JP2017093095A - Battery-driven electronic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a battery-driven electronic device of simple configuration capable of ensuring stable operation of the electronic device body, even if the environmental temperature of the battery is lower than a normal temperature range for guaranteeing the performance of the battery.SOLUTION: A battery-driven electronic device includes an electronic device body operating with a battery as a power supply, a switch for turning power supply from the battery to the electronic device body on/off, and an input capacitor provided in the power supply input section of the electronic device body and smoothing the power supplied from the battery via the switch. In particular, a controller suppresses an inrush current flowing from the battery into the input capacitor below the permissible current of the battery, by changing the on/off control width or on/off control period of the switch according to the environmental temperature of the battery at the time of power-up of the electronic device body, and then supplies a predetermined battery voltage from the battery to the input capacitor by turning the switch on continuously.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a battery-driven electronic device such as a measuring device that operates using a battery as a power source.

  For example, an electronic device constructed with a measuring device that measures weather information such as temperature and humidity, and also natural environment information such as landslides and earthquakes, is installed in various environments. Also, since this type of electronic device often has no commercial power supply facilities in its installation environment, it is often configured as a battery-driven electronic device exclusively operating with a battery (battery) as a power source.

  FIG. 4 is a diagram showing a schematic configuration of this type of battery-driven electronic device (measuring device) 1, 2 is a battery (battery), and 3 is an electronic device main body that operates using the battery 2 as a power source. Incidentally, the electronic device body 3 includes a measuring unit (measuring circuit) 3a for measuring the above-described weather information, natural environment information, etc. in the installation environment of the battery-driven electronic device 1 using various sensors (not shown), for example. Prepare. In addition, the electronic device main body 3 displays, for example, a display unit 3b mainly composed of an LCD for displaying the environmental information obtained by the measuring unit 3a, and the environmental information obtained by the measuring unit 3a. An alarm unit 3c such as a buzzer that issues an alarm when an environmental abnormal state is indicated is provided. The measurement unit 3a may incorporate a wireless communication function for transmitting the measurement information to a monitoring center, for example.

  The measurement unit 3a, the display unit 3b, and the alarm unit 3c in the electronic device body 3 are generally power switches 4a and 4b that are turned on in conjunction with the power-on of the electronic device body 3. , 4c, a predetermined power supply voltage is applied from the battery 2, and the power supplied from the battery 2 is used as an energy source. Note that the input capacitors 5a, 5b, and 5c provided in the power supply input units of the measurement unit 3a, the display unit 3b, and the alarm unit 3c respectively smooth the power supply voltage applied from the battery 2 and It plays the role which each supplies to the measurement part 3a, the said display part 3b, and the said alarm part 3c.

  By the way, in the battery-driven electronic device 1, the power switches 4a, 4b and 4c are collectively turned on when the power is turned on, whereby the electronic device main body 3 is fixed to the electronic device main body 3 as shown in FIG. Power supply voltage is applied. Since charging current flows into the input capacitors 5a, 5b, and 5c when the power is turned on, the current output from the battery 2 is temporarily increased as shown in FIG. However, the capacity of each of the input capacitors 5a, 5b, 5c is designed exclusively on the condition that the battery 2 is used in a room temperature state. Therefore, the input capacitors 5a, 5b, 5c normally flow into the input capacitors 5a, 5b, 5c when the power is turned on. The current does not exceed the allowable current of the battery 2.

  However, when the temperature (environmental temperature) of the installation environment of the battery-driven electronic device 1 is lower than the normal temperature range that guarantees the performance of the battery 2, the battery-driven electronic device 1 is turned off from the battery 2 when the power is turned on. As the internal resistance of the battery 2 increases at the start of power supply, for example, as shown in FIG. 6A, the applied voltage to the electronic device body 3 decreases. As the environmental temperature decreases, the allowable current of the battery 2 decreases as shown in FIG. 6B, for example. For this reason, when the power is turned on, the inrush current flowing from the battery 2 into the input capacitors 5a, 5b, and 5c may exceed the allowable current of the battery 2 that has decreased as described above.

  The occurrence of the inrush current exceeding the allowable current of the battery 2 significantly deteriorates the performance of the battery 2 and becomes a factor that hinders the stable operation of the electronic device body 3. In other words, the measurement unit 3a, the display unit 3b, and the alarm unit 3c may not operate normally. In particular, when the remaining capacity of the battery 2 is reduced, a serious problem arises in operating the electronic device body 3 stably.

  In Patent Document 1, the change in the output voltage of the battery 2 is monitored, and when the output voltage of the battery 2 decreases, the step-up / down converter is set to the boost mode to set the power supply voltage to be applied to the electronic device body 3. Guarantee is disclosed. Patent Document 2 discloses a technique for reducing the inrush current to the power capacitor by controlling the power supply voltage applied to the reactor when the power is turned on.

JP 2003-47238 A JP 2007-60843 A

  However, the technique disclosed in Patent Document 1 addresses a decrease in output voltage accompanying a decrease in the remaining capacity of the battery 2. The technique disclosed in Patent Document 2 reduces the inrush current to the power capacitor in the switching power supply device. That is, none of the technologies disclosed in these Patent Documents 1 and 2 deal with the deterioration of the battery performance accompanying the decrease in the use environment temperature of the battery 2.

  The present invention has been made in consideration of such circumstances, and the object thereof is even when the environmental temperature of a battery that supplies power to the electronic device main body is lower than a normal temperature range that guarantees the performance of the battery. Another object of the present invention is to provide a battery-driven electronic device having a simple configuration capable of assuring stable operation of the electronic device main body.

  In order to achieve the above-described object, a battery-driven electronic device according to the present invention includes a battery, an electronic device body that operates using the battery as a power source, and a switch that turns on / off power supply from the battery to the electronic device body. And an input capacitor that is provided at a power input portion of the electronic device main body and smoothes a voltage supplied from the battery via the switch to be applied to the electronic device main body.

  In particular, the battery-driven electronic device according to the present invention performs on / off control of the switch when the electronic device body is turned on, and the on / off control width of the switch according to the environmental temperature of the battery when the power is turned on. Alternatively, after changing the on / off control period to suppress the inrush current flowing from the battery to the input capacitor below the allowable current of the battery, the switch is continuously turned on to transfer the input capacitor from the battery to the input capacitor. A control device for supplying a battery voltage is provided.

  Preferably, the control device includes a temperature sensor that measures an environmental temperature of the battery, and the ON width of the switch when the environmental temperature of the battery is lower than a normal temperature range that guarantees the performance of the battery. And the waveform of the current supplied from the battery to the input capacitor is smoothed.

  Specifically, the electronic device body is obtained by, for example, a measuring unit that measures environmental information in an installation environment of the battery-driven electronic device, a display unit that displays environmental information obtained by the measuring unit, and the measuring unit. And an alarm unit that issues an alarm when the environmental information provided indicates an abnormality in the installation environment. Further, the measuring unit, the display unit, and the alarm unit in the electronic device main body are configured to operate by receiving power supplied from the battery via a plurality of switches provided in parallel. .

  Preferably, the control device is configured to individually control on / off of the plurality of switches to control power supply to the measurement unit, the display unit, and the alarm unit, respectively. Furthermore, the control device is configured to start power supply to the measurement unit, the display unit, and the alarm unit via the plurality of switches in a predetermined order, for example, when the electronic device main body is turned on.

  According to the battery-driven electronic device having the above configuration, when the environmental temperature of the battery is lower than a normal temperature range that guarantees the performance of the battery, the switch according to the environmental temperature of the battery when the electronic device body is turned on And a control device that changes an on / off control width or an on / off control period of the battery so that an inrush current flowing from the battery into the input capacitor when the power is turned on is less than or equal to an allowable current of the battery. Therefore, even when the environmental temperature of the battery is lower than the normal temperature range, and the internal resistance of the battery increases due to this, and the allowable current of the battery decreases, the input capacitor from the battery is turned on when the power is turned on. The inrush current flowing into the can be kept small.

  As a result, it is possible to effectively suppress the deterioration of battery performance due to an excessive inrush current at the time of turning on the power. Even if the remaining capacity of the battery is low, it is possible to stably supply power from the battery to the electronic device body, and effectively guarantee stable operation of the electronic device body. It becomes possible to do.

1 is an overall schematic configuration diagram of a battery-driven electronic device according to an embodiment of the present invention. The figure which shows the output voltage and output current of the said battery at the time of power activation at the normal temperature in the battery drive type electronic device which concerns on this invention. The figure which shows the output voltage and output current of the said battery at the time of power activation at the time of low temperature in the battery drive type electronic device which concerns on this invention. 1 is an overall schematic configuration diagram of a conventional battery-driven electronic device. The figure which shows the output voltage and output current of the said battery at the time of power activation at the normal temperature in the conventional battery drive type electronic device. The figure which shows the output voltage and output current of the said battery at the time of power activation at the time of low temperature in the conventional battery drive type electronic device.

  A battery-driven electronic device according to an embodiment of the present invention will be described below with reference to the drawings. Here, the same parts as those of the conventional apparatus shown in FIG.

  A battery-driven electronic device 1 according to the present invention includes a control device 7 that is activated via a power switch 6 that is turned on when the electronic device body 3 is turned on, as schematically shown in FIG. Prepare. The control device 7 includes a microprocessor (MPU) provided with a temperature sensor (T) 8 that measures the environmental temperature of the battery 2, for example. The control device 7 plays a role of controlling on / off of the switches 4a, 4b and 4c in accordance with the environmental temperature of the battery 2 detected via the temperature sensor 8 when the power is turned on.

  Incidentally, the power switch 6 is composed of, for example, a mechanical switch such as a relay that is turned on when the electronic apparatus body 3 is turned on. Each of the switches 4a, 4b, and 4c is a semiconductor such as a MOS-FET, for example. It consists of a switch element. The on / off control of the switches 4a, 4b, 4c by the control device 7 is individually and electronically executed via the switch drive circuit 9 under the control of the control device 7.

  Here, basically, when the electronic device body 3 is turned on, the control device 7 first controls the switches 4a, 4b, and 4c to turn on and off, respectively, and pulse-charges the input capacitors 5a, 5b, and 5c. Thereafter, each of the switches 4a, 4b, 4c is continuously turned on. In particular, the control device 7 changes the on / off control width or the on / off control period of the switches 4a, 4b, 4c according to the environmental temperature of the battery 2 when the electronic device body 3 is powered on. By controlling the on / off control width or on / off control period of the switches 4a, 4b, 4c when the power is turned on, the input capacitors 5a, 5b, 5c are turned off from the battery 2 when the power is turned on, as will be described later. The inrush current flowing into each of the batteries 2 is suppressed to be equal to or less than the allowable current of the battery 2.

  That is, when the environmental temperature of the battery 2 at the time of power-on is within a normal temperature range that guarantees the performance of the battery 2, the input from the battery 2 is accompanied by the on / off control of the switches 4a, 4b, 4c. For example, as shown in FIG. 2A, a predetermined battery voltage is applied to the capacitors 5a, 5b, and 5c in a pulsed manner. The current (inrush current) flowing into the input capacitors 5a, 5b, 5c with the pulsed application of a predetermined battery voltage from the battery 2 to the input capacitors 5a, 5b, 5c is, for example, FIG. As shown in FIG.

  In particular, the peak value of the inrush current that flows into the input capacitors 5a, 5b, and 5c when the power is turned on is suppressed to a low level in accordance with the on / off control of the switches 4a, 4b, and 4c. The change in the current flowing into the input capacitors 5a, 5b, 5c gradually converges as the charging voltage rises due to pulse charging of the input capacitors 5a, 5b, 5c, and is constant according to the load of the electronic device body 3. Stable to current.

  Incidentally, the on / off control of the switches 4a, 4b, 4c is such that when the environmental temperature of the battery 2 is within the normal temperature range, the magnitude of the inrush current flowing into the input capacitors 5a, 5b, 5c is It is executed as long as the allowable current that guarantees the performance is not exceeded. As described above, when the current flowing from the battery 2 into the input capacitors 5a, 5b, 5c is stabilized, the on / off control of the switches 4a, 4b, 4c is stopped, and the switches 4a, 4b, 4c are continuously connected. And turn it on. As a result, the battery voltage from the battery 2 smoothed by the input capacitors 5a, 5b, and 5c is stably supplied to the electronic device body 3.

  When the environmental temperature of the battery 2 is lower than the normal temperature range, it cannot be denied that the allowable current of the battery 2 is lower than the allowable current at the normal temperature. Therefore, when the switches 4a, 4b, and 4c are controlled to be turned on / off at the time of turning on the power, the inrush current flowing into the input capacitors 5a, 5b, and 5c has an allowable current that guarantees the performance of the battery 2. There is a risk of exceeding. In order to avoid such problems, in the control device 7, when the environmental temperature of the battery 2 when the power is turned on is lower than the normal temperature range, the on / off control width of the switches 4a, 4b, 4c, or the switch 4a , 4b, 4c are changed to control the inrush current flowing from the battery 2 into the input capacitors 5a, 5b, 5c below the allowable current of the battery 2 by changing the on / off control period.

  Specifically, when the environmental temperature of the battery 2 at the time of power-on is low, the control device 7 makes the on width Ton of the switches 4a, 4b, 4c narrower than that at room temperature as shown in FIG. In addition, the on / off control period T of the switches 4a, 4b, 4c is set wider than that at room temperature. As a result of this change in on / off control, as shown in FIG. 3 (b), the switch 4a, 4b, 4c enters the capacitors 5a, 5b, 5c from the battery 2 within one on / off cycle. The current is reduced so that the inrush current is smaller than the allowable current of the battery 2 at the low temperature.

  Here, since the amount of current supplied from the battery 2 to the input capacitors 5a, 5b, 5c is reduced in one on / off cycle of the switches 4a, 4b, 4c, the switches 4a, 4b, 4c, The number of repetitions of 4c on / off is increased. Then, after the charging voltages of the input capacitors 5a, 5b, 5c converge to a predetermined value, the switches 4a, 4b, 4c are continuously turned on. As a result, the inrush current to the input capacitors 5a, 5b, 5c is suppressed even at low temperatures, and the battery voltage smoothed by the input capacitors 5a, 5b, 5c is stably supplied to the electronic device body 3. It becomes possible.

  As described above, in the battery-driven electronic device 1 according to the present invention, when the electronic device main body 3 is turned on, the switches 4a, 4b, and 4c are controlled to be turned on / off to control the input capacitors 5a and 5b from the battery 2. , 5c is suppressed, and after the input capacitors 5a, 5b, 5c are sufficiently charged, the switches 4a, 4b, 4c are continuously turned on. Therefore, the battery voltage supplied from the battery 2 via the input capacitors 5a, 5b, 5c can be stably supplied to the electronic device body 3.

  In addition, when the environmental temperature of the battery 2 at the time of power-on is lower than the normal temperature range that guarantees the performance of the battery 2, the on / off control width or the on / off control period of the switches 4a, 4b, 4c is set. In this way, the inrush current flowing from the battery 2 into the input capacitors 5a, 5b, 5c when the power is turned on is suppressed so that the allowable current of the battery 2 that has decreased at low temperatures is not exceeded. Therefore, even when the electronic device main body 3 is turned on at a low temperature, the inrush current flowing into the input capacitors 5a, 5b, 5c can be suppressed to the allowable current of the battery 2 or less. It becomes possible to prevent the performance deterioration of the battery 2 due to the above. Therefore, practically great effects such as being able to operate the electronic device main body 3 by fully utilizing the performance of the battery 2 are achieved.

  The present invention is not limited to the embodiment described above. Here, each of the plurality of switches 4a, 4b, 4c has been described as being collectively turned on / off. For example, the switches 4a, 4b, 4c are controlled according to the environmental temperature of the battery 2 when the power is turned on. A time difference may be given to the start timing of the on / off control. For example, in the case where the environmental temperature of the battery 2 is low and the performance (for example, battery capacity) of the battery 2 cannot be sufficiently extracted along with this, first, only the measurement unit (measurement circuit) 3a is used. The switches 4a, 4b, 4c are supplied so that the power from the battery 2 is supplied, and then the power from the battery 2 is sequentially supplied to the alarm unit (buzzer) 3c and further to the display unit (LCD) 3b. It is also possible to control the start timing of the on / off control.

  In addition, the timing for turning on the plurality of switches 4a, 4b, and 4c is shifted to avoid the inrush current from flowing simultaneously from the battery 2 to the input capacitors 5a, 5b, and 5c. It is also useful to keep the inrush current flowing out of the battery 2 lower than its allowable current. The electronic device body 3 can be turned on manually, but the electronic device body 3 is turned on at predetermined intervals, for example, under timer management so as to operate the electronic device body 3 intermittently. Of course, it is also possible to perform. In this way, it is possible to operate the battery-driven electronic device 1 over a long period of time by effectively using the battery capacity of the battery 2. In addition, the present invention can be variously modified and implemented without departing from the scope of the invention.

1 Battery Driven Electronic Device 2 Battery (Battery)
3 Electronic device body 3a Measurement unit (measurement circuit)
3b Display (LCD)
3c Alarm section (buzzer)
4a, 4b, 4c Power switch 5a, 5b, 5c Input capacitor 6 Power switch 7 Controller 8 Temperature sensor 9 Switch drive circuit

Claims (6)

Battery,
An electronic device body that operates using this battery as a power source;
A switch for turning on / off power supply from the battery to the electronic device main body;
An input capacitor that is provided in a power input portion of the electronic device main body and smoothes a voltage supplied from the battery via the switch to be supplied to the electronic device main body,
The battery is controlled by turning on / off the switch when the electronic device is turned on, and the on / off control width or on / off control period of the switch is changed according to the environmental temperature of the battery at the time of turning on the power. And a control device for continuously turning on the switch and supplying a predetermined battery voltage from the battery to the input capacitor after suppressing an inrush current flowing into the input capacitor from below the allowable current of the battery. A battery-driven electronic device. The control device includes a temperature sensor that measures an environmental temperature of the battery,
When the environmental temperature of the battery is lower than a normal temperature range that guarantees the performance of the battery, the ON width of the switch is reduced to smooth the waveform of the current supplied from the battery to the input capacitor. Item 2. The battery-driven electronic device according to Item 1.   The electronic device main body includes a measuring unit that measures environmental information in an installation environment of the battery-driven electronic device, a display unit that displays environmental information obtained by the measuring unit, and environmental information obtained by the measuring unit. The battery-driven electronic device according to claim 1, further comprising an alarm unit that issues an alarm when the installation environment is abnormal.   4. The measurement unit, the display unit, and the alarm unit in the electronic device main body operate by receiving electric power supplied from the battery through a plurality of switches provided in parallel. A battery-driven electronic device according to claim 1.   The battery-driven type according to claim 4, wherein the control device individually controls on / off of the plurality of switches to control power supply to the measurement unit, the display unit, and the alarm unit. Electronic equipment.   The said control apparatus starts the electric power supply to the said measurement part, the said display part, and the said alarm part via a said some switch in predetermined order at the time of power activation of the said electronic apparatus main body. Battery powered electronic device.