JP6063130B2 - Electrical equipment - Google Patents

Description

  The present invention relates to an electrical device.

  In general, an electric device such as a mobile phone or a personal computer has an internal temperature that rises when a built-in circuit generates heat while the built-in secondary battery generates heat during charging. However, an excessive increase in temperature is undesirable because it adversely affects the deterioration of the built-in components. Therefore, there is an electrical device having a mechanism for suppressing heat generation by stopping charging of the secondary battery or stopping a part of functions when the temperature becomes a certain value or more (see, for example, Patent Document 1). ).

JP 2001-147730 A

  The electric device of the conventional example executes control for suppressing heat generation when the absolute value of the temperature becomes a certain value or more. However, if only the absolute value is judged, for example, when the environmental temperature of the place where the electrical equipment is used is relatively high, the temperature immediately becomes higher than a certain value immediately after the start of use, and the adverse effect due to the temperature rise is still not so much. It is possible that the function of the electrical device is limited at a point where no problem occurs.

  The present invention has been made in consideration of the above circumstances, and one of its purposes is to provide an electric device capable of executing control for suppressing heat generation at a timing in consideration of the use environment.

  The electrical device according to the present invention includes a temperature sensor that measures temperature, reference temperature setting means that sets a temperature measured by the temperature sensor at a predetermined timing as a reference temperature, and the temperature sensor during operation of the electrical device. Control means for executing control for suppressing the heat generation of the electric device when the temperature measured by the above is higher than a predetermined threshold value compared with the reference temperature.

It is a lineblock diagram of the electric equipment concerning an embodiment of the invention. It is a functional block diagram which shows the function which the electric equipment which concerns on embodiment of this invention implement | achieves. It is explanatory drawing which shows an example of the control according to the temperature change which the electric equipment which concerns on embodiment of this invention performs.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  As shown in FIG. 1, an electrical device 1 according to an embodiment of the present invention includes a control circuit 11, a temperature sensor 12, a load 13, a communication circuit 14, a charging circuit 15, a secondary battery 16, And a power supply terminal 17. The electric device 1 may be various devices such as a mobile phone, a game machine, and a personal computer that have a communication function and operate with electric power supplied from the secondary battery 16.

  In the present embodiment, the electric device 1 operates in any one of a plurality of operation modes including at least two of a normal operation mode and a power saving mode. The power saving mode is an operation mode in which the power consumption of the entire electric device 1 is less than that in the normal operation mode.

  The control circuit 11 is a microcomputer or the like, and performs function control according to the temperature described later. The control circuit 11 operates similarly in any of the normal operation mode and the power saving mode.

  The temperature sensor 12 is a thermistor or the like and is built in the electric device 1 and measures the temperature inside the casing of the electric device 1. The measurement result of the temperature sensor 12 is input to the control circuit 11.

  The load 13 is a device for realizing the original function of the electric device 1 and includes, for example, a CPU, a memory, and a display device. The load 13 operates with the power supplied from the secondary battery 16 during the normal operation mode, but operates with less power consumption than the normal operation mode during the power saving mode. Specifically, when the load 13 is a microprocessor or the like, during the power saving mode, the load 13 operates in an operation mode with low power consumption or is in a reset state (state before reset release). During the power saving mode, power supply from the secondary battery 16 to the load 13 may be stopped, and the load 13 may stop operating.

  The communication circuit 14 is a circuit element that transmits and receives information to and from other communication devices. Similarly to the load 13, the communication circuit 14 also operates during the normal operation mode, and operates with lower power consumption than the normal operation mode or stops operating during the power saving mode.

  The charging circuit 15 transforms electric power supplied from the outside via the power supply terminal 17 and supplies it to the secondary battery 16 to charge the secondary battery 16. Each part of the electric device 1 is operated by electric power supplied from the secondary battery 16. The power supply terminal 17 is connected to an external power supply source such as a commercial power supply or a USB host device, and accepts supply of power from the power supply source. Note that the charging circuit 15 may charge the secondary battery 16 in both the normal operation mode and the power saving mode.

  The electrical device 1 according to the present embodiment generates heat mainly due to the operation of the load 13 and the communication circuit 14 and the power consumption associated with charging by the charging circuit 15, and the temperature rises. Therefore, in the present embodiment, when the control circuit 11 detects an increase in temperature, it performs function control for suppressing further heat generation. A specific example of this control will be described below.

  The control circuit 11 functionally includes a reference temperature setting unit 21 and a heat generation control unit 22 as shown in FIG. These functions are realized by executing a program stored in a memory built in the control circuit 11.

  The reference temperature setting unit 21 acquires information on the temperature measured by the temperature sensor 12 at a predetermined timing, and sets this temperature as the reference temperature Tr. The reference temperature Tr is a temperature corresponding to the environmental temperature around the electric device 1. Therefore, the reference temperature setting unit 21 can acquire the reference temperature Tr at a timing at which it is assumed that the electrical device 1 itself hardly generates heat and the temperature rise due to the operation of the electrical device 1 is small enough to be ignored. desirable. Therefore, in this embodiment, the timing at which the electrical device 1 is not performing an operation that causes heat generation, or the timing immediately after the operation that causes heat generation is set as the setting timing of the reference temperature Tr. The reference temperature setting unit 21 stores information on the set reference temperature Tr in a memory inside the control circuit 11.

  Specifically, for example, the reference temperature setting unit 21 sets a timing at which the load 13 that is assumed to have a high rate of contribution to the temperature rise not normally operating as the reference temperature Tr setting timing. Furthermore, the reference temperature Tr is set at a timing when the secondary battery 16 is not charged (that is, when the secondary battery 16 is fully charged or when a power supply source is not connected to the power supply terminal 17). ) Is desirable. Therefore, the reference temperature setting unit 21 sets the reference temperature Tr while the electric device 1 is operating in the power saving mode and charging is not performed. In order to set the reference temperature Tr when the temperature inside the electric device 1 is stable, the reference temperature Tr is not set immediately after the power saving mode and the charging is not performed. Alternatively, the reference temperature Tr may be set at a timing when a predetermined time has passed in this state.

  Further, the reference temperature setting unit 21 needs to update the reference temperature Tr in accordance with a change in the temperature around the electric device 1. Therefore, the reference temperature setting unit 21 periodically acquires information on the temperature measured by the temperature sensor 12 while the above-described reference temperature Tr setting timing condition is satisfied, and updates the reference temperature Tr with the acquired temperature. May be.

  Alternatively, the reference temperature setting unit 21 starts the operation of the electric device 1 when the power is turned on from the state where the power of the electric device 1 has been turned off and the operation of the control circuit 11 has also stopped. The reference temperature Tr may be set at the timing when the operation mode of the electric device 1 is changed from the power saving mode to the normal operation mode.

  In addition, when the temperature around the electric equipment 1 is high, a relatively high value is set as the reference temperature Tr. If it does so, there exists a possibility that the execution conditions of control which suppresses the heat generation mentioned later may not be satisfied easily. Therefore, when the temperature measured by the temperature sensor 12 exceeds a predetermined upper limit value at the timing of setting the reference temperature Tr, the reference temperature setting unit 21 uses the upper limit value as a reference temperature instead of the actually measured temperature. It may be set as Tr.

  The heat generation control unit 22 periodically acquires information on the current temperature (hereinafter referred to as the current temperature Tc) measured by the temperature sensor 12 during the operation of the electrical device 1, and the acquired current temperature Tc becomes high. In addition, control (hereinafter, heat generation prevention control) for suppressing further heat generation of the electric device 1 is executed. In particular, in the present embodiment, the heat generation control unit 22 determines whether to execute the heat generation prevention control, not only the absolute value of the current temperature Tc but also the current temperature Tc with respect to the reference temperature Tr set by the reference temperature setting unit 21. Judgment is made using relative values.

Specifically, the heat generation control unit 22 performs heat generation prevention control of the electric device 1 when the current temperature Tc is higher than the reference temperature Tr by a predetermined threshold ΔTth or more. That is, it is determined whether or not the heat generation prevention control is executed using the following determination condition C1.
Determination condition C1: ΔT = Tc−Tr ≧ ΔTth
Here, ΔT is a value indicating how much the temperature of the electrical device 1 has increased as compared to a state in which the electrical device 1 does not generate heat (is at a temperature substantially equal to the ambient temperature). By using such a determination condition C1, the heat generation control unit 22 performs heat generation prevention control when the electrical device 1 rises to a temperature higher than the ambient temperature by ΔTth or more.

The determination condition C1 may be used in combination with other determination conditions. For example, the heat generation prevention control may be executed when the determination condition C1 is satisfied and the following determination condition C2 is satisfied.
Determination condition C2: Tc ≧ T1
Here, T1 is a predetermined boundary value. By using this determination condition C2 in combination with the determination condition C1, when the ambient temperature is relatively low, the condition of ΔT ≧ ΔTth is satisfied even though the current temperature Tc is a temperature that does not cause a problem yet. Thus, it is possible to prevent the heat generation prevention control from being executed.

Further, the heat generation control unit 22 may execute the heat generation prevention control even when the following determination condition C3 is satisfied regardless of the determination condition regarding ΔT.
Determination condition C3: Tc ≧ T2
Here, T2 is a predetermined boundary value and is larger than T1. According to this determination condition C3, when the current temperature Tc becomes a temperature causing a problem, control for suppressing heat generation can be immediately executed regardless of whether the condition of ΔT ≧ ΔTth is satisfied. it can.

  FIG. 3 is a diagram for explaining the execution timing of the heat generation prevention control when the above-described three determination conditions are used in combination. FIG. 3 shows the execution timing of the heat generation prevention control with white triangles in three cases (a) to (c).

  FIG. 3A shows a case where T1 <(Tr + ΔTth) <T2. In this case, when the current temperature Tc reaches the boundary value T1, the determination condition C1 for ΔT is not satisfied, and thus the heat generation prevention control is not executed. Thereafter, when the current temperature Tc further increases and reaches (Tr + ΔTth), since both the determination conditions C1 and C2 are satisfied, the heat generation prevention control is started.

  FIG. 3B shows a case where (Tr + ΔTth) <T1. In this case, the determination condition C1 is satisfied when the current temperature Tc reaches (Tr + ΔTth), but the determination condition C2 is not yet satisfied at that time. Thereafter, when the current temperature Tc further increases and reaches the boundary value T1, heat generation prevention control is started.

  FIG. 3C shows the case where (Tr + ΔTth)> T2. In this case, the determination condition C1 is not yet satisfied when the current temperature Tc reaches the boundary value T2. However, since the determination condition C3 is satisfied when the boundary value T2 is reached, the heat generation prevention control is started at that point regardless of the determination condition C1.

  Here, a specific example of the heat generation prevention control executed by the heat generation control unit 22 will be described. The heat generation prevention control is a control that limits a part of functions that cause heat generation among the functions of the electrical device 1 (that is, stops the function or restricts the function). . For example, the heat generation control unit 22 shifts the communication circuit 14 to a low power consumption state (reset state or the like), or stops power supply to the communication circuit 14 and stops its operation. Such control temporarily disables the communication function of the electrical device 1, but can suppress heat generation due to the operation of the communication circuit 14. The heat generation prevention control may be control for stopping charging of the secondary battery 16 by the charging circuit 15. Alternatively, the heat generation control unit 22 may limit the charging current when the charging circuit 15 charges the secondary battery 16 to a predetermined value or less by instructing the charging circuit 15. As a result, the time required to fully charge becomes longer, but the heat generated by the charging becomes smaller than in a normal case. In addition, the heat generation control unit 22 suppresses heat generation by shifting some circuits that cause heat generation included in the load 13 to a low power consumption state or stopping its operation. May be.

  In addition, when performing a plurality of types of heat generation prevention control, the heat generation control unit 22 may vary the determination conditions for executing the heat generation prevention control for each type of heat generation prevention control. Specifically, when the current temperature Tc becomes higher than the first threshold value ΔTth1 by comparison with the reference temperature Tr, the heat generation control unit 22 performs the first function (for example, communication by the communication circuit 14) of the electric device 1. When the current temperature Tc is higher than the reference temperature Tr by a second threshold value ΔTth2 or more, a second function different from the first function (for example, a charging function of the secondary battery 16) is stopped. ) May be stopped.

  Further, the heat generation control unit 22 may change the value of the threshold value ΔTth according to the state of the electrical device 1. For example, when the temperature sensor 12 is disposed in the vicinity of a specific circuit (for example, the communication circuit 14), the temperature measured by the temperature sensor 12 varies depending on whether the communication circuit 14 is operating or stopped. Therefore, the heat generation control unit 22 may determine whether to execute the heat generation prevention control using ΔTth having different values depending on whether the specific circuit is operating or stopped.

  In addition, when the current temperature Tc measured by the temperature sensor 12 is decreased as a result of executing the heat generation prevention control, the heat generation control unit 22 cancels the heat generation prevention control that has been executed so far. For example, when the current temperature Tc becomes equal to or lower than a predetermined boundary value T3 (here, T3 <T1), the heat generation control unit 22 cancels the heat generation prevention control that has been executed so far, and restarts the function that has been limited so far. Run. Note that ΔT, which is a relative value with respect to the reference temperature Tr, may also be used as a determination criterion in this case.

  According to the electric device 1 according to the present embodiment described above, since it is determined whether or not the heat generation prevention control is executed in consideration of the reference temperature Tr that changes according to the temperature around the electric device 1, the current temperature Tc is determined. Unlike the case where only the absolute value is used, even when the temperature around the electric device 1 is high, it is possible to prevent the heat generation prevention control from being executed immediately after the start of use.

  The embodiment of the present invention is not limited to the above-described embodiment. For example, in the above description, the electric device 1 includes the communication circuit 14 and the secondary battery 16, and the communication circuit 14 is stopped or charging of the secondary battery 16 is restricted as heat generation prevention control. However, the heat generation prevention control can be realized by stopping the operation of various other circuits or limiting the function of the electric device used by the user. In that case, there is no need for a communication circuit. In addition, the present invention is not a secondary battery but an electric device that operates by power supplied from an external power supply source, or an electric device that operates by power supplied from a secondary battery but does not have a secondary battery charging function It can also be applied to equipment.

  DESCRIPTION OF SYMBOLS 1 Electrical equipment, 11 Control circuit, 12 Temperature sensor, 13 Load, 14 Communication circuit, 15 Charging circuit, 16 Secondary battery, 17 Power supply terminal, 21 Reference temperature setting part, 22 Heat generation control part.

Claims (6)

A secondary battery,
A charging circuit for charging the secondary battery;
A temperature sensor for measuring the temperature;
The temperature measured by the temperature sensor when the electric device is operating in a power saving mode that consumes less power than normal operation or when the electric device is turned on and the operation of the electric device starts. A reference temperature setting means for setting as a reference temperature;
During operation of the electrical device, when the temperature measured by the temperature sensor is higher than a predetermined threshold compared to the reference temperature, a control unit that executes control to suppress heat generation of the electrical device;
Including
The reference temperature setting means periodically acquires the temperature measured by the temperature sensor while a part of the operation that causes the electric device to generate heat is stopped, and the reference temperature is determined based on the acquired temperature. Updated,
The control means operates the electric device in a power saving mode.
Electrical equipment characterized by that. The electric device according to claim 1,
The reference temperature setting means sets, as the reference temperature, a temperature measured by the temperature sensor in a state where a part of the operation that generates heat of the electric device is stopped. . In the electric equipment according to claim 1 or 2 ,
The control device suppresses heat generation by limiting a part of functions of the electrical device. In the electric equipment according to any one of claims 1 to 3 ,
The said control means suppresses heat_generation | fever by stopping the electric power supply with respect to the one part circuit with which the said electric equipment is provided. The electric equipment characterized by the above-mentioned. In the electric equipment according to any one of claims 1 to 4 ,
The reference temperature has an upper limit,
When the temperature measured by the temperature sensor exceeds the upper limit value, the reference temperature setting unit sets the upper limit value as the reference temperature. In the electric equipment according to any one of claims 1 to 5 ,
When the temperature measured by the temperature sensor becomes higher than the first threshold value by the first threshold value, the control unit stops the first function of the electric device, and the temperature sensor When the measured temperature becomes higher than the reference temperature by a second threshold or more, the second function different from the first function is stopped.

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