AU607043B2

AU607043B2 - Lighting system

Info

Publication number: AU607043B2
Application number: AU29730/89A
Authority: AU
Inventors: Lionel Mark Wilson Dr. Leggett; Graham David Lill
Original assignee: LIONEL MARK WILSON LEGGETT DR
Current assignee: LIONEL MARK WILSON LEGGETT DR
Priority date: 1988-02-24
Filing date: 1989-02-27
Publication date: 1991-02-21
Anticipated expiration: 2009-02-07
Also published as: AU2973089A

Description

AUSTRALIA 6 Patents Act COMPLETE SPECIFICATION

(ORIGINAL)

Class Int. Class Application Number: Lodged: C r

C

Complete Specification Lodged: Accepted: Published: Priority C( am-, 1: l! I S -rrec t Related Art: APPLICANT'S REF.: CAP of PI 6927 Name(s) of Applicant(s): DR. LIONEL MARK WILSON LEGGETT GRAHAM DAVID LILL Address(es) of Applicant(s): Actual Inventor(s): Address for Service is: 32 Blowhole Road, Blackman's Bay, Tasmania 7152 Dr. Lionel Mark Wilson Leggett Graham David Lill PHILLIPS, ORMONDE AND FITZPATRICK Patent and Trade Mark Attorneys 367 Collins Street Melbourne, Australia, 3000 Complete Specification for the invention entitled: LIGHTING SYSTEM The following statement is a full description of this invention, including the best method of performing it known to applicant(s): I19/3M84 i i LIGHTING SYSTEM The present invention relates to a lighting system.

4 More particularly the present invention relates to a lighting system suitable for display or decorative purposes.

The lighting system of the present invention may be used as an advertising display accessory, e.g. to replace displays currently served by 'chasing' lights etc. or as fairground lights or a civic or carnival decoration system.

A particularly suitable application for the lighting system of the present invention may be as a Christmas decoration, e.g. as Christmas tree lights or related j 10 ipdSsystem of the present invention may be as a Christmas displays.

C The present invention will hereinafter be C C particularly described with reference to a Christmas tree C ccc cc lighting system although it is to be appreciated that it is

C

riot thereby limited to such applications.

Prior art flashing or non-steady lighting systems typically have unison flashing lights all on or all i I ooff together). The effect of such lights is severe and cc unnatural. Other systems include a bimetallic strip for controlling the flashing of each individual liht. This j produces a 'jerky' flashing.

An oject of the present invention is to provide a non-steady lighting system which produces a 'twinkling' effect not unlike stars in the sky or a distant village at night. A related object is to provide a lighting system which achieves a relatively slow or controlled turn-on and turn-off of individual lights. A further related object is to provide a lighting system which achieves essentially random or pseudo-random actuation or turn-on and turn-off of individual lights.

The serene natural quality of the lighting system of the present invention is in contrast to the hard square wave switching of prior art systems.

The lighting system of the present invention includes timing means. The timing means may be adapted to control the basic tempo or frequency (twinkle rate) of the 1689L Ic system. The timing means may be adjustable by the user or it may be fixed at a rate based on e.g. consumer opinion testing.

I The timing means may be provided in any suitable i form. In one form the timing means may comprise an IC j timing circuit such as a circuit type 555.

The lighting system includes generator means. For reasons of ease of implementation, the generator means preferably comprises a pseudo-random device. The pseudorandom generator may be adapted to generate a pseudo-random number sequence. The pseudo-random number sequence i preferably is of sufficient length to avoid visual F perception of a regular pattern of operation. The pseudorandom generator may be implemented in any suitable manner J and by any suitable means. In one form the pseudo-random r c generator may comprise a shift register. The shift register may be configured as a serial-to-parallel converter. The shift register may be arranged such that at least one output of the register is fed back to the input if 20 of the register. The or each output may be fed back via Sone or more logic gates.

The pseudo-random generator may comprise a single 8 bit shift register. Alternatively a plurality of shift registers may be connected in tandem to increase the number of parallel outputs and length of pseudo-random sequence.

In one form the pseudo-random number generator may be implemented by connecting a pair of 5-bit shift registers, such as circuit types 7496, in tandem. The two last parallel outputs of the second shift register in the tandem connected registers may be fed back to the input of the first shift register. The outputs may be fed back to the input via an exclusive OR gate.

The parallel outputs of the shift register or registers configured in the above manner may be adapted to provile a binary number which represents or identifies a particular lamp or lighting channel having a combination of lamps in an array of lamps comprised in the lighting system of the present invention.

1689L r The binary number may include any number of digits.

The number of digits required may be related to the total number of lamps in the lighting system. For example with 16 lamps or lighting channels in the system, at least 4 4 binary digits may be required (2 =16) to uniquely identify or specify each lamp or channel in the system.

Where it is permissible for two or more lamps to operate in unison, the total number of binary digits required may be reduced. In general the total number of binary digits n, required may be represented by the expression: n log 2

N

where N represents the number of distinct lighting channels required in the system. Each lighting channel may comprise one lamp or it may comprise a plurality of lamps.

The present invention may include decoding means.

ii The decoding means may be adapted to decode or uniquely specify each lamp or channel in the lighting system. The decoding means may include as an input an n bit binary digit representing 2 n lamps or channels. The decoding means may include 2 n outputs for controlling switching of 2 n lamps or channels in the lighting system.

2 n n i The decoding means may comprise a one-of-2 n decoder circuit. In one form the decoder circuit may f comprise a one-of-sixteen decoder circuit. A one-of-sixteen decoder circuit may be implemented by connecting a pair of one-of-eight decoders, such as circuit types 74138, in tandem.

The present invention may include shaping means for shaping pulses which control switching of lamps in the lighting system. The shaping means may include a plurality of pulse shaping circuits. Each pulse shaping circuit may be adapted to control switching of a lamp or channel in the lighting system.

The or each pulse shaping circuit may include a square wave generator such as a flip-flop. The flip-flop may be connected in a 'toggle' configuration. The clock input of the flip-flop may be connected to one output of the one-of-2n decoder circuit. The flip-flop may 1689L -4- I

P

r

C

CC

C CC C CCC C C' C C C comprise a J-K flip-flop such as a circuit type 7473. The latter package contains a pair of J-K flip-flops.

The Q or Q output of each flip-flop may be connected to a smoothing circuit such as integrator. Where a circuit type 7473 package is employed, the Q and Q outputs of each respective flip-flop in the package may be connected to respective smoothing circuits. In this case one light goes out as another comes on.

Each smoothing circuit may comprise amplifying means including an AC feedback arrangement for limiting the rate of change of turn-on/turn-off current to lamps in the lighting system. The time constant of the feedback arrangement may be chosen according to the rate of light build up and decay required during turn-on and turn-off of lamps in the lighting system. In one form the time constant of the feedback arrangement may be approximately 0.25 second.

The amplifying means may comprise an inverting amplifier. The amplifying means may be adapted to drive 20 the lamp or lamps of the associated pulse shaping circuit.

The amplifying means may comprise one or more transistors.

The load capability of the or each transistor may be selected according to the current requirement of the asscciated lamp or lamps.

The lamp or lamps may be provided in any suitable arrangement depending on application. Where the lighting system of the present invention is to be applied to a Christmas tree, a cluster of lamps belonging to separate channels, e.g. four, may be connected to respective driving circuits via a single multi-pin plug or socket, such as a audio DIN connector.

Lamps or light sources for the lighting system of the present invention may be provided in any suitable form, e.z incandescent, LED's, laser etc. depending on the application. Also depending on application the lamps or light sources may be adapted to turn completely on and off or simply brighten and dim.

CC

C

1689L According to the present invention there is provided a non-steady lighting system suitable for display or decorative purposes, said lighting system including a plurality of lighting channels adapted to be actuated according to at least a pseudo random sequence, said lighting system comprising: V timing means adapted to control a frequency of actuation for said lighting channel;: generator means for generating at least a pseudo random sequence and adapted to control actuation of said lighting channels; and i shaping means for controlling a time constant associated with actuation of said lighting channels.

A preferred embodiment of the present invention will now be described with reference to the accompanying drawings wherein:- Figs. 1A and lB show a circuit diagram of a lighting i system constructed in accordance with the present invention; SFig. 2 shows a lamp cluster connected in accordance with one form of the present invention; and i Fig, 3 shows a power supply suitable for use with the lighting system of Fig. 1.

j The lighting system shown in Fig. 1 includes timing means shown generally at 10. Timing means 10 comprises a 555 IC timer 11 configured as shown. The output 3 of 555 timer 11 is connected to the clock inputs of shift registers 12 and 13. Registers 12 and 13 are circuit types 7496 5-bit shift registers. Registers 12 and 13 are connected in tandem and configured to provide a serial to parallel converter.

The last two outputs 10, 11 of converter 13 are connected via exclusive OR gates 14 and 15 to the serial input 9 of register 12 as shown. OR gates 14, 15 comprise a circuit type 7486. A pseudo-random 4-bit binary number is available at pin outputs 15, 14, 13, 11 of register 12.

The binary output of pins 15, 14, 13, 11 is connected to a decoder circuit comprising a pair of decoders 16, 17 connected in tandem. Each decoder 16, 17 1689L -6r.

comprises a circuit type 74138 one-of-eight decoder. When connected in tandem as shown, decoders 16, 17 provide a one-of-sixteen decoder function.

The sixteen outputs of decoders 16, 17 are connected to respective pulse shaping circuits 18-25 and 26-33.

Pulse shaping circuits 18-33 are substantially identical with the exception that successive circuits may utilize Q and Q outputs alternatively of associated J-K flip-flops.

Pulse shaping circuit 18 only will be described in detail, it being understood that circuits 19-33 are of similar construction and operation. Pulse shaping circuit 18 includes a circuit type 7473 J-K flip-flop 34 connected in a 'toggle' configuration as shown. Clock input 1 of flip-flop 34 is connected to output 7 of decoder 17. The non-inverting output 12 of flip-flop 34 changes state each time input 1 is triggered by output 7 of decoder 17.

The switched output at 12 is connected to an integrating/ driving circuit comprising transistor 35 and capacitive feedback element 36. Capacitive element 36 and resistive element 37 essentially determine the time constant of the integrating circuit. In one form the time constant may be approx. 0.25 sec. Transistor 35 is adapted to drive lamp 38 (Fig. Similarly transistor 39 of pulse shaping circuit 19 is adapted to drive lamp 40 and so on.

With reference to Fig. 2, there is shown a cluster of 4 lamps 38, 40, 42 and 44 connected to respective i driving transistors 35, 39, 41, 43 via a 5-pin audio-type DIN connector. The fifth pin of the DIN connector is adapted to provide a suitable lamp power supply.

The power supply is provided by the circuit shown in Fig. 3. The power supply comprises a step-down transformer for providing a suitable low voltage compatible with the lamps adopted for the lighting system. The power supply includes a bridge diode rectifier 46 for generating a DC voltage. The power supply includes smoothing capacitors 47, 48. An IC regulator 49 (type 7805) is included to provide a regulated 5 volt power supply for the IC circuits of the lighting system shown in Fig. 1.

1689L It will be appreciated that various alterations, modifications and/or additions may be introduced into the constructions and arrangements of parts previously described without departing from the spirit or ambit of the invention.

cc 1689L -8c cc ec e c r 16891 8-

Claims

1. A non-steady lighting system suitable for display or decorative purposes, said lighting system including a plurality of lighting channels adapted to be actuated according to at least a pseudo random sequence, said lighting system comprising: timing means adapted to control a frequency of actuation for said lighting channels; generator means for generating at least a pseudo random sequence and adapted to control actuation of said boot lighting channels; and °ca t shaping means for controlling a time constant 0 "associated with actuation of said lighting channels. 00 "t

2. A lighting system according to claim 1 wherein said oC' generator means comprises a pseudo random generator.

3. A lighting system according to claim 2 wherein said pseudo random generator is adapted to generate a pseudo random sequence of sufficient length to avoid perception of a regular pattern.

4. A lighting system according to claim 2 or 3 wherein said pseudo random generator comprises at least one shift Sregister, the or each shift register being configured as a serial-to-parallel converter.

A lighting system according to claim 4 wherein at least one output of a shift register is fed back to an input of a shift register via a feedback circuit.

6. A lighting system according to claim 5 wherein said feed back circuit comprises at least one logical gate.

7. A lighting system according to claim 'wherein said feedback circuit comprises a pair of exclusive OR gates. 91I -9- i gL V

8. A lighting system according to any one of claims 4-7 further including decoding means for identifying a lighting channel to be actuated.

9. A lighting system according to claim 9 wherein said decoding means comprises a one-of-2 n decoder circuit.

A lighting system according to any one of the preceding claims wherein said shaping means includes at least one pulse shaping circuit and amplifying means adapted to drive a load associated with a lighting channel.

11. A lighting system according to claim 1 substantially as herein described with reference to the accompanying drawings. DATED: 7 February 1989 PHILLIPS ORMONDE FITZPATRICK Attorneys for: DR. LIONEL MARK WILSON LEGGETT GRAHAM DAVID LILL BI t V 1689L -I0-