JPH0524694B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an improvement in a radio telephone device using a battery as a power source, such as a radio telephone device for automobiles.

(Prior Art) Conventionally, as shown in FIG. 1, this type of device conventionally includes a transmitting section 1, a receiving section 2, and a frequency synthesizer section 3 that supplies a local oscillation frequency to these sections.
, a transmitting/receiving duplexer 5 that connects the transmitting section 1 and the receiving section 2 to the antenna 4, a control section 6 that controls the operation of each of these sections, and a telephone section 7, and each of these sections has a Car battery 8
The device is configured to drive each section by supplying a power output voltage from the power supply section 9 through the power supply section 9 to perform a telephone call.

By the way, in conventional devices of this type, a voltage detection circuit is generally provided in the power supply section 9, and this circuit monitors the output voltage level of the battery 8 to determine whether this voltage level is necessary to ensure that all the sections operate. When the voltage falls outside the voltage range, it is assumed that there is a power supply abnormality and the supply of battery output voltage to each part is cut off. Therefore, malfunction of each part can be prevented.

(Problems to be Solved by the Invention) However, in general, a battery may cause a temporary drop in output voltage when starting an engine or during cold weather. On the other hand, in the conventional device, the lower limit of the power supply abnormality detection level is set to a relatively high value (approximately 10V) corresponding to a level that can guarantee the operation of all parts, for example, the operation guarantee level of the frequency synthesizer section 3. There is. Therefore, if a temporary drop in the output voltage occurs during a call and the voltage drops below the power supply abnormality detection level, the device will disconnect all circuits necessary for the call, including the control unit 6, even though the device is in the middle of a call. The power supply is cut off and the output voltage returns to the initial state. Therefore, even if the battery voltage returns to a normal value, the device will not return to the talking state, and in order to resume the call, you will have to perform the call operation again to call the other party. Because it doesn't happen,
The operation became troublesome and I did not like the service.
Furthermore, since the control channel is once again used exclusively for connection control when making the above-mentioned call, there is also the problem that line usage efficiency is reduced.

The present invention has focused on this point, and when the battery output voltage temporarily decreases to a small extent, the radio section malfunctions to prevent unnecessary radio waves from being sent out, and the control section maintains the control operation to maintain the state before the voltage drop. It is possible to continue device operation after the voltage is restored, and if the battery output voltage has significantly decreased,
An object of the present invention is to provide a wireless telephone device that can reliably prevent malfunctions of the device including a wireless section and a control section.

(Means for Solving the Problems) The present invention focuses on the fact that a control section using a microcomputer generally has a wider range of guaranteed operation than a radio section including a frequency synthesizer, etc.
It is monitored whether the output voltage level of the battery is within the first and second operation guaranteed voltage ranges.
Based on this monitoring result, if the battery output voltage level is within the guaranteed operation range of the control unit and outside the guaranteed operation range of the wireless unit, the battery output voltage level is maintained to be supplied to the control unit. The transmission of radio waves from the radio section is prohibited, and if the battery output voltage level is outside the guaranteed operation range of the control section, the transmission of radio waves from the radio section is prohibited, and the battery output voltage level to the control section is prohibited. It was designed to cut off the supply.

(Function) Therefore, even if a temporary drop in the battery output voltage occurs and the voltage level falls outside the guaranteed operating voltage of the wireless unit, if it is within the guaranteed operating voltage range of the control unit, the wireless unit Since only the transmission of radio waves from the terminal is prohibited and the control section maintains its operating state, if the battery output voltage is restored in this state, it is possible to resume talking, etc. as is. Therefore, in this case, there is no need to call again, so the operation can be omitted and the operability can be improved. Furthermore, since re-calling is not required, there is no need to use a control channel, thereby reducing the traffic on the control channel and increasing line usage efficiency.

In addition, if the battery output voltage falls outside the guaranteed operation range of the control unit, the transmission of radio waves from the wireless unit is prohibited, and the supply of battery output voltage to the control unit is also cut off, preventing unnecessary radio waves. It is possible to prevent a problem in which a signal is sent out, and also to reliably prevent a malfunction of the control section.

(Embodiment) FIG. 2 is a block configuration diagram showing the parts related to the present invention of a radio telephone device according to an embodiment of the present invention, where 10 indicates the main body of the radio telephone device and 20 indicates a telephone set. Note that 8 is a battery for an automobile.

The radio telephone device body 10 includes a radio section 15 consisting of a modulation section 11, a reception section 12, a frequency synthesizer 13, and a power amplification section 14 that amplifies the output of the modulation section 11, and a microprocessor as a central processing circuit (CPU). It also has a control unit 17 incorporating a storage circuit 16 having a random access memory (RAM). And each of these parts 1
The output voltage of the battery 8 is supplied to the telephone set 5, 17 and the telephone set 20 through the DC/DC converter 18, respectively, and the telephone set 20 is driven.

Now, such a radio telephone device main body 10 includes a voltage detection circuit 21 that monitors the output voltage of the battery 8.
and a power supply control circuit 22 that operates according to a detection signal generated from the voltage detection circuit 21. The voltage detection circuit 21 performs the following detection operations. The operation is as follows: (i) The output voltage of the battery 8 is within the operation guaranteed range of the control unit 17 (for example, 5V or more and 17V or less) and the frequency synthesizer 1 of the radio unit 15
When it is less than the guaranteed operation level (10V) of 3.
A first detection signal DS1 is generated, and this signal DS1
The operation of supplying the information to the control unit 17.

(ii) An operation of generating a second detection signal DS2 when the output voltage of the battery 8 falls outside the guaranteed operation range of the control unit 17 (5V or more and 17V or less) and supplying this signal DS2 to the power supply control circuit 22.

On the other hand, the power supply control circuit 22 has an electromagnetic relay circuit, and receives a second detection signal from the voltage detection circuit 21.
When DS2 is supplied, each DC/DC from the battery 8 to the radio unit 15, control unit 17, and telephone 20
A relay contact 23 provided in the path leading to the converter 18 is opened to cut off the supply of output voltage from the battery 8. Note that this voltage supply cutoff state is canceled when the output voltage of the battery 8 returns to within the guaranteed operation range of the control section 17 and the second detection signal DS2 is turned off.

In addition to normal call connection control operations, the control section 17 performs the following control operations related to power supply abnormalities. The control operation is as follows: (i) the first detection signal from the voltage detection circuit 21;
When DS1 is supplied, first, information indicating the operating state of the device at that time, such as information indicating that a call is in progress, is temporarily saved in a register, and then the power amplifier 14 of the radio section 15 and the DC /DC converter 18 by opening the relay contact 24 provided between the power amplifier 1 and the DC converter 18.
Control that cuts off the power supply to 4 and thereby prohibits the transmission of radio waves.

(ii) In addition to the control in (i) above, a control is executed to issue a write prohibition command to the memory circuit 15 to shift the RAM to a storage content retention operation using a backup power source.

(iii) When the output voltage of the battery 8 returns to the operation guaranteed level (10V) of the frequency synthesizer 13 or higher and the first detection signal DS1 turns off, the write inhibited state for the RAM of the storage circuit 15 is released and , reads the operating state control information saved in the register, resets the oscillation frequency (call channel) of the frequency synthesizer 13 according to this information, and restores its own control operation to the state before the power failure occurred. Then, the relay contact 24 is closed and the power amplifying section 1
4 to resume the call.

It is.

In addition, 19 in the figure is a power switch provided in the telephone 20.

With such a configuration, for example, battery 8
When the output voltage of the battery 8 significantly decreases due to exhaustion or cold weather and becomes less than the guaranteed operation level (5V) of the control unit 17, this is detected by the voltage detection circuit 21 and a second detection signal DS2 is generated. . Then, the power supply control circuit 22 causes the relay contact 23 to
is closed and the power supply to the radio unit 15, control unit 17 and telephone 20 is cut off, and as a result, the device shifts to an inactive state. In other words, the same countermeasures for power supply abnormalities as in the past are taken.

Now, for example, when the car engine is started during a phone call and the output voltage of the battery 8 decreases, and this voltage becomes less than the guaranteed operation level (10V) of the frequency synthesizer 13, the voltage detection circuit 2
1 to generate a first detection signal DS1. Then, for example, the control unit 17 enters a state where it receives an interrupt and starts executing a program for use in the event of a power failure, first saves the call control information at this point in a register, and opens the relay contact 24 to transmit radio waves. Prohibit sending. Therefore, due to the decrease in the battery output voltage, the frequency synthesizer 1
Even if the oscillation frequency of No. 3 fluctuates, defective radio waves affected by the fluctuation will not be transmitted.

Further, the control unit 17 subsequently issues a write prohibition command to the storage circuit 16 to separate the RAM from the CPU. Therefore, if the battery output voltage further decreases and becomes below the operation guaranteed level of the control unit 17,
As a result, a second detection signal DS2 is generated, and the power supply to the control section 17 is cut off.
Even if 7 malfunctions, the contents of the RAM will not change, such as being rewritten or erased. Moreover, since the power supply to the control section 17 is maintained in a state where the battery output voltage is less than its guaranteed operation level, malfunction of the control section 17 during this period is reliably prevented.

On the other hand, when the output voltage of the battery 8 returns to the operation guaranteed level (10V) of the frequency synthesizer 13 or higher and the first detection signal DS1 turns off, the control section 17 selects a recovery program and first At the same time, the operating state of the wireless unit 15 and its own operating state are returned to the state before the power failure occurred according to the call control information saved in the register, and in this state, the relay contact 24 is closed to drive the power amplifying section 14. The device then resumes the call.

As described above, in this embodiment, when the operation is within the guaranteed operation range of the control section 17 and below the operation guarantee level of the frequency synthesizer 13, the control section 17 holds the call control information and prohibits the transmission of radio waves, respectively. By doing this, it is possible to reliably prevent the transmission of unnecessary radio waves and to reliably resume calls after the power is restored. Therefore, it is possible to improve operability by eliminating the need for re-call operations as in the past.Furthermore, since there is no need to use the control channel required for re-calling, line usage efficiency can be improved. It can be measured. In addition, when the output voltage of the battery 8 drops, a write prohibition command is issued to the memory circuit 16 to separate the RAM from the CPU, so if the power supply is cut off,
Even if the CPU malfunctions, the contents of RAM can be reliably retained. As a result, the conventional
Since no control operation is required to reset the contents of the RAM, there is no need to use the control channel, and the traffic on the control channel can be reduced. This eliminates the need for re-calling, and together with this, it becomes possible to improve the line usage efficiency, and it is possible to realize good service.

Note that the present invention is not limited to the above embodiments. For example, in the embodiment described above, a case was explained in which an automobile battery was used, but the present invention can be similarly applied even when a non-rechargeable dry cell battery is used. Further, in the above embodiment, as a means for prohibiting the transmission of radio waves, the power supply to the power amplification section 14 is cut off, but it may also be done by cutting off the signal sent from the power amplification section to the antenna. Alternatively, the transmission of unnecessary radio waves may be prohibited by placing the entire wireless section in an inoperable state. In addition, the configuration of the voltage detection means, the control section, and the means for cutting off the supply of output voltage from the battery can be modified in various ways without departing from the gist of the present invention.

(Effects of the Invention) As described in detail above, the present invention monitors whether the output voltage level of the battery is within the first and second guaranteed operation voltage ranges, and based on the monitoring results, If the output voltage level is within the guaranteed operation range of the control unit and outside the guaranteed operation range of the wireless unit, the battery output voltage is kept supplied to the control unit and the transmission of radio waves from the wireless unit is prohibited. On the other hand, if the battery output voltage level is outside the guaranteed operation range of the control section, transmission of radio waves from the wireless section is prohibited and the supply of battery output voltage to the control section is cut off.

Therefore, according to the present invention, when the battery output voltage temporarily decreases to a small extent, transmission of unnecessary radio waves due to malfunction of the wireless section is prevented, and
It is possible to maintain the control operation of the control unit and continue the device operation before the voltage drop after the voltage is restored,
In addition, it is possible to provide a radio telephone device that can reliably prevent malfunction of the device including the radio section and the control section when the battery output voltage significantly decreases.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a schematic configuration of a radio telephone device using a battery as a power source, and FIG. 2 is a block diagram showing essential parts of a radio telephone device according to an embodiment of the present invention. 10...Radio telephone device body, 20...Telephone,
13... Frequency synthesizer, 15... Radio section,
16... Memory circuit, 17... Control unit, 21... Voltage detection circuit, 22... Power supply control circuit, 23, 24
...Relay contact.

Claims (1)

[Scope of Claims] 1. In a wireless telephone device that uses a battery as a power source and performs a predetermined call operation by controlling the operation of each part of the device including a wireless unit by a control unit, the output voltage level of the battery is monitored, and this voltage A first detection signal is generated when the level is within the guaranteed operation range of the control section and outside the guaranteed operation range of the wireless section, and a second detection signal is generated when the level is outside the guaranteed operation range of the control section. a voltage detection means for generating a first detection signal; and when a first detection signal is generated from the voltage detection means, at least a radio wave from the radio section is output while maintaining the supply of the battery output voltage to the control section. a first prohibition means for prohibiting the transmission of radio waves; and when a second detection signal is generated from the voltage detection means, at least prohibiting the transmission of radio waves from the radio section and controlling the transmission of radio waves to the control section. a second inhibiting means for cutting off the supply of the battery output voltage.