JP3085226B2 - Communications system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication system, and more particularly to a power supply host device compatible with a USB (Universal Serial Bus) interface and a secondary battery connected to the power supply host device. The present invention relates to a communication system suitable for use in a system including a peripheral device.

[0002]

2. Description of the Related Art Conventionally, in this type of communication system,
The host-side device that supplies power is configured to be able to switch between normal power and low power consumption in accordance with the power usage of the peripheral device. The peripheral device is a UPS
In some cases, a secondary battery is provided as a part of a secondary power supply such as an (uninterruptible power supply), and the supply current from the host device is divided and supplied to the secondary battery.

[0003]

The conventional communication system described above has the following problems. When the host device supplies low power consumption, the charging current to the secondary battery obtained by shunting the supply current naturally decreases,
A secondary battery in a discharged state or a state close to a discharged state may not be sufficiently charged.

[0004] The present invention has been made in view of the above problems, and when the storage amount of the secondary battery is small,
An object of the present invention is to provide a communication system capable of performing sufficient charging by controlling so as not to supply low power consumption.

[0005]

To achieve the above object, according to an aspect of, the invention according to claim 1, the host-side device supplies power, together comprising a peripheral side device receive power from the host device , The above host side device or above
In either of the serial peripheral side apparatus a communication system having a power request means a request whether normal power or low power consumption by detecting the power usage of the peripheral side apparatus,
The host-side device includes a variable power supply unit that switches between normal power and low power consumption in response to a request signal from the power request unit and supplies the power, and the peripheral device includes a secondary battery. A charging unit that receives power supply from the host-side device and charges the secondary battery; and when the charging unit needs to charge the secondary battery, the power requesting unit transmits the power to the host-side device. Installed on the same host
Monitors signal traffic between the device and the peripheral device.
And a power request control unit for preventing low power consumption from being requested based on a determination based on the power usage status detected and observed .

Namely, the peripheral-side devices are electrically connected by using a suitable connection medium to the host device power supply, while operating at power supply supplied via the same connection medium Then, a part of the supplied power is taken out, and the secondary battery is regularly charged by the charging means.

[0007] Then, the power requirements means placed to either the host device or the peripheral-side apparatus, if the power consumption by detecting the power usage of the peripheral side apparatus is small, low power consumption An attempt is made to request the variable power supply means.

[0008] However, the power demand controlling means provided in the above-described peripheral-side device monitors the need for charging the secondary battery described above, if it is determined that there is a need for charging, the low power consumption Control not to request. For this reason, the variable power supply means does not supply low power consumption, and sufficient power is also supplied to the charging means.

Here, the power request means is, for example, a US
What is necessary is just to consider the host side device and the peripheral side device corresponding to the B interface. That is, the host-side device monitors signal traffic between the peripheral-side device and the host-side device, and when the traffic is high, it is determined that the power consumption of the peripheral-side device is high. In addition, as an example of a specific configuration of the power request control means in the communication system having the above configuration, the invention according to claim 2 is the communication system according to claim 1 , wherein the power request control means has a predetermined configuration. It is configured to determine whether the secondary battery needs to be charged every time, and to increase the traffic by increasing the communication frequency with the host device when the secondary battery needs to be charged.

That is, the power request control means detects the necessity of charging the secondary battery at predetermined time intervals,
When it is determined that the secondary battery needs to be charged, the frequency of communication with the host device is increased to increase traffic. Of course, the communication here may be any signal exchange, for example, simply considering the frequent transmission of dummy signals by the power request control means. When the traffic increases in this way, the power requesting unit determines that the power consumption of the peripheral device is high, and the variable power supply unit does not switch to low power consumption.

On the other hand, when it is determined that the secondary battery does not need to be charged, the power request control means does not increase the traffic, and the variable power supply means switches to low power consumption. Of course, if traffic increases due to transmission and reception of other signals, the power requesting means determines that the power consumption of the peripheral device has increased, and the variable power supply means does not switch to low power consumption.

By the way, various techniques can be applied to the determination of the necessity of charging the secondary battery in the power demand control means. For example, the voltage value of the secondary battery may be measured, and if it is equal to or higher than a predetermined reference voltage value, it may be determined that charging is not necessary. However, if the reference voltage is set to a value close to the voltage at the time of full charge, the charging operation frequently occurs and the efficiency is poor. On the other hand, if the reference voltage value is set to a low value, the charging efficiency of the secondary battery is reduced. The disadvantage is that the temperature decreases.

According to a third aspect of the present invention, in the communication system according to the first or second aspect, the power request control means measures a voltage value of the secondary battery, and the voltage value is set to a predetermined reference value. Non-charging power supply determining means for determining the need for charging during non-charging based on whether or not the voltage is equal to or more than voltage value, and determining whether charging is required during charging based on whether the secondary battery is in a fully charged state. And a charging power supply determining means for determining.

That is, the concept of the hysteresis loop is applied to the determination of the necessity of charging, and when the voltage value of the secondary battery becomes equal to or lower than a predetermined reference voltage value when the secondary battery is not charged, the non-charging time is determined. The power supply determining means detects and determines that charging is necessary. On the other hand, when the secondary battery is fully charged at the time of charging, the charging-time power supply determining means detects and determines that charging is not necessary.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a communication system according to an embodiment of the present invention.

In FIG. 1, a host-side device 10 supporting a USB interface for supplying power and a peripheral device 20 receiving power supply from the host-side device 10 are connected using a cable (not shown). The peripheral device 20 is supplied with power from the host device 10 via the host device 10 and can transmit and receive signals between the host device 10 and the peripheral device 20. In the communication system having such a configuration, the host-side device 10 includes a signal determination unit 11 as the power request unit.

The signal discriminating unit 11 is provided with the I
/ F section, and the peripheral device 20 to the host device 10
Are all input to the signal discriminating unit 11.
The signal discriminating unit 11 monitors the traffic of the input signal. If the traffic is within a predetermined range, a low power consumption request signal is sent to the supply current control unit 12 so that the traffic is within the same range. , The request signal for the normal power is sent to the supply current control unit 12.

The host-side device 10 includes a supply current control unit 12 as the variable power supply unit and a power supply unit (not shown). When the supply current control unit 12 receives the normal power request signal from the signal determination unit 11, the supply current control unit 12 controls the current supplied from the power supply unit to a predetermined normal current and supplies it to the peripheral device 20. When a low power consumption request signal is received from the determination unit 11, the current supplied from the power supply unit is controlled to a predetermined small current to control the peripheral device 2.
Supply 0.

On the other hand, the peripheral device 20 includes a secondary battery 21 and a charging unit (not shown) as the charging means. The secondary battery 21 means a chargeable / dischargeable battery. For example, a nickel-cadmium battery may be used, or a lithium battery may be used. All secondary batteries developed in the future can be applied without being restricted to secondary batteries. Then, as described above, the host-side device 10
Is divided by a shunt (not shown), a part of which is input to the charging unit, and the secondary battery 21 is charged through the charging unit.

Further, the peripheral device 20 includes a voltage monitoring unit 22 and a battery state determination unit 2 as the power request control unit.
3 and a charge request signal generator 24. The voltage monitoring unit 22 detects a voltage value of the secondary battery 21 and monitors whether the voltage value is equal to or more than a predetermined reference voltage value,
On the other hand, the battery state determination unit 23 detects the degree of change of the same voltage value at predetermined time intervals to detect whether or not the secondary battery 21 is in a fully charged state. The signal generation unit 24 is notified of the necessity of charging.

When the charge request signal generator 24 receives a notification from the battery state determiner 23 that charging is necessary, it generates a charge request signal and sends it to the host device 10.
The charge request signal here may be any signal as long as it can communicate with the host device, for example, a dummy signal in which only a frame exists.

The voltage monitoring section 22 and the battery state determination section 23 having the above-described configurations do not operate independently of each other, but form one subroutine in cooperation with each other as shown in the flowchart of FIG. I have. Hereinafter, the operation of the present embodiment will be described with reference to FIG. In FIG. 5, the voltage monitoring unit 22 detects a voltage value of the secondary battery 21 in step S101 to detect whether or not the voltage value is equal to or higher than a predetermined reference voltage value.
If the voltage is equal to or lower than the reference voltage value, the battery state determination unit 23 is notified of the fact. Then, the battery state determination unit 23 determines whether or not the secondary battery 21 is fully charged in step S102 as described above. In step S101, the secondary battery 21 is notified that charging is necessary, and the charging flag indicating that charging is in progress is turned ON.
Loops back to the secondary battery 21 in step S101.
Steps S101 to S1 until the voltage monitoring unit 22 detects that the voltage value is equal to or higher than the reference voltage value.
Loop 03.

That is, the charge request signal generator 24 generates one charge request signal per cycle from step S101 to step S103. In addition, the time required for one cycle is very small. Therefore, the charge request signal generation unit 24 continuously sends the charge request signal to the host device 10 during the loop of steps S101 to S103.

Then, the host device 10 and the peripheral device 2
When the traffic of the signal between 0 increases and the signal discrimination unit 11 detects the increase in the traffic, the signal discrimination unit 11 sends a request signal of the normal power to the supply current control unit 12.

The supply current control unit 12 controls the supply current of a power supply unit (not shown) to a normal current, whereby a sufficient current is supplied to the secondary battery 21 to perform charging. In this sense, the voltage monitoring unit 22 corresponds to the above-described non-charging power supply determination unit.

As the charging progresses, the voltage value of the secondary battery 21 increases, and in step S101, the voltage monitor 22
When it is detected that the voltage value of No. 1 has become equal to or higher than the reference voltage value, it notifies the battery state determination unit 23 of that fact. Then, the battery state determination unit 23 detects whether or not the battery is being charged in step S104 by using a charge flag. Here, when it is detected that charging is being performed, step S1 is performed again.
In step S101, the process loops from step S101 to step S104 until the secondary battery 21 is fully charged.

During this time, the charge request signal generator 2
4 continuously transmits the charging request signal to the host-side device 10, so that the host-side device 10 and the peripheral-side device 2
The traffic between zeros remains high, and peripheral device 20 is normally supplied with current.

When the charging is further advanced and the battery state determination unit 23 detects in step S102 that the secondary battery 21 is fully charged, the charging flag is turned off in step S105. Thereafter, the process loops between step S101 and step S104, and the charge request signal generation unit 24 stops sending the charge request signal.

As a result, the signal traffic between the host device 10 and the peripheral device 20 is reduced. When the signal discrimination unit 11 detects this, a low power consumption request signal is sent to the supply current control unit. I do. The supply current control unit 12, which has received the low power consumption request signal, controls the power supply unit to supply a small current for low power consumption.

In this sense, the battery state determination unit 23 corresponds to the charging power supply determination unit. Of course, if the signal traffic between the host device 10 and the peripheral device 20 increases due to transmission and reception of signals other than the charging request signal, the signal discriminating unit 11 detects this and supplies the normal power request signal again. The current is sent to the current control unit 12, and the normal current is supplied.

In the present embodiment, when the secondary battery 21 needs to be charged, the host device 10 and the peripheral device 20 are charged.
Although the configuration is such that low power consumption is not required by increasing the signal traffic between them, it is not necessary to be limited to such a configuration. When at least the secondary battery 21 needs to be charged, the low power consumption is reduced. The configuration may be appropriately changed as long as the supply can be prevented.

For example, in the modification shown in FIG. 3, the host-side device 30 in the communication system shown in FIG.
And a supply current control unit 33, and the peripheral device 40 includes secondary batteries 41 to a charge request signal generation unit 44 as the charging means.

The signal discriminating unit 31 is the same as that described above. The signal discriminating unit 31 monitors the traffic between the host device 30 and the peripheral device 40, and when the traffic increases beyond a predetermined range, issues a normal power request signal. It is sent to the supply current control unit 33. However, the signal from the charge request signal generation unit 44 of the peripheral device 40 is not input to the signal determination unit 31 here.

When receiving the charge request signal from the charge request signal generator 44, the charge request signal determiner 32 sends a request signal for normal power to the supply current controller 33. Here, once the charge request signal determination unit 32 receives the charge request signal, the charge request signal determination unit 32 continues to transmit the normal power request signal until receiving a charge unnecessary signal indicating that charging is no longer necessary.

The supply current control section 33 is connected to the signal discriminating section 31 and the charging request signal discriminating section 32.
1 and a request signal for the normal power from
A logical sum (OR) is obtained with the request signal of the normal power from No. 2 and when the result is "true", the supply current of the power supply unit (not shown) is controlled to the normal current. That is, the supply current control unit 33 does not supply the low power consumption when the traffic between the host device 30 and the peripheral device 40 is high or the secondary battery 41 needs to be charged.

The charge request signal generator 44 is provided with the voltage monitor 4
In step 2, the necessity of charging the secondary battery 41 is determined, and if it is determined that charging is necessary, a charging request signal is sent to the charging request signal determination unit 32 of the host device 30. Then, when the charging progresses and the battery state determining unit 43 determines that the need for charging is no longer required, a charging unnecessary signal is transmitted. Here, the charging request signal and the charging unnecessary signal are:
At least in the charging request signal determination unit 32, the secondary battery 4
It suffices if it is possible to detect whether or not the first charge is necessary, and the signal content and the like are not particularly limited.

Hereinafter, the operation of the modification will be described with reference to the flowchart shown in FIG. In FIG. 7, the voltage monitoring unit 42 detects the voltage value of the secondary battery 41 in step S201, determines whether the voltage value is equal to or higher than a predetermined reference voltage, and determines whether the charging is necessary. In step S202, the charge request signal generation unit 4
4 and a battery state determination unit 4.
Turns on the charge flag indicating that charging is in progress by notifying 3
To Steps S201 and S202 are performed until the voltage value of the secondary battery 41 becomes equal to or higher than the reference voltage.
Loop.

During this loop, the charge request signal generator 44 receiving the charge request continues to transmit the charge request signal to the charge request signal determiner 32 of the host device 30 and receives the charge request signal. The charging request signal determining unit 32 sends the normal power request signal to the supply current control unit 33, and the supply current control unit 33 receiving the request signal controls the supply current of the power supply unit to the normal current. When charging proceeds and the voltage value of the secondary battery 41 rises, and when the voltage value becomes equal to or higher than the reference voltage value in step S201, the battery state determination unit 43 charges in step S203 whether charging is in progress. Detected by flag, if charging, step S2 until full charge
Loop 04.

When detecting the full charge in step S204, the battery state determination unit 43 notifies that the charging is not necessary in step S205 and turns off the charge flag. The charge request signal generation unit 44 that has received the notification sends a charge unnecessary signal to the charge request signal determination unit 32, and the charge request signal determination unit 32 that has received the charge unnecessary signal transmits the normal power request signal. Stop sending.
At this time, if the signal discrimination unit 31 does not send a request signal for normal power, the supply current control unit 33 controls the supply current of the power supply unit to a small current for low power.

As described above, in a communication system including the host device 10 that supplies power and the peripheral device 20 that receives power supply from the host device 10, the signal discriminator 11 of the host device 10 Upon detecting the power usage status of the peripheral device 20 and switching and supplying the normal power and the low power consumption by the supply current control unit 12, the voltage monitoring unit 22 and the battery state determination unit 23 determine the power consumption of the peripheral device 20. Since the necessity of charging the secondary battery 21 is determined, and when the necessity of the charging is determined, the charging request signal generating unit 24 generates the charging request signal so that the signal determining unit 11 is not required to request low power consumption. Thus, it is possible to provide a communication system capable of reliably charging the secondary battery 21 when the secondary battery 21 needs to be charged.

[0041]

As described above, the present invention can provide a communication system capable of reliably charging the secondary battery when the secondary battery needs to be charged. In addition,
The power usage status of the peripheral devices can be detected by the strike device.
And reduce the load on the peripheral devices.
You.

Further, according to the invention of claim 2 ,
When the secondary battery needs to be charged, it is possible to increase the signal traffic between the host-side device and the peripheral-side device, but not to request low power consumption. Further, according to the third aspect of the present invention, a stable charging operation is provided by differentiating the criterion between non-charging and charging when judging the necessity of charging the secondary battery. be able to.

[Brief description of the drawings]

FIG. 1 is a block diagram of a communication system according to an embodiment of the present invention.

FIG. 2 is a flowchart showing a processing procedure when determining the necessity of charging a secondary battery in the communication system.

FIG. 3 is a block diagram of a communication system according to a modification.

FIG. 4 is a flowchart illustrating a process of determining whether charging of a secondary battery is necessary in the communication system.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Host side apparatus 11 Signal discrimination part 12 Supply current control part 20 Peripheral side apparatus 21 Secondary battery 22 Voltage monitoring part 23 Battery state discrimination part 24 Charge request signal generation part

Claims (3)

(57) [Claims] [1 claim: a host-side device supplies power, together comprising a peripheral side device receive power from the host <br/> strike side device, either one of the host device or the peripheral-side device detects the power usage of the peripheral side device in, an ordinary communication system having a power demand means for a request or power or low power, the host device, a request from the power demand means Variable power supply means for switching between normal power and low power consumption in response to a signal, wherein the peripheral device has a secondary battery, and receives the power supply from the host device to receive the power. Charging means for charging the secondary battery, and when the charging means needs to charge the secondary battery, the power requesting means is installed in the host-side device.
Signal traffic between the host device and the peripheral device.
Monitoring power and making decisions based on detected power usage
And a power request control unit for preventing low power consumption from being requested based on the request. 2. The communication system according to claim 1 , wherein the power request control means determines whether or not the secondary battery needs to be charged at predetermined time intervals, and needs to be charged. A communication system characterized by increasing the frequency of communication with the host-side device to increase traffic. 3. The communication system according to claim 1, wherein the power request control means measures a voltage value of the secondary battery and determines whether the voltage value is equal to or greater than a predetermined reference voltage value. Non-charging power supply determining means for determining the need for charging during non-charging, and charging power supply determining means for determining the need for charging during charging based on whether the secondary battery is in a fully charged state A communication system comprising: