GB2062317A

GB2062317A - A Device for Identifying Individual Conductors of a Group of Conductors

Info

Publication number: GB2062317A
Application number: GB7937751A
Authority: GB
Original assignee: Mason & Morton Electronics Ltd
Current assignee: Mason & Morton Electronics Ltd
Priority date: 1979-10-31
Filing date: 1979-10-31
Publication date: 1981-05-20

Abstract

Conductors are connected at one end to terminals (shown at the left) of a receiver unit (Fig. 2), the other ends being connected to a sender unit (Fig. 1, not shown). A counter 46 is incremented manually 36, each count being displayed 38 and compared 50 with a count 48 of clock pulses 52 also sent to the sender unit, the clock pulses being gated off on equality at 50. The sender unit uses the clock pulses received to drive a shift register to energise one of the conductors, thus lighting a corresponding LED at 44. The other LEDs provided at 44 are used in initial set-up to determine which conductors to connect to the top two terminals in Fig. 2. Instead of being remotely- controlled, the sender unit could be automatic. The sender unit could energise all the conductors simultaneously, each with a different frequency and/or voltage. <IMAGE>

Description

SPECIFICATION A Device for Identifying Individual Conductors of a Group of Conductors The present invention relates to the identification of individual conductors of a group of conductors and finds particular application in the electronics and the electrical building industries.

It is common practice that a group of conductors is placed in position during the construction of electrical equipment or during the construction of buildings since this is often easier than positioning the conductors after construction. This is particularly the case in the building trade where the conductors are liable to be incaserated in plaster and other such materials. In general, the conductors are cut as lengths from a common reel or from similar reels with the result that the conductors are not distinguishable when in situ. Often all individual conductors of a group are covered with the same colour of insulating material. A problem thus exists when the conductors are to be connected.

Heretofore, the problem has been solved by the manual application of a signal to one end of an individual conductor followed by testing the ends of the conductors until the corresponding end of the individual conductor under test is located. The most common form of such a method being the illumination of a light bulb with the use of a separate cable for the return path. In the building industry in particular this task often entails the cooperation of two engineers.

It is an object of the present invention to provide a device for enabling a single operator to identify the corresponding ends of individual conductors of a group of a conductors.

According to the present invention there is provided a device for enabling a signal operator to identify the corresponding ends of individual conductors of a group of conductors comprising an automatic or remotely controlled sender unit and a receiver unit, wherein the sender unit is operable to supply either simultaneously or time sequentially to the first ends of the individual conductors identification signals which are distinguishable at the receiver unit to enable corresponding ends of the individual conductors to be identified.

The invention will now be described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 shows a block diagram of the sender unit, Figure 2 shows a block diagram of the receiver unit, and Figure 3 illustrates the temporal relationship between various signals used by the device.

One embodiment of the present invention is illustrated in Figures 1 and 2. The receiver unit 200 is connected to one end of the group of conductors (not shown). The sender unit 100 is connected to the other end of the group of conductors. Each individual conductor is attached by a respective terminal to the receiver unit 200 and similarly to the sender unit 100. The device operates in the following manner. The sender unit 100 supplies an identification signal to a predetermined one of the sender unit terminals 28. The identification signal is transmitted via the attached conductor to the receiver unit 200 where the corresponding end of this particular conductor is identified by receipt of the signal.

The supply of an identification signal to a predetermined one of the sender unit terminals 28 is remotely controlled from the receiver unit 200 in a time sequential fashion. Consequently, the receiver unit 200 is able to distinguish the corresponding ends of the individual conductors by the application of a single identification signal.

The remote control of the supply of the identification signal to a particular terminal 28 is effected by the transmission of a selection signal from the receiver unit 200 to the sender unit 1 00.

This transmission is conveniently accomplished by the utilisation of at least one but preferably a pair of the conductors of the group of conductors.

Referring to Figure 1, the sender unit 100 comprises a direct current power supply 10 connected via a switch 11 across a pair of the sender unit output terminals (20 and 22). One side of the power supply 10 is also connected to a Schmidt trigger 14. The output of the Schmidt trigger 14 is connected to the input of a shift register 1 2 and also to the inputs of two monostable multivibrators 1 6 and 1 8. The output of the first monostable multivibrator 1 6 is connected to the shift register 1 2. Each digit section of the shift register 12 is connected to a respective terminal 28 of the sender unit 100 via a respective output transistor 26.The output of the second monostable multivibrator 1 8 is connected to the base of a main output transistor 24 which is connected between the power supply 10 and the respective output transistors 26 of the sender unit terminals 28.

Referring to Figure 2, the receiver unit 200 comprises a number of terminals 42 each having a respective indicator mechanism 44 comprising a pair of back-to-back light emitting diodes. One of each pair of light emitting diodes is of one colour whilst the other is of a second colour. The terminals 42 are connected to a common terminal 40. The receiver unit 200 also comprises a signal generating unit 30 connected to an output terminal 32 via an output buffer 33. The signal generating unit 30 is connected to a display 38 and is also connected to an index switch 36 and a reset switch 34. The signal generating unit 30 comprises a first counter 46 having respective inputs connected to the input switches 34 and 36 and an output terminal connected to the display 38.The first counter 46 has an output connected to a comparator 50 which compares the contents of the first counter 46 with the contents of a second counter 48. The comparator 50 has an output connected to a flip-flop 56. The second counter 48 has its input connected to the output of an oscillator 52 and an output connected to the flip-flop 56. The output of the flip-flop 56 is connected to one input of a NAND gate 54.

Another input of the NAND gate 54 is connected to the output of the oscillator 52. The output of the NAND gate 54 is connected to the terminal 32 via the output buffer 33.

In order to utilise the conductors of the group of conductors for the transmission of a selection signal it is convenient to select a pair of the conductors.

The ends of the individual conductors at one end of the group of conductors are connected to respective terminals 28 of the sender unit 100.

Two individual conductors are also respectively connected to terminals 20 and 22 of the sender unit 100. It is to be noted that whilst only six terminals 28 (and eight terminals 42) are illustrated in the drawings, in practice the number of terminals would typically be of the order of sixty. The other ends of the conductors are connected to respective terminals 42 of the receiver unit 200.

The switch 11 is operated and a potential difference is thus applied across the terminals 20 and 22. Consequently a current flows in the conductors connected to terminals 20 and 22, since the circuit is completed at the receiver unit 200 by the terminals 42 and the corresponding indicator mechanisms 44 to which these particular conductors are connected. Since the current flow through the indicator mechanisms 44 is in different directions, different coloured light emitting diodes will be illuminated in each case. The terminal 42 to which the corresponding end of the conductor connected by its other end to terminal 20 can thus be identified. This conductor is removed from terminal 42, causing both light emitting diodes to be extinguished, and then connected to terminal 40 causing the light emitting diode associated with the conductor connected to terminal 22 to be re-illuminated.

This latter conductor may now be removed from the terminal 42 to which it was originally connected and connected to terminal 32 of the receiver unit 200.

The transmission link having thus been established identification of the corresponding ends of the individual conductors may be carried out.

The counter 46 is reset by use of the reset switch 34. The display 38 continually dispiays the contents of the counter 46. In its reset condition the counter 46 is set to 01 and this indicates that the identification signal is to be applied to the first of the terminals 28 of the sender unit 1 00. Each cycle of the oscillator 52 increments the content of the counter 48. When the content of the counter 48 is 01 the state of the flip-flop 56 is such that signals from the oscillator 52 pass to the terminal 32 via the NAND gate 54. The signals from the oscillator 52 pass to the terminal 32 until the state of the flip-flop 56 is changed by a signal from the comparator 50. The comparator 50 changes the state of the flip-flop 56 when coincidence occurs between the contents of the counters 46 and 48.When the counter 48 reaches its maximum value it resets and at the same time changes the state of the flip-flop 56 causing the signals from the oscillator 52 to pass again to the terminal 32 via the NAND gate 54 and the buffer 33. The terminal 32 is thus supplied with a signal as illustrated at a in Figure 3 (Figure 3 is not drawn to scale). When the index switch 36 is operated the content of the counter 46 is incremented by one unit, hence one additional pulse from the oscillator is passed to the terminal 32 before the comparator 50 changes the state of the flip-flop 56. The signal supplied to the terminal 32 is as illustrated at c in Figure 3. This signal (a, c) is the selection signal which is passed from the receiver unit 200 to the sender unit 100.

Selection signals supplied to the terminal 32 of the receiver unit 200 are transmitted to terminal 22 of the sender unit 100 via the interconnected conductor. The selection signals are passed through the Schmidt trigger 14 and are then applied to the input of the shift register 1 2. The selection signals are also supplied to the inputs of the monostable vibrators 1 6 and 1 8. The pulses contained within the selection signal are clocked into the shift register 12 and the corresponding output transistors 26 are switched on or enabled.

However, current does not flow through the transistors 26 to the corresponding terminals 28 because the monostable multivibrator 1 8 is triggered by the pulses of the selection signal to produce an inhibit signal which prevents transistor 24 from switching. When all of the pulses of the selection signal have been entered into the shift register 12 only one of the output transistors 26 will be switched on. The monostabie multivibrator 1 8 ceases to produce the inhibit signal and thus transistor 24 is switched on. Transistor 24 now supplies a signal via the enabled or switched on transistor 26 to the corresponding sender unit terminal 28. The monostable multivibrator 1 6 resets the shift register 1 2 before the next pulse train is received.

A typical selection signal is shown at c in Figure 3 and as described above this signal c corresponds to a count of 02 stored in the counter 46. The inhibit signal produced by the monostable multivibrator 1 8 is shown at din Figure 3 and the signal produced by the monostable multivibrator 1 6 is shown at b. The resultant signal which is applied via the enabled transistor 26 to the corresponding terminal 28 is shown at e in Figure 3.

Each of the terminals 28 of the sender unit 00 is connected to one of the terminals 42 of the receiver unit 200 by one of the conductors of the group of conductors. Supply of an identificatidn signal, such as that shown at e in Figure 3, to one of the terminals 28 causes one of the pair of light emitting diodes associated with one of the terminals 42 to be illuminated. The identification signal passes via the terminals 28 and 42 to the indicator mechanism 44 and returns to the sender unit 100 via terminals 40 and 20. The identification signal causes the illuminated light emitting diode to flash and this aids the visual detection of that light emitting diode. The count stored in the counter 46, which is displayed by the display 38, determines which of the terminals 28 of the sender unit 100 is supplied with the identification signal.Consequently, the corresponding end of the conductor connected to the supplied terminal 28 is identified by the flashing light emitting diode associated with the terminal 42 to which the conductor is connected.

Incrementing the counter 46 enables the corresponding ends of the conductors connected to terminals 28 to be identified.

The fact that a predetermined signal is being applied to a predetermined conductor enables the device to be used by a single operator.

It will be apparent that many possible variations of the embodiment of the present invention are possible. For example, the identification signal may be automatically indexed between the terminals of the sender unit in place of the remotely controlled indexing described above. Further, the identification signal need not be supplied to the terminals of the sender unit time sequentially. The identification signal could in fact be simultaneously applied to all of the terminals of the sender unit provided that the identification signal supplied to each conductor is distinguishable at the receiver unit. Such distinction between the identification signals may be by way of differences in frequency or by differences in the amplitude of the signals.

Similarly alternatives to the above described transmission of the selection signal between the receiver and the sender unit exist. Instead of utilising the conductors the selection signal may be transmitted between the receiver and sender units by a radio link.

Claims

1. A device for enabling a single operator to identify the corresponding ends of individual conductors of a group of conductors comprising an automatic or remotely controlled sender unit and a receiver unit, wherein the sender unit is operable to supply either simultaneously or time sequentially to the first ends of the conductors identification signals which are distinguishable at the receiver unit to enable corresponding ends of the individual conductors to be identified.

2. A device as claimed in claim 1, wherein the sender unit is remotely controlled from the receiver unit to supply identification signals time sequentially to the first ends of the conductors.

3. A device as claimed in claim 2, wherein the identification signals are distinguishable by their occurrence in time alone.

4. A device as claimed in any of claims 1 to 3, wherein the receiver unit comprises a plurality of terminals each having a respective indicator mechanism, each individual conductor being connected to a separate terminal such that the indicator mechanism indicates to which terminal the individual conductor, being supplied with an identification signal by the sender unit, is connected.

5. A device as claimed in claim 4, wherein the indicator mechanism comprises at least one light emitting diode.

6. A device as claimed in claim 3 and any claim appended thereto, wherein the sender unit comprises a plurality of terminals to which the individual conductors are operably connected and wherein the receiver unit comprises a signal generating unit which produces a selection signal which is transmitted to the sender unit in order to select the sender unit terminal to which the identification signal is to be supplied.

7. A device as claimed in claim 6, wherein the signal generating unit operates cyclically and the selection signal comprises a selectable number of pulses per cycle.

8. A device as claimed in claim 7, wherein the sender unit comprises a shift register which monitors the number of pulses per cycle and consequentially supplies one of the sender unit terminals with the identification signal.

9. A device as claimed in claim 7 or 8, wherein the signal generating unit comprises a switch operable to increment a first counter unit, a second counter unit incremented by the output of an oscillator, a comparator which compares the contents of the counter units and a gating unit arranged so as to supply the output of the oscillator to the output of the signal generator until coincidence between the counter units occurs, the gating unit being arranged to be periodically reset.

10. A device as claimed in claim 9, wherein the receiver unit contains a display unit which displays the contents of the first counter unit.

11. A device as claimed in any of claims 6 to 10, wherein the selection signal is transmitted to the sender unit via at least one preselected individual conductor.

12. A device as claimed in claim 11 as dependent upon claim 4, wherein each indicator mechanism comprises two physically distinguishable elements one indicating current flow into the receiver unit and the other indicating current flow out of the receiver unit, and wherein the sender unit is operable to supply a potential difference between two predetermined individual conductors and the receiver unit is adpated such that a current flows between the corresponding ends of the predetermined individual conductors and operates the respective indicator mechanisms, thus preselecting a pair of individual conductors.

13. A device as claimed in claim 12, wherein each indicator mechanism comprises a pair of back-to-back light emitting diodes each one of the pair being of different colours.

14. A device for identifying individual conductors of a group of conductors substantially as herein before described with reference to the accompanying drawings.