JPS61242130A - Battery type communication equipment - Google Patents

Abstract

PURPOSE:To open again a communication channel when a voltage is recovered by backing up also a control circuit for transmission and reception by a power supply which backs up a RAM for data in case the level of the voltage supplied from a battery is reduced. CONSTITUTION:A detecting circuit 55 detects that the voltage of a battery 51 is reduced less than a prescribed level and an interruption is applied to a CPU 31 by a detecting signal Sd. Then an interruption routine is executed by the CPU 31. In the routine all data needed to open again the present communication channel are saved at a RAM 41 and the transmission of a transmission circuit 24 is stopped. Then the port output Pa is set at H and transistors TR Q2 and Q1 are turned on. The voltage of a battery 42 is supplied to circuits 31-35 and the RAM 41 respectively. Both a microcomputer 30 and the RAM 41 are backed up by the battery 42. Thus the communication channel can be opened again correctly when the battery voltage is recovered.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a communication device that operates on a battery.

[Summary of the invention]

For example, in a car phone, when the supply voltage from the battery becomes low during a call, this invention can
The power supply that backs up the IAM also backs up the transmission and reception control circuits, so that when the supply voltage is restored, the existing communication channel can be resumed.

[Conventional technology]

In general, a mobile telephone has a structure as shown in FIG. That is, in the figure, (10) is the receiving line, (20) is the transmitting line, and when receiving a call, the tri-channel FM signal Sd from the base station is received by the antenna (11), and this signal Sd is The voice signal from the other party's telephone is supplied to the reception It!IvIN (11), which has everything from a high frequency amplifier to an FM demodulation circuit, and is then supplied to the receiver (13) through the amplifier (12).

Also, when transmitting a call, the audio signal from the transmitter (21) is
A transmitter circuit (which has everything from an FM modulation circuit to a high frequency power amplifier through an amplifier (22) and an adder circuit (23))
24) as an up-channel FM signal Su, and this signal Su is transmitted from the antenna (1) to the base station.

Furthermore, numeral 30 is a control circuit for controlling calls and the like, and this is constituted by an L-chip type microcomputer. In other words, the microcomputer (
30), (31) is a 4-pin CPU, (
32) is a ROM in which various programs for making calls etc. are written, and (33) is an RA for the work area.
M, (34) is a human-powered boat, (35) is an output boat, and these circuits (32) to (35) are connected to the system bus (3
9) to the CPLI (31).

And this microcontroller (30) has that bus (39)
RAM (41) is connected to the board (3), and the boat (3
4), (35), a detection circuit (15), a calling circuit (
25), a dial key (numeric keypad) (41), and a talk switch (hook switch) (44) are connected.

In this case, the RAM (41) is used to store (save) essential data such as the own station's ■Locode and data for additional functions such as abbreviated numbers. is of the C-MOS type, and is backed up by a rechargeable battery (42) such as a nickel-cadmium battery, and the output of the tail, master, detection circuit (15), and (11) is supplied. When a call is received from the other party, this is detected and notified to the °C microcomputer (30). Further, the calling circuit (25) forms a signal of the telephone number of the other party in accordance with the output of the dial key (44) when making a call to the other party from this car phone.
The signal is supplied to an adder circuit (23) and transmitted to the base station by signal Su.

Further, from the boat (35) of the microcomputer (30), a permission signal TXEN for transmitting the signal Su and a C11 signal specifying the channel of the signals Su and Sd are taken out and sent to the receiving circuit (11) and the transmitting circuit (24). Supplied.

[Problem that the invention seeks to solve]

By the way, if the starter motor does not start due to the engine stalling of the car, a large current flows from the car battery at this time, so the voltage of the car battery may drop significantly.

Then °ζ, when the supply voltage from the car battery decreases,
Since the frequency division ratio of the PLL which determines the communication channel (frequency of the signal Sds Su) in the receiving circuit (11) and the transmitting circuit (24) is disturbed, normal transmission and reception cannot be performed.

Therefore, in the case of American car phones, the power supply ratio is 16.5V to 16.5V to protect the set and prevent abnormal transmissions.
When it is in the range of 9v, it is iJ function and 16.5■
It is specified that the supply voltage is to be turned off when the voltage is above 9, and the transmission is to be stopped when the voltage is 9 or higher.

Therefore, even if the supply voltage from the car battery decreases due to the activation of the starter motor during a car phone call,
Transmission is stopped and abnormal transmission is prevented.

However, with this alone, when the supply voltage from the car battery is restored and transmission is resumed, the frequency division ratio of the PLL of the receiving circuit (11) and the transmitting circuit (24) remains disturbed, so that transmission cannot be resumed. However, it will result in abnormal transmission.

Therefore, when the supply voltage goes low, all necessary data is saved in the RAM (41), and when the supply voltage is restored, the data saved in the RAM (41) is sent to each circuit. Consideration is being given to restarting transmission.

However, even if this is done, the operating voltage of the microcomputer (30) is generally 5V, and when the operating voltage drops below 5V, it will malfunction (runaway) or stop, and then the supply type When J-E recovers, the microcomputer (30)
My phone (30) will start from its initial state after being reset, and as a result, all previous calls will be cut off.

This invention is intended to solve the above problems.

[Means for solving problems]

By the way, when the base station of a car phone cannot receive the signal Su from the car phone, this signal Su
If the no-signal period for signal Su is less than 5 seconds, it is assumed that there is a reception problem due to a car going behind a building, etc. °ζ The communication channel is maintained as is, but the no-signal period for signal Su is for more than 5 seconds. If this occurs continuously, it is assumed that the call has ended and the call channel is disconnected.

Therefore, when backing up the saved data in the RAM (41) using the battery (42), there is no point in backing up the data for more than 5 seconds, that is, it is sufficient to back up the saved data in the RAM (41) for 5 seconds.

Therefore, this invention focuses on this point, and when the supply voltage from the battery drops during a call, the power supply that backs up the data RAM backs up the transmission/reception control circuit, thereby reducing the supply voltage. When the voltage is restored, the existing communication channel can be resumed.

[Effect]

Even if the supply voltage from the car battery drops, the entire control circuit, ie, the microcomputer (30), is backed up, and if the supply voltage is restored within 5 seconds, the previous communication channel will be resumed.

〔Example〕

In FIG. 1, (51) discharges the car battery, and its output voltage is supplied to the starter motor etc. through the switch of the ignition key, although it is not shown. moreover,
The output voltage of the battery (51) is supplied to the regulator (DC-DC converter) (52) through the contact (54S) of the relay (54), and the receiving system (11) to (1) is supplied to the regulator (DC-DC converter) (52).
3) and the transmission system (21) to (24), etc., and this voltage is supplied to each circuit, and only the sequential direction voltage of the diode is lower than the operating voltage of the microcomputer (30). For example, an operating voltage Va of 5.6 V is formed.

Then, ζ, the output terminal of the voltage νa of the regulator (52) is connected to the circuit (31) through the diode D1 for backflow prevention.
(35), and is also connected to the power supply terminal of RAM (41) through another backflow prevention diode D2. Furthermore, the hot side electrode of the battery (42) is connected to the emitter 22 of the switching transistor Q1.
'? of circuits (31) to (35) through the connectors. Ji source terminal, one output terminal of the port (35) is connected to the base of the transistor Q2 whose emitter is common, its collector is connected to the base of the transistor Q1 through the resistor +aR1, and the base and emitter of the transistor Ql are connected to each other. A resistor 'aR2 is connected to. In addition, port (3
5), a port output Pa that turns off the transistor Q1 is outputted to the output terminal connected to the transistor Q2 when +E is applied, as will be described later.

Furthermore, the hot side electrode of the battery (42) is connected to the power supply terminal of the RAM (41) through a diode D3 for backflow prevention, and the output side of the diode D2 and the battery (
A charging resistor R2 is connected between the hot side electrode of 42).

Also, the number of detection times for detecting the output voltage of the battery (51) is 1/! (53) and (54) are connected, and the detection circuit (5
The detection output of 3) is supplied to the relay (54), and its contact (54S) indicates that the output voltage of the battery (51) is 16.
When the voltage is 5V or more, it is turned on, and when it is 1B, it is turned off when it is 5V or more. Further, the detection circuit (55) outputs a detection signal Sd that accepts the output voltage of the battery (51) when it is 9V or less, and this signal Sd is CPIJ (3
1) as an interrupt human power, and is also supplied to the input port (34) as a signal indicating the voltage of the battery (5I).

Furthermore, an interrupt routine (60) shown in FIG. 2, for example, is added to 120M (32). Note that the signal threads for transmission and reception are as shown in Fig. 3.

According to such a configuration, when the voltage of the battery (51) is positive, the contact (54S) is on, the voltage Va is obtained from the regulator (52), and this voltage Va
is connected to the circuits (30) to (35) through diodes DI and D2.
) and RAM (old). therefore,
Circuits (30) to (35) and RAM (41) operate normally, and this car phone can be used normally.

At this time, the output Pa of the boat (35) is set to "L", and the transistor Q2 is turned off, thereby turning off the transistor Qs.
3, the voltage of the battery (42) is reverse biased by the voltage Va from the diode D2 and is off. Therefore, the battery (42) is being charged through diode D2 and resistor R2.

If the voltage of the battery (51) drops below 9V or even 5V due to the starter motor being activated during a call, etc.
When V is too low, this is detected by the detection circuit (55), and the detection signal S(] causes CPt1 (31)
An interrupt occurs and the interrupt routine (60)
Executed by U (31).

That is, this routine (60) starts at step (61), and in step (62) all the data necessary to restart the current congested channel are
N (41), and then in ζ step (63), the output signal TX[! Transmission times vpI (24) (7
) Transmission is stopped, and then in step (64) the boat output Pa is set to "H", which causes the transistor Q to
2 is turned on, and the °ζ transistor Q1 is turned on.

Therefore, from this point on, the voltage of the battery (42) is supplied to the circuits (31) to (35). In addition, RAM (41
) is also supplied with the voltage of the battery (42) through the diode D3. That is, from step (65) onwards, the microcomputer (30) and RAM (41) are backed up by the battery (42).

Then, the processing of the CPU (31) continues in step (65).
), a software timer TMER is started in this step (65), and then step (65) is started.
In step 6), it is checked whether or not the timer TMER has reached 5 seconds or more, and when it is less than 5 seconds, the process proceeds to step (67), and in this step (67), the battery is activated by the signal Sd supplied to the boat (34). (
51) is checked to see if it has recovered to 9V or more, and if it is 9V or more, the process returns to step (66). Therefore, within 5 seconds after the voltage of the battery (51) drops to 9V or lower and the voltage has not recovered to 9V or higher, step (66),
(67) will be repeated.

If the voltage of the battery (5I) is restored within that 5 seconds, the process proceeds from step (67) to step (71).
), and in this step (71) °ζ step (
62), the data saved in the RAM (41) is sent again to each circuit, and then in step (72), the data is sent to the transmitting circuit (24) by
) is turned on, and in step (73) the process returns from this scraping routine (60) to the original routine.

Therefore, from this point on, the communication channel will be restarted as usual.

On the other hand, if the power of the battery (51) is not recovered within 5 seconds, the process proceeds from step (66) to step (74), and in this step (74), transistor Q1 is turned off. Therefore, from now on, normal operating voltage is no longer supplied to the circuits (31) to (35), so the operation of the microcomputer (30) is stopped.However, even at this time, the diode D3 is connected to the RAM (41). Since the voltage of the battery (42) is supplied through R
Various data stored in AM (41) are protected. Furthermore, at this time, since 5 seconds have passed since the transmission stopped, the base station considers that the call has ended and closes the previous call channel.

After this, when the voltage of the battery (51) is restored, the microcomputer (30) is reset and starts from the initial routine.

Thus, according to the invention, the battery (5
When the electrification in 1) falls below the specified value, not only will transmission be stopped, but all data necessary to restart the communication channel up to that point will be evacuated to the RAM (41), and the RAM (41) will be saved. Since the microcomputer (30) is backed up by the battery (42) which backs up the microcomputer (41), when the power of the battery (51) is restored, the communication channel can be restarted.

Moreover, in this case (41) and battery (42), etc.!
It is originally necessary to store (maintain) various types of data such as log codes, and therefore requires only a few additional parts and is low cost.

In the above, when the voltage of the battery (51) drops, the data necessary to restart the call channel is saved in the RAM (old) in step (62), but when the call starts under normal conditions, the data is saved in the RAM (old). It may be stored in advance in the RAM (41).

In addition, if the CPt1 (31) etc. has a power down mode, this may be used to stop operation (to reduce current consumption.Furthermore, not only mobile phones but also
Any transmitter or receiver powered by a battery may be used.

〔Effect of the invention〕

According to this invention, when the voltage of the battery (51) drops below a specified value during a call, not only does transmission stop, but all of the data necessary to restart the previous call channel is In addition to saving data to the RAM (41), the microcomputer (30) is backed up by the battery (42) that backs up the RAM (41), so when the voltage of the battery (51) is restored, the communication channel can be switched to the IF switch. Can be restarted.

Moreover, in this case, RAM (41) and battery (4
Items 2) and the like are originally necessary for storing various types of data such as ``Locode''. Therefore, only a few parts need to be added, and the cost is low.

[Brief explanation of the drawing]

FIG. 1 is a connection diagram of an example of the present invention, and FIGS. 2 and 3 are diagrams for explaining the same. (lO) is the receiving line, (20) is the sending line, (30
) is a control circuit, and (51) is a car battery. 2nd evil figure 3

Claims (1)

[Claims] In a communication device that operates using a battery as an operating power source, there is provided a RAM for storing communication-related data, and a RAM for storing communication-related data.
It has a backup power source that backs up the AM, a control circuit that controls the communication, and a detection circuit that detects the voltage of the battery, and when the voltage of the battery drops below a specified value, the backup power source controls the RAM. A battery-powered communication device that backs up the above control circuit as well as backs up the control circuit for a predetermined period of time.