JP3497225B2 - Equipment overcurrent protection device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an overcurrent protection device for equipment. 2. Description of the Related Art When a large number of devices are connected to one power supply, usually, a fuse is provided between the power supply and each device, and when an overcurrent flows to any one of the devices. , The corresponding fuse is blown and the current to the device is cut off. When the fuse blows, a person inspects the device, and if there is no abnormality, replaces the device with a new fuse and starts again. [0004] However, when the above-mentioned equipment and the like are provided in a place where humans cannot easily enter, for example, in outer space or the deep sea, the fuse cannot be replaced, so that the fuse system cannot be adopted. For this reason, in recent years, an electronic current limiting switch circuit has been developed which limits the upper limit value of the current supplied to the device and automatically cuts off the current when an overcurrent flows to the control device. . It is planned that the current limiting cutoff switch circuit is provided between a power supply and each device instead of a fuse. [0007] However, the above-mentioned conventional overcurrent protection device for equipment has the following problems. That is, the current-limiting cutoff switch circuit is an advanced electronic control device, so it is very expensive at a price of 10 million yen per unit, and is large in both weight and size. If they are attached, it will be impossible from the viewpoint of cost and mounting. The present invention has been made in view of the above circumstances, and has as its object to provide an overcurrent protection device for a device in which each device can be protected by a small number of current limiting switch circuits. According to the present invention, when a large number of devices are connected to one power supply, several independent device groups into which the devices are grouped, and each device group are provided. A current limiting cut-off switch circuit provided for each device, an overcurrent detector and a control switch provided for each device, and a reset circuit for sending a reset signal to the current limiting cut-off switch circuit. The current cutoff switch circuit limits the upper limit value of the current supplied to each device to which the device belongs , and the reset circuit outputs an overcurrent detection signal from an overcurrent detector provided to each device to which the device belongs for each device group. When monitoring, when the corresponding current limiting cutoff switch circuit is cut off, the control signal is sent only to the control switch for controlling the device in which the overcurrent has occurred, and in this state,
Sends a reset signal to the interrupted current-limit cutoff switch circuit.
If an overcurrent flows to any device,
Switch off the current with the switch circuit and
To protect the equipment to which it belongs,
The current supply is prohibited by the control switch, and
The remaining devices belonging to the group are restarted by the reset circuit
The present invention relates to an overcurrent protection device for a device, wherein the overcurrent protection device is configured to cause the overcurrent protection device. The operation of the present invention is as follows. A current is supplied from one power supply to each current limiting cutoff switch circuit, and the current is distributed from each current limiting cutoff switch circuit to each device of the corresponding device group. Usually, each current limiting cutoff switch circuit limits the upper limit value of the current supplied to each device to which it belongs. The reset circuit constantly monitors an overcurrent detection signal from an overcurrent detector provided in each device. For example, when an overcurrent flows to a certain device due to a ground fault or the like, the corresponding current limiting cutoff switch circuit instantaneously cuts off the current and supplies the current to all devices belonging to the device group. Stop and protect each device. In this case, the current supply is continued as it is for the remaining equipment groups because the systems are independent by the current-limit cutoff switch circuit. When a certain current limiting cutoff switch circuit is cut off, the reset circuit specifies a device in which a ground fault has occurred based on an overcurrent detection signal from an overcurrent detector provided in each device. Then, the control signal is sent only to the control switch of the device in which the ground fault has occurred to prohibit the supply of current to the device, and in this state, the reset signal is sent to the cut-off current limiting switch circuit. Thus, the remaining devices belonging to the device group are restarted. As described above, according to the present invention, a large number of devices can be protected from overcurrent with only a small number of current limiting cutoff switch circuits. The current limiting cutoff switch circuit can be mounted even in a limited space. Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an embodiment of the present invention. In the figure, reference numeral 1 denotes one power supply provided in a spacecraft or a deep sea exploration ship (not shown), and 2 to 5 denote equipment such as heaters and motors provided in a plurality of spacecrafts or a deep sea exploration ship. , 6 is a control panel provided between the power supply 1 and each of the devices 2 to 5 for controlling each of the devices 2 to 5, 7 is each of the devices 2 to 5
Is connected to ground. First, the devices 2 to 5 are grouped to form some device groups 8 and 9. Next, in the control panel 6, each device group 8,
9 belong to each device 2, 3 and 4,
In addition to limiting the upper limit value of the current supplied to 5, when an overcurrent due to a ground fault 10 or the like flows to any of the devices 2, 3, 4, and 5, all devices 2, 3, 4, and 5 belonging to Current limit cutoff switch circuits 11 and 12 for cutting off current
Are provided one by one. In the control panel 6, control switches 13 to 16 and overcurrent detectors 17 corresponding to the devices 2 to 5 are provided.
To 20 are provided. Further, in the control panel 6, based on the signals 21, 22 from the respective current limiting cutoff switch circuits 11, 12, control switches 13, 14, 15 and 16 of the corresponding devices 2, 3 and 4, 5 are transmitted. A control device 28 is provided with a control circuit 27 for sending control signals 23, 24 and 25, 26. Then, for each of the device groups 8 and 9,
Overcurrent detection signals 2 from overcurrent detectors 17, 18 and 19, 20 provided in the respective devices 2, 3, 4, 5
9, 30 and 31 and 32 are monitored, and when the corresponding current limiting cutoff switch circuits 11 and 12 are cut off, the control signal is sent only to the control switches 13 to 16 for controlling the devices 2 to 5 in which overcurrent has occurred. 23 to 26 to prohibit the supply of current to the devices 2 to 5 and, in this state, to provide the reset signals 33,
A reset circuit 35 for sending 34 is provided in the control device 28. The control device 28 may be provided independently for each of the device groups 8 and 9, but is common in this embodiment. Next, the operation will be described. First, each of the current limiting cutoff switch circuits 11, 1 is supplied from one power supply 1 provided in a spacecraft, a deep sea exploration ship, or the like.
2, current is supplied to each of the current limiting cutoff switch circuits 11, 1
The current is distributed from 2 to the devices 2, 3 and 4, 5 of the corresponding device groups 8, 9. Normally, each current limiting cutoff switch circuit 1
1 and 12 limit the upper limit value of the current supplied to each of the devices 2, 3 and 4, 5 to which they belong, and the control circuit 27 of the control device 28 controls the current limiting cutoff switch circuits 11 and 12 Control signals 23, 24 and 25, 26 to the corresponding control switches 13, 14, 15 and 16 of the corresponding devices 2, 3 and 4, 5 based on the signals 21 and 22
The devices 2, 3 and 4, 5 are controlled by opening and closing 3, 14, 15 and 16 respectively. The reset circuit 35 of the control device 28
Overcurrent detector 1 provided in each device 2, 3 and 4, 5
Overcurrent detection signals 29,3 from 7,18 and 19,20
0 and 31, 32 are monitored. For example, when an overcurrent flows through a certain device 2 due to a ground fault 10 or the like, the corresponding current limiting cutoff switch circuit 11 cuts off the current instantaneously and all the devices belonging to the device group 8 Stop supplying current to devices 2 and 3,
The devices 2 and 3 are protected. In this case, as for the remaining equipment groups 9, the current supply is continued as it is because the system is independent by the current limiting cutoff switch circuit 12. When the current limiting cutoff switch circuit 11 is cut off, the reset circuit 35 of the control device 28 controls the overcurrent detection signals 29 and 29 from the overcurrent detectors 17 and 18 provided in the devices 2 and 3, respectively. 30, the device 2 that has caused the ground fault 10 is specified, and the control switch 1 of the device 2 that has caused the ground fault 10 is specified.
The control signal 23 is sent to only the device 3 to prohibit the current supply to the device 2, and in this state, the reset signal 33 is sent to the cut-off current limiting switch circuit 11. Thus, the remaining devices 3 belonging to the device group 8 are restarted. As described above, according to the present invention, a large number of devices 2 to 5 can be protected from overcurrent with only a small number of current limiting cutoff switch circuits 11 and 12, so that the current limiting cutoff switch circuits 11 and 12 can be protected. And the current limiting switch circuits 11 and 12 can be mounted in a limited space. It should be noted that the present invention is not limited to the above-described embodiment, but is applicable not only to outer space and the deep sea bottom, but also to general equipment on the ground and the like. Of course, various changes can be made without departing from the spirit of the invention. As described above, according to the overcurrent protection device for a device according to the present invention, each device can be protected by a small number of current limiting cutoff switch circuits. The present invention can achieve an excellent effect that the cost required for the current limiting can be reduced and the restriction on the mounting of the current limiting cutoff switch circuit can be eliminated.

[Brief description of the drawings] FIG. 1 is a schematic system diagram of one embodiment of the present invention. [Explanation of symbols] 1 power supply 2-5 equipment 8,9 Equipment group 11,12 Current-limit cutoff switch circuit 17-20 Overcurrent detector 13-16 Control switch 29-32 Overcurrent detection signal 23-26 control signal 33, 34 reset signal 35 Reset circuit

Claims (1)

(57) to connect a large number of devices relative to Patent Claims 1. A single power source, and several independent device group to be grouped devices, each device group A current limiting switch circuit provided, an overcurrent detector and a control switch provided for each device, and a reset circuit for sending a reset signal to the current limiting switch circuit. The switch circuit limits an upper limit value of a current supplied to each device to which the device belongs , and the reset circuit monitors, for each device group, an overcurrent detection signal from an overcurrent detector provided for each device to which the device belongs. Therefore, when the corresponding current limiting cutoff switch circuit is cut off, the control signal is sent only to the control switch for controlling the device in which the overcurrent has occurred, and in this state, the cutoff current limiting cutoff switch is cut off. The switch circuit Ri send a reset signal, when an overcurrent flows through any of the devices, limiting blocking Sui
Switch to cut off the current and
Equipment that has overcurrent,
Prohibit current supply by switch and further to equipment group
Restart the rest of the devices to which they belong
An overcurrent protection device for a device characterized by being configured as described above .