JPS63157216A - Power unit having selecting/breaking function for faulty load - Google Patents

Abstract

PURPOSE:To improve the operating efficiency of a power unit by cutting and deleting only a faulty area within a load. CONSTITUTION:If a load 103b, for example, of a load device 103 has a short circuit trouble, a load current is suddenly increased compared with a steady state current. This increased current is detected by a current detector 1 and a pulse signal S2 of an H level is supplied to an IC 5 from the output of a comparator 4. While a pulse signal S3 of a time constant t1 is supplied to a 1st input terminal of a start/stop command circuit 11 from an output terminal of the IC 5. The signal S3 functions as an interruption signal to the command circuit 11 therefore, the output voltage V0 drops down to 0V. When the constant t1 elapses, a pulse signal S1 is applied again to a cushion start circuit 13. Thus an output current rises gradually up to the current I0. The output voltage is supplied also to a load device 102b having a trouble and therefore the short circuit area generates heat with the lapse of time to be broken.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a power supply device having a failure load selection cutoff function;
Specifically, even if an overcurrent including a short circuit flows in some of the loads when multiple loads are driven by a single power supply, the overcurrent will continue to flow while supplying current. The present invention relates to a power supply device having a faulty load selection cutoff function that disconnects and excludes a faulty portion of a load.

[Conventional technology]

For example, telephone exchange, broadcast equipment 1 communication equipment.

In highly public systems such as computer-related equipment, a highly reliable power supply device is required.

Here, a DC power supply system, which is a general power supply device, will be explained based on FIG. 4.

A commercial power source is input to the input side of the DC power s1o1 via a first circuit breaker 102.

A load device 103 is connected to the output side of this DC power supply 101 via a second circuit breaker 104.
This load device 103 includes a first load device 103a, a second load device 103b, ... nth load device 10
n load devices are connected in parallel, such as 3n.

In a system in which power is supplied from one DC power supply to multiple load devices in this way, for example, if an overcurrent failure including a short circuit occurs in the second load device 103b, the DC power supply 101 1. is detected by an appropriate means, and if it is determined that there is some abnormality with respect to the normal value of this current T, the first or second circuit breaker 102 or 104 is turned off, or the output voltage of the DC power supply 101 is By letting it hang down,
A general protection operation is to protect the DC power supply 101 from an overcurrent accident in the load device 103.

[Problem to be solved]

In order to perform the above-mentioned protective operation at high speed, the fuse 105 and MCB 1 are installed on the input side of the load device.
It is difficult to automatically shut off feeders such as 06a-106n, and the method is to stop the load system, manually find the faulty load device, and disconnect only that device.

A large amount of time is spent discovering and isolating the faulty load.

Furthermore, when a plurality of loads are connected in parallel as described above, it is unreasonable that the failure of just one load device would cause other healthy devices to stop functioning.

[Means for solving problems]

In order to solve the above problems, the present invention compares an output current detection means for detecting the magnitude of the output current and a detected value of this output current detection means with a reference m, and if the detected value is larger than the reference value, Comparing means for outputting a predetermined signal; and switching means for turning off the main switching element for a certain period of time each time the predetermined signal is output, and the output current becomes smaller than a predetermined value (failure load The device is designed to supply power while repeating the switching operation until the device is disconnected.

[Effect]

The present invention, as described above, is useful if a load (e.g. telephone exchange)
Even if the load begins to flow an overcurrent, including a short circuit, by continuing to supply current, it is possible to disconnect and exclude only the part of the load that has caused the failure, thereby preventing the rest of the normal load from flowing. continues to provide power.

Therefore, according to the present invention, by quickly selecting and disconnecting a faulty load, a normal load can be used immediately after a short period of stoppage.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a power supply device having a selective cutoff function according to the present invention will be explained based on an illustrated embodiment. It should be noted that members that have already been explained in FIG. 4 will not be explained again, and will simply be labeled with reference numerals.

As shown in FIG. 1, the load device 103 is connected to an output section of a power supply device (hereinafter referred to as a power supply device) 10 having a faulty load device selection cutoff function.

That is, the output section of this power supply device 10 is equipped with a current detector (CD
: Current Detector) 1 is connected, and the first output of this current detector 1 is connected to the input of the load device 103, which corresponds to the current detected by this current detector 1. The resulting output voltage V is connected to be supplied to the non-inverting input terminal of the comparator 4.

The second current detector 1. The third output terminal is connected to one end of the resistor 2 and also to one end of the variable resistor 3,
It is also grounded. The other end of the resistor 2 is connected to the non-inverting input terminal of the comparator 4, and the other end of the variable resistor 3 is connected to a terminal that supplies the operating voltage +VCC.

The variable terminal of the variable resistor 3 is connected to the inverting input terminal of the comparator 4, and by adjusting the variable terminal of the variable resistor 3, the reference voltage V2 is supplied to the inverting input terminal of the comparator 4. It looks like this.

The power supply terminal of this comparator 4 has an operating voltage +VC
C and -VCC are supplied, and the output terminal of the comparator 4 is connected to the first input terminal of an IC 5 that generates a one-shot pulse.

The operating voltage -VCC is supplied to the second input terminal of this IC5, and OV is supplied to the third input terminal.

Further, a capacitor 6 constituting a time constant circuit is connected between the fourth and fifth input terminals of the IC 5, and the above-mentioned capacitor 6 is connected between the fifth input terminal and the first input terminal. Resistors 7 and 8 forming a time constant circuit together with the capacitor 6 are connected, and the connection point between these resistors 7 and 8 is grounded.

The output terminal of the IC 5 is connected to a start/stop terminal that commands the start/stop of the power supply device via a resistor 8 and a current blocking diode 9.
It is connected to the first input terminal of the stop command circuit 11. The second input terminal of this command circuit 11 is a start switch 12
is connected to one terminal of the terminal, and the other terminal is grounded.

The output terminal of the start/stop command circuit 11 is a cushion start circuit 1 for preventing a sudden increase in rush current.
The output terminal of this circuit 13 is connected to a main switching element control circuit 14 that controls the main switching elements of the power supply device 10. The output terminal of this control circuit 14 is connected to an amplifier circuit 15, and the output terminal of this amplifier circuit 15 is the input terminal of a main circuit power supply section 17 that includes a main switching element for power (for example, an FET). It is connected to the.

The output terminal of the main circuit power supply section 17 is connected to the input terminal of the current detector 1, and the output terminal of the current detector 1 is connected to the input terminal of the load device 103 as described above. There is.

Next, the operation of the power supply device 10 configured as described above will be explained based on FIGS. 1 to 3.

First, the case of normal operation will be described.

In FIG. 1, when the start switch 12 is turned on, a start signal S0 is supplied to the input end of the start/stop command circuit 11. Then, the signal S1 is applied to the cushion start circuit 13, and the start circuit 13 sends a signal that gradually increases the current to the load (load device I03 in this case) to the main switching element control circuit 14.
added to. The control signal output from this control circuit 14 is amplified by an amplifier circuit 15 and applied to an output circuit 16.

Then, the current from this output circuit 16 is a steady current! . This steady-state flow I0 also passes through the N,2it detector 1.

This steady current■. Even if it passes through current detector 1, it is a steady value in this case, so the output voltage of current detection '2'& 1 is ■1, and this output voltage VI is equal to the reference set in comparator 4. The value is smaller than the voltage V2. Therefore, since no signal is generated from the output terminal of this comparator 4 (as it remains an L level signal), an L level signal continues to be generated from IC5.
It is supplied to the stop command circuit 11.

The steady current ■ mentioned above. is supplied to the load device 103, the individual load devices 103a, 103b, 103C1 . . .
All n pieces of 103n are operating normally.

Next, of the load devices 103, for example, the second load 103
The operation when b causes a "short circuit failure" will be explained.

It is assumed that all healthy load devices 103a, 103c, . . . -103n other than the second load device 103b are normal.

In this case, the load current supplied to the load device 103 is a steady current ■. It increases rapidly from then on to a peak value of 1p+ (see Figure 2). Then, since this peak current IP+ passes through the current detector 1, the output voltage of this current detector 1 becomes . Since this output voltage V is larger than the reference voltage 2.2, the H level signal is output from the output terminal of the comparator 4 as a narrow pulse signal S2 to the IC 5.
supplied to Then, from the output terminal of this IC5, a pulse signal S3 with a time constant t1 determined by a time constant circuit (capacitor 6, resistor 7.8) is sent to the first input of the start/stop command circuit 11 via a resistor 8 and a diode 9. Supplied at the end.

Then, this pulse signal S acts as an interrupt signal on the command circuit 1l, so that the output voltage v0 decreases and eventually reaches O■ as shown in FIG.

Then, when the time constant tl elapses, the signal S1 is applied to the cushion start circuit 13 again, so the output current gradually increases again in the same manner as described above and becomes the steady current I0, but when further time elapses, it peaks again. The current becomes IP2.

This second peak current tri is detected again by the current detector 1 in the same manner as described above, and soon a signal S having a time width t1 is input to the start/stop command circuit 11.

Then, the output voltage ■ is supplied to the load device 103 in the same manner as described above. will gradually decline.

However, since this output voltage is also supplied to the second load device 103b that has caused the failure, a large current flows through the short circuit that caused the failure of this load device 103b, and over time At the same time, this short-circuited point will eventually generate heat and be disconnected, or the fuse of the input of the load device or the feeder such as the MCB will be cut off.

That is, if the short circuit part of the second load device 103b is disconnected in this way, the second load device 103b is disconnected.
This is equivalent to the case where the load device 103b is removed.

In this way, as shown in FIG. 3, the peak current IPl+rPZrIF3... continues until the short-circuited part of the faulty load (load device 103b in this case) is disconnected.
...... will be supplied.

When the short circuit is removed as described above, the steady current returns as shown in Figure 2! . is applied.

Therefore, the load device 103 can continue to operate normally.

Then, during this normal operation, if the failure of the second load device 103b that was removed as described above is repaired and it is confirmed that it is operating normally by appropriate means, normal operation is resumed. The load device 103 that continues to
Just add it again.

In this way, the individual load devices 103a, 103b, 103b, configuring the load device 103, old...
, 103n, it becomes possible to use the entire system normally again.

In this way, failures can be discovered quickly.

In this embodiment, the case of a general load system has been described, but it goes without saying that the present invention can be applied to a load composed of a plurality of load units.

〔effect〕

According to the present invention, it is possible to exclude only the load that has caused a short circuit (for example, a telephone exchange) using the selective cutoff function, so that the load that has not caused the failure can receive a current that ensures continued operation after a very short shutdown. It becomes possible to supply

[Brief explanation of the drawing]

FIG. 1 is an electric circuit diagram of a power supply device having a selective cutoff function according to the present invention, FIG. 2 is a time chart showing the operation of the power supply device having a selective cutoff function, and FIG. 3 is a power supply device shown in FIG. 1 above. FIG. 4 is a schematic diagram of voltage/current supply when selective cutoff is performed, and FIG. 4 is a system configuration diagram showing application of the power supply device to a conventional load device. 1... Current detector (output current detection means), 4.
...Comparator (comparison means), 5...
One-shot IC (switching means), 10...
...Power supply device with selective cutoff function, 11...
Start/stop command circuit, 13...Cushion start circuit, 17...Main circuit power supply section, 103...Load device.

Claims (1)

[Claims] 1. An output current detection means for detecting the magnitude of the output current, and a detected value of this output current detection means is compared with a reference value, and if the detected value is larger than the reference value, a predetermined signal is output. and a switching means that turns off the main switching element for a certain period of time each time the predetermined signal is output, and repeats the switching operation until the output current becomes smaller than the predetermined value. 1. A power supply device having a failure load selection cutoff function, characterized in that it supplies electric power.