JPH02146936A - Power source equipment, power source system and residual amount display for secondary cell power source - Google Patents

Abstract

PURPOSE:To inform accurate residual amount by obtaining the residual amount of a cell based on first data concerning to the amount of charging power and second data concerning to the amount of consumed power. CONSTITUTION:The power source system comprises a charging power measuring circuit 311 for obtaining first data concerning to the amount of charging power to be fed from a charger 300 to a secondary cell 201, a power consumption measuring circuit 111 for obtaining second data concerning to the amount of consumed power to be fed from the secondary cell 201 to the load circuit 110 in a body 100, a residual amount indicator 113 for the secondary cell 201, and a memory 202 for receiving/storing the first and second data and feeding the stored data to an indicator 113. The indicator 113 obtains data concerning to the residual amount of the secondary cell 201 based on the first and second data received from the memory 202. By such arrangement, residual amount of the cell 201 can be informed accurately.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a power supply device, and particularly to a power supply device detachable from a portable device, a power supply system, and a secondary battery power remaining amount display device.

[Prior Art] When a power source is required for portable equipment such as a camera-integrated VTR, still camera, or headphone stereo,
A so-called secondary battery such as a nickel-cadmium battery is often used as a power source.

According to a conventional removable power supply device, for example, a strobe power supply device, the number of times the strobe operates or the power value during operation is reduced to A.
/D conversion and calculate the power consumption from this digital value. This power consumption is integrated to obtain an integrated power value. If a primary battery is used in the strobe device, the remaining number of flashes is displayed based on the integrated power value.

[Problems to be solved by the invention] Secondary batteries and lithium batteries, which have recently become widely used, have improved depolarization effects and there is no significant change in internal resistance during nearly 80% of the discharge cycle. Although there is little change in the terminal voltage, the internal resistance rapidly increases at the end of discharge, and the terminal voltage decreases. When the characteristics of such a battery are compared with those of a manganese battery, the discharge characteristics are shown in FIG. In the figure, A shows the discharge characteristics of a manganese battery, and B shows the discharge characteristics of a nickel-cadmium secondary battery. As can be seen from this figure, it is extremely difficult to determine the remaining battery capacity of a secondary battery based on the terminal voltage.

In addition, even if the battery is charged, if the charging time is insufficient and the battery is not at full capacity, there is no way to know how much of the battery has been charged, and how much the device will charge if the battery is used. It was not possible to know whether it would be possible to use it for a long time.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a power supply device that can accurately display the remaining capacity of a power supply that is detachable from an electronic device.

Means and operation for solving problem E] According to the present invention, the charging power amount of the battery is measured, the measured value is memorized, and the remaining capacity is determined by subtracting the measured value of the discharged power amount from this measured value. , a power supply device that accurately displays remaining capacity is provided.

According to the present invention, in a power supply device including a secondary battery that is detachable from the device main body, a switch is provided that can selectively switch the power supply to the load circuit on the device main body side and the charging power supply to the rainbow battery. A power measurement circuit is provided that outputs first data regarding the amount of charging power used to charge the next battery and second data regarding the amount of power consumed by the load circuit.

The power supply device has a memory that stores first and second data. The remaining battery power is determined based on the first and second data in the memory, and the remaining power is displayed.

The memory is composed of a nonvolatile storage element that can retain data even when completely discharged.

A device main body including a load circuit that operates by receiving power from a power supply, a power supply device including a secondary battery that is detachable from the device main body, and the device main body or power supply device for supplying charging power to the secondary battery. In a power supply system consisting of a charging device built in or separately installed, a charging energy measuring circuit that obtains first data regarding the amount of charging energy from the charging device to the secondary battery, and a charging energy measuring circuit that obtains first data regarding the amount of charging energy from the charging device to the device itself. a power consumption measurement circuit that obtains second data regarding the amount of power consumption supplied to the load circuit; and a battery remaining amount display that is provided in the main body of the device and displays the remaining battery amount of the secondary battery of the attached power supply device. A power supply system is provided that includes a device and a memory provided in the power supply device for receiving and storing first data and second data and transmitting the stored data to a remaining battery power display device. The amount display device processes the first data and second data received from the memory based on a predetermined algorithm, obtains data regarding the remaining amount of the secondary battery of the power supply device, and displays information corresponding to this data. do.

The main body of the device is provided with a remaining battery power display device that displays the remaining battery power of the secondary battery of the installed power supply device, and the power supply device has a
A memory is provided for receiving and storing the first data and the second data and further transmitting the stored data to the battery level display device. The battery remaining amount display device processes the first data and second data read from the memory based on a predetermined algorithm to obtain data regarding the remaining amount of the secondary battery of the power supply device, and based on this data, the It also displays information about the remaining amount.

When the load circuit of the device body consumes a predetermined amount of power from the power supply when it performs a predetermined operation, the power consumption measurement circuit calculates the amount of power consumption from the number of times or time that the device main body performs the predetermined operation. do.

The power supply system further includes a temperature detection member, and the charging power amount measuring circuit corrects the first data to compensate for the temperature characteristics of the secondary battery during charging based on the temperature data from the temperature detection member during charging.

The power supply system further includes a temperature detection member, and the power consumption measuring circuit corrects the second data based on the temperature data from the temperature detection member at the time of power consumption so as to compensate for the temperature characteristics at the time of discharge of the secondary battery.

The power supply system further includes a temperature detection member, and based on the detected temperature data from the temperature detection member, the power consumption m1Jj constant circuit has a second circuit so as to compensate for the temperature characteristics of the power consumption of the load circuit.
Correct the data.

A secondary battery that supplies power to the load circuit of the main body of the device, a charging power source that supplies charging current to the secondary battery, and a first charge energy amount that is obtained by integrating the charging current from the charging power source to the secondary battery over time. a charging power amount measurement circuit that obtains data;
a discharged power amount measuring circuit that obtains second data regarding the amount of discharged power as consumed power supplied from the next battery to the load circuit; a memory that stores the first data and the second data; a remaining battery capacity calculation circuit that reads the data and the second data and calculates a value related to the remaining battery capacity of the secondary battery from the relationship between each data, and displays a value related to the remaining battery capacity calculated by the remaining battery capacity calculation circuit. A remaining power display device for a secondary power source is provided.

(Embodiment) According to the present invention, as shown in FIG. 1, a device main body 100 such as a camera-integrated VTR is coupled to a power supply device 100, and a charging device 300 is built into the device main body 100. This charging device 300 may be provided outside the device main body.

A secondary battery 201 is housed within the power supply device 200 .

This secondary battery is charged when the selector switch 115 is switched to the b side. The charging device 300 has a power supply circuit 31 connected to a commercial power supply via a power connector 312.
0, and one output terminal of this power supply circuit 310 is connected to a contact point of the changeover switch 115 via a charging power measurement circuit 311 and a terminal 321. The other output terminal of power supply circuit 310 is connected to terminal 222 via terminal 322.

Therefore, when the changeover switch 115 is switched to the contact position, the secondary battery 201 is charged by the output voltage of the power supply circuit 310.

When charging the secondary battery 201, the charging power amount measuring circuit 311 measures the charging power amount, and the measured value is sent to the control circuit 1 of the device main body 100 via the control circuit 312.
Transferred to 12. The control circuit 112 transmits data regarding the amount of charging power to the terminal 2 at regular intervals or at the end of charging.
23 to the rewritable memory 202 in the power supply device 200. When data writing is finished,
The changeover switch 115 is switched to contact a.

Next, when the device main body 100 is operated by the user by operating an operating member (not shown), power is supplied from the battery 201 to the load circuit 110, and the load circuit 110 is activated. The power supplied from the battery 201 to the load circuit 110 is calculated by the power consumption measurement circuit 111 in total 11111. Data regarding this measured value is written to the memory 202 via the control circuit 112 at fixed time intervals or at the end of the operation.

While the device main body 100 is in use or the power supply device 200 is being charged, the control circuit 112 reads data regarding the charging power amount and the power consumption amount from the memory 202, and displays the remaining capacity (usable time) of the battery 201 on the display device 113. and displays a warning when the remaining capacity falls below a predetermined value.

Next, to explain the embodiment shown in FIG. 3, as shown in FIG. A detection circuit 116 and a clock circuit 117 are built-in. FIG. 3(b) shows a charging device 300, which includes a voltage detection circuit 313.
, a temperature detection circuit 314 and a control circuit 312 are provided.

When the power supply device 200 is connected to the charging device 300, the commercial power supply is rectified by the power supply circuit 310, made into a constant current, and outputted to the terminals 221 and 222.

At the start of charging, control circuit 312 resets the discharge end flag and charge completion flag in memory 202. The voltage detection circuit 313 detects the terminal voltage of the battery being charged and outputs the terminal voltage value of the battery to the control circuit 312 after A/D conversion. Figure 4 shows the relationship between charging time and terminal voltage of a secondary battery.The terminal voltage is different at low temperature (a) and at high temperature (b), and the terminal voltage at the end of charging is also exactly C1 at low temperature. It differs as shown by C2 at high temperature. The control circuit 312 inputs temperature data from the temperature detection circuit 314 and switches the charging completion voltage detection level according to the temperature. Even during charging, the charging state is known from the terminal voltage depending on the temperature, and the data in the charging capacity data area of the memory 202 is rewritten at regular intervals. When charging completion is detected by the output of the voltage detection circuit 313, a charging completion flag is written into the memory 202 and at the same time, the power consumption data area is cleared.

Next, the charged power supply device 200 is attached to the device main body 100, and the device main body 100 is operated by operating an operation member (not shown) of the device main body 100. As a result, a current flows from the secondary battery 201 to the load circuit 110, but this current is measured by the power consumption side regulating circuit 111, and data regarding the consumed power is obtained from the measurement data and the clock data of the clock circuit 117. Calculated by control circuit 112.

It is generally known that the discharge characteristics of batteries, including secondary batteries, are greatly influenced by temperature. This discharge characteristic is shown in FIG. In this figure, a shows the characteristics at low temperature, and b shows the characteristics at room temperature. Therefore, the control circuit 112 detects the temperature at the time of current consumption using the temperature detection circuit 116.
, and performs processing such as multiplying the data regarding the consumed power amount by a coefficient based on the input temperature data to obtain the final power consumption data.

In addition, the controller 112 reads the data in the power consumption data area and the data related to the charging power amount that have already been written from the memory 202 of the power supply device 200, and adds the read charging power amount data and power consumption data to the new data. The remaining capacity is determined from the power consumption data determined in , and displayed on the display device 113 .

At regular intervals or at the end of the operation, the control circuit 112 rewrites the data in the power consumption data area of the memory 202 to the sum of the newly obtained power consumption data and the previously written data.

When it is detected from the detection output of the voltage detection circuit 118 that the terminal voltage of the battery has fallen below the operating limit voltage of the load circuit 110 (level 03 in FIG. 5), the control circuit 1
12 causes the display device 113 to display the battery life.

When the battery life is determined, a discharge end flag is set in the memory 202. In the case of a secondary battery, over-discharging significantly impairs the battery capacity, so the control circuit 112 always checks the discharge end flag when reading data from the memory 202, and if this flag is set, the load circuit 11
0 operation is prohibited to stop current consumption.

Further, when the usage limit voltage is detected, the control circuit 112 checks whether the charge completion flag is set, and if the charge completion flag is set, calculates the total value of the power consumption data, and calculates the total value of the power consumption data. If the value is below , an abnormal condition is displayed on the display device 113, a warning is given that the capacity of the power supply device 200 is abnormally reduced, and a capacity abnormal flag is set on the scale 202.

This allows you to charge a battery whose capacity has decreased without knowing it, recognize it as fully charged and use it, and immediately display the battery life.
This can prevent the inconvenience of the battery becoming unusable.

The unique value for setting this abnormality flag is E2 FRO
If stored in a predetermined area of M, it will be effective even for different types of batteries.

In the above embodiment, the amount of power consumption is determined by measuring the current consumption and integrating the amount of time the power is on. When the current consumption is already almost determined depending on the type of operation, such as when the current consumption is determined by the type of operation, the power consumption measurement circuit 111 is unnecessary, and the control circuit is determined by the actuator or circuit that is performing the operation. The power consumption can also be determined by integrating the operating time based on the current value.

Also, like a still camera, the percentage disappears each time you take a frame.
If the amount of power used is approximately fixed, the type of operation (shooting, strobe charging, film rewinding, etc.)
You can also know the amount of electricity from the number of times.

Generally, the power consumption of a secondary battery is several tens of percent less than the amount of charging power, but it goes without saying that this is appropriately corrected when calculating the remaining capacity.

Furthermore, the amount of power that can be consumed (discharged) changes depending on the amount of current consumption, but these can of course be corrected.

FIG. 7 shows a display pattern on the display panel of the display device 113. (a) is fully lit, Cb> is when a fully charged power supply is attached to the main unit, (C) is about 40% remaining, (d) is only segment B is flashing, and soon Indicates a state in which a warning is issued that the usage limit is coming. (e) shows a state in which the battery capacity has decreased abnormally and cannot be used even if it is charged.

FIG. 8 shows an example in which a clock circuit 210 is provided on the power source side of the power source device 200 in FIG. 3. In FIG. When the power supply device 200 is charged by the charging device 300, charging date and time data is read by the charging device side control circuit 312, and the date and time data is written in the memory 202. The clock circuit 210 is a clock circuit that operates with a current consumption much lower than the self-discharge current of the battery 201.
The time will continue to be counted as long as there is remaining capacity. When the power supply device 200 is attached to the tube main body, the control circuit 1
12 reads the charged clock data from the memory 202 and the current clock data from the clock circuit 210, subtracts the clock data at the time of charging from the current clock data, calculates the elapsed time after charging, and calculates the elapsed time per unit time. The self-discharge amount is integrated, and the self-discharge amount integrated value is subtracted from the charging power amount data read from the memory 202 together with the power consumption data, and the remaining capacity is determined and displayed.

Such a method makes it possible to display the remaining battery capacity, taking into account capacity reduction due to self-discharge of the secondary battery.

In this explanation, since the clock circuit is provided inside the power supply device 200, the clock circuit 117 inside the device main body can be made unnecessary. Alternatively, if the clock circuit 117 on the main body side is backed up with a separate battery, the clock circuit 210 in the power supply device 200 is unnecessary.

FIG. 9 is a conceptual diagram of the memory area of the memory element 202. In this figure, (A) is the part where data is rewritten when the user uses the device, and (B) is the part in which the manufacturer stores data unique to this power supply unit before shipping, and the data is rewritten during the user's use. This is the part where rewriting is prohibited.

In (A), a is a part that stores charging power amount, b is a part that stores power consumption amount, C is a part that stores charging date and time data, d is a flag storage area such as a charging completion flag, (
In B), e is an area in which a value indicating the lowest capacity value of this power supply device is written at the time of shipment, and this value is used for the above-mentioned abnormal capacity reduction warning. Further, f is written with the standard self-discharge rate of this secondary battery.

Of course, in reality, in addition to this, by storing the number of charging and discharging times in area A, and operating the remaining capacity display as the number of times increases, and by storing unique data of the power supply device in area B, It can be used as a power supply-specific recognition signal when using various power supply devices interchangeably.

[Effects of the Invention] According to the present invention, since the remaining capacity of the battery is determined from the amount of charging power and the amount of consumed power, the remaining capacity can be notified with high accuracy. Additionally, even if you don't have enough time to fully charge a battery, you can accurately display how long it can be used. Furthermore, since calculations are performed in consideration of temperature characteristics, accuracy is further improved. Furthermore, it is also possible to display the remaining capacity in consideration of self-discharge.

[Brief explanation of the drawing]

FIG. 1 is a block circuit diagram of a power supply system according to one embodiment of the present invention, FIG. 2 is a graph diagram showing battery discharge characteristics, and FIG. 3 is a block circuit diagram of a power supply system according to another embodiment. , (a) shows the connection of the main power supply of the device, (b) shows the connection of the charging device and the power supply, FIG. 4 is a graph showing the charging characteristics of the battery, and FIG. 5 shows the temperature change. FIG. 6 is a flowchart for explaining the operation of charging and discharging the battery, where (a) is a diagram showing charging, (b) is a diagram showing discharging, and FIG. 7 is a diagram showing the display device. FIG. 8 is a block circuit diagram of the power supply device according to the embodiment of the present invention, and FIG. 9 is a diagram showing the format of the storage area of the memory. 100... Device main body, 110... Load circuit, 111
... Power consumption ffi measurement circuit, 112 ... Controller circuit, 113 ... Display device, 200 ... Power supply device, 201 ... Secondary battery, 202 ... Memory, 30
0... Charging device, 310... Power supply circuit, 311...
-Charging power measurement circuit, 312...control circuit. -1112---7

Claims (3)

[Claims] (1) In a power supply device that is detachable from the device main body, the device includes a secondary battery that supplies load power to the device main body and receives charging power from a charging device, and first data regarding the amount of charging power used to charge the secondary battery. and storage means for receiving and storing second data regarding the amount of power consumption in the load circuit of the device main body, and the first and second data read from the storage means are stored in the battery. A power supply device characterized in that it is used for determining remaining power and displaying this remaining power. (2) a device main body including a load circuit that operates upon receiving power from a power supply; a power supply device including a secondary battery that is removably attachable to the device main body; In a power supply system consisting of a charging device built in or separately installed in the device main body or the power supply device,
a charging power amount measuring means for obtaining first data regarding the amount of charging power from the charging device to the secondary battery; and a consumption device for determining second data regarding the amount of power consumption supplied from the secondary battery to the load circuit of the main body of the device. a power amount measuring means; a battery remaining amount display means provided in the apparatus main body for displaying the remaining battery amount of a secondary battery of the installed power supply device; and a battery remaining amount display means provided in the power supply device for displaying the first data and the second storage means for receiving the first data and the second data received from the storage means, and sending the stored data to the battery remaining amount displaying means; The data of
A power supply system characterized in that the power supply system performs processing based on a predetermined algorithm to obtain data regarding the remaining amount of a secondary battery of the power supply device, and displays information corresponding to this data. (3) A secondary battery that supplies power to the load circuit of the device main body, a charging power source that supplies charging current to the secondary battery, and charging that integrates the charging current from the charging power source to the secondary battery over time. charging power amount measuring means for obtaining first data regarding the amount of power; and discharging power amount measuring means for determining second data regarding the amount of discharged power as consumed power supplied from the secondary battery to the load circuit; A storage means for storing the first data and the second data; and a storage means for reading the first data and the second data from the storage means, and determining the remaining battery level of the secondary battery from the relationship between each data. A remaining battery power display device for a secondary power source, comprising: a remaining battery power calculating means for calculating a value related to the remaining battery power; and a display means displaying a value regarding the remaining battery power calculated by the remaining battery power calculating means.