JPH04193036A - Battery-driven electric appliance - Google Patents

Abstract

PURPOSE:To use batteries efficiently by connecting a switch in parallel with a diode on the side of high saturation voltage and turning the switch ON when the battery voltage drops below a predetermined level in a battery drive electric appliance in which diodes having different saturation voltages are connected between each battery and a load and the batteries are discharged sequentially according to the difference of saturation voltage. CONSTITUTION:A diode 8 is connected in parallel with a switching element comprising a transistor 10. Discharge is started from a secondary battery 1A on the side of lower saturation voltage of thus connected diode and when the voltage of the secondary battery 1A drops by an amount of the saturation voltage VF to satisfy a relation VA-VF=VB-2XVF, voltages are fed from both secondary batteries 1A, 1B. Furthermore, when the detected voltage is lower than a predetermined level, a control circuit 6 turns a transistor 10 ON. At that time, voltage drop upto the power switch 3 equals to VF+VCE. Consequently, the saturation voltages VF, VCE of the diode and the transistor 10 are equal, respectively, to 0.6V and 0.2V and thereby the dischargeable capacity is increased.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a battery-powered electrical device that can be equipped with a plurality of batteries.

[Conventional technology]

FIG. 6 shows the configuration of this type of conventional example, in which two secondary batteries IA and IB can be installed.
A main body circuit 2 that can be driven by secondary batteries IA and IB, a power switch 3 that turns on and off the main body circuit 2, a battery connecting terminal 4A that connects the first secondary battery 1Δ, and this battery connecting terminal 4A. A diode 5 between the power switch 3, a battery connection terminal 4B connecting the second secondary battery IB, a diode 7.8 connected between the battery connection terminal 4B and the power switch 3, and the main circuit. 2, and a control circuit 6 that monitors the battery voltage and displays an indication when the voltage falls below a predetermined value.

Here, a case will be described in which the secondary battery IA is connected to the battery connection terminal 4A, and the secondary battery IB is connected to the battery connection terminal 4B.

First, when the power switch 3 is turned on, battery voltage is applied to the main circuit 2. At this time, the voltage applied to the main circuit 1 is determined by the diode 5 or 1 between the secondary battery IA and the power switch 3.
Therefore, VA (voltage of secondary battery IA) - VF (saturation voltage of diode).

On the other hand, since there are two diodes 7.8 between the secondary battery IB and the power switch 3, the voltage applied to the main circuit 2 is (voltage of secondary battery IB) -2×■. Become.

Therefore, when the battery voltages of secondary batteries IA and IB are the same voltage, discharge starts from secondary battery IA first, the voltage of secondary battery IA decreases by 72 minutes to the saturation voltage, and VA-VF=
When it becomes V11-2XVF, the secondary battery IA and IB
Voltage is supplied from both. At this time, the control circuit 6
displays a charging reminder. Here, if the battery is not a used battery or a secondary battery, but a dry battery, the control circuit 6 may display an indication to replace the battery.

As described above, by utilizing the difference in the saturation voltage of the diodes, the secondary battery IA can be discharged preferentially (and a charging reminder can be displayed when the secondary battery IA is discharged to a predetermined voltage).

[Invention or problem to be solved]

By the way, in recent battery-powered electrical devices, especially portable personal computers, etc., a plurality of batteries are replaced in sequence and used continuously. However, in the above conventional example, the secondary battery IB is 2×V4 higher than the driveable voltage of the main circuit 12.
Since the secondary battery IB can only be discharged to a higher voltage, if it is to be replaced and used continuously as described above, the secondary battery IB must be replaced with its capacity remaining, which is a problem of poor efficiency.

The present invention has been made in view of the above-mentioned problems, and an object of the invention as claimed in claim 1 is to enable efficient use of batteries when a plurality of batteries are replaced and used continuously. To provide battery-powered electrical equipment.

In addition to the object of the above-mentioned claim 1, the object of the invention as claimed in claim 2 is to provide a battery-driven electric device capable of obtaining stable operation of a switching element that short-circuits both ends of a diode with a large saturation voltage. There is a need to provide equipment.

In addition to the object of the invention as claimed in claim 2, it is an object of the invention as claimed in claim 3 to automatically release the ON state of the activated switch element at the same time as the battery is replaced so that the priority order is always maintained. The purpose of the present invention is to provide battery-powered electrical equipment that can be discharged or discharged.

[Means to solve the problem]

In order to achieve the above object, the invention according to claim 1,
In battery-powered electrical equipment, in which multiple batteries can be detachably installed, diodes with different saturation voltages are provided between each battery and the load, and the saturation voltages of the diodes differ, the battery-driven electrical equipment discharges sequentially. A switch element is connected in parallel with the larger diode, and the switch element is turned on when the battery voltage falls below a predetermined value.

The invention as set forth in claim 2 is the invention as set forth in claim 1, wherein when the switch element is turned on, the on state of the switch element is latched even if the battery voltage exceeds a predetermined value.

The invention according to claim 3 is the invention according to claim 2,
It detects that the battery with the smaller saturation voltage difference has been replaced and turns off the switch element.

[Effect]

According to the present invention, it is possible not only to prioritize and discharge a plurality of batteries based on the difference in the saturation voltage of the diodes connected between the load and the battery, but also to When the battery voltage falls below a certain level, the switch element short-circuits the diode with the higher saturation voltage, so the battery connected to the load via the diode with the higher saturation voltage will be short-circuited by the saturation voltage of the shorted diode. By increasing the capacity that can be discharged, more efficient discharge can be performed.

If the ON operation of the switch element is latched even when the battery voltage exceeds a predetermined value, the chattering operation is eliminated and stable discharge can be performed.

Furthermore, by detecting that the battery with the smaller saturation voltage difference has been replaced and turning off the switch element in the latched state, discharging can always be performed in priority order even if the battery is replaced.

〔Example〕

The present invention will be explained below with reference to Examples.

FIG. 1 shows the circuit configuration of an embodiment of the present invention. In this embodiment, a switching element consisting of a transistor 10 is connected in parallel to the diode 8 in the conventional example shown in FIG. When the control circuit 13 detects that the voltage applied to the main body circuit 2, which is the load detected by the output, has fallen below a predetermined value, a detection signal from the control circuit 13 turns on the transistor IO.

Discharging is then started from the secondary battery IA with the smaller saturation voltage of the connected diode, and the voltage of the secondary battery IA drops by the saturation voltage V1. −Vv=Ve2×
When the voltage becomes VF, voltage is supplied from both secondary batteries IA and IB. Furthermore, the control circuit 6 turns on the transistor 10 when the detected voltage becomes less than a predetermined value. At this time, the voltage drop across power switch 3 is V.

Ju■o yells. Here, the saturation voltage of the diode and diode.

is 0.6v, the saturation voltage of transistor lO■6. (V
, A, ) is 0.2V, which means that the capacity that can be discharged increases.

In addition, transistor 1 is connected in parallel to the series circuit of diode 7 and 8.
0 may be connected in parallel, and in this case, the voltage drop is only the saturation voltage VcE (V3A,) of the transistor 10, and more discharge can be performed. Note that the control circuit 6 displays a charging reminder display when the transistor 10 is turned on.

By the way, in the above-mentioned embodiment, the control circuit 6 displays a display reminding the user to charge, but this display does not indicate whether the capacity of the secondary battery is low or low when the secondary battery is replaced.

Therefore, in another embodiment shown in FIG. 2, each secondary battery IA, I
Voltage dividing resistors 11A and IIB are respectively connected to battery connection terminals 4A and 4B connected to B, and the respective divided voltage outputs are taken into the control circuit 6 to detect the battery voltage of each secondary battery IA and IB, Secondary battery 2A with lower saturation voltage
When the voltage of each battery falls below a predetermined voltage, the transistor 10 is turned on, and when each battery voltage falls below a predetermined voltage, a charging reminder is displayed for each of the secondary batteries IA and IB.

FIG. 3 is a flowchart for explaining the operation of this embodiment, and the operation of the circuit of FIG. 2 will be explained based on this flowchart.

First, when the power switch 3 of the electrical equipment is turned on, the control circuit 6 first turns off the transistor 1O, then checks whether the voltage of the secondary battery IA is OV or not, and whether the secondary battery IA is installed. Check. When the secondary battery IA is installed instead of the detection voltage or OV, the voltage of the secondary battery IA is compared with the reference voltage VD for reminding charging, and if the battery voltage is lower than the reference voltage VD, the secondary battery IA is installed. Displays a reminder to charge battery IA, and at the same time displays transistor 1.
0 to switch to discharging the secondary battery IB. When the secondary battery IA is not installed, the charging reminder display for the secondary battery IA is reset and stopped.

When the battery voltage is higher than the reference voltage VD, the transistor IO remains off and the charging reminder display remains reset.

Next, it is checked whether the voltage of the secondary battery IB is 0 and whether the secondary battery IB is installed. When the secondary battery IB is installed instead of the detection voltage OV, the voltage of the secondary battery IB is compared with the reference voltage VD for reminding charging, and if the battery voltage is lower than the reference voltage VD, the secondary battery IB is installed. Displays a reminder to charge battery IB. When the secondary battery IB is not installed, the transistor 10 is turned off, the charging reminder display for the secondary battery IB is reset and stopped, and the process returns to the process for determining the secondary battery IA.

As described above, when both the secondary batteries IA and IB are installed, the secondary battery IA can be discharged to the voltage VD at which charging is requested with priority, and then the secondary battery IB is switched to the voltage at which charging is requested. Can be discharged to VD.

In this way, the embodiment shown in FIGS. 2 and 3 can prioritize and discharge a plurality of secondary batteries IA and IB, and the second secondary battery IA and IB can be discharged with priority.
B can be discharged to a larger capacity, and is a secondary battery]
You can tell whether the capacity of A or 1B is insufficient.

In the embodiment of the above function, when the transistor 10 is turned on, the secondary battery IA stops discharging and the voltage returns to a predetermined voltage or higher, so the control circuit 11 either turns off the transistor 10 or immediately adjusts the detected voltage. Since the voltage drops below a certain level, the control circuit 11 turns on the transistor 10, and as a result, this on and off operation is repeated.
The charging reminder display blinks and chattering, and the voltage applied to the main circuit is unstable.

Therefore, when the l-transistor 10 is turned on, it is latched even if the battery voltage of the secondary battery IA with the smaller saturation voltage difference exceeds a predetermined value. The control circuit 6, which is the same as the circuit in FIG. 2, operates based on the flowchart 1 shown in FIG.

In other words, when the control circuit 11 starts operating, the transistor 2 transistor 1
0 is turned off and the charging reminder flag is reset.

Next, check whether the secondary battery IA is installed or not in the same way as in the embodiment shown in FIG. It is checked by the charging reminder flag whether or not the battery is being charged. When the charging reminder flag is set and the battery has already been discharged to the reference voltage VD at which the charging reminder is issued, a check is made to see if the secondary battery IB is installed.

When the charging reminder flag is set, the voltage of the secondary battery IA is compared with the charging reminder reference voltage VD, and when the battery voltage is lower than the reference voltage VD, a charging reminder display for the secondary battery IA is displayed, and charging is performed at the same time. At the same time as setting the reminder flag, the transistor 10 is turned on to discharge the secondary battery IB.
Switch to discharge. When the secondary battery IA is not installed, the charging reminder display for the secondary battery IA is reset, and the charging reminder flag is reset to stop the display. Thereafter, the same processing as in the embodiment shown in FIG. 3 is performed.

By the above operation, even if the voltage of the secondary battery returns when the discharged battery is switched, the charging reminder display can be reset and the discharge of the secondary battery IB can be continued without turning off the transistor 10. As a result, the abnormal display when switching the discharge battery disappears, and the voltage stabilizes.

However, in the embodiment of FIG. 4, when the secondary battery IA is replaced after the transistor 10 is turned on, the transistor IO is latched in the on state, so the secondary battery IA cannot be discharged preferentially.

Therefore, in an embodiment corresponding to the invention recited in claim 3, as shown in the flowchart of FIG. 5, a process is added to turn off the transistor 10 when the secondary battery IA is replaced. When the battery is installed and the charging reminder flag is set, the transistor 10 is turned off, and after the secondary battery IA is discharged to the charging reminder voltage VD, the transistor 10 is turned on and the discharge is switched to the secondary battery IB. , when the secondary battery IA is removed (not installed), the charging reminder flag is reset. If the secondary battery IA is attached while the secondary battery IB is being discharged, the charging reminder flag is set, so the transistor 10 is turned off and the secondary battery 1Δ starts discharging again.

Therefore, when the secondary battery IA is replaced, the secondary battery IA can always be discharged preferentially.

〔Effect of the invention〕

The invention as claimed in claim 1 is such that a plurality of batteries can be detachably attached, diodes with different saturation voltages are provided between each battery and a load, and the discharge is performed sequentially based on the difference in the saturation voltage of the diodes. In battery-powered electrical equipment, a switch element is connected in parallel with the diode with the higher saturation voltage, and the switch element is turned on when the battery voltage falls below a certain level, so there is no connection between the load and the battery. Of course, it is possible to discharge multiple batteries by prioritizing them based on the difference in the saturation voltage of the diodes connected to the diodes. The switch element can be short-circuited, so that a battery connected to the load via the diode with the higher saturation voltage can increase the discharge capacity of the battery by the saturation voltage of the shorted diode. hand,
This has the effect of allowing efficient discharge.

Further, the invention as claimed in claim 2 is the invention as claimed in claim 1, in which when the switch element is turned on, the on state of the switch element is latched even if the battery voltage exceeds a predetermined value, so that the chattering operation of the switch element is latched. This has the effect of allowing stable discharge from the battery.

The invention according to claim 3 is the invention according to claim 2,
Since it detects that the battery with the smaller saturation voltage difference has been replaced and turns off the switch element, it detects that the battery with the smaller saturation voltage difference has been replaced and turns off the switch element in the latched state. Turning it off has the effect that even if the battery is replaced, it can always be discharged in priority order.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram of one embodiment of the present invention, FIG. 2 is a circuit diagram of another embodiment of the present invention, FIG. 3 is a flowchart for explaining the operation of the same, and FIG. 4 is a circuit diagram of another embodiment of the present invention. FIG. 5 is a flowchart for explaining the operation of the embodiment of the invention, FIG. 5 is a flowchart for explaining the operation of the embodiment of the invention according to claim 3, and FIG. 6 is a circuit diagram of a conventional example. LA and IB are secondary batteries, 2 is the main circuit, 3 is the power switch, 4A, 4B are battery connection terminals, 5.7.8 is a diode, 6 is a control circuit, 9 is a voltage dividing resistor, 10 is a transistor, IIA , IIB are voltage dividing resistors.

Claims (1)

[Claims] 1) A battery drive in which a plurality of batteries can be detachably attached, diodes with different saturation voltages are provided between each battery and the load, and discharge is performed sequentially based on the difference in the saturation voltage of the diodes. 1. A battery-driven electrical device characterized in that a switch element is connected in parallel with a diode with a higher saturation voltage, and the switch element is turned on when the battery voltage falls below a predetermined value. 2) The battery-powered electric device according to claim 1, wherein when the switch element is turned on, the on state of the switch element is latched even if the battery voltage exceeds a predetermined value. 3) Claim 2 characterized in that the switch element is turned off by detecting that the battery with the smaller saturation voltage difference has been replaced.
Battery-operated electrical equipment as described.