JPH03182176A - Battery residual quantity calculation device - Google Patents

Abstract

PURPOSE:To estimate the residual quantity with high accuracy by obtaining the residual quantity in response to the operating time even when there is no change in the operating state. CONSTITUTION:The device consists of a camera section 30, a VTR section 32, a battery 34, switches 36, 38, a system control circuit 40, an indicator 42, a measurement circuit 44, an arithmetic circuit 46 and a display device 48. The means detecting the residual quantity of the power battery using a change in the electric characteristic attended with the change in the operating mode and the means using the operating time to detect the residual quantity of the battery are used selectively. Thus, the battery residual quantity arithmetic device able to estimate the residual quantity with high accuracy is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a remaining battery amount calculating device for estimating the remaining battery amount m of a device using a battery as a power source by calculation.

[Prior Art] This type of remaining battery power calculation device is a device that integrates the power consumption according to the usage state according to the usage time, and subtracts this from the power amount of a full charge to estimate the remaining power. It has been known. FIG. 6 shows an example of a configuration applied to a camera-integrated video tape recorder (so-called camcorder). 10 is a camera section, 12 is a VTR section, 14 is a camera section 10 and V
16 is a system control circuit that controls the operation of the camera section 10 and the VTR section 12; 18 is an instruction section that inputs predetermined instructions to the system control circuit 16; 20 is a system control circuit 16 A display section 22 that displays the operating state of the device is a counter that totals the power consumption. 24 is a TV device that displays the reproduced video from the camera section 10 or the VTR section 12.

For example, in the camcorder shown in FIG. 6, in the photographic recording mode, the camera section 10 and the VTR section 12 are both in operation, and the current consumption is 2.4A, and in the playback mode, the camera section 10 and the VTR section 12 are both in operation.
0 stops, only the VTR section 12 operates, and the current consumption is 1.88.

When the operator inputs an instruction for the photographing/recording mode using the instruction section 18, power is supplied from the battery 14 to the camera section 10 and/or the VTR section 12, and operation according to the specified operation mode is started. At the same time, the counter 22 accumulates count values per unit time according to each operation mode.

That is, a count coefficient is set according to the power consumption of each operation mode, and the system control circuit 16 controls the counter 22 according to the operation mode.

In the above example, the current consumption is 2.4 A and 1.8 A in the shooting/recording mode and the playback mode, respectively, so the respective count coefficients are set to "4" and "3". The counter 22 counts up by 4 per second in the photographic recording mode, and counts up by 3 per second in the playback mode.

The system control circuit 16 includes a camera section 10 and a VTR section 1.
Each time the main operating section 13 consisting of the main operating section 2 stops or interrupts its operation, the held value of the counter 22 is taken in, the power consumption of the battery 14 is calculated from this held value, and the remaining amount is displayed on the display section 20.

The counter 22 is reset when the battery 14 is replaced.

By dividing the remaining amount obtained in this way by the current consumption in the shooting/recording mode, the available recording time for shooting can be determined and displayed.

[Problems to be Solved by the Invention] However, in the above conventional example, errors in power consumption due to differences in usage status and detailed mode settings accumulate,
It is not possible to obtain high accuracy.

Furthermore, in the case of a partially used battery, there is a drawback that the remaining capacity cannot be estimated at all.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a battery remaining amount calculation device that can estimate the remaining amount with higher accuracy.

[Means for Solving the Problems] A remaining battery power calculation device according to the present invention includes a means for detecting the remaining power of a power supply battery using a change in electrical characteristics accompanying a change in an operating mode, and a means for detecting a remaining power of a power supply battery using a change in electrical characteristics accompanying a change in an operating mode. and means for detecting the remaining amount of the battery, and these means are selectively used.

[Operation] With the above means, even when there is no change in the operating state, the remaining amount can be determined according to the operating time. Furthermore, even if a so-called used battery is used for the first time, it becomes possible to estimate the remaining battery level with high accuracy.

[Example] Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram of an embodiment of the present invention. 3
0 is a camera section, 32 is a VTR section, 34 is a battery that supplies power to the camera section 30 and VTRTa205 through switches 36 and 38, and 40 is a camera section 30 and VTRTa2
05 and a system RII control circuit that controls the opening and closing of switches 36 and 38; 42 is an instruction device for manually issuing predetermined operation instructions to the system control circuit 40; 44 is a battery 3;
4 is a measurement circuit for measuring the output voltage, 46 is a measurement circuit 44
A calculation circuit 48 calculates the remaining capacity of the battery 34 based on the output of the system control circuit 40 and an operation signal from the system control circuit 40.
This is a display device that displays the remaining battery power calculated in step 6.

In this example, two types of loads are selectively connected to the battery 34 to be measured, and the respective internal electromotive voltages (open circuit voltages) are measured. The remaining capacity of the battery 34 is estimated by comparing with the line. That is, the relationship between the internal resistance R1 of the battery 34, the internal electromotive voltage v1, the output voltage V, and the output current I in each depleted state is measured using the circuit shown in FIG. rl+r* is the load resistance for measurement, 50
is a switch for selecting load resistance rl+r*. r.

is the load resistance in the recording mode, for example, and r is the load resistance in other modes. The current when the switch 50 is connected to the load r is expressed as v8, and the voltage drop due to the load r is expressed as v8.
, the current when the switch 50 is connected to the load r is ■1
, load r! Letting the voltage drop due to v be R= (Vt-Vl)/(II-11)
(1), and if the output voltage of the battery 34 is v1 and the output current is I, then v = V + IR (2), so v = V + I (Vt L) / (It I
t) (3).

Since the internal electromotive voltage V is not affected much by the internal resistance R, it has relatively little fluctuation and corresponds well to the remaining battery capacity.

The relationship between the internal electromotive voltage V and the remaining battery capacity [111 line is determined in advance, and the appropriate timing during use is determined from the above T+, 1*,
V1. By measuring Vx, V, and I and applying the calculated internal electromotive voltage V to the relational curve, the battery remaining m at that point can be estimated.

- As an example, assuming continuous use in the recording mode of camera photography, a case will be explained in more detail using an example in which the remaining battery level is displayed as a value T converted into usable time.

For each battery used in the camcorder, a characteristic curve showing the correspondence between the internal electromotive voltage V and the usable time T (remaining ff1) is measured. In this case, to increase accuracy,
The above characteristic curve is determined by averaging the measured values of a plurality of batteries of the same type or types that may be used. Fifth
The figure shows a characteristic curve for a Ni-Cd secondary battery. The data of this characteristic curve is stored in the memory of the arithmetic circuit 46.

Note that if it is desired to estimate the remaining amount value in another operation mode, the above T may be multiplied by a coefficient k corresponding to the current consumption.

Next, the processing procedure for displaying the remaining amount will be explained with reference to FIGS. 3 and 4. Start by turning on the power, first set the operation mode (M) to stop mode (Sl), first,
The measuring circuit 44 measures the output voltage V of the battery 34, and the arithmetic circuit 46 determines the output current I corresponding to the stop mode (S2).

Next, enter the recording pause state (S3), measure the output voltage vf of the battery 34 with the measuring circuit 44, and determine the current value corresponding to the recording mode! , is determined by the arithmetic circuit 46 (S4). and,
V is determined from equation (3), and residual fltT is determined from the characteristic curve (S5).

Check whether the mode has been changed (Sl), and if the mode has been changed, reset the timer (510); if not, start counting the timer (S7), and repeat 86 to 8 until the predetermined time elapses. It circulates (S8). When a predetermined period of time has elapsed, flag F is set to 1 and the timer is reset (S10).

Flag F is a flag indicating whether to perform integration calculation processing or recalculation processing, and when the same processing continues for a predetermined time, F=1 and the process proceeds to integration calculation processing, which will be described later.
If the mode remains unchanged, the flag F remains 0 and the process proceeds to recalculation processing.

After resetting the timer (S10), check the mode.
l), according to each mode (stop, record, record pause), set the value obtained by converting the consumption value to the remaining amount in the variable t.S1
2, 13.14), current values 1a, Ib, depending on the mode
Ic is set to variable ■ (S15, 16.17). Then, according to flag F (818), if F=1 (accumulation calculation process), first, flag F is returned to O (519),
The consumed amount t is subtracted from the current remaining amount T (520), and the latest remaining amount T is displayed (S21). In the case of F=0 (recalculation process) (S18), the output voltage V after the mode change is measured (522), and the latest remaining amount T is calculated (S2
3). Here, we substitute into equation (3).

vl and 1. ,V, are exchanged. Similarly, in the T calculation step, the subscripts "1" and "2" are exchanged as needed. After S23, the calculated remaining amount T is displayed (S21).

After S21, the process returns to Sl, and the steps from S6 onwards are executed cyclically.

If there is a mode change (Sl), by forcibly resetting the timer (S7), the recalculated value will be prioritized as the displayed value of the remaining amount.

FIG. 4 illustrates the mode transition during actual operation and the accompanying changes in the timer/counter and the displayed remaining amount value.

The upper row shows the mode transition, the lower row shows the timing of timer/counter reset and overflow, and the graph below that shows the time change of the displayed remaining amount T. The step t2 in the remaining amount value T is a representative subtraction value during recording, and t3 is a representative subtraction value during recording pause. It can be seen that subtraction is performed within the same mode period as time passes.

[Effects of the Invention] As can be easily understood from the above explanation, according to the present invention, not only can the remaining amount be estimated with high accuracy even when switching modes, but also when the battery is used continuously without switching modes. The estimated remaining amount value can be appropriately estimated.

[Brief explanation of drawings]

Fig. 1 is a block diagram of the configuration of an embodiment of the present invention, Fig. 2 is a circuit for explaining the operating principle of this embodiment, Fig. 3 is an operation flowchart of this embodiment, and Fig. 4 is a timing diagram for explaining the operation.・The chart, FIG. 5 is a characteristic concave line of the internal electromotive voltage of the battery versus the remaining capacity, and FIG. 6 is a block diagram of the configuration of a conventional example.

Claims (1)

[Claims] A means for detecting the remaining power of the power supply battery using a change in electrical characteristics accompanying a change in the operating mode, and a means for detecting the remaining power of the battery using the operating time, and these means can be selectively operated. A battery remaining amount calculation device characterized in that it is used.