JPH0743439A - Battery remaining computing apparatus - Google Patents

Abstract

PURPOSE:To generate a warning when a predetermined time is reached by computing time at which a power source voltage lowers to a reference voltage from a drop in voltage of a battery power source after a fixed time measured passes and a difference between a power source voltage and the reference voltage after the passage of a fixed time. CONSTITUTION:System control circuit controls the measuring, computing and warning of a power source voltage. First, the counting of time is started after the passage of a fixed time is checked and a battery voltage is inputted to measure a voltage by A/D conversion thereof. The power source voltage at this moment is compared with a reference voltage and when it is larger, a power reduction flag is checked. When the flag is H, a returning is made or when it is L, the present voltage drop is calculated from the preceding voltage and a difference between the present voltage and a power source OFF voltage is calculated as remaining voltage. Then, a remaining time is calculated from the remaining voltage and the voltage drop and when the remaining time is smaller than a scheduled alarm time, an alarm display demand and a battery voltage reduction flag are set to complete a processing. Thus, time is determined accurately until the operation of a battery is disabled thereby enabling the keeping of usable time constant after a warning.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a battery residual amount calculating device in a device using a battery.

[0002]

2. Description of the Related Art Conventionally, a battery low voltage warning in a device or the like using a battery should be used regardless of how the device is used; Attempts have been made to detect that the battery voltage has dropped below a certain value.

[0003]

However, in the above-mentioned device, the time from when the warning is issued to when the device becomes unusable varies depending on how the device is used, and it is not possible to grasp the proper replacement time of the battery. On the other hand, if the battery is replaced at the same time as the warning is issued, it is uneconomical because the capacity of the battery cannot be fully used, and the frequency of replacement of the battery is high and it is very difficult to use.

The present invention has been made in view of these problems, and a battery according to the operation mode of the apparatus is used.
It is an object of the present invention to provide a battery-remaining amount calculation device capable of grasping the usable time of a battery.

[0005]

In order to achieve the above object, a battery-remaining amount calculating device according to the present invention is a battery at a predetermined time point and at a time point when a certain time has elapsed from the battery time point.
Power supply voltage measuring means for measuring the power supply voltage of the battery, and the voltage drop at the fixed time and the difference between the power supply voltage of the battery and the reference voltage at the time when the fixed time has elapsed based on the measured value, and the value of the voltage drop and the value And a calculation unit that calculates a time until the power supply voltage drops to the reference voltage based on the difference between the power supply voltage of the battery and the reference voltage at the time when a fixed time has elapsed.

A warning means may be provided for issuing a predetermined warning when the time until the power supply voltage drops to the reference voltage matches a predetermined time. Further, the predetermined time may be the time from the present time to the inoperable time when the battery-powered device is used under the same conditions.

[0007]

According to the battery-remaining amount calculation device of the present invention, the power supply voltage measuring means measures the power supply voltage of the battery at a predetermined time point and at a time point when a fixed time has elapsed from the predetermined time point, and the calculation means outputs the measured value. Based on the voltage drop at the fixed time and the difference between the power supply voltage of the battery and the reference voltage at the time when the fixed time has elapsed, the value of the voltage drop and the battery at the time when the fixed time has elapsed
The time until the power supply voltage drops to the reference voltage is calculated based on the difference between the power supply voltage and the reference voltage.

If a warning means is provided,
A predetermined warning is given when the time until the power supply voltage drops to the reference voltage matches a predetermined time. Also,
If the device is continuously used under the same condition after the warning, the device becomes inoperable after the predetermined time has elapsed if the predetermined time is the predetermined time.

[0009]

Embodiments of the present invention will now be described with reference to the drawings. FIG. 1 is a block diagram showing an example of an information reproducing apparatus to which a battery-remaining amount calculating apparatus according to the present invention is applied, which is an example of application to a VTR. In this apparatus, a video signal input from the input terminal 6 at the time of recording is subjected to predetermined processing by a known circuit such as the video signal input circuit 5 and the recording signal processing circuit 4, and the terminal 3a of the switch 3 and the magnetic head 2 are processed.
Is recorded on the magnetic tape 1 via the.

At the time of reproduction, the reproduction signal read from the magnetic tape 1 through the magnetic head 2 passes through the terminal 3b of the switch 3 and the reproduction signal processing circuit 7 and the reproduction signal detection circuit 1
Sent to 1. The reproduction signal subjected to the predetermined reproduction processing in the reproduction signal processing circuit 7 is mixed with the character signal generated from the character signal generation circuit 12 in the mixing circuit 8 and output to the output terminal 10 via the video signal output circuit 9. It is transmitted as a video signal.

The reproduction signal detection circuit 11 outputs a signal for discriminating the recorded portion and the unrecorded portion of the video signal, and sends the detection signal to the system control circuit 13. The operation unit 18 is used to instruct various operations such as reproduction, fast-forward, and rewind by operation, and outputs operation signals to the system controller.
To the circuit 13. System control circuit 13
Is supplied with power from a battery 22 via a power supply voltage interface circuit 21, and is supplied with a backup power supply 20 for operating an internal clock, as well as with E ² PRO.
Various adjustment data stored in M19 is supplied.

The system control circuit 13 is a capstan motor drive circuit 1 based on the detected FG signal.
Drive the capstan motor 15 via 4,
Cylinder motor drive circuit 16 based on FG and PG signals
Cylinder motor 17 is driven via. FIG. 2 shows a processing procedure of the system control circuit 13 in FIG.

After the reset start and after the initial setting process (step S1), the adjustment mode in the manufacturing process is set.
It is determined whether or not it is the mode (step S2). If it is the adjustment mode, the adjustment process is performed (step S3), and the process returns to the step S2. If it is not the adjustment mode, the OSD (On Screen Driver) for displaying characters on the monitor.
After performing the automatic adjustment process (step S4), the normal main program is started (step S5).

First, it is determined whether or not the power is off (step S6). If not, the OSD display processing (step S7) and the clock display processing when the power is on (step S).
8), operation key input processing (step S9), various sensor input processing (step S10), and mode change processing (step S11) such as reproduction, fast forward, rewind, etc., and then a predetermined time count. After the lapse of time, the main processing such as external input is awaited to be completed (step S12), and when the processing is completed, the processing returns to step S6.

In step S6, if the power is off, the power off process (step S13) and power off
After the clock processing at F o'clock is executed (step S14), the process returns to step S6. Next, the battery-remaining amount warning processing according to the embodiment of the present invention will be described. In the present embodiment, by predicting the time when the battery-voltage reaches the operation stop voltage of the device, the warning generation time related to the battery-remaining amount is made constant, and the user can easily grasp the usable time from the warning generation. It also improves usability.

By the way, in a conventional VTR using a battery as a power source, a warning is issued when the battery voltage reaches a certain constant voltage, and when the voltage further decreases, the operation is automatically stopped, and there is a function when the voltage decreases. It prevents operational troubles. For example, when the current consumption is small as shown in FIG. 3 (A), for example, a time t after 5 minutes has elapsed from the time t21 when the battery voltage has dropped to the alarm voltage.
Turn off the power supply voltage to 22. Further, as shown in FIG. 7B, when the current consumption is large, the power supply voltage is turned off at a time point t24 when, for example, 3 minutes have elapsed from the time point t23 when the voltage dropped to the alarm voltage.

Therefore, in this embodiment, the slope of the decreasing curve with the use time of the battery voltage is set as ΔVBATT / Δtx = (VB2-VB1) / (tx2-Ttx1) as shown in FIG. Then, the remaining time tOFF until reaching the power-off voltage (VOFF) is calculated as tOFF = (VOFF-VB2) / (ΔVBATT / Δtx). The time from the start of the operation to the stop of the operation is made constant regardless of the operation mode, so that the user can easily grasp the available time after the warning is issued.

FIG. 5 is a diagram for explaining the operation in the case where the battery voltage drop curve is peculiar (when the Ni-Cd battery is used). As shown in the figure, as can be understood from the lowering characteristics of the case where the current consumption is low and the case where the current consumption is high, there are linear characteristics of slope 1 and slope 2 up to the power-off voltage. Below the vicinity, it drops sharply. Therefore, when obtaining tOFF, the correction value t2 = tα1 = tα2 is considered, and tOFF = tOFF-tα is obtained.

Next, the battery-voltage detection processing operation procedure of this embodiment will be described with reference to FIG. These processes are performed by the system control circuit 13 which constitutes a power supply voltage measuring means, a calculating means, and a warning means.
As shown in FIG. 2B, it is executed in the process of various sensors in FIG. 2 (step S151). Referring to FIG. 3A, first, it is judged whether or not Δt time has elapsed (step S131), and if it has not elapsed, a return is made, and if it has elapsed, the measurement of Δt is started ( Step S13
2) Then, the battery voltage is A / D converted and input to obtain VB (step S133). Next, VB is the reference voltage V
It is determined whether it is larger than OFF (step S134),
If it is larger, check the power reduction flag, that is, already
It is confirmed whether or not it is in motion (step S13
5) If it is "H", it is a return, and if it is "L", the voltage drop of the previous data (VBB) -current data (VB) ΔVBA
TT (step S136), this time data (VB) -V
OFF is set to the residual voltage Vz (step S137). Then, the remaining time is calculated from Vz and ΔVBATT (step S138), and the remaining time is compared with the alarm time (for example, 5 minutes) which is a predetermined time (step S138).
139), if the remaining time is greater than the alarm time, return
Otherwise, an alarm display request is set, and the battery-reduction voltage flag is set to "H" (step S
140) and the process ends. In step S134, if VB is not larger than VOFF, that is, if the power supply is too low, a mode stop request and power supply OF are made.
The F request is set (step S141), and the process ends.

As described above, according to the battery-remaining amount computing device of the present embodiment, it is possible to relatively accurately ascertain the time until the device becomes inoperable according to the operation mode of the device driven by the battery. . In addition, since the time from the warning until the operation is disabled can be made constant, the usability is improved.

[0021]

According to the present invention, since the usable time of the battery according to the operation mode of the apparatus can be known relatively accurately, the usability is improved. Further, the usability is further improved by making the time from the warning to the time when the voltage drops to the reference voltage at which the device becomes inoperable constant.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an example of an information reproducing device to which a battery-remaining amount calculating device according to the present invention is applied.

FIG. 2 is a diagram showing a processing procedure of a system control circuit 13 in FIG.

FIG. 3 is a diagram for explaining a battery-remaining amount warning process according to the present embodiment.

FIG. 4 is a diagram for explaining a battery-remaining amount warning process according to the present embodiment.

FIG. 5 is a diagram for explaining a battery-remaining amount warning process according to the present embodiment.

6 is a diagram showing a battery-voltage detection processing operation procedure shown in FIG. 5;

[Explanation of symbols]

 13 system control circuit 18 operation unit 21 power supply voltage interface circuit 22 battery

Claims (3)

[Claims] 1. A power supply voltage measuring means for measuring a power supply voltage of a battery at a predetermined time point and a time point after a predetermined time has passed, and a voltage drop at the predetermined time point based on the measured value and a battery at a time point when the predetermined time has passed. The difference between the power supply voltage and the reference voltage, and the time until the power supply voltage drops to the reference voltage based on the value of the voltage drop and the difference between the power supply voltage of the battery and the reference voltage at the time when the fixed time has elapsed. A battery-remaining amount computing device comprising: a computing unit for computing. 2. The battery according to claim 1, further comprising warning means for issuing a predetermined warning when the time until the power supply voltage drops to the reference voltage matches a predetermined time. Remaining amount calculation device. 3. The battery-remaining amount according to claim 2, wherein the predetermined time is a time from a current time point to a non-operation time point when the device driven by the battery is used under the same conditions. Arithmetic unit.