JP2833293B2 - DC power supply switching device - Google Patents

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 device,
Particularly, the present invention relates to a power supply switching device for a DC power supply.

[0002]

2. Description of the Related Art When a power supply trouble such as a power failure occurs, switching to a spare power supply immediately to prevent a system down of connected equipment is one of the most important techniques, especially in an online system.

FIG. 6 shows a first conventional example. In the conventional example of FIG. 6, a first input terminal 601 and a second input terminal 602 are provided.
A first switch S1 for turning on and off a first DC power supply supplied from a first input terminal 601; and a second switch S2 for turning on and off a second DC power supply supplied from a second input terminal 602. And an output terminal 600 for outputting the DC power selected by the first switch S1 or the second switch S1.

Next, the operation of the first conventional example will be described with reference to FIGS. 6 and 7. FIG.

[0005] A first DC power supply is connected to a first input terminal 601, a second DC power supply is connected to a second input terminal 602, and a load is connected to the output terminal 600. As shown in a state T71 of FIG. 7, the first switch S1 is turned on, and the second switch S2 is turned on.
Is off, the output terminal 600 is connected to the first input terminal 6.
01, the voltage V601 of the first DC power supply is output. When both the first switch S1 and the second switch S2 are off as shown in the state T72 of FIG. 7, the voltage V600 at the output terminal 600 becomes 0 because only the load is connected to the output terminal 600 and the power supply is not connected. . As shown in a state T73 in FIG. 7, the first switch S1 is turned off, and the second switch S1 is turned off.
When the switch S2 is ON, the output terminal 600
The voltage V602 of the first DC power supply supplied from the input terminal 602 is output.

As described above, the first switch S1
The power supply to the load connected to the output terminal 600 is switched by controlling the on and off of the second switch S2.

FIG. 8 shows a second conventional example. In the conventional example shown in FIG. 8, a first input terminal 801, a second input terminal 802, and a first input terminal 801 which turns on and off a first DC power supply supplied from the first input terminal 801 via a first diode D 1. 1 switch S1 and the second input terminal 802 to the second
A second switch S2 for turning on and off a second DC power supply supplied through a diode D2 of
And an output terminal 800 for outputting the DC power selected by the first or second switch S1.

Next, the operation of the second conventional example will be described with reference to FIGS.

A first DC power supply is connected to a first input terminal 801, a second DC power supply is connected to a second input terminal 802, and a load is connected to the output terminal 800. As shown in a state T91 of FIG. 9, the first switch S1 is turned on, and the second switch S2 is turned on.
Is off, the output terminal 800 is connected to the first input terminal 80.
From the voltage V801 of the first DC power supply supplied from
Of the forward voltage Vf of the diode D1 (V801-V
f) is output. As shown in a state T93 of FIG. 9, when the first switch S1 is off and the second switch S2 is on, the output terminal 800 is connected to the second DC power supply supplied from the second input terminal 802. A voltage (V802-Vf) obtained by subtracting the forward voltage Vf of the diode D2 from the voltage V802 is output. When both the first switch S1 and the second switch S2 are on as shown in the state T92 of FIG. 9, the voltage (V801-Vf) and the voltage (V802-V
The higher voltage of f) is output. The state T92 of FIG. 9 shows the case where V801> V802, and the voltage (V801-Vf) is output to the output terminal 800.

[0010]

However, in the above-mentioned first conventional example, as shown in a state T72 of FIG. 7, a state occurs in which no power is supplied to the load at the time of switching, so that an instantaneous stoppage of the equipment occurs. There were inconveniences that the data disappeared and device control became impossible. In order to avoid this state, in a power supply switching device in which a diode is connected in series with a switch as shown in the second embodiment, a voltage drop occurs because the diode is always inserted between the power supply and the load. There was a problem.

[0011]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a DC power supply switching apparatus which improves the disadvantages of the prior art, reduces the fluctuation of the voltage applied to the load at the time of power supply switching, and does not cause the voltage drop during normal use. To provide.

[0012]

Therefore, in the present invention, a direct
Provide multiple input terminals for connecting the power supply to the output terminals,
Power ON / OFF circuits are provided between each input terminal and output terminal
Control each power ON / OFF circuit and
And a control circuit for selectively connecting one input terminal.
I have. Each power on / off circuit has an input terminal and an output terminal.
Connect a diode and a switch in series between
The anode is connected with the anode facing the input terminal
With the anode and cathode of this diode
It has a possible bypass switch. And control times
Path disconnects one power on / off circuit and the other power on / off circuit
Switch, turn on the switch of the other power on / off circuit.
Before connecting, turn off the bypass switch of one power ON / OFF circuit.
It is configured to be cut in advance . This aims to achieve the above-mentioned object.

[0013]

The operation will be described with reference to FIG. In FIG.
First, as the first switch of one power ON / OFF circuit 31
Relay K1a and relay K1 as a bypass switch
b is connected, and the second switch of the other power ON / OFF circuit 32 is connected.
Switch K2a as a switch and a switch as a bypass switch.
It is assumed that the ray K2b is open. At this time, one input
The DC output of the power supply connected to terminal 301 is output terminal 30
0 is obtained. Here, it is connected to the other input terminal 302.
If you want to send the output of the
The circuit 33 disconnects one power supply on / off circuit 31 and supplies the other power supply.
The power on / off circuit 32 is connected. At this time, the control circuit 33
Operates each switch in the following order. First, relay K
1b is disconnected, and then the relay K2a is connected. Continued
To disconnect relay K1a and then connect relay K2b
I do. At this time, the voltage of one input terminal 301 is
If the voltage is lower than the force terminal 302, the relay K1b is disconnected and reset.
When the connection of the second input terminal 302 is performed simultaneously,
Current flowing from one side flows back to one input terminal 301 momentarily
This is not preferable in terms of circuit. However,
In the following description, before connecting the relay K2a, the relay K1b
Is cut off, so that the above-mentioned inconvenience does not occur.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. However, in the following embodiment, only the case of two DC power supplies will be described for simplicity.

In the first embodiment shown in FIG.
01, the second input terminal 102, and the first input terminal 10
A first power on / off means 11 for turning on / off the first DC power supplied from the first DC power supply 1; a second power on / off means 12 for turning on / off the second DC power supplied from the second input terminal 102; And an output terminal 100 for outputting the DC power selected by the first power on / off means 11 or the second power on / off means 12.

The first power supply on / off means 11 includes a first switch S1a as first on / off means for turning on / off the output to the output terminal 100, and a first input terminal 10
1 to a first switch S1.
and a first bypass switch S1b as second on / off means for controlling whether or not to output the signal to a through the first diode D1.

The second power supply on / off means 12 includes a second switch S2a as first on / off means for turning on / off the output to the output terminal 100, and a second input terminal 102.
The second DC power supplied from the second switch S2a
And a second bypass switch S2b as second on / off means for controlling whether or not to output to the second diode D2.

Next, the operation of the first embodiment will be described with reference to FIG.
This will be described with reference to FIG.

A first DC power supply is connected to the first input terminal 101, a second DC power supply is connected to the second input terminal 102, and a load is connected to the output terminal 100. Here, the voltage V101 of the first DC power supply is higher than the voltage V102 of the second DC power supply,
Moreover, the voltage (V101-Vf) obtained by subtracting the forward voltage Vf of the first diode D1 from the voltage V101 of the first DC power supply is also the second voltage.
Is larger than the voltage V102 of the DC power supply.

The first state T21 and the ninth state T of FIG.
As shown in FIG. 29, the first switch S1a is turned on,
Is turned on, the second switch S2
a is off and the second bypass switch S2b is off, the first DC power supplied from the first input terminal 101 does not pass through the first diode D1, and the first switch S2
1a, the voltage at the output terminal 100 is equal to the voltage V10 of the first DC power supply supplied from the first input terminal 101.
It becomes 1.

The second state T22 and the eighth state T of FIG.
28, the first switch S1a is turned on,
Is off, the second switch S2
a is off and the second bypass switch S2b is off, the first DC power supplied from the first input terminal 101 is supplied to the first switch S1 via the first diode D1.
a, the voltage at the output terminal 100 is equal to the voltage V101 of the first DC power supply supplied from the first input terminal 101.
From (V101-Vf) obtained by subtracting the forward voltage Vf of the first diode D1 from the above.

The third state T23 and the seventh state T of FIG.
As shown in FIG. 27, the first switch S1a is turned on,
Is off, the second switch S2
a is on and the second bypass switch S2b is off, the first DC power supplied from the first input terminal 101 is supplied to the first switch S1 via the first diode D1.
a and the second DC power supplied from the second input terminal 102 is output to the second switch S2a without passing through the second diode D2.
01 minus the forward voltage Vf of the first diode D1 from the voltage V101 of the first DC power supply supplied from the first DC power supply (V101−
Vf) is higher than the voltage V102 of the second DC power supply supplied from the second input terminal 102, so that the output terminal 1
00 is the first voltage supplied from the first input terminal 101.
(V101−Vf) obtained by subtracting the forward voltage Vf of the first diode D1 from the voltage V101 of the DC power supply.

The fourth state T24 and the sixth state T of FIG.
26, the first switch S1a is turned off,
Is off, the second switch S2
a is on and the second bypass switch S2b is off, the second DC power supplied from the second input terminal 102 is supplied to the second switch S2 via the second diode D2.
a, the voltage at the output terminal 100 is equal to the voltage V102 of the second DC power supply supplied from the second input terminal 102.
And the voltage (V102-Vf) obtained by subtracting the forward voltage Vf of the second diode D2 from the above.

As shown in a fifth state T25 in FIG. 2, the first switch S1a is turned off, and the first bypass switch S
1b is off, the second switch S2a is on, and the second bypass switch S2b is on, the second input terminal 1
02 is output to the second switch S2a without passing through the second diode D2, the voltage of the output terminal 100 is changed to the second DC power supplied from the second input terminal 102. The voltage of the power supply becomes V102.

The first state T21, the ninth state T29, and the fifth state T25 are normal use states. When the power is switched, the switch state is changed from the first state T21 to the second state T.
22 → third state T23 → fourth state T24 → fifth state T25
Alternatively, by changing the fifth state T25 → the sixth state T26 → the seventh state T27 → the eighth state T28 → the ninth state T29, the voltage V100 of the output terminal 100 becomes as shown in FIG. Between V101 and (V102-Vf).

The second embodiment shown in FIG.
01, the second input terminal 302, and the first input terminal 30
A first power on / off means 31 for turning on / off the first DC power supplied from the first DC power supply 1; a second power on / off means 32 for turning on / off the second DC power supplied from the second input terminal 302; A first pulse switch S3a for setting switching from the first DC power supply to the second DC power supply, a second pulse switch S3b for setting switching from the second DC power supply to the first DC power supply, The pulse input from the first pulse switch S3a or the second pulse switch S3
A control means 33 for controlling the first power on / off means 31 and the second power on / off means 32 in response to a pulse input from 3b, a first power on / off means 31 or a second power on / off means 32
And an output terminal 300 for outputting a DC power supply.

The first power supply on / off means 31 outputs an output terminal 300 in response to a control signal 331a from the control means 33.
A first relay K1a as first on / off means for turning on / off the output to the first relay K1a, and a controller 33 for outputting the first DC power supplied from the first input terminal 301 to the first relay K1a. And a first bypass relay K1b as second on / off means for controlling whether or not to pass through the first diode D1 according to the control signal 331b.

The second power on / off means 32 is a second on / off means for turning on / off the output to the output terminal 300 in response to a control signal 332a from the control means 33.
And whether or not to output the second DC power supplied from the second input terminal 302 to the second relay K2a by the control signal 332b from the control means 33 via the second diode D2. And a second bypass relay K2b as second on / off means for controlling the power supply.

The operation of the second embodiment will be described with reference to FIGS.

The first input terminal 301 is connected to a first DC power supply, the second input terminal 302 is connected to a second DC power supply, and the output terminal 300 is connected to a load. Here, the voltage V301 of the first DC power supply is higher than the voltage V302 of the second DC power supply,
Moreover, the voltage (V301-Vf) obtained by subtracting the forward voltage Vf of the first diode D1 from the voltage V301 of the first DC power supply is also the second voltage.
Is higher than the voltage V302 of the DC power supply.

As shown in the first state T41 of FIG. 4, the first pulse switch S3a is also the second pulse switch S3.
When b is not depressed, the control means 33 sets the control signal 331a to the "high level" control signal 331b as an initial state.
Is set to the “high level” control signal 332a and the “low level” control signal 332b to the “low level”, and the first relay K1
a, the first bypass relay K1b is turned on, the second relay K2a is turned off, and the second bypass relay K2b is turned off. As a result, the output voltage from the second power supply on / off means 32 becomes 0, but the first DC power supplied from the first input terminal 301 is supplied to the first relay K1a without passing through the first diode D1. Output terminal 300
Is the voltage V301 of the first DC power supply supplied from the first input terminal 301.

Here, as shown in the second state T42 of FIG. 4, when only the first pulse switch S3a is pressed and a pulse signal is input to the control means 33, the control means 33 changes the control signal 331b to " First to change to "low level"
Is turned off. As a result, the first DC power supplied from the first input terminal 301 is output to the first relay K1a via the first diode D1, so that the voltage at the output terminal 300 is reduced to the first input terminal 30.
From the first DC power supply voltage V301 supplied from
(V301-V) obtained by subtracting the forward voltage Vf of the diode D1
f).

When a certain time has elapsed and the output voltage has stabilized, as shown in the third state T43 of FIG.
3 changes the control signal 332a to "high level", so that the second relay K2a is turned on. As a result, the first DC power supplied from the first input terminal 301 is output to the first relay K1a via the first diode D1, and the second DC power supplied from the second input terminal 302 Although the power is output to the second switch S2a via the second diode D2, the forward voltage Vf of the first diode D1 is changed from the voltage V301 of the first DC power supplied from the first input terminal 301. The reduced voltage (V301-Vf) is larger than the voltage (V302-Vf) obtained by subtracting the forward voltage Vf of the second diode D2 from the voltage V302 of the second DC power supply supplied from the second input terminal 302. Output terminal 10
The voltage of 0 is a voltage (V301-Vf) obtained by subtracting the forward voltage Vf of the first diode D1 from the voltage V301 of the first DC power supply supplied from the first input terminal 301.

When a certain time has elapsed and the output voltage has stabilized, as shown in the fourth state T44 of FIG.
3 changes the control signal 331a to "low level", so that the first relay K1a is turned off. As a result, the output voltage from the first power on / off means 31 becomes 0, but the second DC power supplied from the second input terminal 302 is supplied to the second switch S2a via the second diode D2. Output, the voltage at the output terminal 100 becomes the second input terminal 30
From the voltage V302 of the second DC power supply supplied from
(V302−V) obtained by subtracting the forward voltage Vf of the diode D2 of FIG.
f).

When a certain period of time has passed and the output voltage has stabilized, as shown in the fifth state T45 in FIG.
3 changes the control signal 332b to "high level", so that the second bypass relay K2b is turned on. As a result, the second DC power supplied from the second input terminal 302 is supplied to the second switch S2 without passing through the second diode D2.
a, the voltage of the output terminal 100 is equal to the voltage V30 of the second DC power supply supplied from the second input terminal 302.
It becomes 2.

As shown in the sixth state T46 in FIG. 4, when only the second pulse switch S3b is pressed and a pulse signal is input to the control means 33, the control means 33 changes the control signal 332b to "low level". , The second bypass relay K2b is turned off. As a result, the second DC power supplied from the second input terminal 302 is output to the second switch S2a via the second diode D2, so that the voltage of the output terminal 100 is output from the second input terminal 302. Voltage (V302-Vf) obtained by subtracting the forward voltage Vf of the second diode D2 from the supplied voltage V302 of the second DC power supply.
Becomes

When a certain time has elapsed and the output voltage has stabilized, as shown in the seventh state T47 of FIG.
3 changes the control signal 331a to "high level", so that the first relay K1a is turned on. As a result, the first DC power supplied from the first input terminal 301 is output to the first relay K1a via the first diode D1, and the second DC power supplied from the second input terminal 302 Although the power is output to the second switch S2a via the second diode D2, the forward voltage Vf of the first diode D1 is changed from the voltage V301 of the first DC power supplied from the first input terminal 301. The reduced voltage (V301-Vf) is larger than the voltage (V302-Vf) obtained by subtracting the forward voltage Vf of the second diode D2 from the voltage V302 of the second DC power supply supplied from the second input terminal 302. Output terminal 10
The voltage of 0 is a voltage (V301-Vf) obtained by subtracting the forward voltage Vf of the first diode D1 from the voltage V301 of the first DC power supply supplied from the first input terminal 301.

When a certain time has elapsed and the output voltage has stabilized, as shown in the eighth state T48 in FIG.
3 changes the control signal 332a to "low level", so that the second relay K2a is turned off. As a result, the output voltage from the second power supply on / off means 32 becomes 0, but the first DC power supplied from the first input terminal 301 is supplied to the first relay K1a via the first diode D1. Since the voltage is output, the voltage of the output terminal 300 is a voltage (V301-Vf) obtained by subtracting the forward voltage Vf of the first diode D1 from the voltage V301 of the first DC power supply supplied from the first input terminal 301.
Becomes

When a certain period of time has passed and the output voltage has stabilized, as shown in the ninth state T49 of FIG.
3 changes the control signal 331b to "high level", so that the first bypass relay K1b is turned on. As a result, the first DC power supplied from the first input terminal 301 is supplied to the first relay K1a without passing through the first diode D1.
, The voltage at the output terminal 300 becomes the voltage V301 of the first DC power supply supplied from the first input terminal 301.

The first state T41, the ninth state T49, and the fifth state T45 are normal use states. When the power is switched, the switch state is changed from the first state T41 to the second state T41.
42 → third state T43 → fourth state T44 → fifth state T45
Alternatively, by changing the fifth state T45 → the sixth state T46 → the seventh state T47 → the eighth state T48 → the ninth state T49, the voltage V300 of the output terminal 300 becomes as shown in FIG. Between V301 and (V302-Vf).

In the third embodiment shown in FIG.
01, the second input terminal 502, and the first input terminal 50
A first power on / off means 51 for turning on / off the first DC power supplied from the first DC power supply 1; a second power on / off means 52 for turning on / off the second DC power supplied from the second input terminal 502; And an output terminal 500 for outputting the DC power selected by the first power on / off means 51 or the second power on / off means 52.

The first power on / off means 51 includes a first switch S1a as first on / off means for turning on / off an output to the output terminal 500, and a first input terminal 50.
1 to a first switch S1.
and a first bypass switch S1b as second on / off means for controlling whether or not to output the signal to a through the first diode D1.

The second power supply on / off means 52 includes a second switch S2a as first on / off means for turning on / off the output to the output terminal 500, and a second input terminal 502.
The second DC power supplied from the second switch S2a
And a second bypass switch S2b as second on / off means for controlling whether or not to output to the second diode D2. This is because the polarity of the power supply in the first embodiment shown in FIG. 1 is positive, whereas the third embodiment shown in FIG. 5 is for the case where the polarity of the power supply is negative. Things. Therefore,
The operation is similar to that of the first embodiment.

In the above description, two power supply switching devices have been described. The same applies to three or more power supply switching devices.

[0045]

As described above, according to the present invention, a power on / off means is provided between an output terminal and a plurality of input terminals, and each of the power on / off means turns on / off an output to an output terminal. 1 switch and a bypass switch for selecting whether or not to pass through a diode when the DC power supplied from the input terminal is output to the first switch . In this case, the voltage of the selected power supply device can be output as it is, and when the power supply is switched, the output voltage changes only by the drop of the forward voltage of the diode (about 0.5 to 1 V) and in a short time. The heat generation can be suppressed even when the current flowing to the load is large. For this reason, even when the power supply is switched due to a power failure or the like, the fluctuation of the voltage applied to the load is small, so that it is possible to prevent data destruction in a computer, data loss in a measuring instrument, system down in an online system, and the like. Furthermore, one power on / off means is disconnected and the other power on / off
When connecting one of the power supply
After turning off the bypass switch, switch on the other
Switch to connect to the output terminal from the other power on / off means.
Current flowing back to one power on / off means
Can be effectively prevented, and an excellent DC power supply switching device, which has never existed before, can be provided.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a first embodiment of the present invention.

FIG. 2 is an operation state diagram of the embodiment of FIG. 1;

FIG. 3 is a configuration diagram showing a second embodiment of the present invention.

FIG. 4 is an operation state diagram of the embodiment of FIG. 3;

FIG. 5 is a configuration diagram showing a third embodiment of the present invention.

FIG. 6 is a configuration diagram showing a first conventional example.

7 is an operation state diagram of the conventional example of FIG.

FIG. 8 is a configuration diagram showing a second conventional example.

9 is an operation state diagram of the conventional example of FIG.

[Explanation of symbols]

S1a: First switch S1b: First bypass switch S2a: Second switch S2b: Second bypass switch S3a: First pulse switch S3b: Second pulse switch D1: First diode D2: Second K1a: First relay K1b: First bypass relay K2a: Second relay K2b: Second bypass relay 11, 31, 51: First power on / off means 12, 32, 52: Second Power on / off means 101, 301, 501, 601, 801: first input terminal 102, 302, 502, 602, 802: second input terminal 100, 300, 500, 600, 800: output terminal

Claims (1)

(57) [Claims] An input terminal for connecting a DC power supply is an output terminal.
Power supply between each input terminal and output terminal.
A power-off circuit is provided, and each power-on / off circuit is controlled.
To selectively connect one input terminal to the output terminal.
A control circuit, wherein each of the power ON / OFF circuits is provided between the input terminal and the output terminal.
Connect a diode and a switch in series to the
The anode is connected with the anode facing the input terminal
With the anode and cathode of this diode
DC power supply switching device with a possible bypass switch
And the control circuit disconnects one of the power on / off circuits and the other power supply.
When connecting the power on / off circuit, the other power on / off circuit
Before connecting the switch, the one power on / off circuit
Characterized in that the bypass switch is cut off in advance.
DC power switching device.