JPH03181874A - Displaying device of capacity of battery - Google Patents

Abstract

PURPOSE:To enable exact display of the capacity of a battery even when the battery is of a removal type, by providing a set switch for changing over a capacity display device to a full charge display. CONSTITUTION:When a battery 3 of which charging is completed is used as a power source of VTR or the like, it is connected, together with an adaptor 1, to a load of the VTR or the like. When a current flows from the battery 3 to the load, a magnetic flux is generated in an inductor 4 in the reverse direction to the one generated at the time of charging, and therefore an H signal is generated on the terminal side in a Hall element 6. A microcomputer 8 executes decremental count of a pulse inputted from a count terminal. The speed of this count is proportional to the amplitude of a discharge current. With the decremental count, the number of lighted LEDs 2 decreases, which shows the amount of discharge. When the battery having completed the discharge in this way is replaced by a new charged battery, all the LEDs 2 are lighted by pushing a set switch A. By starting the use of the new from this state, the residual capacity thereof can be displayed.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a battery capacity display device that detects and displays the amount of charge and discharge of a battery used as a power source for a VTR or the like.

(b) Conventional technology As a technology for displaying battery capacity, Japanese Patent Application Laid-Open No. 55-841
91 and JP-A-61-29079 are known. The former displays the voltage of the battery as its capacity, and the latter calculates the charge/discharge capacity by integrating the current flowing through a resistor connected in series with the battery.

(c) Problems to be solved by the invention However, in the case of batteries, the voltage and capacity are not necessarily in a proportional relationship, and even if the initial voltage is high, the voltage may drop as soon as you start using it. Although it is sometimes used as a simple means to detect battery capacity, it is not very accurate.

Also, although the method of integrating the current to obtain the battery capacity is accurate, it can only be used for devices with built-in batteries. The reason is that this method does not detect the battery voltage, so if the battery is removable, the capacity display will not change even if you replace it with a new battery, and the new battery will continue to display the remaining capacity of the previous battery. This is because it ends up happening.

(d) Means for Solving the Problems The present invention makes it possible to adopt a capacity display method by integrating the charging and discharging current of the battery even when the battery is detachable. This has been made possible by providing a set switch that changes the display device to a fully charged display when the battery is closed.

(e) When a battery that has finished discharging is replaced with a new battery, the battery voltage changes, but since the voltage is not detected, the capacity display remains the same as that of the previous battery. At this time, by pressing the set switch, the display is forcibly switched to the full charge display. From this state, the discharge current is integrated, and the display is switched as the capacity decreases.

(F) Example Example To explain based on the following figures, (1) is an adapter that has LEDs (2) (2) for displaying charge/discharge amount on the side and a set switch (A). Batteries (3) on top
The lower surface is selectively connected to a charger or load. (B) (B) is a connection terminal with a battery. The third throat switch (A) is inserted into the recess (C) formed in the side surface of the adapter (1), as detailed in Fig. 2.
) to prevent you from accidentally pressing this set switch.

FIG. 3 is an electrical circuit diagram inside the adapter, in which an inductor (4) and a relay coil (5) are connected to a charging/discharging circuit of a battery (3) connected to the adapter. (6) is a Hall element that detects the magnetic flux generated in the inductor and generates a voltage.The generated voltage is proportional to the magnitude of the current flowing through the inductor (4), and the direction of the voltage generation is
4) It changes depending on the direction of the current flowing. (7) is a constant voltage generating IC, the output side of which is connected to a microcomputer (8), and an LED (2) for displaying the charge/discharge amount is connected to this microcomputer. The relay coil (5) closes a contact (9) when energized, and through the contact, the Hall element (6), an overdischarge detection comparator (10), and an overcharge prevention comparator (11) are connected. ), a voltage-frequency converter (12), etc. are connected. Note that the relay coil (5) and contact (9)
It can also be activated by a weak current if it is activated by a reed switch. The overdischarge detection comparator (10
) is designed to output an H signal when the battery (3) drops to a constant level of 1r7H due to discharge, and this signal is applied to the ■ terminal of the microcomputer. In addition, the overcharge prevention comparator (11) outputs an H signal when the battery rises to a certain value due to charging, and by applying this to the ■ terminal of the microcomputer (8), the microcomputer (8) starts time counting. After a certain period of time, rapid charging is switched to trickle charging.

On the other hand, the output terminals (1) and (2) of the Hall element (6) are connected to a first comparator (13) that outputs an H signal when charging the battery (3), and a second comparator (Rake) that outputs an H signal when discharging the battery (3). 14) are connected in antiparallel, and the output terminal of each comparator is inputted to the count terminal ■ of the microcomputer (8) via voltage-frequency converter 9# (12). (15) is a third comparator which inputs the output signal of the second comparator (14) and applies the output to the charge/discharge identification terminal ■ of the microcomputer (8). When an H signal is input to the terminal, the pulses applied to the count terminal ■ are counted up, and when an L signal is input, the pulses are counted down. (A) is the set switch; By pressing this and closing the contact for a certain period of time, the LED (2
) is displayed in a fully charged state.

In the above configuration, when the battery (3) is connected to the adapter (1) and this adapter is connected to a charger (not shown), the terminal (16) connects the inductor (4), the battery (3), and the relay coil ( 5) A charging current flows to the terminal (17) and the battery (3) is charged. In addition, when current flows through the relay coil (5), the contacts (9) are closed, and the over-discharge prevention comparator (10) and the over-charge prevention comparator (11) are closed.
), the Hall element (6), and the voltage-frequency converter (12) are activated, and at the same time, the microcomputer (8) is also activated. During charging, the Hall element (6) generates an H signal on the ■terminal side, sets the output of the first comparator (13) to H, and performs voltage-frequency conversion! (12) through the microcontroller (8
) to add a pulse signal. Thus, the voltage generated by the Hall element (6) is proportional to the magnitude of the current flowing through the inductor (4), and the voltage-frequency converter (12) generates a pulse with a frequency proportional to the input voltage. Therefore, the microcomputer (8) receives pulses with a frequency proportional to the current flowing through the inductor (4), that is, the charging current, and counts the pulses. During charging, since the output of the second comparator (14) is L, the output of the third comparator (14) is L.
The output of 15) becomes H, which is applied to the charge/discharge identification terminal (2) of the microcomputer (8), so that the microcomputer counts and knobs the pulses. As the count increases, the number of LEDs (2), (2), etc. that are lit increases to display the amount of charge. When the battery (3) is fully charged, the overcharge prevention comparator (]0) outputs an H signal, which is detected by the microcomputer (8) and switches to trickle charging after a certain period of time. When the battery (3) that has been charged in this way is used as a power source for a VTR or the like, it is connected to a load such as a VTR together with the adapter (1). When current flows from the battery (3) to the load, the magnetic flux generated in the inductor (4) is in the opposite direction to that during charging, so the Hall element (6)
), an H signal is generated on the ■terminal side. As a result, the output of the second comparator (14) is
The output of 5) becomes L, and the microcomputer (8) counts down the pulses input from the count terminal ■. The distance of this count is proportional to the magnitude of the flow. As the countdown continues, the LEDs (2) (2)
The number of lights will decrease and the amount of discharge will be displayed. i
When the voltage is discharged to the minimum voltage required to drive the load, the over-discharge prevention comparator (11) detects this and applies an H signal to the microcomputer (8), causing the LED (2)... Display by blinking. When replacing a battery that has finished discharging in this way with a new, charged battery, press the set switch (A) with the tip of a ballpoint pen, etc., and the LED (2) (
2) Turn on all... If you start using a new battery in this state, you can display the remaining capacity of the new battery.

(G) Effects of the Invention As described above, the present invention is equipped with a set switch that forcibly switches the capacity display device to display full charge, so even if the battery is removable, the battery capacity can be accurately displayed. I can do it.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a battery and an adapter, FIG. 2 is a sectional view of a main part, and FIG. 3 is a diagram of an electric circuit inside the adapter.

Claims (1)

[Claims] A device that calculates the capacity by integrating the charging and discharging current of a removably attached battery and displays the result is provided with a set switch that switches the display device to a fully charged display when the contact is closed for a certain period of time or more. Battery capacity display device.