JPH0122370Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an N-to-1 redundant power supply system with a remote sensing function.

2. Description of the Related Art An N-to-1 redundant power supply system is conventionally known, which is composed of N power supplies (N is an integer), N loads, and one backup power supply. FIG. 1 is a diagram showing an example of the configuration of a conventional system of this type. In the figure, PS ₁ to PS _N are power supplies. LD ₁ to LD _N are loads connected to each power source, respectively. PS _B is a backup power supply.
The positive output line of the backup power supply PS _B is connected to the positive output line of each of the above power supplies with a diode _D12 connected to the positive output line of each power supply.
to D _N2 . D ₁₁ to D _N1
is a backflow prevention diode connected in series with the output line. Further, the negative output line of the backup power supply PS _B is directly connected to the negative output line of each of the power supplies.

In the circuit configured in this way, the power supply PS ₁
When all of PS _N to PS N are operating normally, diodes _D12 to D _N2 are reverse biased, so
Backup power supply PS _B is not operating. now,
Suppose that the power supply PS ₂ goes down for some reason. Since power is no longer supplied from the diode _D21 side, the potential _V2 on the cathode side of _D21 is about to drop rapidly. Then, diode D ₂₂ becomes forward biased and starts conducting, which connects the backup power supply.
Power from PS _B is supplied to load LD ₂ . Diode D ₂₁ is reverse biased so that the power supply PS ₂
No current flows to the side. In order to ensure the above operation, the value of the backup power supply PS _B is selected to be slightly lower than the values of the power supplies PS ₁ to PS _N.

This type of system has the advantage that even if one or more power supplies go down, only one backup power supply is required. However, there is a drawback that the voltage supplied to the load is reduced due to the large voltage drop of the diodes D ₁₂ to _{D N2} and the voltage drop due to wiring. This is especially a problem with low-voltage power supplies in the 5V system.

The present invention has been made in view of these points, and has realized a power supply system that compensates for voltage drops by adding a remote sensing function to the system shown in FIG. Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 2 is a diagram showing the concept of the remote sensing function. The power supply PS has a four-terminal structure having a voltage detection terminal and a current output terminal for each of positive output and negative output. S ₊ is the positive output side,
S _- is the voltage detection terminal on the negative output side. Also, V ₊
is the current output terminal on the positive output side, and V _- is the current output terminal on the negative output side. Voltage line _L1 and current line _L1 on the positive output side are load LD
are connected at one point A. Also, the voltage line on the negative output side
l ₂ and current line L ₂ are connected at one point B of the load LD.
In the circuit connected in this way, the voltage lines and current lines to the connection points A and B all constitute the internal circuit of the power supply PS, and the A and B points serve as output terminals as the power supply. Therefore, a constant voltage is applied to the load LD.

FIG. 3 is a configuration diagram of an N:1 redundant power supply system showing an embodiment of the present invention. Components that are the same as those in FIG. 1 are indicated with the same symbols. Power supply PS ₁ ~ _{PS N}
and backup power supply PS _B all have a four-terminal structure for remote sensing. The current line on the positive output side of the backup power source PS _B is connected to the current line on the positive output side of each power source via diodes D ₁₂ to D _N2 , respectively. The current line on the negative output side of PS _B is connected to the current line on the negative output side of each power supply. Also, the voltage line on the positive output side of PS _B is connected to diode D _B1 and voltage detection diode.
It is connected to the positive side connection points A ₁ to A _N of each load via D ₁₃ to D _N3 . The voltage line on the negative output side of PS _B is connected to the voltage line on the negative output side connected to each load.

In addition, a resistor R _B1 is connected from the point G on the anode side of the diode D _B1 to the positive current source of the backup power supply PS _B.
is connected. A resistor R _B2 is connected between a point F of the positive voltage line of PS _B and the negative voltage line. In addition, voltage clamp diodes _D14 to _DN4 and
D ₁₅ to D _N5 are connected in the direction shown in the figure. The diodes D _B2 and D _B3 of the backup power supply PS _B are also used for the same purpose. The operation of the circuit configured in this way will be explained below.

When the power supply and load are in normal operating conditions, the voltage sensing diodes D ₁₃ -D _N3 are all reverse biased and therefore in a cut-off state. Also at this time, since each voltage line and current line of the power source PS _B are configured to be connected at one point, the output value of the power source PS _B is kept constant. Therefore, even if any of the power supplies _PS1 goes down, the same voltage can be quickly supplied.

Now, let's assume that the power supply PS ₂ is down. Only diode D ₂₃ is forward biased and this diode starts conducting. That is, power is supplied to the load LD ₂ from the backup power supply PS _B. Since the output voltage is sensed at the load end, voltage drops along the line do not pose a problem. Note that, in practice, the forward voltage drop of the diode _D23 cannot be ignored. Diode D _B1 is for compensating the effect of the voltage drop of this diode _D23 . Therefore, the voltage at the load end appears at point F on the cathode side of diode D _B1 .

Once diode D ₂₃ becomes conductive, the remote sensing function is activated and a constant voltage is supplied to load LD ₂ . Resistor R _B1 is for biasing diode D ₂₃ in the sensing state. The above description has been made by taking as an example the case where the power supply PS ₂ goes down, but the same applies to the case where the other power supplies go down. As described above, according to the present invention, remote sensing of an N-to-1 redundant power supply can be realized with extremely simple means. Furthermore, since the backup power supply output can be maintained at the desired output during normal operation, switching time is quick and voltage dips are small during backup.

As described above in detail, according to the present invention, an N:1 redundant power supply system that compensates for voltage drops can be realized by adding a remote sensing function.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a conventional example of an N-to-1 redundant power supply system. FIG. 2 is a diagram showing the concept of the remote sensing function. FIG. 3 is a diagram showing an embodiment of the present invention. P _S1 ~P _SN ...Power supply, LD ₁ ~LD _N ...Load, D ₁₁
〜D _N1 , D ₁₂ 〜D _N2 , D ₁₃ 〜D _N3 , D ₁₄ 〜D _N4 , D ₁₅ 〜
D _N5 , D _B1 ...Diode, R _B1 , R _B2 ...Resistor.

Claims (1)

[Claim for Utility Model Registration] An N-to-1 redundant power supply system consisting of N power supplies, N loads, and one backup power supply, which has a four-terminal structure of a current output terminal and a voltage detection terminal. each of the power supplies, two current lines connected to each current output terminal, two voltage lines connected to each voltage detection terminal, and four voltage lines connected to the corresponding current and voltage lines of the power supply.
each of the loads connected by a line; the backup power supply having a four-terminal structure including a current output terminal and a voltage detection terminal that output a voltage lower than the normal output voltage of each power supply; and a current output terminal of the backup power supply. a backup current line having one end connected to the current line of each of the power supplies and the other end connected to the current line of each of the power supplies via a first diode, one end of which is connected to the voltage detection terminal of the backup power supply, and the other end of each of the power supplies An N-to-1 redundant power supply system comprising: a backup voltage line connected to a load connection point of a power supply via a second diode.