JPH0481911A - Power source protecting circuit - Google Patents

Abstract

PURPOSE:To obtain the protective circuit which has sufficient safety and can be repaired easily by allowing the protective circuit to execute an operation for maintaining an operating state, as for a power source circuit whose stop is unnecessary even at the time of abnormality. CONSTITUTION:In the protective system by plural abnormality detecting circuits A5, B6 and C13 added to a system constituted of plural power source circuits A2, B8 and C11, the power source circuit stopped by each abnormality detecting circuit is limited to the power source circuit whose stop is necessary by its abnormal part. Accordingly, since the circuit which is operated even at the time of abnormality and has no problem is operated, the abnormal part can be limited. In such a manner, the repairing can be executed safely and quickly.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a power supply protection circuit having a feature of protecting a multi-output power supply device.

[Prior Art] As described in Japanese Unexamined Patent Publication No. 63-114521, a conventional device operates so that all power supply circuits are stopped simultaneously when an abnormality occurs. This configuration has a small number of parts and can maintain sufficient safety. Another method is to provide a protection circuit for each power supply circuit and shut down only the abnormal circuit. Additionally, a method of adding an operation indicator to the protection circuit is sometimes used (for example,
74025).

[While the invention is trying to solve the problem] In the above prior art, the protection circuit configuration in which all power supply circuits stop simultaneously is safe, but it is difficult to tell which power supply circuit has an abnormality. The system was taking a long time to repair. This is because if the protection circuit is removed and the system is forcibly activated in order to identify the abnormal part, in addition to the abnormal part, parts that were protected by the protection circuit will often cause new failures, which can be dangerous. It's for a reason. In the above-mentioned conventional technology, the protection circuit configuration that stops only the abnormal power supply circuit makes it easy to identify the abnormal part during repair. However, for load-side circuits, if only a specific system among a plurality of input power supply systems stops, some circuits may generate a new fault, and the use of this configuration is limited.

An object of the present invention is to provide a protection circuit that has sufficient safety and is easy to repair.

[Means for Solving the Problem] In order to achieve the above object, a protection circuit is caused to perform an operation to maintain an operating state of a power supply circuit that does not need to be stopped even in an abnormal situation.

[Function] In a protection system using multiple abnormality detection circuits added to a system configured with multiple power supply circuits, the power supply circuits to be stopped by each abnormality detection circuit are limited to the power supply circuits that need to be stopped depending on the abnormality part. do. As a result, even in the event of an abnormality, circuits that are in operation and have no problem will continue to operate, making it possible to limit the abnormality and making repairs easier.

[Example code] An embodiment of the present invention will be described below with reference to FIG.

In this example, power applied to power supply input 1 passes through relay 18 and is supplied to power supply circuit A2, power supply circuit B8, and power supply circuit C1l, and output A3, output B9, and output C10 are supplied to the load. This is an output type power supply device. When incorporated into the system, a power amplifier circuit is connected to output A3, a signal processing circuit is connected to output B9, and a standby circuit and main power control circuit 15 are connected to output CIO as loads. do. Regarding the safety condition of this load circuit, there is no problem even if the power supply circuit A2 is stopped alone.

If the power supply circuit B8 is stopped alone, the signal processing circuit of the load may malfunction and the power transistor of the power amplifier circuit may be destroyed, so it must be stopped at the same time as the power supply circuit A2. It is assumed that there is no problem even if the power supply circuit C11 is stopped alone. For this reason, the protection circuit was configured as follows.

An abnormality in the power supply circuit A2 is detected by the abnormality detection circuit A5,
A signal is input to the stop circuit A4 to stop the power supply circuit A2. An abnormality in the power supply circuit B8 is detected by the abnormality detection circuit B6, and a signal is input to the stop circuit B7 and the stop circuit A4 to stop the power supply circuit B8 and the power supply circuit A2 at the same time. Power outlet M
An abnormality in rC11 is detected by abnormality detection circuit C13, and a signal is input to stop circuit CI2 to stop power supply circuit C1l. In addition, for abnormalities in the load circuit, abnormality detection circuits A5, B6, etc. such as short circuits are used. Abnormalities that can be detected in C13 are detected by each abnormality detection circuit A5, B6. It is detected at C13 and the power supply circuit of the required part is stopped. Abnormality detection circuit A5, B6, C1
3, a load abnormality detection circuit 17 is configured to detect the abnormality and turn off the relay 18 through the main power control circuit 15.

According to this embodiment, since the protection circuit is configured as described above, an abnormal part can be identified as follows at the time of repair. Output A
3 is stopped, and if output B9 and output CIO have the specified values, it can be determined that the abnormality is the power supply circuit A2 or this load circuit. If the outputs A3 and B9 are stopped, the output CIO is at the specified value, and the relay 18 is turned on, the abnormality can be identified as the power supply circuit B8 or this load circuit.

If output C10 is stopped, the abnormality is in power supply circuit C.
It can be identified as 1l or this load circuit. If the outputs A3 and B9 are stopped, the output CIO is at the specified value, and the relay 18 is turned off, this is due to the operation of the load abnormality detection circuit 17, so it can be determined that the abnormality is in the load circuit.

FIG. 2 shows a second embodiment of the invention.

The characteristics of the load circuit connected to this embodiment are the power supply circuit D2
No. 6 can be stopped alone without causing any safety problems.

However, it is assumed that there is a problem if the power supply circuit E24 stops alone. Therefore, when the power supply circuit D24 is abnormal, only the power supply circuit D26 is stopped by the protection circuit constituted by the abnormality detection circuit D20 and the stop circuit D21. Assuming that the fuse 23 is sufficient to protect the power supply circuit E24 alone in the event of an abnormality in the power supply circuit E24, we would like to eliminate the abnormality detection circuit and stop circuit that monitors the output E25 in order to reduce costs. Control part D inside
22, and the output E25 is monitored by the control unit D22. When the fuse 23 blows out due to a circuit abnormality and the power supply circuit E24 stops, the control unit D22 causes the power supply circuit D26 to stop.
stops and protective operation can be performed.

A specific example of the power supply circuit D26 that enables such an operation is shown in FIG. Figure 3 is a series regulator,
The transistor 34 is for output, and the Zener diode 42 is a reference voltage source. Here, the terminal 31 is connected to the power source 1,
Terminal 32 is connected to output E25, terminal 44 is connected to 8-power D19, and terminal 45 is connected to stop circuit D21. terminal 3
2. Both terminals 45 are II H77 when normal, and t when abnormal.
rL", and the power supply circuit D26 is stopped by turning off the transistor 34. The terminal 32 is outputted from the terminal E25.
If the power supply circuit E24 stops by connecting to
The power supply circuit D26 can also be stopped at the same time.

[Effects of the Invention] According to the present invention, all the power supply circuits do not stop when there is an abnormality in the power supply circuit or the load circuit, so that it becomes easy to identify the abnormal part at the time of repair. This makes repairs safe and
And it can be done quickly.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a first embodiment of the present invention, and FIG.
The figure is a block diagram showing a second embodiment of the present invention, and FIG. 3 is an explanatory diagram showing the contents of the power supply circuit D26 in FIG. 2. 1...Power input terminal, 2...Power supply circuit A, 3...
Output A terminal, 4...Stop circuit A for power supply circuit A, 5--
- Abnormality detection circuit A for power supply circuit A, 6... Abnormality detection circuit B for power supply circuit B, 7... Stop circuit B for power supply circuit B, 8
...Power supply circuit B, 9...Output B terminal, 10...Output C terminal, 11...Power supply circuit C, 12...Stop circuit for power supply circuit C, 13...For power supply port JGC Abnormality detection circuit, 14...Power ON/○FF terminal, 15...Main power supply control, 16...PL, 17...Load abnormal side ratio circuit,
18...Relay, 19...Output D terminal, 2o...
Power supply circuit abnormality detection circuit D, 21... Power supply circuit stop circuit D, 22... Power supply circuit internal control unit D, 23.
... Fuse, 24... Power supply circuit E, 25... Output E terminal, 26... Power supply circuit D, 31... Connection with power input terminal, 32... Connection with output E terminal, 44. ...Connected to the output D terminal, 45...Connected to the power supply circuit stop circuit, 34...PNP type transistor, 35.36.
41...NPN transistor, 4o, 42...Zena Figure 1 Figure 1 Procedure amendment (voluntary) M relationship with the person making the amendment case

Claims (1)

[Claims] 1. In a power supply system using a plurality of power supply circuits, a first
When there is an abnormality in the power supply circuit, there is a means for stopping only the first power supply circuit, and when there is an abnormality in the second power supply circuit, there is a means for stopping other power supply circuits including the first power supply circuit in addition to the second power supply circuit. A power protection circuit characterized in that it has two types of means: a means for also stopping the circuit. 2. The power supply protection circuit according to claim 1, further comprising means for stopping a power supply circuit selected from a plurality of power supply circuits by means of an abnormality detection means provided on the load side.