JPS62225188A - Air cooling for electronic device - Google Patents

Abstract

PURPOSE:To reduce the noise and to lengthen the life of a unit, by supplying high voltage in starting and by converting the high voltage into low after starting. CONSTITUTION:when a power source switch 9 is turned ON, the emitter current flows to a transistor 6 through a relay winding 5 and a capacitor 8 is charged through a resistance 7. This current turns out the base current and the collector- emitter current flows. The relay winding 5 is excited and a relay contact 4 is changed over to a contact 4-2. The power is supplied from a high voltage source 2 to start rotating a cooling fan l. As a capacitor 8 is kept on being charged, the base current of the transistor 6 gets reduced and the relay winding 5 is changed over to contact 4-2 on account of exciting current shortage, so that the voltage V2 is impressed from a low voltage power source 2 to the cooling fan l.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention supplies a voltage exceeding the rated voltage to the cooling fan at the time of startup, and drops the voltage at 9 revolutions to reduce the air volume. The present invention relates to an air cooling method for electronic devices that saves energy.

<Prior art> Conventionally, a power supply 21 is connected to a cooling fan l having rotary blades attached to a motor, as shown in the circuit diagram of the fourth tooth, to cool down the heat generated by electronic devices commonly used. let me,
Air cooling methods are used to generate wind through forced convection of air to cool the internal temperature of electrical equipment.

<Problems to be solved by the invention> When the air volume decreases due to the conventional air cooling method, the cooling fan 1
The rotating shaft, bearings, etc. are subject to severe mechanical wear and generally have a shorter lifespan than semiconductors and electronic parts used in electronic devices, and the lifespan of the electronic device is determined by the cooling fan 1. Moreover, even if the load of the electronic device changes and the heat generation decreases, the cooling fan 1 rotates, and there are only two types of cooling fan 1, which has the disadvantage that an excessive amount of air is sent for the amount of heat generated, and a large amount of electric power is wasted. Therefore, the electric potential of the supplied power source 21 is lowered and the power supply 21 rotates at a low speed to reduce noise and extend the life of the fan. The disadvantage is that it does not rotate below this value.

Means for Solving the Problems> The present invention eliminates such drawbacks of the conventional technology and provides a cooling fan 1 that forcibly convects heat generated from electronic components by supplying a voltage higher than the rated voltage at the time of startup. In an air-cooling method for electronic devices that supplies and maintains a voltage below the rated voltage during rotation, when the power switch is turned on to start up, a voltage higher than the rated voltage is supplied from the high-voltage power supply, and the transistor current is The control operates switching elements such as relays and switches, and after startup, switches to a low-voltage power supply with a voltage lower than the rated voltage, and rotates the cooling fan at low speed.

In addition, a temperature switch such as a temperature-sensitive switch whose contacts open and close at a specified temperature or a thermistor whose resistance changes is connected in parallel or series to the capacitor to change the supply voltage and control the rotation of the cooling fan for air cooling of electronic equipment. It's a method.

Function> The switching element is operated by controlling the current of the transistor due to the charging/discharging of the capacitor or the current change due to the temperature switch, and the cooling fan is driven by the low-voltage power supply after startup using the high-voltage power supply at startup, thereby preventing changes in air volume. It will be done.

<Embodiment> As shown in FIG. 1, an embodiment of the electronic device of the present invention includes a high-voltage power supply 2 having a voltage V higher than the rated voltage of the cooling fan 1 and a low-voltage power supply 3 having a voltage V2k lower than the rated voltage. A power source is connected to the cooling fan 1 through the contact 4-2 of the relay contact 4 to the high voltage power source 2. Further, the high voltage power supply 2 is connected to the collector and emitter of a transistor 6 through a relay winding 5, and is connected to a capacitor 8 through a resistor 7 to the base. Also, the low voltage power supply 3 is connected to the contact 4 of the relay contact 4.
Power is supplied to the cooling fan 1 through -3.

When power switch 9 is now turned on, emitter current flows through relay winding 5 to transistor 6 and capacitor 8 is charged through resistor 7. This current is a pace current, and a collector-emitter current flows and excites the relay winding 5.
Relay contact 4 is switched to contact 4-2, power is supplied from high power source 2, and cooling fan 1 begins to rotate. As the capacitor 8 is further charged, the pace current of the transistor 6 decreases, and the collector-emitter current also decreases.The relay winding 5 is switched to contact 4-2 when the excitation current is insufficient. v2 is applied to cooling fan l.

In another embodiment of the present invention, as shown in FIG. 2, the high voltage power source 2 is connected to a transistor 11 through a diode 10, and its base is connected to a transistor 13 through a resistor 12. Further, the low power supply 3 is connected to the cooling fan 1 through a diode 14, and is also connected to a capacitor 8 through a resistor 15 and a transistor 16 through a resistor 17.

Moreover, this capacitor 8 is connected to the pace of the transistor 13.

When the power switch 9 is connected now, current flows through the resistor 15 to the capacitor 8 and charges it, so the transistor 1
The 60 pace voltage drops and no collector-emitter current flows, causing the current through resistor 17 to conduct with the pace current of transistor 13.

Therefore, the base current of the transistor 110 flows through the resistor 12, making the transistor 11 conductive, and the voltage vl of the high voltage power supply 2 is supplied to the cooling fan 1 through the diode 10, thereby starting the cooling fan 1. When the capacitor 8 is further charged and the potential at both ends rises, the base current of the transistor 16 flows, and the transistor 11 is turned off in the opposite operation to the above, and the voltage v2 is supplied from the low-voltage power supply 3 to the cooling fan l through the diode 14. .

Furthermore, in a third embodiment of the present invention, a resistor 20 and a capacitor 8 are connected to the antenna 1 as shown in FIG.

flows, the capacitor 8 is charged, the emitter-collector current of the transistor 18 flows, and the voltage of the high power supply 2 is supplied. Furthermore, the capacitor 8 is charged, and the base current decreases and gradually stops flowing. At the same time, current flows to the cooling fan 1 through the resistor 19, and the cooling fan 1 rotates at a low speed in the same way as when a low voltage is supplied.

Therefore, in the circuits of FIGS. 1, 2, and 3 according to the present invention, a high voltage is applied at startup.

After startup, the voltage is switched to a low one, so the cooling fan 1 rotates at a low speed, lowering the air volume to an appropriate amount compared to when the air volume is larger than the heat generation amount, reducing noise, and extending the mechanical life of the cooling fan I.

Here, in FIG. 3, by connecting the contacts of a temperature switch 20 to both ends of the capacitor 8 and closing the contacts when the temperature exceeds a set value, the transistor x, plB (Dxs
: The ivy/base current always flows and is in a conductive state. Power is supplied from the high power supply 2, and the cooling fan 1 rotates at high speed and starts cooling rapidly. If the temperature drops further, temperature switch 2
When the shear capacitor 8 is charged, the transistor 18 is turned off, power is supplied through the resistor 19, and the cooling fan 1 rotates at a low speed again.

By connecting this type of temperature switch 20 in parallel to the capacitor 8 in FIGS. 1 and 2, the same effect as in FIG. 3 can be obtained. The temperature switch 20 may also be a temperature-sensitive switch, a thermistor, or a positive thermistor whose resistance value changes depending on the temperature.

<Effects of the Invention> As described above, according to the present invention, a high voltage is supplied at startup to ensure startup, and after startup, the voltage is switched to a low voltage to rotate at low speed, resulting in low noise and long life.

Combining low power consumption and temperature switch,
It can supply an appropriate amount of air volume for the amount of heat generated by electronic devices.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram of an embodiment of the method for cooling an electronic device according to the present invention, FIG. 2 is a circuit diagram of another embodiment according to the present invention, and FIG. 3 is a circuit diagram of yet another embodiment according to the present invention. FIG. 4 is a circuit diagram of a conventional example. Note: 1: Cooling fan, 2: High power supply, 3: Low power supply, 4: Relay contact, 5: Relay winding, 6, 11, 13° 16.18:
) Lansosta, 7, 12, 15° 17.19: Resistance, 8
: Capacitor, 9: Power switch, 10.14: Diode, 20: Temperature switch. Figure 1 Figure 2

Claims (2)

[Claims] 1. In an air cooling method that uses a cooling fan to force air convection to transfer heat generated from electronic components, a voltage higher than the rated voltage is supplied from a high-voltage power supply at startup, and
An electronic device characterized in that a relay or a switching element is operated and switched by controlling the current of a transistor due to a current change during charging by a current flowing through a capacitor, and after startup, a voltage lower than the rated voltage is supplied from a low power source. Air cooling method. 2. The electronic device according to claim 1, wherein in the air cooling method, a temperature switch whose contacts open and close or whose resistance changes depending on a prescribed temperature is connected in series with the capacitor to control the transistor and change the supply voltage. Air cooling method.