JP3138210B2 - LAN concentrator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a system for exchanging data by connecting computers in a limited area such as in an office or a building, that is, a LAN (Lo
The present invention relates to a LAN concentrator for constructing a cal area network, and particularly to a power supply backup technology for maintaining the function of the concentrator in the event of a power failure or power supply wiring accident.

[0002]

2. Description of the Related Art Recently, LANs have rapidly spread to the level of personal computers. 10B for most PC LANs
The transmission line of the ASE standard is adopted. Above all, the 10BASE-T standard is widely used because it is easy to wire and can flexibly cope with the movement and expansion of a personal computer. 10BASE-T uses an unshielded twisted pair, similar to a normal telephone line, and its connection is much simpler than other standard transmission lines. A concentrator called a hub (HUB) is commercially available, and it is only necessary to connect the jack at the end of the cable connected to the LAN board of the personal computer to the multiport connector of the concentrator.

[0003] The LAN concentrator with the simplest configuration is
A built-in transmission signal processing circuit performs electrical isolation between a plurality of nodes (such as personal computers) connected to the multiport connector, and relays and shapes the waveform of transmission signals exchanged between the nodes. In addition to this basic function, various LAN concentrators called intelligent hubs or switching hubs that incorporate advanced control functions such as multi-stage connection function using multiple hubs and connection function with backbone line are required It is used according to.

Of course, this type of LAN concentrator requires an operating power supply, and is used by connecting a power plug to an outlet of a normal commercial AC power supply. A power supply circuit (AC / DC converter) in the device converts an AC power supply into a stabilized predetermined DC, and operates a load circuit system such as the transmission signal processing circuit described above. The LAN concentrator has no power switch, and can be operated only by connecting to an effective AC power supply.

If a LAN concentrator is installed in an office or the like and necessary cable wiring is performed, the concentrator becomes a LAN concentrator.
It is a “holding under the edge” that supports the system and does not need to be noticed by the user in normal times. Therefore, it is usually installed in an appropriate place, and in some cases, it may be installed under the floor of the free access floor together with the wiring. Of course, the power remains on.

In addition to the LAN, computer systems that are responsible for important information processing take measures to back up the power supply so as not to damage the system even if a power failure or power supply wiring accident occurs. In the case of a small-scale system, each device such as a personal computer is equipped with an uninterruptible power supply (connected to a commercial AC power supply and converts the output of a built-in battery to AC when a power failure occurs). The LAN concentrator is also connected to a commercial AC power supply via an uninterruptible power supply.

[0007]

The uninterruptible power supply has a problem that it is expensive and large. In a configuration in which a large number of devices included in the LAN system are connected to one or more uninterruptible power supply units, the price of the entire power supply facility becomes extremely high, and the arrangement of individual devices such as personal computers and the uninterruptible power supply unit It is difficult to properly set the combination of the arrangement and the capacitance. When a small number of large-capacity uninterruptible power supplies are shared by many devices, wiring of a power cable becomes troublesome. When a large number of small-capacity uninterruptible power supplies are used, there is a problem that the entire installation space increases with the price.

Therefore, in the present invention, a power supply backup function is built in the LAN concentrator itself. This is the basic purpose of the present invention. Specifically, like a notebook computer, it has a built-in secondary battery for backup, trickle-charges the battery when receiving power from an AC power supply, and outputs the battery when no AC power is supplied. To operate the circuit.

A conventional electronic device such as a notebook personal computer having a built-in secondary battery for backup has a manual power switch. When this switch is turned off, the device does not operate and the battery does not discharge. (Slight self-discharge is ignored). However, the LAN concentrator is a unique device that does not have a power switch, as described in detail above. Therefore, if a power supply backup circuit is simply configured by incorporating a secondary battery in the LAN concentrator, the following problem occurs.

When the secondary battery built in the LAN concentrator is shipped from the factory in a fully charged state, and the user installs it in the place of use and performs necessary wiring, the power supply backup function using the battery becomes effective immediately after that. It is desirable (it is necessary). However, since the LAN concentrator does not have a power switch, the device is always in operation if the battery is charged, and depending on the battery capacity, the battery is discharged several hours or several days from the factory shipment. I'm done
When the LAN concentrator reaches the user via the distribution sales channel, the backup function using the battery cannot be used. The backup function will not be effective until the user installs the LAN concentrator at the place of use and connects to the AC power supply and after a considerable charging time.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems peculiar to the LAN concentrator, and has as its object to provide a LAN concentrator in which a power supply backup function using a battery becomes effective upon start of use by a user. Is to do.

A LAN concentrator according to the present invention includes a multi-port connector for connecting a cable connected to each node, a transmission signal processing circuit having at least a function of relaying a transmission signal exchanged between each node and a waveform shaping function, And a power supply circuit for supplying a DC power supply for driving the transmission signal processing circuit, the LAN concentrator being mounted on a single housing, wherein the power supply circuit is configured to supply power when an external AC power supply is applied to a power supply connector. Always receiving the AC power without a switch and converting it to a predetermined DC,
An AC / DC power supply that always supplies the DC power to a load circuit system including the transmission signal processing circuit without passing through a power switch.
A DC converter, a backup secondary battery, a charging circuit for trickle charging the secondary battery with the DC output of the AC / DC converter, and a path for supplying the output of the secondary battery to the load circuit system are turned on. A switching circuit for turning off the secondary power supply;
Power transistor interposed in the output path of the pond and this
It has a control circuit to control the power transistor on / off
The control circuit includes a manual switch,
Effective output from AC / DC converter or the charging circuit
When the manual switch is turned on in the state where
The power transistor is turned on, and
After that, the output of the secondary battery is
The on state is maintained (claim 1). Also,
The LAN concentrator of the present invention has a cable connecting to each node.
Cable between the multi-port connector and each node
Function of relaying and waveform shaping of transmission signals exchanged by
Transmission signal processing circuit having at least
Power supply circuit that supplies DC power to drive the circuit
A LAN concentrator mounted on a housing,
The power supply circuit applied external AC power to the power supply connector
Sometimes, the AC power supply is turned on without passing through the power switch.
It always accepts and converts it to a given DC power,
The transmission signal processing circuit can be operated without a power switch.
AC / DC converter that always supplies to load circuit system including
, A backup secondary battery, and the AC / DC
Trickle-charges the secondary battery with the DC output of the barter
Charging circuit, and the output of the secondary battery to the load circuit system.
And a switch circuit for turning on / off the supply path.
This switch circuit is provided in the output path of the secondary battery.
Interposed power transistor and this power transistor
And a control circuit for controlling on / off of the power supply.
The control circuit is connected to a valid node to the connector.
Output from the transmission signal processing circuit when the
Receiving the link valid signal, the power transistor
Is turned on (claim 2).

[0013]

[0014]

Further, in the LAN concentrator of the present invention, there is no effective output of the AC / DC converter, and the switch circuit is turned on, so that the effective output from the secondary battery is supplied to the load circuit system. to dispose a backup detection circuit for detecting that it is supplied not to desired. Then, Ru provided buzzer circuit to sound a buzzer in response to the detection signal of said backup detection circuit. In this case, the buzzer circuit Ru provided a manual buzzer stop switch for inhibiting driving of the buzzer. Further, if necessary, to the transmission signal processing circuit, the detection signal from said backup detection circuit Ru can be provided with communication means for notifying to the outside through a predetermined port that has occurred. It should be noted that the present invention
It is desirable to use an FET as the power transistor.
No.

[0015]

FIG. 1 shows a schematic configuration of a LAN concentrator according to an embodiment of the present invention. This is a circuit diagram expressing the power supply backup circuit system in close-up. When the power plug 1 is connected to an outlet of an effective commercial AC power supply, the LAN concentrator operates. That is, the AC power is directly input to the AC / DC converter 2 without going through the power switch, and is converted into a +15 volt DC power. This DC output is directly input to the DC / DC converter 3 without passing through a power switch, and becomes a highly stabilized +12 volt and +5 volt DC power supply.
The drive power supply for the hub body circuit 4.

Although not shown, the LAN concentrator has a multi-port connector for connecting a cable connected to each node, and a function for relaying and shaping transmission signals exchanged between the nodes. At least a transmission signal processing circuit is provided. The connector includes a pulse transformer for transmitting a transmission signal to the processing circuit while electrically separating each node system, a large number of LED lamps for displaying a circuit state of the device, and a display control circuit therefor. Although the main part of the hub main circuit 4 in FIG. 1 is the transmission signal processing circuit, it is assumed that all the auxiliary circuits such as the display circuit are also included in the hub main circuit 4. In the above-described intelligent hub, switching hub, and the like, a microprocessor system for performing advanced control is incorporated. In this case, the microprocessor system is also included in the hub main circuit 4.

As the secondary battery 5 for backup, for example, a lead storage battery is used. A charging circuit 6 for trickle-charging the secondary battery 5 is connected to the +1 of the AC / DC converter 2.
Connected to 5 volt output. Assuming that the battery 5 is almost fully charged, a small charge current flows through the diode D1 so as to compensate for the self-discharge. If the battery 5 is not sufficiently charged, a relatively large charging current is supplied from the charging circuit 6 to the battery 5. In this case, a signal from the charging circuit 6 turns on an LED lamp (not shown) for charging display. .

The output terminal of the battery 5 is a power transistor Q1
DC / DC converter 3 in parallel with the output line of AC / DC converter 2 through a series circuit of
Connected to the input line. Battery 5 is sufficiently charged, power transistor Q1 is on, and AC
When there is no effective output of the DC / DC converter 2, the discharge current of the battery 5 becomes DC through the transistor Q1 and the diode D2.
/ DC converter 3. In this state, the battery 5
Is in a backup state in which the hub body circuit 4 is driven by the output of.

On the base side of the power transistor Q1, resistors R1 and R2, a manual switch SW1, a transistor Q2
There is a control circuit centered on. When both the manual switch SW1 and the transistor Q2 are turned on, the base current of the power transistor Q1 flows, and the power transistor Q1 is turned on (backup is enabled).

When the AC power is input and the charging circuit 6 is functioning normally with the effective output of the AC / DC converter 2, a specified voltage is generated in the charging circuit 6. At this time, a current flows through the series circuit of the resistors R3 and R4 connected to the output of the charging circuit 6, and a base current is supplied to the control transistor Q2 from the midpoint between the resistors R3 and R4, turning on the transistor Q2. . That is, when the LAN concentrator is operating by the input of the AC power, the control transistor Q2 is on.

As described above, when the control transistor Q2 is on and the manual switch SW1 is also on, the power transistor Q1 of the backup switch circuit is turned on (backup is enabled). When there is an AC input and the battery 5 can be backed up, a green LED lamp is turned on by a display circuit (not shown). It is desirable that this green LED lamp be turned off while the above-mentioned red LED lamp indicating that charging is being performed is turned on, and is also turned off during blinking of the red LED lamp indicating that backup is being performed as described below.

In the above-mentioned backup enabled state, when the battery 5 is sufficiently charged and the power transistor Q1 is turned on, the voltage of the battery 5 is reduced to the power transistor Q1.
And a Zener diode D4 connecting the collector and the base of the control transistor Q2.
The base current of the control transistor Q2 is supplied by the output of the battery 5 via the series circuit of the resistor R5 and the resistor R5. In this route, the ON state of the control transistor Q2 and the power transistor Q1 is self-held.

Therefore, even if the base current from the route of the Zener diode D3 and the resistor R3 due to the output of the charging circuit 6 disappears, if the output voltage of the battery 5 is equal to or higher than the specified value, the power transistor Q1 is held on by itself. ing. That is, when the power plug 1 is disconnected from the outlet or a power failure occurs, the discharge current of the battery 5 is supplied to the DC / DC converter 3 through the power transistor Q1 and the diode D2 which are held as described above. . This is the backup state in which the hub body circuit 4 is driven by the output of the battery 5. When the voltage of the battery 5 becomes equal to or lower than the specified value due to the discharge, no current flows through the route of the Zener diode D4 and the resistor R5, and the control transistor Q2 and the power transistor Q1 are turned off to prevent the battery 5 from being over-discharged.

As shown in FIG. 1, the voltage detection circuit 7 connected to the output side of the AC / DC converter 2
It is discriminated whether a specified +15 volt is output from the DC converter 2. In addition, DC / DC converter 3
The alarm circuit 8, which is a central element of the backup detection circuit, is connected to the +5 volt output side. The alarm circuit 8 is operable if the +5 volt output of the DC / DC converter 3 is valid.
When the output of the voltage detection circuit 7 indicates that there is no valid output of the AC / DC converter 2, it recognizes that the battery 5 has entered the backup state and generates an alarm output. That is, the LED lamp 81 blinks and the buzzer 82 sounds intermittently. By this alarm, the user in the vicinity is notified that “AC power is not applied to the LAN concentrator and the LAN concentrator is in a backup state by the built-in battery”. If the user notices turns off the buzzer stop switch 83, the buzzer 82 does not sound, suppressing unnecessary battery consumption and becoming noisy.

FIG. 2 schematically shows a second embodiment of the present invention. An ordinary transmission signal processing circuit included in the hub body circuit 4 constantly monitors whether or not a cable connected to the node is connected to the multiport connector and whether or not signal transmission with the node transceiver is possible through the cable. It has a circuit function to perform For a port to which a valid node is connected and which can communicate, a corresponding link valid signal is output from the transmission signal processing circuit, and a link valid display L provided for each port is provided.
The corresponding ED lamp is turned on. The hub body circuit 4 of the embodiment of FIG. 2 is configured such that when a link valid signal is output for any one of the ports,
The link valid signal OK (the OR signal of the link valid signals of all the ports) is output.

In the embodiment shown in FIG. 2, the control circuit for the power transistor Q1 includes a manual switch SW1 shown in FIG.
But instead, another control transistor Q3
Are connected in series with the transistor Q2. When the link valid signal OK is output from the hub body circuit 4 to the base of the transistor Q3, the signal is received by the base and turned on. Therefore, when the output of the charging circuit 6 is valid and the link valid signal OK is output,
The power transistor Q1 is turned on, and backup by the output of the battery 5 becomes possible.

The LAN concentrator of the embodiment shown in FIG. 2 is a so-called intelligent hub,
Contains a microprocessor system for advanced control and data processing, and a working LAN
It has a function of monitoring the state of the system and notifying various information to a network management terminal that is a member of the LAN system. As one of the functions, when the alarm circuit 8 generates an alarm output (backup detection signal) as described above, the signal is also transmitted to the hub body circuit 4 and the LAN concentrator is in a backup state by a battery. This is notified to the network management terminal.

[0028]

As described above, the LAN concentrator of the present invention has a general L
Like the AN concentrator, there is no power switch, and it operates immediately when external AC power is applied to the power connector. In addition, since the LAN concentrator itself is provided with a power backup function using a trickle-charged battery, a system down can be avoided even in the event of a power failure or power supply wiring without using an expensive uninterruptible power supply. As a further characteristic, although there is no power switch, a switch circuit for turning on and off a path for supplying the output of the battery to the load circuit system is provided, so that this switch circuit can be turned off manually or automatically. If the battery does not discharge. Therefore,
If the battery built in the LAN concentrator is shipped from the factory in a fully charged state, and the user installs the battery at the place of use and performs necessary wiring, the power backup function using the battery becomes effective immediately thereafter. This greatly improves the reliability at system startup. If the on / off of the switch circuit is automated, there is no particular trouble in handling. When a battery is used for backup, a buzzer sounds to notify nearby people or informs a network management terminal that is a member of the system, so that it is effective to promptly take a subsequent measure.

[Brief description of the drawings]

FIG. 1 is a circuit diagram mainly showing a power supply backup circuit system of a LAN concentrator according to an embodiment of the present invention.

FIG. 2 is a circuit diagram of another embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 1 power plug (power connector) 2 AC / DC converter 3 DC / DC converter 4 hub body circuit (including transmission signal processing circuit) 5 secondary battery for backup 6 charging circuit 7 voltage detection circuit 8 alarm circuit (backup detection circuit 81 Buzzer Q1 Power transistor of switch circuit Q2, Q3 Transistor of control circuit SW1 Manual switch

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Koji Kobayashi Inside Araido Telesis Co., Ltd. 4-6-6 Higashi Gotanda, Shinagawa-ku, Tokyo

Claims (6)

(57) [Claims] 1. A multi-port connector for connecting a cable connected to each node, a transmission signal processing circuit having at least a function of relaying and shaping a transmission signal exchanged between the nodes, and a transmission signal processing circuit. And a power supply circuit for supplying a driving DC power supply, the LAN concentrator being mounted on a single housing, wherein the power supply circuit is configured such that when an external AC power supply is applied to a power supply connector, the power supply circuit does not pass through a power supply switch. An AC / DC converter that always receives an AC power supply, converts it to a predetermined DC power, and always supplies the DC power supply to a load circuit system including the transmission signal processing circuit without passing through a power switch, and a backup secondary battery. , The AC / DC
A charging circuit for trickle charging the secondary battery with a DC output of a converter; and a switch circuit for turning on / off a path for supplying an output of the secondary battery to the load circuit system . Output power of the secondary battery
Power transistor that is interposed in the
It has a control circuit to control the on / off of the
The control circuit includes a manual switch, and the AC / DC
If the converter or the charging circuit produces an effective output
When the manual switch is turned on in the
The power transistor is turned on, and
The on state of the power transistor at the output of the next battery
A LAN concentrator characterized by being held . 2. A cable connected to each node is connected.
Multi-port connectors are exchanged between each node
Has at least the function of relaying transmission signals and waveform shaping
A transmission signal processing circuit and driving the transmission signal processing circuit
A power supply circuit for supplying DC power is
A instrumentation has been LAN line concentrator, the power supply circuit applying an external AC power supply to the power connector
The AC power supply without passing through the power switch.
Source and always convert it to a given DC
The transmission signal processing circuit is not connected to the power source through the power switch.
AC / DC converter that always supplies a load circuit system including a circuit
Data, a backup secondary battery, and the AC / DC
The trickle charge of the secondary battery by the DC output of the converter
A charging circuit for charging the battery and an output of the secondary battery to the load circuit.
Switch circuit for turning on / off the path supplied to the system
The switch circuit is provided with an output path of the secondary battery.
A power transistor which is interposed road, the power Trang
A control circuit for controlling the on / off of the transistor.
The control circuit has a valid node connected to the connector.
Out of the transmission signal processing circuit when communication is possible.
Receiving the link valid signal,
A LAN concentrator characterized in that a star is turned on . 3. An apparatus according to claim 1 or claim 2, wherein the AC / DC converter without a valid output of and effective output from the secondary battery wherein the switch circuit is turned on is supplied to the load circuit system A LAN concentrator, wherein a backup detection circuit for detecting the presence of the LAN is included in the load circuit system. 4. The LA according to claim 3 , wherein a buzzer circuit that sounds a buzzer in response to a detection signal of the backup detection circuit is included in the load circuit system.
N concentrator. 5. The LAN concentrator according to claim 4 , wherein the buzzer circuit includes a manual buzzer stop switch for inhibiting driving of the buzzer. 6. The LAN concentrator according to claim 3 , wherein said transmission signal processing circuit includes communication means for notifying, via a predetermined port, that a detection signal has been generated from said backup detection circuit to the outside. apparatus.