JPH05190329A - Cooling fan controller for audio/power amplifier - Google Patents

Abstract

PURPOSE:To prevent the steep increase in cooling fan noise, minimize the temperature fluctuation to lengthen the life of parts and eliminate the unnecessary rotation from the cooling fan to lengthen its life. CONSTITUTION:Provided are a temperature-voltage converter 3 for converting a temperature detected at the audio/power amplifying unit 2 in an audio/power amplifier 1 into a voltage; and a continuous speed change controller 6 for continuously changing the number of revolution of a cooling fan 15. Thus, the number of cooling fan 15 revolutions is continuously increased/decreased according to the temperature rise/drop at the audio/power amplifying unit 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling fan control device provided in an audio power amplifier used for amplifying an audio signal in a hall, a live house, a studio or the like.

[0002]

2. Description of the Related Art FIG. 4 shows the configuration of a conventional cooling fan control device for an audio power amplifier. In FIG. 4, 61 is an audio power amplifier main body, and 62 is an audio power amplifier. 63 is a temperature-voltage converter, and a bias power source 64
And a temperature detector 65, and the temperature detector 65 is attached to the heat dissipation plate of the audio power amplifier 62. Reference numeral 66 is a cooling fan control reference voltage power supply, 67 is a cooling fan control voltage comparator, 68 is a cooling fan controller, and 69 is a cooling fan.

Next, the operation of the above conventional example will be described.
When the audio power amplifier 62 amplifies the audio signal, the audio power amplifier 62 generates heat and its temperature rises. When the volume of the loud sound is low, the sound power amplifying unit 62 has a small amount of heat generation, and thus is cooled by the wind sent from the cooling fan 69 at a normal low speed to suppress the temperature rise.

When the volume of the loud sound is increased, the amount of heat generated by the audio power amplifier 62 increases, and the temperature gradually rises.
As the temperature rises, the internal resistance value of the temperature detector 65 increases, and the bias power supply 64 increases the output voltage of the temperature-voltage converter 63. This temperature-voltage converter 63
Output voltage of the cooling fan control reference voltage power source 66 exceeds a preset voltage, the cooling fan control voltage comparator 67 detects this and the cooling fan controller 68 operates to cool the cooling fan 69. Rotate at high speed. As a result, the amount of air sent from the cooling fan 69 is increased, and the temperature rise of the audio power amplifier 62 is suppressed.

Here, if an operation such as turning down the volume of the loud sound is performed, the amount of heat generated by the audio power amplifying section 62 decreases, and the temperature drops. As a result, when the output voltage of the temperature-voltage converter 63 becomes lower than the voltage of the cooling fan control reference voltage power supply 66, the cooling fan control voltage comparator 67 detects this and controls the cooling fan controller 68. By the operation, the cooling fan 69 returns to the initial state, and the normal low speed rotation is performed.

As described above, in the conventional cooling fan control device for the audio power amplifier, when the temperature of the audio power amplifier 62 rises to reach a predetermined temperature or higher, the cooling fan 69 is used.
Is switched from normal low-speed rotation to high-speed rotation to increase the amount of blown air, so that the temperature rise of the audio power amplification unit 62 can be suppressed.

[0007]

However, in the conventional cooling fan control device for the audio power amplifier, when the temperature of the audio power amplifier rises and exceeds a preset temperature, the cooling fan is immediately driven at high speed. Since it rotates, there is a problem that the noise of the cooling fan rapidly increases. Further, since the cooling fan rotates only at two speeds, low speed and high speed, the temperature variation of the power amplification section is large and the thermal stress applied to each component increases, which affects the life of the cooling fan itself. There is a problem that the life of the bearing is shortened due to the high speed rotation. Further, there is a problem that the cooling fan cannot be controlled even if the temperature of the power transformer of the audio power amplifier rises.

The present invention solves such a conventional problem. By continuously controlling the number of rotations of the cooling fan in accordance with the temperature rise of the audio power amplifier, the noise of the cooling fan is suddenly increased. The excellent voice power that can prevent the increase in temperature and increase the life of each part by minimizing the temperature fluctuation of the voice power amplification part and further eliminate the unnecessary rotation of the cooling fan. An object is to provide a cooling fan control device for an amplifier.

Another object of the present invention is to control the rotation speed of the cooling fan continuously in accordance with the rise of the internal temperature of the power transformer, so that the power transformer can be cooled similarly and the rise of the temperature can be suppressed. Another object of the present invention is to provide a cooling fan control device for an audio power amplifier.

Still another object is to monitor both the temperature rise of the audio power amplifier and the internal temperature rise of the power transformer to continuously control the rotation speed of the cooling fan according to the temperature rise. Accordingly, it is an object of the present invention to provide an excellent cooling fan control device for an audio power amplifier, which can suppress the rise of each temperature and can share the cooling fan for cooling the audio power amplifier and cooling the power transformer.

[0011]

In order to achieve the above object, the present invention provides a temperature-voltage converter for converting a temperature detected from an audio power amplifier of an audio power amplifier into a voltage, and a temperature-voltage converter. And a cooling fan continuous shift controller that continuously changes the rotation speed of the cooling fan according to changes in the output voltage of the cooling fan, and continuously changes the rotation speed of the cooling fan according to the rise or fall of the temperature of the audio power amplifier. It is designed to increase or decrease.

According to the present invention, the temperature-voltage converter for converting the temperature detected from the power transformer of the audio power amplifier into a voltage, and the rotation speed of the cooling fan are continuously changed according to the change of the output voltage of the temperature-voltage converter. And a cooling fan continuous shift controller that changes the cooling fan continuously. The rotation speed of the cooling fan is continuously increased or decreased as the temperature of the power transformer rises or falls.

Furthermore, the present invention further comprises a temperature-voltage converter for an audio power amplifier, which converts the temperature detected from the audio power amplifier of the audio power amplifier into a voltage, and a power supply which converts the temperature detected from the power transformer into a voltage. Voltage-to-voltage converter for transformer, temperature-to-voltage converter for audio power amplifier or temperature-to-voltage converter for power transformer, whichever is higher And a cooling fan continuous shift controller for continuously changing the rotation speed of the cooling fan according to the change of the temperature of the cooling fan. The rotation speed of is continuously increased or decreased.

[0014]

Therefore, according to the present invention, the output voltage of the temperature-voltage converter changes according to the rise or fall of the temperature of the audio power amplifier, and the cooling fan continuous shift controller causes the cooling fan to change in accordance with the change of the output voltage. Since the rotation speed of is continuously increased or decreased, a more appropriate cooling effect can be obtained.

Further, according to the present invention, the output voltage of the temperature-voltage converter changes in accordance with the rise or fall of the temperature of the power transformer, and the cooling fan continuous shift controller controls the cooling fan of the cooling fan in accordance with the change of the output voltage. Since the rotation speed is continuously increased or decreased, a more appropriate cooling effect can be obtained.

Further, according to the present invention, the temperature for the audio power amplifier is reduced according to the rise or decrease of the temperature of the audio power amplifier.
The output voltage of the voltage converter changes, and the output voltage of the temperature-voltage converter for the power supply transformer changes according to the rise or fall of the temperature of the power supply transformer. The voltage is selected, and the cooling fan continuous shift controller continuously increases or decreases the rotation speed of the cooling fan according to the change in the selected output voltage, so that a more appropriate cooling effect is obtained.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows the configuration of the first embodiment of the present invention. In FIG. 1, 1 is an audio power amplifier main body, and 2 is an audio power amplifier. 3 is a temperature-voltage converter, which is composed of a bias power supply 4 and a temperature detector 5,
The temperature detector 5 is attached to the heat dissipation plate of the audio power amplifier 2. A cooling fan continuous shift controller 6 includes a bias power source 7, an open collector type comparator 8,
Shift point setting resistors 9 and 10 and feedback resistor 11
And constant voltage diodes 12 and 13.
Reference numeral 14 is a fan driving transistor, and 15 is a cooling fan.

Next, the operation of the above embodiment will be described.
When the audio power amplifier 2 amplifies the audio signal, the audio power amplifier 2 generates heat and its temperature rises. When the volume of the loud sound is low, the amount of heat generated by the voice power amplification unit 2 is small, so that the internal resistance value of the temperature detector 5 is small and the temperature-voltage converter 3 is small.
Output voltage is low. If the output voltage of the temperature-voltage converter 3 is equal to or lower than the shift point voltage determined by the shift point setting resistors 9 and 10 in the cooling fan continuous shift controller 6, the output of the comparator 8 becomes Low and the constant voltage. Since the diode 13 is short-circuited, only the Zener voltage of the constant voltage diode 12 becomes the output of the cooling fan continuous shift controller 6, which is current-amplified by the fan driving transistor 14 to drive the cooling fan 15. Therefore, when the heat generation amount of the audio power amplification unit 2 is small and the temperature is low, the cooling fan 15 rotates at low speed, and the cooling fan 15 rotating at low speed.
The wind blown from the air hits the audio power amplification unit 2 and suppresses the temperature rise of the audio power amplification unit 2.

When the volume of the loud sound is gradually increased, the amount of heat generated by the voice power amplification section 2 increases and the temperature gradually rises. With this temperature rise, the internal resistance value of the temperature detector 5 increases, and the output voltage of the temperature-voltage converter 3 increases due to the bias power supply 4. When the output voltage of the temperature-voltage converter 3 exceeds the shift point voltage determined by the shift point setting resistors 9 and 10 in the cooling fan continuous shift controller 6, the comparator 8 operates. Generally, the output of the comparator is instantaneously inverted in the operation of the comparator, but the output of the comparator 8 is held at a constant voltage according to the output voltage of the temperature-voltage converter 3 by the feedback resistor 11, and the cooling fan continues to operate. It becomes the output of the shift controller 6, and the current is amplified by the fan driving transistor 14 to drive the cooling fan 15. Therefore, the voltage applied to the cooling fan 15 continuously increases as the temperature of the audio power amplifier 2 increases, so that the rotation speed of the cooling fan 15 continuously increases and the temperature of the audio power amplifier 2 increases. Hold down.

Here, when an operation such as reducing the volume of the loud sound is performed, the temperature decreases due to the decrease in the amount of heat generated by the audio power amplifier 2. When the output voltage of the temperature-voltage converter 3 decreases with this temperature decrease, the output voltage of the cooling fan continuous shift controller 6 continuously decreases, and the rotation speed of the cooling fan 15 continuously changes. Decrease.

Further, when the volume of the loud sound is kept high, the temperature of the power amplifying section 2 rises, the rotation speed of the cooling fan 15 continuously increases, the temperature of the power amplifying section 2 drops, and the cooling fan 15 rotates. By cooling the audio power amplification unit 2 in a cycle in which the number of the audio power amplification units 2 is continuously reduced, the temperature of the audio power amplification unit 2 is kept substantially constant, and the rotation speed of the cooling fan 15 is not suddenly changed.

If the volume of the loud sound is further increased,
Although the temperature of the sound power amplifier 2 further rises and the output voltage of the temperature-voltage converter 3 further rises, the cooling fan 15
Constant voltage diode 1 so as not to exceed the maximum applied voltage of
3 is provided so that the voltage does not exceed the total voltage of the constant voltage diodes 12 and 13.

As described above, according to the first embodiment,
By continuously increasing and decreasing the rotation speed of the cooling fan 15 as the temperature of the audio power amplifier 2 rises and falls, it is possible to prevent the noise of the cooling fan 15 from rapidly increasing. Since the temperature of the audio power amplification unit 2 can be kept substantially constant, the life of each component can be extended, and further, the life of the cooling fan 15 can be extended because the cooling fan 15 does not rotate unnecessarily at high speed. it can.

FIG. 2 shows the configuration of the second embodiment of the present invention. In FIG. 2, reference numeral 21 is an audio power amplifier body, and 22 is a power transformer. A temperature-voltage converter 23 is composed of a bias power source 24 and a temperature detector 25, and the temperature detector 25 is attached to the power transformer 22. Reference numeral 26 denotes a cooling fan continuous shift controller, which includes a bias power source 27, an open collector type comparator 28, shift point setting resistors 29 and 30, a feedback resistor 31, and constant voltage diodes 32 and 33. Reference numeral 34 is a fan driving transistor, and 35 is a cooling fan.

Next, the operation of the second embodiment will be described. When the audio power amplifier 21 amplifies the audio signal, the power transformer 22 generates heat and the temperature rises. When the volume of the loud sound is low, the amount of heat generated by the power transformer 22 is small, so that the internal resistance value of the temperature detector 25 is small and the output voltage of the temperature-voltage converter 23 is low. If the output voltage of the temperature-voltage converter 23 is equal to or lower than the shift point voltage as in the first embodiment, the cooling fan 35 is rotated at a low speed by the control of the cooling fan continuous shift controller 26, and this low speed. The power transformer 2 is driven by the wind sent from the rotating cooling fan 35.
Cooling 2 suppresses temperature rise.

When the volume of the loud sound is gradually increased, the heat generation amount of the power transformer 22 increases and the temperature rises. As the temperature rises, the internal resistance value of the temperature detector 25 increases, and the bias power supply 24 increases the output voltage of the temperature-voltage converter 23. This temperature-voltage converter 23
When the output voltage of the cooling fan exceeds the shift point voltage, as in the first embodiment, the rotation speed of the cooling fan 35 is continuously increased by the control of the cooling fan continuous shift controller 26, and the output voltage of the power transformer 22 is increased. Controls temperature rise.

Here, when an operation such as reducing the volume of the loud sound is performed, the temperature of the power transformer 22 decreases due to the decrease of the heat generation amount. As the temperature drops, the temperature-voltage converter 23
The output voltage of the cooling fan continuous shift controller 26 continuously decreases, and the rotation speed of the cooling fan 35 continuously decreases.

When the volume of the loud sound is kept high, the cooling fan continuous shift controller 26 controls the temperature of the power transformer 22 to increase or decrease, as in the first embodiment. By increasing or decreasing the rotation speed of the cooling fan 35 to keep the temperature of the power transformer 22 substantially constant,
Moreover, the number of rotations of the cooling fan 35 is not suddenly changed.

When the volume of the loud sound is further increased, the temperature-voltage converter 2 is used as in the first embodiment.
The output voltage of 3 does not exceed the total voltage of the constant voltage diodes 32 and 33 so that the maximum applied voltage of the cooling fan 35 is not exceeded.

As described above, according to the second embodiment,
By continuously increasing and decreasing the rotation speed of the cooling fan 35 as the temperature of the power supply transformer 22 rises and falls, it is possible to prevent the noise of the cooling fan 35 from rapidly increasing. Since the temperature can be kept almost constant, the life of each component can be extended, and further, the cooling fan 35 does not rotate at an unnecessarily high speed, so that the life of the cooling fan 35 can be extended.

FIG. 3 shows the configuration of the third embodiment of the present invention. In FIG. 3, 41 is an audio power amplifier main body, 42 is an audio power amplifier, and 43 is a power transformer. Reference numeral 44 is a temperature-voltage converter for an audio power amplifier, and 45 is a temperature-voltage converter for a power supply transformer, both of which have the same configuration as the temperature-voltage converters 3 and 23 shown in the above embodiments. is doing. Reference numeral 46 denotes a voltage comparison unit, which is composed of diodes 47 and 48. Reference numeral 49 denotes a cooling fan continuous shift controller, which has the same structure as the cooling fan continuous shift controllers 6 and 26 shown in the above-described embodiments.
Reference numeral 50 is a fan driving transistor, and 51 is a cooling fan.

Next, the operation of the third embodiment will be described. When the voice power amplifier 42 or the power transformer 43 generates heat due to the amplification of the voice signal of the voice power amplifier 41, the temperature-voltage converter for the voice power amplifier is similar to the first and second embodiments. 44 or the output voltage of the power transformer temperature-voltage converter 45 increases. The voltage comparison unit 46 selects the higher voltage and outputs the higher one of the temperature-voltage converter 44 for the audio power amplification unit and the temperature-voltage converter 45 for the power transformer. When the output voltage exceeds the shift point voltage as in the above-described embodiments, the cooling fan continuous shift controller 49 controls the rotation speed of the cooling fan 51 to continuously increase, thereby increasing the sound power amplifier 42 and the power source. Both of the transformers 43 are cooled to suppress the temperature rise.

As described above, according to the third embodiment,
Since the rotation speed of the cooling fan 51 is continuously increased or decreased depending on which of the audio power amplifier 42 and the power transformer 43 has the higher temperature, the same effects as those of the above-described embodiments can be obtained. In addition, the cooling fan 51 can be commonly used for the power amplifier and the power transformer.

[0034]

As is apparent from the first embodiment, the present invention includes a temperature-voltage converter for converting the temperature detected by the audio power amplifier of the audio power amplifier into a voltage, and a temperature-voltage converter. Provided with a cooling fan continuous shift controller that continuously changes the rotation speed of the cooling fan in response to changes in the output voltage, and continuously increases or decreases the rotation speed of the cooling fan as the temperature of the audio power amplifier rises or falls. By doing so, it is possible to prevent the noise of the cooling fan from rapidly increasing, and since the temperature of the audio power amplifier can be kept substantially constant, the life of each component can be extended, Further, since the cooling fan does not rotate unnecessarily at a high speed, the life of the cooling fan can be extended.

As is apparent from the second embodiment, the present invention also includes a temperature-voltage converter for converting the temperature detected from the power transformer of the audio power amplifier into a voltage, and an output voltage of the temperature-voltage converter. A fan continuous shift controller that continuously changes the rotation speed of the cooling fan according to the change is provided, and the rotation speed of the cooling fan is continuously increased or decreased according to the temperature rise or fall of the power transformer. The rotation speed of the cooling fan can be controlled according to the rise in the temperature of the power transformer, and moreover, the noise of the cooling fan can be prevented from rapidly increasing, as in the case of the audio power amplifier. In addition, the temperature of the power transformer can be kept almost constant, so that the life of each component can be extended and the cooling fan does not rotate unnecessarily at high speed. An effect that can be extended down the life.

As is apparent from the third embodiment, the present invention includes a temperature-voltage converter for an audio power amplifier for converting the temperature detected by the power amplifier of the audio power amplifier into a voltage, and a power transformer. A voltage comparison that selects the higher output voltage of the temperature-voltage converter for the power transformer that converts the detected temperature to the voltage, and the temperature-voltage converter for the audio power amplifier or the temperature-voltage converter for the power transformer. Department,
A cooling fan continuous shift controller that continuously changes the rotation speed of the cooling fan according to the change of the output voltage of the voltage comparison unit is provided, and the temperature of the voice power amplification unit rises or falls and the temperature of the power transformer rises or falls. According to the above, since the rotation speed of the cooling fan is continuously increased or decreased, in addition to the above-described effects, the cooling fan can be shared for cooling the power amplification unit and cooling the power transformer.

[Brief description of drawings]

FIG. 1 is a schematic block diagram of a cooling fan control device according to a first embodiment of the present invention.

FIG. 2 is a schematic block diagram of a cooling fan control device according to a second embodiment of the present invention.

FIG. 3 is a schematic block diagram of a cooling fan control device according to a third embodiment of the present invention.

FIG. 4 is a schematic block diagram of a conventional cooling fan control device.

[Explanation of symbols]

 1 voice power amplifier main body 2 voice power amplification section 3 temperature-voltage converter 4 bias power supply 5 temperature detector 6 cooling fan continuous shift controller 7 bias power supply 8 open collector type comparator 9, 10 shift point setting resistor 11 feedback resistor 12, 13 Constant Voltage Diode 14 Fan Driving Transistor 15 Cooling Fan 21 Audio Power Amplifier Main Body 22 Power Supply Transformer 23 Temperature-Voltage Converter 24 Bias Power Supply 25 Temperature Detector 26 Cooling Fan Continuous Shift Controller 27 Bias Power Supply 28 Open Collector Type Comparator 29, 30 Shift Point Setting Resistor 31 Feedback Resistor 32, 33 Constant Voltage Diode 34 Fan Driving Transistor 35 Cooling Fan 41 Audio Power Amplifier Main Body 42 Audio Power Amplifier 43 Power Transformer 44 Audio Power Amplifier Temperature- Pressure transducer 45 power transformer for temperature - voltage converter 46 voltage comparator 47, 48 diodes 49 cooling fan continuously shift controller 50 fan drive transistor 51 cooling fan

Claims (3)

[Claims] 1. A temperature-voltage converter for converting a temperature detected from an audio power amplifier of an audio power amplifier into a voltage, and a rotation speed of a cooling fan is continuously changed according to a change in an output voltage of the temperature-voltage converter. Cooling fan control device for a voice power amplifier, comprising: 2. A temperature-voltage converter for converting a temperature detected from a power transformer of an audio power amplifier into a voltage, and a rotation speed of a cooling fan continuously according to a change in an output voltage of the temperature-voltage converter. A cooling fan control device for an audio power amplifier, comprising a cooling fan continuous shift controller for changing the cooling fan. 3. A temperature-voltage converter for an audio power amplifier which converts a temperature detected by an audio power amplifier of the audio power amplifier into a voltage, and a temperature for a power transformer which converts a temperature detected by a power transformer into a voltage. A voltage converter, a voltage comparison unit that selects the higher output voltage of the temperature-voltage converter for the audio power amplification unit or the temperature-voltage converter for the power supply transformer, and the output voltage of the voltage comparison unit. A cooling fan control device for an audio power amplifier, comprising: a cooling fan continuous shift controller that continuously changes the rotation speed of the cooling fan in response to a change.