Luminous indicator device for mining cable connector and mining cable connector including the luminous indicator device

Abstract

The present invention relates to a mining cable connector including a light-emitting LED indicator device and a light-emitting LED device indicating the status of a pilot-ground loop, wherein the light-emitting indicator device includes a GC terminal connected to a fuse; the output node of the fuse is connected to a transient voltage suppressor (TVC) diode and a driver, and the driver is connected to a lamp, specifically to a light-emitting diode (LED); then, the output node of the LED lamp is connected to the TVS and GND terminals, wherein the pilot terminal and the ground terminal of the loop of the present invention are suitable for being connected to the control (GC) core and the ground (GND) core of the mining cable through a connector and a junction box mechanically fastened to the connector.

Description

Technical Field

[0001] The invention belongs to the technical field of cable fault detection devices, and in particular relates to a luminous LED indicator device for a mining cable connector. Background Art

[0002] In the prior art, there is a patent document US4228475A entitled "Ground Monitoring System" published on October 14, 1980, which describes such a device: the device includes relays, transient voltage suppressors, Zener diodes, bandpass filters, drivers, transformers, detection signal generation, current sources and other components, which helps to detect the grounding cable and correctly connect it to the type of power cable commonly used in open-pit mining sites; it establishes a complete conductive loop between one or more grounding cores and the grounding check cable or the control core of the cable. However, this precedent discloses a fixed-position pilot-ground loop monitoring relay (for example, in a distribution substation), which injects a time-varying signal with a frequency of 1KHz; that is, it does not refer to a device that displays the status of the pilot-ground loop and is portable (because it is installed on a connector). The relay of the above precedent performs the following functions: detect when a fault occurs in the above loop and command the switch to open to cut off the power supply through the cable; on the other hand, the light indicator of the invention does not inject any type of signal into the loop, nor does it disconnect any cutting element. Furthermore, this precedent does not allow the connection of more than one luminous indicator on the same cable extension, so it is impossible to know the status of the pilot-ground loop on site, not to mention that it is not conducive to determining the location (place) of the fault.

[0003] It should be clear that throughout this document, "connector" or "mine cable connector" will be understood as any connection device between mine cables, such as couplers, splitters, etc., used in the open field, mines or tunnels. Similarly, the terms "ground", "GND" and "G" are used to refer to the electrical connection to the system ground core, while the terms "pilot", "ground check" and "GC" are used to refer to the electrical connection to the control core of the system. Summary of the invention

[0004] The present invention is developed to solve the above problems. The present invention relates to a mining cable connector including a light-emitting LED indicator device, and a light-emitting LED indicator device for displaying the state of a pilot-ground loop and suitable for coupling to low-voltage and medium-voltage mining cable connectors, wherein the light-emitting indicator device includes a GC terminal connected to a fuse; the output node of the fuse is connected to a transient voltage suppressor diode (TVS) and a current controller (driver), and the current controller is connected to a lamp, specifically to a light-emitting diode (LED), and then the output node of the LED lamp is connected to the TVS and GND terminals; wherein the pilot terminal and the grounding terminal of the loop of the present invention are suitable for being connected to the control (GC) core and the grounding (GND) core of the mining cable through a connector and a junction box mechanically fastened to the connector.

[0005] Preferably, a cable connects each terminal of the loop to a junction box; the junction box is then connected to the pilot and ground feeders of the connector using cables coated with a synthetic fiber braid, preferably glass. The synthetic fiber braid coating is important because it increases the tensile strength of the junction box-feeder cable, which is relatively thin and may be subject to some mechanical stress during assembly and disassembly of the connector. Finally, these are the connectors that make direct electrical contact with the control and ground cores of the trailing cable.

[0006] The loop is powered by a DC signal from the pilot monitoring relay to the loop through the GC terminal and the GND terminal. In normal operation, the resistance of the fuse is negligible (short circuit), while the resistance of the TVS is very high (open circuit). Therefore, it can be said that all the power is given to the current controller and the LED. The current controller includes a constant current source, which is implemented together with the active and passive components required to set the current so that the LED is significantly bright without affecting the normal operation of the pilot monitoring relay.

[0007] If there is an AC voltage between the GC and GND terminals of the loop, and its magnitude is sufficient to put the TVS into its polarized state, the TVS will change from its low conduction state to a high conduction state. This current will flow through the fuse and cause it to disconnect (open circuit). Therefore, the AC voltage will not damage the current controller or the LED lamp.

[0008] The present invention has the following technical effects:

[0009] The illuminated indicator device is powered directly by the DC signal from the terminated pilot monitoring relay, so it does not require any additional power supply to operate.

[0010] The advantage of the luminous indicator device is that it can be placed directly in the path of the field, mine cable, as it is part of the connector. This makes the location of wiring, connectors and faults easy.

[0011] The combination of TVS and fuse protects the current controller and LED lamp from the unexpected external AC voltage. The TVS will generate enough current to open the fuse.

[0012] The light indicator device uses a constant current source to power the LED light, which makes it easier to keep the light intensity of the LED constant in the face of changes in the DC voltage appearing in the ground-lead conductor. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] As a supplement to the description of the invention and to facilitate the understanding of the invention, this specification is accompanied by a set of two figures as an integral part thereof, in which the following preferred forms of the invention are detailed illustratively and non-limitingly:

[0014] Figure 1 A schematic diagram showing a light emitting LED indicator device and the connections between its components.

[0015] Figure 2 Three illuminated LED indicator devices are shown connected between the monitoring relay loop of the pilot-to-ground loop and its terminals.

[0016] List of reference numerals:

[0017] 1: Monitoring termination relay of pilot-ground loop;

[0018] 2: Pilot / ground check conductor in mine trailing cables;

[0019] 3: Grounding core in mining towing cable;

[0020] 4: Monitoring relay terminal;

[0021] 5: Protection fuse for LED indicator;

[0022] 6: Transient voltage suppressor diode (TVS);

[0023] 7: Driver for powering the LED;

[0024] 8: Light emitting diode (LED);

[0025] 9: Luminous LED indicator device (LED indicator). DETAILED DESCRIPTION

[0026] More specifically, the fuse 5 may be a delay type (time-delay type) with a cut-off current of 100 mA; it may also be a PCB mounting type. However, the time-delay fuse may be replaced by a normal fuse or by a resettable fuse (polymer positive temperature coefficient (PPTC) fuse). The cut-off current may be changed to any other value as long as the associated TVS 6 is capable of conducting the current when the defined AC voltage is present.

[0027] The TVS 6 can be bidirectional, and its breakdown voltage V_br can have at least the same value as the external voltage supported by the associated pilot monitoring relay 1, for an indefinite duration. The TVS 6 can be replaced by a varistor as long as it can carry the cut-off current of the associated fuse when a defined AC voltage is present.

[0028] The current controller (driver) 7 uses a constant current source and the passive and active components required to configure it, which can be done by a person skilled in the art. The constant current source can be of integrated circuit type or implemented with discrete components. The current value to be configured will depend on the magnitude of the DC current injected into the pilot-ground loop by the relevant pilot monitoring relay 1. For example, for an injected current of 25mA, a constant current source of 300uA is configured. On the other hand, a DC-DC converter with a constant current output can be used instead of a constant current source, which can provide the same current as the constant current source. In addition, the DC-DC converter must be close to the power conductors of the cables and connectors to work under electromagnetic conditions.

[0029] The light emitting diodes (LEDs) 8 used are preferably low current consumption, with a light intensity of at least 500 mcd at a positive current of 2 mA. Preferably, the color of the LED should contrast with the color of the connector; for example, if the connector is orange, a blue or green LED can be used.

[0030] The present invention is suitable for connection with a pilot monitoring relay 1. Although this relay is not a direct component of the present invention, it plays an important functional role and must be mentioned here. This relay serves as the power supply and pilot-ground loop status signal of the present invention. The relay must work with terminal 4 (Zener diode, ordinary diode, impedance, etc.) and must inject direct current into the pilot loop. The minimum voltage it must be able to provide is 5VDC and the minimum current is 25mA. The monitoring relay 1 performs two functions: power supply and loop status signal. The power supply function can be replaced by any other power means, such as a battery / accumulator, a system of feeders connected to the connector, or an energy harvesting / electromagnetic energy capture system.

[0031] This light indicator device 9 can be provided for public use pre-installed in a connector for mining cables; similarly, it can be provided as part of a set of connector sub-components (aluminum cover and copper connector) for use in cases where the customer requires to keep the connector already in place but wishes to add a pilot LED light device.

[0032] Figure 1 The elements of the light indicator device 9 and the connection of the light indicator device 9 to the ground-pilot relay circuit are shown. It should be understood that the mine cable connector is arranged beside the light indicator device 9.

[0033] Figure 2 An example of an embodiment of the present invention is shown, which illustrates that when the pilot-ground loop is in good condition and the monitoring relay is turned on, all the lighted LED indicator devices (LED indicators) will be turned on. If a fault such as segmentation / disconnection / loss of continuity occurs in the cable section designated as fault 1, all LEDs will be turned off. On the other hand, if such a fault occurs in the fault 3 position, only LED indicator 3 will be turned off, while indicators 1 and 2 will remain on. If a short circuit fault occurs between the ground and the pilot loop, all LED indicators will be turned off. Table 1 summarizes the status of each LED for two possible fault types in the loop at different positions.

[0034]

[0035] All LEDs will turn off only if the fault occurs in the Fault 1 position, or if the fault is a short circuit between the ground and pilot loops. Finally, this explains how faults in the pilot-ground loop can be located more easily by using multiple LED indicators.

Claims

1. A light-emitting indicator device for displaying the status of a pilot-ground loop and suitable for a mining cable connector, characterized in that including a pilot terminal connected to a fuse; an output node of the fuse connected to a transient voltage suppressor diode and a current controller; The current controller is connected to a light emitting diode; finally, an output node of the light emitting diode is connected to the transient voltage suppressor diode and a ground terminal.

2. The luminous indicator device according to claim 1, wherein: The fuse is a delay type with a cut-off current of 100 mA.

3. The luminous indicator device according to claim 1, wherein: The fuse is a polymer fuse with a positive temperature coefficient.

4. The luminous indicator device according to claim 1, wherein: The transient voltage suppressor diode is replaced by a varistor.

5. The luminous indicator device according to claim 1, wherein: The current controller adopts a constant current source, or adopts a DC-DC converter having a constant current output and being suitable for delivering the same current as the constant current source.

6. A mining cable connector, characterized in that A terminal block is provided in the connector; on the terminal block, a light indicator device for displaying a status is connected to a pilot-ground loop; the light indicator device includes a pilot terminal connected to a fuse; an output node of the fuse is connected to a transient voltage suppressor diode and a current controller; The current controller is connected to a light emitting diode; finally, an output node of the light emitting diode is connected to the transient voltage suppressor diode and a ground terminal.

7. The mining cable connector according to claim 6, wherein: The junction box is connected to the pilot feeder and the ground feeder of the connector through a cable covered with a synthetic fiber braid.

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