JP3202918B2 - Portable wireless communication device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a portable radio communication device, and more particularly to a portable radio communication device provided with a battery failure display device capable of reliably detecting and displaying a short-mode battery failure.

[0002]

2. Description of the Related Art Conventionally, nickel cadmium batteries have been used as batteries for cordless telephones and portable telephones. When the nickel cadmium batteries are repeatedly charged and discharged, the positive and negative terminals are short-circuited, and how much charge is required. It was also known that even the short-circuit failure in which the voltage did not rise could result.

[0003]

In an apparatus using the conventional nickel-cadmium battery as described above, for example, as a guide for replacing a battery pack, a manual operation is performed such that the battery pack is replaced when the operable time becomes short. In many cases, it is instructed by the user. However, for example, in the case of a cordless telephone handset, a new battery can be used to make a call for about 6 hours. Even if this is reduced to, for example, 3 hours, there is no problem in a general home. Can be used without. Furthermore, in the case of a cordless handset, usually, it is often connected to a charger except during a call, and most users do not notice a decrease in battery capacity at present.

[0004] When the battery is further deteriorated, one of the battery packs is in a short-circuit mode failure state. For example, in a battery pack in which three nickel cadmium batteries are connected in series, a new battery has an output voltage of 3.6 volts, but if one battery fails in the short mode, the output voltage drops to 2.4 volts. Resulting in. Then, the internal control CPU becomes inoperable, and the slave unit does not operate at all. However, the user considers that the device itself has failed because the child unit that had been operating normally has suddenly stopped operating at all, and has improperly requested repair such as simply replacing the battery. There was a problem of taking measures.

An object of the present invention is to solve the above-mentioned problems of the prior art, and to provide a portable radio communication device provided with a battery failure display device capable of reliably detecting and displaying a battery failure in a short mode. Is to do.

[0006]

In order to achieve the above object, the present invention relates to a portable radio communication apparatus using a plurality of batteries connected in series which may cause a short-mode failure. Voltage range detecting means for detecting whether or not the voltage between both ends of the plurality of batteries is within a voltage range that can be taken when one of the plurality of batteries has a failure in the short mode, comprising a battery failure display means and display means for displaying the output state of the voltage range detector, the voltage range detection means, Li of the control means of the apparatus
It is characterized in that it also serves as a setting means .

The present invention can reliably detect a short-mode battery failure even in a portable wireless communication device in which it is difficult to confirm a decrease in battery capacity by the above-described configuration. Is less likely to take the wrong action by mistake for another fault.

[0008]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a block diagram showing the configuration of a cordless handset device to which the present invention is applied. The battery 1 is, for example, a nickel cadmium battery 3
This is a battery pack in which the battery packs are connected in series, and the voltage at point B is usually 3.6 volts. Both ends of the battery 1 are connected to the charging terminal 4 via a charging current limiting resistor R4, and are also connected to respective circuits in the slave unit such as the CPU 2. C
PU2 is a central control device for controlling the slave unit, and can operate if the power supply voltage is 3 volts or more, for example.
The CPU 2 has a reset terminal RES, and stops operating when the terminal is low (0 volts) and is initialized.

The reset IC 3 has a built-in circuit for outputting a low signal when the power supply voltage becomes equal to or lower than a predetermined value. In this example, the output terminal (point A) is set to 3 volts or less, which is the operation guarantee lower limit voltage of the CPU. Go low. This value of 3 volts is a normal value of the battery voltage at point B of 3.6 volts,
One of the batteries 1 is in the middle of the voltage of 2.4 volts at the point B when the short mode failure occurs.

FIG. 2 shows the power supply voltage (voltage at point B) applied to the reset IC 3 and the signal at the output terminal (voltage at point A).
6 is a graph showing the relationship of. The reset IC 3 keeps the power supply voltage unchanged when the power supply voltage is 3 volts or more.
Alternatively, a high-level signal is output. However, when the power supply voltage becomes less than 3 volts, the output voltage becomes almost 0 volt. This signal is connected to the reset terminal of the CPU 2 and is also supplied to the display circuit 5.

The display circuit 5 is a circuit for turning on the light emitting diode D for battery failure indication when the output of the reset IC 3 becomes low. When the voltage at point A is high, the base current of transistor TR2 does not flow, and TR2
Is off. Accordingly, TR1 is also off, and no current flows through the light emitting diode D, so that the light emitting diode D is turned off.
When the power supply voltage drops below 3 volts and the voltage at point A goes low, the base current of TR2 flows through resistor R3,
TR2 is turned on. Therefore, the base current of TR1 flows through R2, and TR1 is also turned on. Then, a current flows through the diode D via the current limiting resistor R1,
Light. When the power supply voltage further decreases and falls below the forward voltage drop P (about 2 volts) of the diode D, the light emitting diode D turns off.

Next, the operation will be described. For example, in the case of a cordless handset, the light emitting diode D is turned off because the battery voltage does not usually fall below 3 volts.
However, when the battery is completely discharged, the battery voltage drops to 3 volts or less, the battery becomes inoperable, and if it is 2 volts or more, the diode is turned on. However, when the battery is used until the battery is completely discharged, the user often recognizes that the battery is insufficiently charged, and attempts to charge the battery regardless of the display. Some time after the start of charging, if the battery is normal, the voltage becomes 3 volts or more, and the light emitting diode D is turned off.

If one of the batteries fails in the short mode, the operation is disabled and the light emitting diode D is turned on. Then, even if the user attempts to charge, the operation is not possible, and the light emitting diode D remains lit.
Therefore, it is determined that the battery has failed. Note that the light emitting diode D for indicating the battery failure may be provided in the slave unit alone, but it is also turned on at the time of complete discharge, so that if it is described as a failure display, there is a risk of misleading the user.
Therefore, for example, a device in which a plurality of light-emitting diode elements having different colors are mounted in one package is used, and other indications such as the remaining battery level are usually displayed in, for example, green. The explanation may be made only to a maintenance person or a person in charge of repair without explanation.

[0014] In this way, for example, when a user inquires about a failure, despite charging,
By asking the user whether the red display continues to light up, it is easy to determine whether it is a mere battery failure.If the battery is defective, simply send the battery and replace it. You only need to ask them to take appropriate measures.

FIG. 3 is a block diagram showing the configuration of another embodiment of the cordless telephone handset device to which the present invention is applied. In the case of the first embodiment, the reset IC of the CPU 2
The operating voltage of 3 volts can be used as the identification voltage when one of the three nickel cadmium batteries in the series pack has a failure in the short mode. When the CPU can operate at 2 volts and the reset IC operates at 2 volts, it is necessary to separately provide a voltage detection circuit for detecting a battery failure according to the present invention.

In FIG. 3, the CPU 11 can operate up to, for example, 2 volts, has a reset terminal RES and a 1-bit input terminal I, and further has a liquid crystal display device 10.
It also has. The reset IC (B) 12 is an IC whose output terminal goes low when the power supply voltage falls below 2 volts, and the output terminal is connected to the reset terminal RES of the CPU 11. The reset IC (C) 13 is an IC provided for battery failure detection.
Output goes low below volts.

The output terminal of the IC 13 has the ability to directly drive the light emitting diode D with, for example, an open collector output, and is connected to the cathode side of the light emitting diode D and also connected to the 1-bit input terminal I of the CPU 11. It is connected. Note that the same components as those in FIG. 1 are given the same numbers.

In the slave unit having the configuration shown in FIG. 3, the light emitting diode D is normally turned off, but when a battery failure occurs in the short mode, the output of the IC 13 becomes low, so that the light emitting diode D is turned on. . When the battery voltage drops to 2.4 volts, the communication circuit becomes inoperable, but the CPU 11 can still operate. So, CPU
When it is detected at 11 that the input terminal I has gone low, a display such as “dense pepper” may be displayed on the liquid crystal display 10. By displaying characters in this way, the user can easily recognize the cause of the failure and take appropriate measures. When displaying characters, the light emitting diodes D and R1 may not be provided.

Although the embodiment has been described above, the following modified examples are also conceivable. In the embodiment, the example of equipping a cordless telephone handset using a nickel cadmium battery is disclosed.However, the battery is applicable to all batteries that may cause short-mode failure such as a nickel hydride battery, for example. Further, the device can be applied to any device using a battery. Furthermore, 2
The charger for the next battery may be equipped with the battery failure display device of the present invention. Although an example in which a reset IC is used as the voltage detection circuit has been disclosed, any circuit configuration may be adopted as long as it detects a voltage lower than a predetermined voltage such as a combination of a reference voltage source and a voltage comparison circuit. is there.

Although the example in which the threshold voltage for failure determination is 3 volts in the case of three nickel cadmium batteries is disclosed, the voltage of one battery is generally V, and the number of batteries connected in series is N. Then, the threshold voltage E becomes (N-1) V
<E <NV, and preferably E is (N−
1/2) V.

[0021]

As described above, in the present invention,
Even in a portable wireless communication device in which it is difficult to confirm a decrease in battery capacity in a normal use mode, a short-circuit mode battery failure can be reliably detected, and the user or maintenance person mistakenly mistakes for another failure. This has the effect of reducing the risk of taking appropriate measures.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a cordless handset device to which the present invention is applied.

FIG. 2 is a graph showing a relationship between a power supply voltage (voltage at point B) applied to a reset IC 2 and a signal at an output terminal (voltage at point A).

FIG. 3 is a block diagram showing a configuration of another embodiment of a cordless telephone handset device to which the present invention is applied.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Battery, 2 ... CPU, 3 ... Reset IC, 4 ... Charging terminal, 5 ... Display circuit, 10 ... Liquid crystal display, 11 ... CP
U, 12, 13 ... Reset IC (voltage detection circuit)

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI H04M 1/02 H04B 7/26 L H04Q 7/38 109T (72) Inventor Yuji Ota 3-19-2 Nishishinjuku, Shinjuku-ku, Tokyo No. Nippon Telegraph and Telephone Corporation (56) References JP-A-4-75433 (JP, A) JP-A-5-211762 (JP, A) JP-A-6-14472 (JP, A) JP-A-4 -91620 (JP, A) JP-A-5-218942 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H02J ^7/ 00-7/12 H02J ⁷ /34-7/36 H04B 1/40 H04B 1/26 H04M 1/02

Claims (2)

(57) [Claims] 1. A portable wireless communication apparatus using a plurality of batteries connected in series which may cause a failure in a short mode, wherein the voltage across both ends of the plurality of batteries connected in series is reduced by the plurality of batteries. A voltage range detecting means for detecting whether or not one of them is within a voltage range that can be taken when a short-mode failure occurs, and a display means for displaying an output state of the voltage range detecting means. Battery fault display means, the voltage range detecting means being reset means of control means of the apparatus.
A portable wireless communication device, which also serves as 2. The battery according to claim 1, wherein the plurality of batteries include three nickel cadmium batteries.
Battery, and the voltage range detecting means is 3 volts or less.
CP that generates output under and controls the device
U is reset, and the display means is based on the output.
2. The portable wireless communication device according to claim 1, wherein the portable wireless communication device is a light emitting diode that performs lighting display .