperature in this type of image forming apparatus and the means for detecting the temperature of the heat-generating components in the switching power supply circuit, a plurality of sensors are used to separately detect the temperature. Also, as a countermeasure against overload
The main switching FET, which is a heat-generating component in the switching power supply circuit, is provided with a temperature fuse, and a bleeder resistor is inserted in the output line of the power supply to guarantee the minimum current value of the secondary output that the power supply guarantees. I have.

[0005]

However, in the above-mentioned conventional temperature raising control device, since a plurality of temperature sensors are required, not only does the cost increase, but also because a bleeder resistor is inserted, an additional resistor is added. Cost increase.

Furthermore, since the rotation of the fan is controlled in a fixed direction simply based on the temperature detected by the temperature sensor, the internal temperature of the apparatus cannot be rapidly lowered, and the internal temperature rise at a constant load exceeding the guaranteed minimum current value is not possible. This has been a problem from the viewpoint of insufficient margin, energy saving due to unnecessary fan rotation, and noise prevention.

SUMMARY OF THE INVENTION In view of the above-mentioned conventional problems, the present invention provides a low-cost, temperature-increasing control system for electronic equipment which can secure a sufficient margin for internal temperature increase under a constant load and can precisely control fan rotation. It is an object of the present invention to provide a device and a method for controlling a temperature rise of an electronic device.

[0008]

According to a first aspect of the present invention, there is provided a switching power supply circuit for intermittently transmitting DC power on the primary side of a transformer by a switching transistor to a secondary side. An electronic device is provided in an electronic device that performs a predetermined operation using the output of the switching power supply circuit as a power supply, and includes a fan that sucks in or discharges outside air into the device and a fan control unit that controls the operation of the fan. In the device temperature rise control device, a temperature detecting unit is provided in a heat radiating unit of the switching transistor, and the fan control unit estimates an internal atmosphere temperature of the electronic device based on a detection value of the temperature detecting unit, and estimates the temperature. The operation of the fan is controlled in accordance with the value.

According to a second aspect of the present invention, in the first aspect, a thermal fuse is provided in a heat radiating portion of the switching transistor, and power supply to the switching power supply circuit is cut off when the thermal fuse is blown. is there.

[0010] In a third aspect based on the second aspect, the fan control section refers to the information obtained by ranking the intermediate temperature rise of the switching transistor until the thermal fuse is blown, and refers to the internal atmosphere. The estimated temperature values are ranked, and the operation of the fan is controlled according to the ranking result.

In a fourth aspect based on the first to third aspects, the temperature detecting means is attached to a heat radiating portion of the switching transistor while being located in an air path of the fan.

According to a fifth aspect of the present invention, in the first to fourth aspects, cycle monitoring means for reading a cycle of the switching transistor in the switching power supply circuit is provided, and the fan control section includes a reading value of the cycle monitoring means. The internal atmosphere temperature of the electronic device is estimated based on the detected value of the temperature detecting means and the operation of the fan is controlled according to the estimated value.

In a sixth aspect based on the fifth aspect, a load increasing means for increasing a load on a secondary side of the switching power supply circuit is provided, and the electronic device is provided based on a read value of the cycle monitoring means. The current consumption of
When the estimated value falls below a minimum current consumption value required to guarantee a specified output voltage on the secondary side of the switching power supply circuit, the load increasing means is operated.

According to a seventh aspect of the present invention, there is provided a switching power supply circuit for intermittently transmitting DC power on the primary side of a transformer to a secondary side by a switching transistor, and performing a predetermined operation using an output of the switching power supply circuit as a power supply. A fan for sucking outside air into the machine or discharging the outside of the machine and a fan control unit for controlling the operation of the fan. Cycle monitoring means for reading the cycle of the switching transistor is provided; the fan control unit estimates power consumption of the electronic device based on a value read by the cycle monitoring means, and controls the operation of the fan according to the estimated value; The configuration is as follows.

In an eighth aspect based on the seventh aspect, a load increasing means for increasing a load on a secondary side of the switching power supply circuit is provided, and the electronic device is provided based on a read value of the cycle monitoring means. The current consumption of
When the estimated value falls below a minimum current consumption value required to guarantee a specified output voltage on the secondary side of the switching power supply circuit, the load increasing means is operated.

According to a ninth aspect of the present invention, there is provided a switching power supply circuit for intermittently transmitting DC power on the primary side of a transformer to a secondary side by a switching transistor, and performing a predetermined operation using an output of the switching power supply circuit as a power supply. For the electronic device to be performed, a fan for sucking outside air or discharging outside the device is provided inside the device, and a temperature detecting means is attached to a heat radiating portion of the switching transistor, and the electronic device is set based on a detection value of the temperature detecting device. Is estimated and the operation of the fan is controlled according to the estimated value.

In a tenth aspect based on the ninth aspect, a thermal fuse is provided in a heat radiating portion of the switching transistor, and power supply to the switching power supply circuit is cut off when the thermal fuse is blown. .

According to an eleventh aspect, in the tenth aspect, a rank of the estimated value of the internal atmosphere temperature is referred to by referring to information obtained by ranking the rising intermediate temperature of the switching transistor until the thermal fuse is blown. The operation of the fan is controlled according to the ranking result.

In a twelfth aspect based on the ninth to eleventh aspects, the temperature detecting means is attached to a heat radiating portion of the switching transistor in a state where the temperature detecting means is located in an air path of the fan.

In a thirteenth aspect based on the ninth to twelfth aspects, the internal atmosphere temperature of the electronic device is estimated based on a cycle of the switching transistor and a value detected by the temperature detecting means. The operation of the fan is controlled in accordance with.

In a fourteenth aspect based on the thirteenth aspect, the current consumption of the electronic device is estimated based on the cycle of the switching transistor, and the estimated value is a specified output voltage on the secondary side of the switching power supply circuit. When the current consumption falls below the minimum current consumption value required to guarantee the above, the control for increasing the load on the secondary side of the switching power supply circuit is performed.

According to a fifteenth aspect, there is provided a switching power supply circuit for intermittently transmitting DC power on the primary side of a transformer by a switching transistor to a secondary side, and performs a predetermined operation using an output of the switching power supply circuit as a power supply. For the electronic device to be performed, a fan that sucks in the outside air or discharges the air outside the machine is provided, and cycle monitoring means for reading the cycle of the switching transistor in the switching power supply circuit is provided. The power consumption of the electronic device is estimated based on the estimated value, and the operation of the fan is controlled according to the estimated value.

In a sixteenth aspect based on the fifteenth aspect, the current consumption of the electronic device is estimated based on the read value of the period monitor means, and the estimated value is defined on the secondary side of the switching power supply circuit. When the current consumption falls below the minimum current consumption value required to guarantee the output voltage, control is performed to increase the load on the secondary side of the switching power supply circuit.

[0024]

Embodiments of the present invention will be described below with reference to the drawings.

(First Embodiment) FIG. 1 is a block diagram showing a schematic configuration of a temperature rise control device of an electronic device (printer) according to a first embodiment of the present invention.

In FIG. 1, reference numeral 10 denotes an ECU mounted on a control board of the printer, and reference numeral 20 denotes a power supply unit of the printer. Further, 1 is a fan motor, 2 is a thermistor which is a temperature sensor, and 4 is a temperature fuse for cutting off the power supply of the power supply unit 20 when the FET 5 is overheated. Reference numeral 5 denotes a main switching FET which is a heat-generating component whose temperature rises with an increase in load. Reference numeral 6 denotes a heat sink for dissipating heat generated from the FET 5. A / D converter for causing the Reference numeral 8 denotes a CPU, and 9 denotes a driver for driving the fan motor 1.

The ECU 10 and the power supply unit 20 are arranged adjacent to each other, and the heat sink 6 fixing the FET 5 is arranged so as to contact the tip of the thermistor 6.

Next, the operation of the first embodiment will be described.

After the power is turned on, the primary side FET 5 is switched by the switching power supply control circuit (see FIG. 3). The switching cycle and the on-duty time fluctuate according to the load current. That is, as the load increases, the switching duty ratio for turning on increases, and the temperature of the FET 5 increases. Accordingly, the resistance value of the thermistor 2 decreases.

The analog voltage value at that time is input to the A / D converter 7, and the CPU 8 reads the digital read numerical value after the A / D conversion. The CPU 8 determines that the ambient temperature is “high” and sends a “high-speed rotation command” to the driver 9.
To rotate the fan motor 1 at high speed to improve the heat radiation characteristics in the housing.

Similarly, when the load is in the middle rank, the resistance value of the thermistor 2 becomes "slightly higher" than when the temperature is "high temperature", and the analog voltage value at this time is input to the A / D converter 7, The CPU 8 reads the digital read numerical value after the A / D conversion. The CPU 8 determines that the ambient temperature is “medium temperature”, and issues a “medium temperature rotation command” to the driver 9.
, The fan motor 1 is rotated at a medium speed, and the fan motor 1 is controlled at a lower rotational speed than at the time of “high temperature”.

When the load is at the minimum load level, the resistance value of the thermistor 2 is "slightly higher" than at the "medium temperature", and the analog voltage value at this time is A / A.
The CPU 8 reads the digital read value that has been input to the D converter 7 and has been A / D converted. The CPU 8 determines that the ambient temperature is "low temperature", sends a "low speed rotation command" to the driver 9, rotates the fan motor 1 at a low speed, and controls the fan motor 1 at a lower rotational speed than in "medium temperature". is there.

As described above, in the present embodiment, the ECU 10 and the power supply unit 20 are adjacent to each other, and the heat sink 6 fixing the FET 5 is arranged so as to be in contact with the tip of the thermistor 2. With such a configuration, the FET
The CPU 8 senses the heat generation temperature of the FET 5, estimates the internal atmosphere temperature of the apparatus from this information, and ranks the intermediate temperature rise of the FET 5 until the thermal fuse 4 is blown. Perform rotation control.

In the present embodiment, the detection of the internal temperature of the device and the temperature detection of the heat-generating component (FET 5) in the power supply circuit can be shared by the thermistor 2, so that the number of temperature sensors is reduced by one as compared with the conventional device. And cost reduction can be achieved.

(Second Embodiment) FIG. 2 is a block diagram showing a schematic configuration of a temperature rise control device of an electronic apparatus (printer) according to a second embodiment of the present invention. The same reference numerals are given and the description is omitted.

The fan motor of this embodiment can rotate forward / reverse, and the other components are the same as those of the first embodiment.

The CPU 8 sets the atmospheric temperature in the apparatus to "high temperature".
If it is determined that a high-speed rotation command
To rotate the fan motor 1 at a high speed in the normal rotation direction (the direction in which air is blown from the inside of the housing to the outside of the housing). After keeping this state for a while, the A / D converted value at that time is stored in the CPU 8. Subsequently, the fan motor 1 is rotated at a high speed in a reverse rotation direction (a direction in which air is sucked into the housing from the outside of the housing), and after maintaining this state for a while, the A / D conversion value at that time is stored in the CPU 8. Then, the CPU 8 compares the former with the latter, and determines to rotate the fan motor 1 in the direction of lower temperature.

Even when the load is in the middle rank, the forward / reverse rotation of the fan is sensed by the "medium speed rotation command" in the same manner as in the first embodiment, and the rotation speed at the lower sense temperature is determined. Also, when the load is at the minimum rank, the forward / reverse rotation of the fan is sensed by the "low-speed rotation command" as in the first embodiment, and the rotational speed with the lower sense temperature is selected.

In the second embodiment, the control for rotating the fan motor 1 in the direction of lower temperature is performed.
The temperature in the apparatus can be lowered more quickly than in the embodiment, and the shortage of the margin for internal temperature rise at the time of constant load is eliminated. In addition, since unnecessary fan rotation is eliminated, energy saving and reduction of noise can be achieved.

(Third Embodiment) FIG. 3 is a diagram showing a configuration of a temperature rise control device and a switching power supply circuit of an electronic apparatus (printer) according to a third embodiment of the present invention.

In FIG. 3, reference numeral 10 denotes an ECU mounted on a control board of the printer, and 8 denotes a CP.
U and 9 are drivers for driving the fan motor 1. The power supply unit 20 has a switching power supply circuit of a forward type as shown in FIG.

The commercial power supply 101 is a diode bridge 1
02 and a capacitor 103 are converted to a DC power supply, and this DC power supply is connected to the power MOSFET 5 (FE shown in FIG.
T5)) and the transformer 104 intermittently transmits energy to the secondary side. On the secondary side, this intermittent energy is smoothed by the diodes 120 and 121, the choke 122 and the capacitor 123, and the terminal 1 is used as a DC power supply.
Output to 35.

The output voltage is divided by the resistors 132 and 133 and input to the error amplifier 131. The error amplifier 131 compares the reference voltage 134 with the voltage divided by the resistors 132 and 133, and controls the switching power supply control circuit 1 through the photocoupler 117 so as to minimize the difference.
Tell 07. Switching power supply control circuit 10
7, the power M based on the information from the photocoupler 117
The on-duty of the OSFET 5 is controlled. The snubber circuit 105 resets the transformer.

The output to the terminal 135 is controlled to a constant voltage by the above series of operations. In this case, the switching power supply control circuit 107 oscillates at a constant frequency and controls with on-duty.

Switching power supply control circuit 107
Is configured as follows. That is, before the switching power supply circuit rises, a voltage is generated across the capacitor 110 through the resistor 108, and when the voltage exceeds a specified voltage, oscillation starts. When the oscillation starts, a voltage is generated in the auxiliary winding of the transformer 104 and the diode 1
09 is supplied to both ends of the capacitor 110 and becomes a power supply of the switching power supply control circuit 107.

The diode 119, the resistor 124,
125, the transistor 126, and the resistor 127,
Switching clock of switching power supply circuit is terminal 1
38. This information is transmitted via the circuit 11 to the CP
Tell U8. The CPU 8 has an F for main switching.
The power consumption is estimated by monitoring the cycle and duty of the terminal 138, which is the ON information of ET5, and when the power consumption is large, the ambient temperature is determined to be “high” and the rotation speed of the fan motor 1 is increased. When the power consumption is small, it is determined that the ambient temperature is "low temperature" and the fan motor 1
Reduce the number of revolutions.

In the third embodiment, the fan motor 1 can be accurately estimated by estimating the power consumption without providing a temperature sensor.
Can be controlled, so that the cost can be significantly reduced as compared with the conventional apparatus.

(Fourth Embodiment) FIG. 4 is a diagram showing a configuration of a temperature rise control device and a switching power supply circuit of an electronic apparatus (printer) according to a fourth embodiment of the present invention.

This embodiment is different from the third embodiment in that the power supply unit 20 is provided with a main switching FE.
Thermistor (temperature sensor) 2 closely attached to the heat radiation part of T5
And an A / D converter for digitally converting a voltage change value due to the resistance value of the thermistor 2 is provided in the ECU 10.

The CPU 8 monitors the cycle and the duty of the terminal 138, which are the ON information of the FET 5, to estimate the power consumption. Is monitored via the A / D converter 7. By reading the information of these two factors, the estimation of the internal temperature rise is made more accurate, and it is determined whether to increase or decrease the rotation speed of the fan motor 1.

In the fourth embodiment, the temperature of the internal atmosphere of the apparatus can be estimated more accurately, so that an accurate fan operation can be performed. As a result, the shortage of the margin for the internal temperature rise at the time of the constant load is eliminated, and energy saving and noise reduction due to useless rotation of the fan can be achieved.

(Fifth Embodiment) FIG. 5 is a diagram showing a configuration of a temperature rise control device and a switching power supply circuit of an electronic apparatus (printer) according to a fifth embodiment of the present invention.

This embodiment is different from the third embodiment in that a pulse motor 31 is provided as load increasing means for increasing the load on the secondary side of the switching power supply circuit, and a pulse motor driver for driving the pulse motor 31 is provided. 30 is provided in the ECU 10.

The CPU 8 estimates the power consumption by monitoring the cycle and duty of the terminal 138 which are the ON information of the main switching FET 5. At this time, if the load on the secondary side is so small that the output accuracy of the power supply cannot be guaranteed, the switching cycle and duty become longer than the specified width. At this time, the CPU 8 sets the rotation speed of the fan in the minimum mode as specified by the load. If the switching cycle or duty is longer than the specified width, the CPU 8 supplies a small current to the pulse motor 31, for example, to increase the load on the secondary side. To keep

As described above, in the fifth embodiment, the switching cycle of the primary-side main switching FET 5 is monitored, the minimum load current value guaranteed by the power supply is detected, and the load control is controlled. The bleeder resistor inserted into the output line of the power supply in the conventional device can be eliminated, and the cost can be reduced.

[0056]

As described in detail above, according to the first to fourth aspects of the temperature rise control device for electronic equipment, the heat radiation part of the switching transistor is provided with the temperature detecting means, and the fan control part is provided with the temperature control means. The internal atmosphere temperature of the electronic device is estimated based on the detection value of the detection means, and the operation of the fan is controlled in accordance with the estimated value, so that the detection of the internal temperature of the device and the temperature of the heat-generating components in the power supply circuit are performed. Since the detection can be shared by one temperature detecting means, the number of temperature sensors can be reduced as compared with the conventional device, and the cost can be reduced.

According to a fifth aspect of the present invention, in the first aspect of the present invention, the cycle control means for reading the cycle of the switching transistor in the switching power supply circuit is provided. Estimating the internal atmosphere temperature of the electronic device based on the read value of the cycle monitor means and the detection value of the temperature detection means,
Since the operation of the fan is controlled in accordance with the estimated value, the internal ambient temperature of the apparatus can be more accurately estimated. As a result, accurate fan operation is possible, so that a shortage of margin for internal temperature rise at a constant load is eliminated, and unnecessary fan rotation is eliminated, so that there is an effect of energy saving and reduction of noise.

According to a sixth aspect of the present invention, in the above-mentioned fifth aspect of the present invention, the load increasing means for increasing the load on the secondary side of the switching power supply circuit is provided. The current consumption of the electronic device is estimated based on the read value of the power supply. When the estimated value falls below the minimum current consumption required to guarantee the specified output voltage on the secondary side of the switching power supply circuit, the load increasing means is activated. Since the operation is performed, the accuracy of the secondary-side output guaranteed by the power supply can be maintained without inserting a bleeder resistor, so that cost can be reduced.

According to the electronic equipment temperature rise control device of the seventh invention, there is provided cycle monitoring means for reading the cycle of the switching transistor in the switching power supply circuit,
The fan control unit estimates the power consumption of the electronic device based on the reading value of the cycle monitoring unit, and controls the operation of the fan according to the estimated value. Since the fan can be controlled more accurately by estimating, it is possible to achieve a significant cost reduction as compared with the conventional device.

According to an eighth aspect of the present invention, in the above-mentioned seventh aspect of the present invention, there is provided the electronic equipment temperature rise control apparatus according to the seventh aspect, further comprising a load increasing means for increasing a load on the secondary side of the switching power supply circuit, The current consumption of the electronic device is estimated based on the read value of the power supply. When the estimated value falls below the minimum current consumption required to guarantee the specified output voltage on the secondary side of the switching power supply circuit, the load increasing means is activated. Since the operation is performed, the accuracy of the secondary output guaranteed by the power supply can be maintained without inserting a bleeder resistor, so that further cost reduction can be achieved.

According to the ninth to twelfth aspects of the method for controlling the temperature rise of electronic equipment, the same effects as those of the first to fourth aspects can be obtained.

According to the thirteenth aspect of the present invention, there is provided a method for controlling a temperature rise of an electronic device, wherein the effects of the ninth to twelfth aspects are the same as those of the fifth aspect.

According to the method for controlling temperature rise of electronic equipment of the fourteenth aspect, the thirteenth aspect has the same effect as the sixth aspect.

According to the electronic equipment temperature rise control method of the fifteenth aspect, the same effects as those of the seventh aspect can be obtained.

According to the method for controlling temperature rise of electronic equipment according to the sixteenth aspect, the same effects as those of the eighth aspect can be obtained in the fifteenth aspect.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a schematic configuration of a temperature rise control device of an electronic device (printer) according to a first embodiment of the present invention.

FIG. 2 is a block diagram illustrating a schematic configuration of a temperature rise control device of an electronic device (printer) according to a second embodiment of the present invention.

FIG. 3 is a diagram illustrating a configuration of a temperature rise control device and a switching power supply circuit of an electronic device (printer) according to a third embodiment of the present invention.

FIG. 4 is a diagram illustrating a configuration of a temperature rise control device and a switching power supply circuit of an electronic device (printer) according to a fourth embodiment of the present invention.

FIG. 5 is a diagram illustrating a configuration of a temperature rise control device and a switching power supply circuit of an electronic apparatus (printer) according to a fifth embodiment of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 fan motor 2 thermistor 4 thermal fuse 5 FET for main switching 6 heat sink 7 A / D converter 8 CPU 9 driver 10 ECU 20 power supply unit 31 pulse motor

Claims (16)

[Claims] An electronic device which has a switching power supply circuit for intermittently transmitting DC power on a primary side of a transformer by a switching transistor to a secondary side and performs a predetermined operation using an output of the switching power supply circuit as a power supply. A fan provided to inhale or discharge outside air into the machine,
A temperature control device for an electronic device, comprising: a fan control unit that controls an operation of the fan; and a temperature detection unit provided in a heat radiation unit of the switching transistor, wherein the fan control unit sets a detection value of the temperature detection unit. Estimating the internal atmosphere temperature of the electronic device based on
A temperature rise control device for an electronic device, wherein an operation of the fan is controlled according to the estimated value. 2. The electronic device according to claim 1, wherein a thermal fuse is provided in a heat radiating portion of said switching transistor, and power supply of said switching power supply circuit is cut off when said thermal fuse is blown. Heating control device. 3. The fan control unit ranks the estimated value of the internal atmosphere temperature with reference to information obtained by ranking the rising intermediate temperature of the switching transistor until the thermal fuse is blown. 3. The apparatus according to claim 2, wherein the operation of the fan is controlled in accordance with a ranking result. 4. The switching device according to claim 1, wherein said temperature detecting means is attached to a heat radiating portion of said switching transistor while being located in an air passage of said fan.
A temperature rise control device for an electronic device according to the above. 5. A cycle monitoring means for reading a cycle of the switching transistor in the switching power supply circuit, wherein the fan control unit controls the electronic control based on a value read by the cycle monitoring means and a value detected by the temperature detecting means. 5. The electronic device temperature rise control device according to claim 1, wherein the internal atmosphere temperature of the device is estimated, and the operation of the fan is controlled according to the estimated value. 6. A load increasing means for increasing a load on a secondary side of the switching power supply circuit, wherein current consumption of the electronic device is estimated based on a read value of the period monitor means, and the estimated value is 6. The electronic apparatus according to claim 5, wherein said load increasing means is activated when a current consumption value lower than a minimum current value required for guaranteeing a specified output voltage on the secondary side of said switching power supply circuit is reduced. Temperature rise control device. 7. An electronic apparatus having a switching power supply circuit for transmitting DC power on the primary side of a transformer intermittently by a switching transistor to a secondary side, and using an output of the switching power supply circuit as a power supply to perform a predetermined operation. A fan provided to inhale or discharge outside air into the machine,
A temperature control device for electronic equipment, comprising: a fan control unit configured to control an operation of the fan; and a cycle monitoring unit configured to read a cycle of the switching transistor in the switching power supply circuit. Estimating the power consumption of the electronic device based on the reading of the means,
An apparatus for controlling temperature rise of an electronic device, wherein an operation of the fan is controlled according to the estimated value. 8. A load increasing means for increasing a load on a secondary side of the switching power supply circuit, wherein current consumption of the electronic device is estimated based on a read value of the period monitor means, and the estimated value is 8. The electronic apparatus according to claim 7, wherein said load increasing means is activated when a current consumption value lower than a minimum current value required for guaranteeing a specified output voltage on a secondary side of said switching power supply circuit is reduced. Temperature rise control device. 9. An electronic apparatus having a switching power supply circuit for transmitting DC power on the primary side of a transformer intermittently by a switching transistor to a secondary side, and using a power supply output from the switching power supply circuit to perform a predetermined operation. On the other hand, a fan that sucks in or discharges outside air is provided inside the device, and a temperature detecting unit is attached to a heat radiating portion of the switching transistor, and an internal atmosphere temperature of the electronic device is determined based on a detection value of the temperature detecting unit. And controlling the operation of the fan according to the estimated value. 10. The method according to claim 9, further comprising: providing a thermal fuse in a heat radiating portion of the switching transistor; and cutting off a power supply of the switching power supply circuit when the thermal fuse is blown. . 11. An estimated value of the internal atmosphere temperature is ranked with reference to information that ranks the intermediate temperature rise of the switching transistor until the thermal fuse is blown, and according to the ranking result, The method according to claim 10, wherein the operation of the fan is controlled. 12. The electronic device according to claim 9, wherein said temperature detecting means is attached to a heat radiating portion of said switching transistor while being positioned in an air passage of said fan. Control method. 13. The method according to claim 1, further comprising estimating an internal ambient temperature of the electronic device based on a cycle of the switching transistor and a value detected by the temperature detecting means, and controlling the operation of the fan according to the estimated value. The method for controlling a temperature rise of an electronic device according to claim 9. 14. A current consumption of the electronic device is estimated based on a cycle of the switching transistor, and the estimated value is a minimum current consumption value required to guarantee a specified output voltage on a secondary side of the switching power supply circuit. 14. The method according to claim 13, further comprising: performing a control to increase a load on a secondary side of the switching power supply circuit when the power supply voltage falls below a threshold value. 15. An electronic device which has a switching power supply circuit for intermittently transmitting DC power on the primary side of a transformer by a switching transistor to a secondary side, and performs a predetermined operation using an output of the switching power supply circuit as a power supply. On the other hand,
A fan for sucking in or discharging outside air is provided in the machine, and a cycle monitor for reading a cycle of the switching transistor in the switching power supply circuit is provided, and the electronic device is controlled based on a read value of the cycle monitor. A method for controlling a temperature rise of an electronic device, comprising estimating power consumption and controlling operation of the fan according to the estimated value. 16. A current consumption of the electronic device is estimated based on a read value of the period monitor means, and the estimated value is a minimum consumption necessary to guarantee a specified output voltage on a secondary side of the switching power supply circuit. If the current falls below
The control method for increasing the temperature of an electronic device according to claim 15, wherein control is performed to increase a load on a secondary side of the switching power supply circuit.