JP2013005364A - Electronic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic apparatus that can satisfy specifications in various operating temperature ranges in the same configuration without causing increases in apparatus size and cost.SOLUTION: The electronic apparatus includes: an oscillator 2; a temperature measurement section for measuring a temperature around the oscillator 2; resistors 3-6 mounted in the vicinity of the oscillator 2 on a substrate 1 mounted with the oscillator 2; and a control section for controlling energization of the resistors 3-6 in accordance with the temperature measured by the temperature measurement section.

Description

  The present invention relates to an electronic device incorporating an oscillator.

  For example, in a radio base station, an oscillator such as a crystal oscillator is used as a reference signal source such as a PLL circuit that determines the frequency of a transmission / reception signal. This oscillator has a characteristic that the oscillation frequency changes depending on ambient temperature conditions.

  The operating temperature range of the radio base station is required to have various performances depending on the application and installation location. In particular, in the cold region, the lower limit of the operating temperature range may be −30 ° C. or less. Under such specifications of the operating temperature range, there are cases where very severe characteristics such as a frequency deviation of 50 ppb are required for the oscillator. In order to satisfy this requirement, a specially-designed oscillator that is very expensive and large in size is used. There was a need.

  On the other hand, conventionally, for example, an oscillator is installed near a heat generating component, or a method of contacting a heat generating component through a sheet having a good thermal conductivity, or a heater on the inner wall of the casing of a radio base station is used. Measures have been taken to heat up the ambient temperature of the oscillator by a method such as installation (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2000-188171 (FIG. 6)

  However, if the above measures are taken, it becomes difficult to satisfy the temperature operating range on the high temperature side when installing the base station in a place other than the cold region, and the base station having the same configuration is regarded as a cold region. There was a problem that it could not be used in other places and had to be a separate specification. In particular, as disclosed in Patent Document 1, when a heater is installed on the inner wall of the housing, a large installation space is required, which increases the size of the apparatus, and a mechanism such as a metal fitting for fixing the heater. There is a problem that the cost increases because it is necessary. Such a problem occurs not only in the radio base station but also in various electronic devices having a built-in oscillator.

  The present invention is intended to solve the above-described problems, and an object of the present invention is to provide an electronic device that can satisfy specifications of various operating temperature ranges with the same configuration without causing an increase in size and cost of the device. It is to provide.

  An electronic device according to the present invention is an electronic device including an oscillator, and includes a temperature measurement unit that measures a temperature around the oscillator, and a resistor mounted in the vicinity of the oscillator on a substrate on which the oscillator is mounted. And a control unit that controls energization of the resistor according to the temperature measured by the temperature measurement unit.

  In a preferred embodiment of the invention, the resistor comprises a cement resistor.

  In another preferred embodiment of the present invention, there are a plurality of the resistors, and the resistors are mounted in series near the oscillator.

  In another preferred embodiment of the present invention, the resistor is mounted to surround the oscillator.

  ADVANTAGE OF THE INVENTION According to this invention, the electronic device which can satisfy the specification of various operating temperature ranges with the same structure can be provided, without causing the enlargement and cost increase of an apparatus.

It is a figure which shows the structure of the principal part of the electronic device concerning one Embodiment of this invention. It is a block diagram which shows an example of the electricity supply control circuit of a resistor.

Hereinafter, a base station according to an embodiment of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a diagram illustrating a configuration of a main part of an electronic device according to an embodiment of the present invention.
As shown in FIG. 1, an oscillator 2 is mounted on a substrate 1 of an electronic device, and resistors 3, 4, 5, 6 is implemented.

  FIG. 2 is a block diagram illustrating an example of the energization control circuit of the resistor. The energization control circuit includes a temperature measurement unit 7, a control unit 8, a drive unit 9, and a voltage source 10. The resistors 3, 4, 5, 6 are connected in series between the voltage source 10 and the drive unit 9.

The temperature measuring unit 7 measures the temperature around the oscillator 2 shown in FIG. 1 in the housing of the electronic device. Here, the “ambient temperature” means a temperature at a position suitable for use as an index of the operating temperature of the oscillator.
The temperature measurement unit 7 is connected to the control unit 8 and outputs the measurement result of the ambient temperature of the oscillator to the control unit 2.

  The control unit 8 controls on / off of energization to the resistors 3 to 6 by the driving unit 9 according to the measurement result of the ambient temperature of the oscillator by the temperature measuring unit 7. That is, when the ambient temperature of the oscillator is lower than a predetermined threshold value, the current path of the resistors 3 to 6 is turned on by the drive unit 9. As a result, the resistors 3 to 6 are heated by Joule heat to raise the ambient temperature. On the other hand, when the ambient temperature of the oscillator is equal to or higher than a predetermined threshold, the drive unit 9 turns off the current paths of the resistors 3 to 6. Thereby, the heat generating action by the resistors 3 to 6 is stopped, and the ambient temperature is lowered. The threshold value can be determined based on, for example, the lower limit of the operating temperature range of the oscillator.

  Here, it is preferable to use, for example, a cement resistor having excellent heat resistance as the resistors 3 to 6. In order to efficiently generate heat from the resistors 3 to 6 with the same drive current, it is preferable to connect the resistors 3 to 6 in series as shown in FIG.

Thus, by arranging the resistors 3 to 6 symmetrically in the vicinity of the oscillator 2 on the substrate 1 on which the oscillator is mounted, the ambient temperature of the oscillator can be efficiently raised in a small space.
Note that the number and arrangement of the resistors are not limited to this example, and can be appropriately changed according to the type and installation location of the electronic device.

  As described above, in the electronic apparatus according to the present embodiment, the temperature measurement unit 7 measures the temperature around the oscillator 2 and controls on / off of the energization to the resistors 3 to 6 according to the measured temperature. Therefore, the temperature around the oscillator 2 can be appropriately controlled. Therefore, it is possible to satisfy the specifications of various operating temperature ranges with the same configuration without changing the configuration depending on the installation location of the electronic device.

  Accordingly, it is not necessary to use an oscillator having a special specification even in a cold region, and the cost can be reduced. Further, since there is no need to install a heater or the like in the housing, space saving can be achieved.

  In addition, this invention is not limited to the said embodiment, A various change is possible in the range which does not deviate from the meaning of invention. For example, in the above embodiment, the resistors are connected in series, but the present invention is not limited to this, and may be connected in parallel.

DESCRIPTION OF SYMBOLS 1 Board | substrate 2 Oscillator 3, 4, 5, 6 Resistor 7 Temperature measurement part 8 Control part 9 Drive part 10 Voltage source

Claims (4)

An electronic device comprising an oscillator,
A temperature measurement unit for measuring the ambient temperature of the oscillator;
On the substrate on which the oscillator is mounted, a resistor mounted in the vicinity of the oscillator;
In accordance with the temperature measured by the temperature measurement unit, a control unit that controls energization to the resistor,
An electronic device comprising:   The electronic device according to claim 1, wherein the resistor is a cement resistor.   The electronic device according to claim 1, wherein there are a plurality of resistors, and the resistors are mounted in series near the oscillator.   The electronic device according to claim 3, wherein the resistor is mounted so as to surround the oscillator.

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