JPH1032539A - Power source switch system for portable radio telephone equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify a signal connection system between a portable radio telephone equipment and an on-vehicle adapter by providing a portable radio telephone equipment side with a power source switch part for interrupting the input of a battery power source only when an external power source is inputted to an external power source input terminal and preventing the external power source from flowing back to the input terminal of the battery power source input terminal. SOLUTION: The power source switch part 10 operates to select a power source from one of the battery power source from a battery part 14 and a battery power source from an on-vehicle external device 20 based on the presence/absence of the voltage of an external power source line 30b being an external power source supply line and to supply it to the portable radio telephone equipment. In a state where an ignition signal line 20a is turned off, operation power source to the equipment 1 is supplied from the battery part 14 and the equipment 1 is controlled by a control part 7. In a state where an ignition signal line 20a is turned on, the external power source is supplied as the operation power source from the battery of a vehicle to the equipment 1 through the device 20.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power supply switching method for a portable radio telephone, and more particularly, to a power supply switching method for a portable radio telephone which obtains an operation power supply from a secondary battery when it is carried and an operation power supply from a vehicle battery power supply when it is mounted on a vehicle. About.

[0002]

2. Description of the Related Art A general portable radio telephone is configured so that it can be used as a vehicle radio telephone by being connected to an external device (vehicle adapter) mounted on a vehicle. When the vehicle is mounted on a vehicle, a power supply switching method for obtaining operating power from a vehicle battery power supply (hereinafter, also referred to as an external power supply) is adopted.

FIG. 3 is a block diagram for explaining this kind of conventional power supply switching system disclosed in Japanese Patent Application Laid-Open No. 6-61909. The mobile radiotelephone 301 includes the transmitting unit 30
2, receiving unit 303, duplexer 304, antenna 305, signal processing unit 306, control unit 307, operation unit 308, display unit 309, power supply switching unit 310, external interface unit 31
1, a microphone 312, a speaker 313, and a battery unit (secondary battery) 314. In-vehicle external device 3
20 is a vehicle-mounted device interface unit 321, a power control unit 3
22; a battery power input terminal 323; and an ignition signal input terminal 324. When the portable wireless telephone 301 is installed in the external device 320, the data transmission / reception line 330a and the external power line 33
0b, a connection cable 330 composed of an ignition signal line 330c.

Next, the operation will be described. In the mobile wireless telephone 301, the sound input from the microphone 312 is transmitted to the microphone amplifier, bandpass filter,
The signal is converted into a radio signal via a compressor, a pre-emphasis circuit or the like (not shown), is FM-modulated by the transmission unit 302, passes through the duplexer 304, and is transmitted as a radio wave from the antenna 305. In reception, the radio wave input from the antenna 305 is transmitted to the
M demodulated, de-emphasis in the signal processing unit 306,
The signal is converted into an audio signal via a band-pass filter, an expander, a receiver amplifier circuit and the like (not shown), and is output from the speaker 313 as audio or sound.

[0005] The control unit 307 includes a channel designation, a carrier on / off control in the transmission unit 302, and a reception unit 303.
Channel designation, monitoring control of the received electric field strength, designation of the voice path of the signal processing unit 306, data processing with the base station, data processing with the operation unit 308, control processing of the display unit 309, on-board via the external interface unit 311 External device 320
Data transmission / reception processing, power supply control processing of the vehicle-mounted external device 320, power supply control processing of the vehicle-mounted external device 320 by monitoring the external interface unit 311, and power supply control processing of the vehicle-mounted external device 320 by monitoring the external interface unit 311. Perform connection presence detection processing. Also, the power supply switching unit 31
0 is the power supply battery from the battery unit 314 and the external device 3 for the vehicle.
Power from either one of the battery power from
The selection is performed based on the control signal from the ignition signal line 330b, and operation is performed to supply the selection to the portable wireless telephone 301.

In the vehicle-mounted external device 320, the vehicle battery power input from the battery power input terminal 323 is converted into a predetermined voltage by the power control unit 322, and is externally transmitted to the portable wireless telephone 301 via the external power line 330b. It is configured to be output as a power source, and a vehicle ignition signal input through an ignition signal input terminal 324 is supplied to a power source control unit 322 and the portable wireless telephone 301 through an ignition signal line 330c.
And information for controlling on / off of the external power supply output from the power supply control unit 322. Power control unit 32
2 transmits / receives data to / from the portable wireless telephone 301 via the on-board unit interface unit 321 to monitor data received from the portable wireless telephone 301, and monitors the ignition signal line 330c to connect to the external power supply line 330b. Turns on / off the output external power supply.

[0007] That is, when the power supply control unit 322 receives the external power supply information from the portable radio telephone 301, the power supply control unit 322 enters a connection state for supplying external power to the portable radio telephone 301.
In a connection state for supplying external power, an ignition signal line 33 indicating on / off of the ignition of the car.
According to 0c, when the ignition signal line 330c is on, external power is supplied to the portable wireless telephone 301, and when the ignition signal line 330c is off, the power supply to the portable wireless telephone 301 is stopped.
That is, when the ignition signal line 330c is off, even if external power supply information is received from the portable wireless telephone 301, no external power is supplied.

[0008] The portable radio telephone 3 configured as described above.
The operation of the power supply system when the external device 01 and the external device 320 are connected will be described. First, a case will be described in which the vehicle is in a non-operating state, that is, an ignition signal line 330c indicating an on / off state of the ignition of the vehicle is in an off state. In the power switching unit 310, the terminals 310a and 310c
The power is supplied to the portable wireless telephone 301 from the battery unit 314 after the connection is established, and the portable wireless telephone 301 is activated under the control of the control unit 307.

Next, a description will be given of a case where the vehicle is in the operating state, that is, the ignition signal line 330c indicating the on / off state of the ignition of the vehicle is in the on state. When the ignition signal line 330c is turned on, the power supply switching unit 310 operates to switch the terminal connection by using this signal as a control signal, and the terminals 310b and 310c are connected to each other. The portable wireless telephone 301 is supplied from the battery of the vehicle via the external device 320 and is started under the control of the control unit 307. As described above, in the conventional power supply switching method of the portable radio telephone, the portable radio telephone 301 includes the power supply switching unit 310 that operates using the ignition signal as a control signal, and the external power supply input to the terminal 310a and the power supply input to the terminal 310b. The operation power supply is obtained from one of the battery power supplies.

[0010]

In the above-described conventional power supply switching method for a portable radio telephone, since the power supply switching unit is operated by using an ignition signal as a control signal, the portable radio telephone and the external device for the vehicle are installed. In addition, it is necessary to form an ignition signal line in addition to the data transmission / reception line and the external power supply line, and the signal connection system between the portable wireless telephone and the vehicle adapter becomes complicated,
There are problems such as a large restriction in design and an increase in manufacturing cost due to an increase in the number of parts.

The present invention has been made in order to solve such a problem, and has a structure in which a power supply switching unit is operated when an ignition signal is on without requiring a special control line such as an ignition signal line. It is an object of the present invention to provide a portable radio telephone power supply switching system in which a signal connection system between the portable radio telephone and a vehicle-mounted adapter is simplified.

[0012]

A power supply switching system for a portable radio telephone according to the present invention is installed in a vehicle-mounted external device mounted on a vehicle, and is provided only when an ignition signal of the vehicle is turned on. In the power supply switching system of a portable wireless telephone that operates to supply operating power from a battery power supply of the vehicle through the device and to supply operating power from the other battery power supply, the vehicle is provided on the vehicle-mounted external device side, A power supply control unit that outputs an external power supply from the battery power supply of the car only when the ignition signal is in an on state, a battery power supply input terminal that is provided on the mobile wireless phone side and that inputs the battery power supply; An external power supply input terminal for inputting, and an output terminal for outputting an operation power supply of the portable wireless telephone, wherein an external power supply is input to the external power supply input terminal. While blocking the input of the battery power supply only when, characterized in that the external power source with a power switching unit, which is configured to prevent the backflow into the battery power input terminal.

The battery power supply and the external power supply are set to have different voltage values, and the power supply switching unit is configured such that its drain is the battery power supply input terminal and its ground is connected to the source via a diode. It is characterized by comprising a circuit in which the external power supply input terminal is used, and the source of which is the output terminal, and a circuit in which a drain and a source are connected by a parasitic diode for preventing backflow. Therefore, the power supply switching unit does not need a control signal such as an ignition signal, and can perform appropriate power supply switching control similar to that of the conventional device.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of a power supply switching method for a portable radio telephone according to the present invention. In the drawing, reference numeral 1 denotes a portable radio telephone, and reference numeral 20 denotes a vehicle-mounted external device (vehicle adapter). The mobile radiotelephone 1 includes a transmitting unit 2, a receiving unit 3, a common unit 4, an antenna 5, a signal processing unit 6, a control unit 7, an operating unit 8, a display unit 9, a power switching unit 10, an external interface unit 11, and a microphone 12. , Speaker 13, battery unit 1
4. The vehicle-mounted external device 20 includes a vehicle-mounted device interface unit 21, a power control unit 22, a battery power input terminal 23, and an ignition signal input terminal 24. When the mobile radiotelephone 1 is installed on the external device 20, the data transmission / reception line 30
connection cable 3 composed of a and an external power supply line 30b
0 is connected.

Next, the operation of the portable radio telephone 1 will be described. In the mobile wireless telephone 1, the sound input from the microphone 12 is converted into a wireless signal via a microphone amplifier, a band-pass filter, a compressor, a pre-emphasis circuit and the like (not shown) in the signal processing unit 6, and the transmission unit 2 The signal is FM-modulated, transmitted through the duplexer 4, and transmitted from the antenna 5 as a radio wave. In reception, the radio wave input from the antenna 5 is FM-demodulated by the receiving unit 3 through the duplexer 4, and the de-emphasis, band-pass filter,
The audio signal is converted into an audio signal via an expander, a receiver amplifier circuit, etc. (not shown), and output from the speaker 13 as audio or sound.

The control unit 7 specifies a channel in the transmission unit 2, controls carrier on / off, specifies a channel in the reception unit 3, monitors and controls the received electric field strength, specifies a voice path in the signal processing unit 6, and controls communication with the base station. Data processing, data processing with the operation unit 8, control processing of the display unit 9, data transmission / reception processing with the external vehicle-mounted device 20 via the external interface unit 11, power supply control processing of the vehicle-mounted external device 20, external interface unit 1
1 to detect whether or not the vehicle-mounted external device 20 is connected. In addition, the power supply switching unit 10 switches the power supply from one of the battery power supply from the battery unit 14 and the battery power supply from the vehicle-mounted external device 20 based on the presence or absence of the voltage of the external power supply line 30b which is the external power supply line. Then, the operation is performed so as to be supplied to the portable radio telephone 1.

Next, the operation of the external device 20 will be described. The vehicle battery power input from the battery power input terminal 23 is converted into a predetermined voltage by the power control unit 22 and output to the portable wireless telephone 1 as an external power via the external power line 30b. The ignition signal of the car input from the ignition signal input terminal 24 is
Power control unit 2 via ignition signal line 20a
2 to control on / off of an external power supply output from the power supply control unit 22. Therefore, the external power supply is not output from the vehicle-mounted external device 20 to the portable wireless telephone 1 unless the ignition signal is turned on. That is, the power supply control unit 22 transmits / receives data to / from the portable wireless telephone 1 via the on-board unit interface unit 21 to monitor data received from the portable wireless telephone 1 and also monitors the ignition signal line 20a, thereby enabling external control. On / off of an external power supply output to the power supply line 30b is controlled.

That is, when the power supply control unit 22 receives the external power supply information from the portable radio telephone 1, the power supply control unit 22 is connected to supply the external power to the portable radio telephone 1, and in the connection state for supplying the external power, the ignition of the vehicle is started. In response to an ignition signal line 20a indicating ON / OFF, when the ignition signal line 20a is ON, external power is supplied to the portable wireless telephone 1, and when the ignition signal line 20a is OFF, external power is supplied to the portable wireless telephone 1. Stop output of That is, the external power supply is not performed even when the external power supply information is received from the portable wireless telephone 1 when the ignition signal line 20a is off.

The mobile radio telephone 1 configured as described above
The operation of the power supply system when the vehicle and the in-vehicle external device 20 are connected will be described. In the following description, a case is described in which the power supply voltage supplied to the portable wireless telephone 1 is set higher in the external power supply than in the battery power supply. First, a case will be described in which the vehicle is in a non-moving state, that is, the ignition signal line 20a indicating the ON / OFF state of the ignition of the vehicle is in an OFF state. When the ignition signal line 20a is in the off state, there is no input of external power from the vehicle-mounted external device 20.
0c is connected, the operating power supply to the portable wireless telephone 1 is supplied from the battery unit 14, and the portable wireless telephone 1 is activated under the control of the control unit 7. In addition, the vehicle-mounted external device 20
Is not connected, the external power source is not input to the power source switching unit 10 from the external power source line 30b, so that the power source switching unit 10 is started with the battery power source.

Next, the case where the vehicle is in the operating state, that is, the ignition signal line 20a indicating the on / off state of the ignition of the vehicle is in the on state will be described. When the ignition signal line 20a is in the ON state, external power is supplied from the vehicle-mounted external device 20 to the external power supply line 30b.
The state between a and 10b is set to the release state. On the other hand, external power line 3
0b is output from the power supply switching unit 10 to the portable wireless telephone 1 as an operating power supply via the diode 10d in the power supply switching unit 10, that is, the vehicle is supplied to the portable wireless telephone 1 via the vehicle-mounted external device 20. The external power supply from the battery is supplied as the operation power supply, and the portable radio telephone 1 is started under the control of the control unit 7. That is, as will be described later, the power supply switching unit 10 detects the voltage of the power supply line 30b and releases the connection between the terminal connections 10a and 10c, so that the power supply unit can be connected to the battery power supply without using another control signal as in the conventional device. It is configured to switch between an external power supply.

Next, an example of the actual circuit configuration and operation of the power supply switching unit 10 shown in FIG. 1 will be described. FIG. 2 is a block diagram showing a circuit configuration (power supply switching system) around the power supply switching unit 10. As shown in FIG. 2, the power supply switching method of the portable wireless telephone according to the present embodiment includes a control unit 7, a power switch unit 221, an operation unit 8, a battery power input terminal 202 for inputting battery power, and an external power input terminal 202 for inputting external power. Power line 30b
The external power supply input terminal 204 connected to the external power supply, the power supply output terminal 210 for outputting either the external power supply or the battery power supply, and the voltage of the battery power supply line 201a are monitored to detect and control the presence or absence of the battery power supply based on the voltage. A battery power detection unit 203 that sends information to the unit 7, and an external power line 201b
The external power supply detecting unit 205 detects the presence or absence of the external power supply voltage by monitoring the voltage of the external power supply and sends the information to the control unit 7, and the power supply switching unit 201.

The power supply switching section 201 has a drain terminal connected to the battery power supply line 201a, a source terminal connected to the power supply switch section 221, and a gate terminal connected to the resistor 20.
F of P channel connected to GND via 7,208
ET 206 and its anode terminal are connected to the resistor 207 and the resistor 2
A diode 209 is connected to the external power supply input terminal 204 at a connection point 08 and has a cathode terminal connected to the source terminal of the FET 206. The control unit 7 includes an operation unit 8
The power switch unit 221 is controlled based on the respective power monitoring results of the battery power detection unit 203 and the external power detection unit 205 based on the operation information from the PC to perform on / off control of the operation power supply to the portable wireless telephone 1. .

When battery power is being input to battery power input terminal 202 and external power is not being input to external power input terminal 204, power supply switching section 201 outputs battery power to power output terminal 210. This is because, since there is no external power input, the voltage of the external power supply line 210b is at the GND level, so that the gate terminal of the FET 206 is at the GND level, and the battery power is input to the source terminal of the FET 206, so that the source of the FET 206 is input. A voltage is generated by the parasitic diode between the drain and the FET 20
A potential difference occurs between the gate and the source of No. 6. Therefore, the FET 206 is turned on by the potential difference between the gate and the source, and the battery power is output from the power output terminal 210.

When battery power is input to the battery power input terminal 202 and external power is also input to the external power input terminal 203, the power switching unit 201 outputs the external power from the power output terminal 210. This is because when the external power is input to the external power input terminal 204, the FET 206 is turned off, the battery power is cut off, and the external power is
9 through the power switch unit 221. The FET 206 is turned off because, as described above, the voltage of the external power supply is set higher in the battery power supply and the external power supply, and therefore, a current flows from the gate terminal to the source terminal by the diode 209, and the voltage between the gate and the source is increased. This is because they have the same potential.

Further, since the parasitic diode is inserted, even if the external power supply voltage is set higher than the battery power supply voltage, the influence on the battery power supply can be ignored. Therefore, the power supply switching unit 201 only needs to input an external power supply,
It is possible to switch to an external power supply without a reverse current to the battery power supply input terminal 202 side.

With the circuit configuration as described above, the power supply switching method of the portable radio telephone according to the present embodiment supplies the battery power as the operating power of the portable radio telephone 1 when only the battery power is supplied, and the external power supply when only the external power is supplied. Is supplied as operating power. When both the battery power and the external power are input, the external power is supplied. Also, when the external power is supplied by inputting only the external power, the external power is supplied as it is even when the battery power is input. However, when the battery power is supplied only by the input of the battery power and the external power is input, the power is switched to the external power and supplied. Also, if both battery power and external power are input and the battery power is not supplied while the external power is being output, the external power is supplied as it is, but both battery power and external power are input. When the external power is not supplied while the external power is being supplied, the operation is performed so as to switch to the battery power and supply the battery power. Of course, as described above, this external power supply is input to the power supply switching unit 10 only when the ignition signal is in the ON state, so that control can be performed by turning on / off the ignition signal as in the conventional method.

Since the output of the battery power detection unit 203 and the output of the external power supply detection unit 205 can detect the presence or absence of the power supply, the control unit 7 can easily determine which power supply the output of the power supply switching unit 201 is. It can be detected. Control unit 7
By controlling the power switch 221 as necessary, the power supply of the portable wireless telephone can be controlled. For example, in a state in which both the battery power supply and the external power supply are input and the external power supply is supplied, and if the external power supply is lost, it is desired to turn off the power of the portable radio telephone. Since the output of the external power supply detection unit 205 is monitored in step (3), when it is detected that there is no external power supply, the power supply switch 221 can be turned off to shut off the supply of battery power.

[0028]

As described above, the power supply switching method for a portable radio telephone according to the present invention uses a battery power supply and a vehicle battery power supply via a vehicle-mounted adapter, and an ignition signal line or the like between the portable radio telephone and the vehicle-mounted adapter. Can be appropriately switched without the need to form a control line, and the signal connection system between the portable wireless telephone and the on-vehicle adapter can be simplified, thereby reducing design constraints. In addition, there is an effect that cost can be reduced by reducing the number of parts.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a mobile phone according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a circuit configuration around a power supply switching unit 10;

FIG. 3 is a block diagram for explaining a power supply switching method of a conventional portable radio telephone of this type.

[Explanation of symbols]

 1,301 Portable radiotelephone 2,302 Transmitting unit 3,303 Receiving unit 4,304 Common unit 5,305 Antenna 6,306 Signal processing circuit 7,307 Control unit 8,308 Operation unit 9,309 Display unit 10,310 Power supply Switching unit 11, 311 External interface unit 12, 312 Microphone 13, 313 Speaker 14, 314 Battery unit 20, 320 Vehicle-mounted external device 20a, 330c Ignition signal line 21, 321 Vehicle-mounted device interface unit 22, 322 Power supply control unit 23, 323 Battery power input terminal 24,324 Ignition signal input terminal 30a, 330a Data transmission / reception line 30b, 330b External power line 201 Power supply switching unit 201a Battery power line 201b External power line 202 Battery power input terminal 203 Battery power detection unit 2 4 external power input terminal 205 external power detecting unit 206 FET 207, 208 resistors 209 diode 210 power output terminal 221 power switch unit

Claims (2)

[Claims] 1. An operation power supply is provided from a battery power supply of a vehicle via the vehicle-mounted external device only when an ignition signal of the vehicle is set to an ON state. Other than the above, in a power supply switching method of a portable radio telephone that operates so as to supply operating power from a battery power supply, provided outside the vehicle-mounted external device and provided only when the ignition signal is in an ON state. A power control unit that outputs power, a battery power input terminal that is provided on the mobile wireless phone side and that inputs the battery power, an external power input terminal that inputs the external power, and outputs an operating power of the mobile wireless phone And an input terminal for shutting off the input of the battery power only when external power is input to the external power input terminal. Power switching system of the mobile radio telephone, characterized in that it comprises a power switching unit, which is configured to prevent the backflow into the battery power input terminal. 2. The battery power source and the external power source are set to have different voltage values, and the power source switching unit is configured such that its drain is the battery power source input terminal and its ground is connected to a source via a diode. FET with the external power input terminal and the source as the output terminal
And a circuit in which a drain and a source are connected by a parasitic diode for preventing a backflow.
The power supply switching method of the portable radio telephone according to the item.