GB2254156A

GB2254156A - Voltage and continuity testing

Info

Publication number: GB2254156A
Application number: GB9106620A
Authority: GB
Inventors: Edward Marshall
Original assignee: British Gas PLC
Current assignee: British Gas PLC
Priority date: 1991-03-28
Filing date: 1991-03-28
Publication date: 1992-09-30
Also published as: GB9106620D0

Abstract

A device (1) for testing for voltage and hence continuity in leads (8, 19) comprises a body (2) with sockets (3, 4) which receive complementary plugs (7, 18) on the ends of the leads (8, 19). If the leads (8, 19) have both voltage and continuity therein, LED's (11, 14 and 25 Figure 5 not shown) will emit light accordingly. The leads may be associated with a computer system. <IMAGE>

Description

Electrical Continuity Testina Devices The present invention relates to electrical continuity testing devices and, more particularly, to a device for testing electrical continuity in electrical leads.

In local area networking (LAN) in which a plurality of personal computers are connected together to that they can share data and peripherals, it becomes necessary to test components if faults occur in the network. For example, a fault may be apparent from the display on one of the terminals or VDU's in the network but this does not mean that the fault lies with the terminal or VDU.

The fault could lie in a communications line connected to that unit.

One known method of checking whether or not a VDU is faulty is to replace it with one that is known to be working properly.

However, this can cause the users much inconvenience. An alternative method is to replace the suspect VDU with an oscilloscope and test the continuity or integrity of the network line now connected to the oscilloscope. If the tests show that the line is satisfactory, the VDU can with justification be subjected to examination. However, oscilloscopes are relatively large and expensive items for computer maintenance staff to carry around.

An object of the invention is to provide a continuity testing device which can be of relatively simple and compact construction and which can be made relatively cheaply.

Accordingly, the invention consists in a device for testing continuity in electrical leads comprising a body supporting an electrical circuit incorporating indicator means for indicating completion of the circuit and a connector to receive a complementary connector on a lead to be tested. Thus when the device is used and the indicator means indicates completion of the circuit, continuity of the lead is confirmed.

The connector may be in the form of a socket for receiving a complementary plug on the lead.

The body may support two or more independent circuits incorporating respective indicator means and connectors, wherein each circuit is for testing leads having connectors of different kinds or different sizes.

The connector or one of the connectors of the device may be for connection to a coaxial lead.

The connector or one of the connectors may comprise a plurality of pairs of contacts with each pair of contacts being connected to and part of a respective common electrical circuit. Such a construction enables discrete line pairs associated with a common cable and connector to be tested at the same time. Thus, if there are two pairs of lines associated with a connector, one circuit may indicate continuity in one pair of lines whilst a separate second circuit may indicate discontinuity in the other pair of lines in the cable.

Preferably, the indicator means in the or each circuit is a visual indicator means such as a single light emitting diode (LED). Thus, where one connector is associated with two or more separate circuits it will readily be seen whether none, both, some or all of the circuits have been completed during testing.

The invention will now be described, by way of example only, with reference to the accompanying drawings, in which Figure 1 is a front perspective view of one embodiment of a device according to the invention, Figure 2 is a similar view to Figure 1 but with the closure member of the connector accessible through the front face of the device in a held-open position and also showing the plugs of two different leads which can be tested by the device, Figure 3 is a rear perspective view of the device with the back cover removed, Figure 4 shows representations of the two circuits associated with the connection accessible through the front of the device, and Figure 5 shows a representation of the circuit associated with the connection on the bottom side of the device.

With reference to the Figures 1 to 3, a device 1 for testing continuity or integrity in electrical leads comprises a body in the form of a housing or box 2 made of plastics material. Two sockets 3,4 are mounted on the housing. The socket 3 is mounted behind the front face 5 of the housing and the socket opening is normally closed by slidable closure member 6 which is incorporated into the front of the housing and is spring biassed to the closed position as shown in Figure 1. Socket 3 is for receiving a complementary plug 7 as shown in Figure 2 attached to one end of a high-level data link control cable 8 connected at its other end to, for example, a LAN system (not shown).

Normally, the plug 7 would be plugged into a VDU or terminal (not shown). The plug 7 has discrete pairs of contacts which, when the plug is in use, are part of separate respective circuits.

Thus, for example, the pair of contacts B and C are part of one circuit and the pair of contacts D and E are part of another circuit. Referring also to Figure 4, in socket 3 the pair of contacts B' and C' are for cooperating with contacts B and C of plug and form part of one circuit 9 which comprises, in series, a diode 10 and a LED 11 and the pair of contacts D' and E' are for cooperating with contact pair D and E and form part of a similar but separate circuit 12 which comprises, in series, a diode 13 and a LED 14. The LED's 11 and 14 are visible through respective apertures 15,16 in the front face 5 of the housing 2, one to each side of the socket. The device will thus test each line pair in the cable forming part of the associated circuit.

The other socket 4 is a BNC bayonet connection socket which is mounted on and projects from the bottom 17 of the housing and is for receiving a complementary plug 18 at the end of a coaxial cable 19 and normally plugged into a VDU.

With reference to Figure 5, the contacts 20,21 in socket 4 form part of a circuit 22 which comprises, in series, a diode 23, a resistor 24 and a LED 25 which is visible through an aperture 26 in the front face 5 of the housing 2 beneath the socket 3.

In order to test the continuity of the cable 8, the closure member 6 is slid to the position shown in Figure 2 and the plug 7 is pushed into the socket 3 whilst the cable remains connected to the network. The lighting up of both LED's 11,14 indicates continuity in the cable 8. Failure of one or both of the LED's 11,14 to light up indicates lack of continuity in one or both of the line pairs in the cable 8 and/or a fault elsewhere in the system.

The coaxial cable 19 is tested by connecting the plug 18 to the socket 4. If the LED 25 lights up continuity and the presence of a video signal through the cable 19 is indicated, whereas if it does not, lack of continuity in the cable 19 and/or a fault elsewhere in the system is indicated.

The device 1 may, conveniently, be made sufficiently small to be pocket size, portable and easily held in the hand. The device enables the cables to be tested quickly.

Whilst the embodiment described above relates to cables connected to a computer network system it will be appreciated that a device according to the invention may be used to test cables, leads, flex and the like which are connected to other electrical systems, apparatus, and the like.

It will also be appreciated that various modifications may be made without departing from the scope of the invention. For example, the indicator means need not provide a visual signal but may be one which provides an audible signal to indicate continuity. Furthermore, different kinds of sockets or different forms of connectors may be used in the device.

Claims

1. A device for testing continuity in electrical leads comprises a body supporting an electrical circuit incorporating indicator means for indicating completion of the circuit and a connector for receiving a complementary connector on a lead to be tested.

2. A device as claimed in claim 1, wherein the connector is in the form of a socket for receiving a plug on the lead.

3. A device as claimed in claim 1 or 2, wherein the body supports two or more independent circuits incorporating respective indicator means and connectors.

4. A device as claimed in any one of the preceding claims, in which the connector or one of the connectors is for connection to a coaxial lead.

5. A device as claimed in any of claims 1 to 3, in which the connector or one of the connectors comprises a plurality of pairs of contacts, each pair of contacts being connected to and part of a respective common electrical circuit.

6. A device as claimed in any of the preceding claims, in which the indicator means is a light emitting diode.

7. A device as claimed in any of the preceding claims, in which the body is in the form of a housing which houses at least a part or all of the or each electrical circuit.

8. A device substantially as hereinbefore described with reference to the accompanying drawings.