JP2965800B2 - Power saving circuit of slave unit of mobile communication device - Google Patents

Abstract

PURPOSE:To provide a power wave circuit for the slave device of a mobile communication equipment consisting of a master and slave devices in order to eliminate the power consumption of the slave device in a power failure state by detecting automatically a power failure by the slave device and isolating a secondary battery serving as a power supply of the slave device. CONSTITUTION:A slave device 100 is provided with a voice circuit 110, a radio circuit 120, a microprocessor 130, a constant voltage circuit 140, a power supply part 150, and a charging circuit 160. Furthermore a 1st switch 170 is added to the device 100 to detect the supply of power from a charger 100B and to be turned on together with an on-base/off-base detecting circuit 180 which detects whether the voltage supplied to the circuit 160 is higher than a prescribed level or not, and a 2nd switch 190 which is turned off when the circuit 180 detects an off-base and also the carrier sent from a master device 200 is not detected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power saving circuit of a slave unit of a mobile communication device comprising a slave unit and a master unit.

[0002] In recent years, mobile communication devices utilizing wireless communication such as automobile telephones, bocket bells, cordless telephones, etc., have become communication devices that can communicate with anyone, anytime, anywhere.
It is spreading and developing rapidly.

[0003] Such a device for mobile communication includes a device "parent device" directly connected to a communication line, and a device "portable device" which can be carried freely within the range of constraints restricted by the reach of radio waves. It is composed of a portable device “slave device” that communicates with the device.

For example, a cordless telephone handset is required to be small and light in order to be freely carried. For this reason, it is necessary to reduce the size and weight of a power supply unit which accounts for a large part of the weight. is necessary. Therefore, in the slave unit, use a secondary battery, charge during standby,
At the time of communication, the power is used, and it is used in a pattern in which charging is performed after communication is completed.

When such a cordless telephone is connected to an NTT line and used, even if a power failure occurs, a primary battery is usually installed in the base unit and a secondary battery is installed in the slave unit.
You can talk normally while the battery is full.

FIG. 3 is a diagram for explaining a cordless telephone system accommodating a private branch exchange. Slave device 100, master device 200
Have the same configuration, and the audio circuits 110, 210,
The radio circuits 120 and 220 and a microprocessor (hereinafter M
The slave unit 100 includes a secondary battery 150A, and the master unit 200 includes a primary battery 250A as an antenna A and power supplies.

With this configuration, the secondary battery 150 of the slave unit 100
A is constantly charged through the AC adapter 100A and the charger 100B. CN in the figure indicates an outlet. The base unit 200 of such a cordless telephone system (hereinafter referred to as a cordless telephone) is a private branch exchange (hereinafter referred to as a PB
X), the PBX 300 is operable during a power failure while the backup power supply 300A has a capacity, for example, 30 minutes to 60 minutes, and the cordless telephone base unit 200, A primary battery 250A and a secondary battery 150A, each of which includes the slave unit 100.
You can talk while the capacity is up.

[0008] The PBX 300 is a backup power supply 300A.
When the power of the cordless telephone is exhausted, it becomes inoperable, and the primary battery 25 of the cordless telephone base unit 200 and the child unit 100
Even if the capacity of the secondary battery 150A remains at 0A, communication becomes impossible because the line accommodating the cordless telephone cannot be used.

On the other hand, the PBX 300 is a software 310
The secondary battery 320 is provided to back up the software 310 in the event of a power failure, and the service can be operated normally immediately after the power is restored. Such a backup time is set to, for example, one week.

A cordless telephone housed in such a PBX also requires a power saving circuit of a cordless telephone handset which can operate normally immediately when power is restored after a power failure within a predetermined time.

[0011]

2. Description of the Related Art FIG. 4 is a diagram for explaining a conventional example. In the figure, 100a is a slave unit, and 200 is a master unit. Slave device 100a
The audio signal is converted into an electric signal by the audio circuit 110 in the
This electric signal is converted into a radio signal by radio circuit 120 and transmitted to base unit 200.

The MPU 130 includes the slave unit 100a and the master unit 20.
Control of communication between 0 is performed. In order to operate this circuit, the charging circuit 160 charges the secondary battery 150A with the power supplied from the charger 100B and supplies power to the constant voltage circuit 140, and the constant voltage circuit 140 The voltage is converted to a constant voltage, and the audio circuit 110 and the radio circuit 120
And the MPU 130. Rechargeable battery 150A
During standby, charging is always performed through the AC adapter 100A, the charger 100B, and the charging circuit 160.

On the other hand, base unit 200 accommodated in PBX 300 performs AC-DC conversion by AC adapter 200A, and its output is supplied to operate. The internal configuration of parent device 200 is omitted because it has no direct relation to the present invention.

With the above-described configuration, the movable slave unit 100
a communicates with the parent device 200.

[0015]

In the above-mentioned conventional example, when a power failure occurs, power is not supplied through the charger 100B, so that the power from the secondary battery 150A charged by the charging circuit 160 is kept at a constant voltage. The signal is supplied to the audio circuit 110, the wireless circuit 120, and the MPU 130 through the circuit 140. Therefore, a power outage occurs, the PBX 300 becomes unusable, and the cordless telephone is unusable, so that the standby state is continued and the slave unit 100a consumes power.

Although such power consumption is slight, the backup time of the above-mentioned software 310 is one.
Since it is about two weeks, the power of the secondary battery 150A may be completely consumed after a long time, and the cordless telephone may not operate normally after the power is restored from the power failure.

The present invention relates to a mobile communication device that can completely eliminate power consumption during a power failure by automatically detecting a power failure of the child device and disconnecting a secondary battery of a power source of the child device. It is intended to realize a power save circuit.

[0018]

FIG. 1 is a block diagram for explaining the principle of the present invention. 100 in the figure is a slave unit of a mobile communication device to which power is supplied through an AC adapter 100A and a charger 100B, and 200 is an AC adapter 200A
Is a parent device of a mobile communication device to which power is supplied through the communication device, and 300 is a PBX accommodating the parent device 200.

Reference numeral 110 in the slave unit 100 denotes a voice circuit for communicating with the other party, reference numeral 120 denotes a wireless circuit for converting the output of the voice circuit 110 into a wireless signal to perform wireless communication with the master unit 200, and reference numeral 130 denotes a master circuit. MPU that controls communication with the device 200, 1
40 is an audio circuit 110, a radio circuit 120, and an MPU
A constant voltage circuit that supplies a constant voltage power supply to 130, a power supply unit 150 that supplies power to the constant voltage circuit 140, and a charging circuit 160 that charges the power supply unit 150.

Further, a first signal 170 is turned on when it detects that power is supplied from the charger 100B.
The switch 180 is an on-base / off-base detection circuit that detects an on-base when the supply voltage to the charging circuit 160 is equal to or higher than a predetermined voltage, and detects an off-base when the supply voltage is equal to or lower than the predetermined voltage. Reference numeral 190 denotes an on-base / off-base detection circuit 180 for detecting off-base,
A second switch 190 that is turned off when no carrier is detected from base unit 200;
0 is applied, the charging circuit 16
0 to the first switch 170 and the second switch 19
When the power is supplied to the constant voltage circuit 140 through 0 and the supply voltage to the charging circuit 160 is not applied, it is detected that the power supply from the charger 100B has been cut off, and the first The switch 170 is turned off. In this state, no carrier is detected from the master unit 200, so that the second switch 190 is turned off, and the power consumption of the slave unit 100 is completely eliminated.

[0021]

The cordless telephone handset 100 is a charger 100.
When set to B, AC adapter 100A, charger 1
00B, the power supply 150
And supplies a constant-voltage power supply to the audio circuit 110, the wireless circuit 120, and the MPU 130 (hereinafter, collectively referred to as an internal circuit) of the slave unit 100.

The first electronic switch 170 is connected to the charger 10
The power is turned on by the supply of the DC power from 0B, the constant power circuit 140 converts the DC power supplied from the charger 100B to a constant voltage and supplies it to the internal circuit, and the slave unit 100 is in an operating state.

The on-base / off-base detection circuit 180 detects that the base unit 100 is on-base when the DC power is supplied when the slave unit 100 is set in the charger 100B, and the MPU
Notify 130. The MPU 130 is connected to the second switch 19
0 is turned on.

Master unit 200 is in operation by DC power supplied from AC adapter 200A. Here, at the time of calling, when handset 100 is detached from charger 100B, handset 100 transmits the carrier to base unit 200. Master 200 receives the carrier from slave 100 and returns the carrier to slave 100 to enter the call mode.

At the time of an incoming call, the parent device 200
0, the slave unit 100 receives the carrier from the master unit 200, replies the carrier to the master unit 200, rings the bell, and the user sets the slave unit 100 to the charger 1
The call mode is set by removing from 00B.

Here, when a power failure occurs, the supply of DC power from the charger 100B is interrupted.
70 is turned “off”, but the second switch 190 continues to be in the “on” state, and the charged power supply 150
Is supplied through the constant voltage circuit 140, and the internal circuit is operable.

On the other hand, the on-base / off-base detection circuit 1
Reference numeral 80 detects off-base because no DC power is supplied from the charger 100B. The MPU 130 takes in the detection result of the on-base / off-base detection circuit 180 at a fixed cycle. The slave 100 detects the off-base, and sends the carrier to the master 200, but cannot return the carrier because the master 200 is out of power.

The MPU 130 determines that a power failure has occurred since the slave unit 100 is off-base and there is no carrier reply from the master unit 200, and turns off the second switch 190.
And

As described above, the slave unit 100, when detecting a power failure, turns off the first and second switches 170 and 190 and disconnects the internal circuit from the power supply unit 150, thereby eliminating power consumption at the time of the power failure. Normal operation can be performed immediately after the power is restored.

[0030]

FIG. 2 is a diagram for explaining an embodiment of the present invention.
The figure shows an example in which the first switch 170 and the second switch 190 described with reference to FIG. 1 are constituted by electronic switches using transistors.

In FIG. 2, the battery unit BATT and the charging circuit 16 are used as the power supply unit 150 described in the principle diagram of FIG.
As 0, the resistor R3, the diode D1, the resistors R1, R2 as the on-base / off-base detection circuit, the transistors Tr1, Tr2, the resistor R4, as the first switch 170,
R5, R6, R7, and the second switch 190 include a transistor Tr3 and resistors R8, R9.

Audio circuit 110, radio circuit 120, MPU
130, constant voltage circuit 140, AC adapter 100A, 2
00A, the charger 100B, the parent device 200, and the PBX 300 are the same components as described in the principle diagram.

Normally, when handset 100 is set in charger 100B, DC adapter 100A
Power is supplied to the battery BATT through the charger 100B, the resistor R3, and the diode D1 to perform charging.

In this state, the portion between the base and the emitter of the transistor Tr1 is turned "on".
The portion between the collector and the emitter of r1 is turned on, and a current flows between the emitter and the base of the transistor Tr2. Then, between the emitter and the collector is also turned on, and the constant voltage circuit 140 supplies DC constant voltage power to the internal circuit to
“0” indicates an operating state.

When the voltage drop of the resistor R2 of the on-base / off-base detection circuit 180 composed of the resistors R1 and R2 is V1, this voltage is applied to the port P0 of the MPU 130.
, The MPU 130 determines that it is on-base, and outputs a “low” level (hereinafter, referred to as “L”) from the port P1. Due to this "L", a current flows between the emitter and the base of the transistor Tr3, and the region between the emitter and the collector is also turned "on".

On the other hand, base unit 200 is an AC adapter 200A.
It is operated by the DC power supply supplied by. Here, at the time of transmission, the carrier is transmitted to base unit 200 by setting handset 100 off-base. The parent device 200 is the child device 10
When a carrier from 0 is received, the carrier is returned to the slave unit 100, and the communication mode is set.

At the time of an incoming call, master device 200 transmits a carrier to slave device 100. Slave device 100 receives the carrier from master device 200, replies the carrier to master device 200, rings the bell, and sets the slave device 100 to the off-base mode so that the user enters the call mode.

Here, when a power failure occurs, no DC power is supplied from the charger 100B, and the battery BATT is not charged. Therefore, no current flows between the base and the emitter of the transistor Tr1, and the region between the collector and the emitter is turned off. Transistor Tr1 is "off"
Therefore, no current flows between the emitter and the base of the transistor Tr2, and the region between the emitter and the collector is turned off.

In this state, the port P1 of the MPU 130
Output “L” from the transistor Tr.
3 is "on" between the emitter and the collector, and the power from the battery BATT is supplied to the internal circuit through the transistor Tr3 and the constant voltage circuit 140, so that the operation state is continued.

Further, the voltage drop of the resistor R2 is
When the power is taken into the port P0, the power is not supplied from the charger 100B and is lower than the threshold level.

On the other hand, master device 200 is
The power supply from A is lost, and the device cannot operate. Therefore, slave 100 detects the off-base and transmits the carrier, but master 200 cannot reply the carrier to slave 100.

The MPU 130 of the slave unit 100 determines that the power failure has occurred since the slave unit 100 is off-base and there is no carrier reply from the master unit 200, and the port P1
Output a "high" level (hereinafter referred to as "H"). This "H" indicates that the emitter of the transistor Tr3
No current flows between the bases, and the region between the emitter and the collector is turned off.

By the above-described operation, the transistors Tr1, Tr2 and Tr3 are turned off at the time of power failure, and the battery BATT and the constant voltage circuit 140 are disconnected. When power is restored, normal operation can be performed immediately.

In the above description, the slave unit is set in the charger to charge the internal battery of the slave unit and supply power to the internal circuit. It is also possible to set.

[0045]

According to the present invention, it is detected that power is not supplied to the slave unit of the wireless device and that there is no return of the carrier from the master unit, it is determined that a power failure has occurred, and the power source of the slave unit is disconnected. Thus, it is possible to realize a power saving circuit of a slave unit of a wireless device that can reduce the power consumption during a power failure to “0”.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating the principle of the present invention.

FIG. 2 is a diagram illustrating an embodiment of the present invention.

FIG. 3 is a diagram illustrating a cordless telephone system accommodating a private branch exchange.

FIG. 4 illustrates a conventional example.

[Explanation of symbols]

100, 100a Slave device 100A, 200A AC adapter 100B
Charger 110, 210 Audio circuit 120, 2
Reference Signs List 20 wireless circuit 130, 230 MPU 140 constant voltage circuit 150 power supply unit 150A, 320 secondary battery 160 charging circuit 170 first switch 180 on-base / off-base detection circuit 190 second switch 200 master unit 250A primary battery 300 PBX 300A Backup power supply 310 Software Tr1, Tr2, Tr3 Transistors R1 to R9
Resistance D1 Diode A Antenna BATT Battery CN Outlet

Continued on the front page (72) Inventor Satoshi Hirose 1-33-1 Higashisakura, Higashi-ku, Nagoya City, Aichi Prefecture Inside Fujitsu Nagoya Communication System Co., Ltd. (72) Inventor Kiyofumi Hayashi 1015 Uedanaka, Nakahara-ku, Kawasaki City, Kanagawa Prefecture (56) References JP-A-2-151134 (JP, A) JP-A-5-130012 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) H04B 7/24 -7/26 102 H04Q 7/00-7/38

Claims (2)

(57) [Claims] 1. A power saving circuit of a slave unit (100) of a mobile communication device including a slave unit (100) and a master unit (200), wherein the audio circuit (110) performs a call with a partner, and The output of the circuit (110) is converted into a radio signal to
00), a microprocessor (130) for controlling communication with the master unit (200), the audio circuit (110), the wireless circuit (120), and the wireless circuit (120). Microprocessor (130)
A constant voltage circuit (140) for supplying a constant voltage to the power supply, and a power supply unit (150) for supplying power to the constant voltage circuit (140)
And a charging circuit (16) for charging the power supply unit (150).
0), a first switch (170) that is turned on by detecting that power is supplied from the charger (100B), and the charging circuit (160). An on-base / off-base detection circuit (180) for detecting as an on-base when the supply voltage to the power supply is equal to or higher than a predetermined voltage and as an off-base when the supply voltage is equal to or lower than the predetermined voltage; A second switch (190) that is turned off when a detection circuit (180) detects an off-base and no carrier from the master unit (200) is detected; and supplies the second switch (190) to the charging circuit (160). When a voltage is applied, the first switch (1) is supplied from the power supply unit (150).
70) and the second switch (190) to supply power to the constant voltage circuit (140). If the supply voltage to the charging circuit (160) is not applied, the charging circuit (160) ), The first switch (170) is turned off, and the carrier from the master unit (200) is not detected in this state, so that the second switch (170) is turned off. A power saving circuit for a slave unit of a mobile communication device, wherein (190) is turned off and the slave unit (100) consumes no power. 2. The power saving circuit of a slave unit of a mobile communication device according to claim 1, wherein the first switch (170) and the second switch (190) are electronic switches. .