GB2189642A

GB2189642A - Apparatus and systems for producing a sudden or abrupt sound

Info

Publication number: GB2189642A
Application number: GB08709523A
Authority: GB
Inventors: Alan Tomkins
Original assignee: AMATEUR ATHLETIC ASS
Current assignee: AMATEUR ATHLETIC ASS
Priority date: 1986-04-22
Filing date: 1987-04-22
Publication date: 1987-10-28
Also published as: GB8609726D0; GB8709523D0

Abstract

Apparatus for producing a transient sound comprises: a) an electrically operated sound producing device (17); and b) a circuit (2) to be energised from an electrical power source (4) whereby a steep-fronted electrical pulse can be supplied to the device (17) thereby to produce the transient sound. A system may comprise such apparatus and switch means (3) operable to cause the circuit (2) to supply the steep-fronted electrical pulse when the transient sound is required to be produced. Also a system may comprise a plurality of such apparatus and switch means (3) operable to cause the circuits (2) simultaneously to supply the steep-fronted electrical pulses when the transient sounds are required to be simultaneously produced. The invention is of particular applicability for providing "start" signals for athletic and other races. <IMAGE>

Description

SPECIFICATION Apparatus and system for producing a sudden or abrupt sound The present invention relates to apparatus for producing a transient sound at a single location or a plurality of such sounds simultaneously at respective different locations.

In particular, but not exclusively, the invention relates to apparatus for producing a transient sound or simultaneous transient sounds, said sound or sounds being of relatively short duration, but of high volume and suitable for use as a starting signal or starting signals for competitive sporting events.

Traditionally athletic and other races have been started by the report of a firearm such as a pistol. The use of such a firearm, even if it has been made or modified so that only blank cartridges can be used, has inherent disadvantages. Such disadvantages are: 1. The firearm is potentially dangerous and, as such, has to be kept secure to prevent its being stolen and has to be carefully handled.

2. The report may cause offence or nuisance to people unconcerned with the race.

3. The sound of the report takes significantly longer to reach athletes further from the firearm than athletes nearer to the firearm.

4. Ammunition costs, even for blank cartridges, are high.

5. For the operation of an electronic or electric timing system the report from the firearm needs to be converted into an electrical signal using a tranducer and other electrical components and such conversion may not be reliably accomplished.

The present invention, at least in its preferred aspects, aims to overcome the aforementioned disadvantages.

According to the first aspect of the invention there is provided apparatus for producing a transient sound, comprising: (a) an electrically operated sound producing device; and (b) a circuit to be energised from an electrical power source whereby a steep-fronted electrical pulse can be supplied to the device to produce a transient sound.

According to a second aspect of the invention, there is provided a system comprising such apparatus and switch means operable to cause the circuit to supply the steep-fronted electrical pulse when the transient sound is required to be produced.

According to the third aspect of the invention, there is provided a system comprising a plurality of such apparatus and switch means operable to cause the curcuits simultaneously to supply the steep-fronted electrical pulses when the trasient sounds are required to be simultaneously produced.

In this specification the term "electrically operated sound producing device" connotes any device which generates a sound when an electric current is supplied to it. In particular, but not exclusively, such a device may comprise a motor car horn, a piezo-electric horn or other electro-acoustic transducer which, when a pulse of electric current is supplied to it, can produce a sudden, abrupt sound.

The or each said circuit may include a capacitor arranged to be charged from the power source and to be discharged through the respective device to provide the steep-fronted electrical pulses.

The or each said circuit may include switch contacts operable to connect the steepfronted electrical pulse to and to disconnect the steep-fronted electrical pulse from the respective device.

Such switch contacts may comprise "changeover" contacts or alternatively "make" contacts of respective electromagnetic relays operable in response to closure of the switch means. Preferably the or each electromagnetic relay is arranged to be fast to operate and fast to release so that each steep-fronted electrical pulse has a fast rise time and a fast delay time.

Preferably the duration of the transeint sound is between fifty and three hundred milliseconds and the frequency is within the range 300 Hz to 3000 Hz.

The operation of the switch means may actuate a time-recording mechanism and may also be arranged to energise means for producing visual signals at remote positions.

The invention is further described below, by way of example, with reference to the accompanying drawings, wherein: Figure 1 is a schematic circuit diagram of apparatus according to a first aspect of the invention; Figure 2 is a schematic circuit diagram of a modified form of the apparatus shown in Fig.

1; and Figure 3 is a plan view of part of an athletics track showing diagrammatically apparatus according to the second aspect of the invention.

Referring to Fig. 1 the apparatus shown therein comprises a single starter's control unit 1 and a plurality of electric starting "guns" 2, only one of which is shown in the figure.

The starter's control unit 1 comprises a manually operable starter's switch 3 and an electric battery or accumulator 4 having termi nals 5 and 6. The switch 3 is connected through a line 7 to the terminal 5 of the battery 4. Each starting gun 2 is connected through lines 8 and 9 to, respectively, terminals 5 and 6 of the battery 4.

Each gun 2 comprises a first, relatively large, capacitor 10 connected between the lines 8 and 9. Also a second capacitor 11 is connected to the line 8 and through a line 12 and a resistance 13 to the line 9. The capaci tor 10 is of relatively high capacitance, for example, 5000 ,uF. The capacitor 11 is of relatively low capacitance, for example, 500 to 1000 ,uF.

An electromagnetic relay 14 comprises a pair of "make" contacts 15 and an energising winding 16 which when energized causes the contacts 15 to engage each other. An electrically operated sound producing device 17 in the form of a piezo-electric horn is connected to the line 8 and the moving one of the contacts 15, the other fixed contact 15 being connected to the line 9.

The winding 16 of the relay 14 is connected to the line 12 between the capacitor 11 and the resistance 13 and through a line 18 to the starter's switch 3. The winding 16 of the relay is such that when energised the contacts 15 are quick to operate and quick to release.

When the starter's switch 3 is open the battery 4 charges the capacitors 10 and 11.

Subsequently, when the switch 3 is closed, current from the battery 4 flows to each gun 2 through the line 9. The current flows through the resistance 13, the winding 16, the switch 3 and the line 7 to return to the battery 4. Current also flows from the capacitor 11 through the winding 16 and the switch 3 to the battery 4. The winding 16 is accordingly energized by the flow of current through it and causes the contacts 15 to engage each other. Current then flows from the battery 4 through the horn 17. A surge of current in the form of a steep-fronted electrical pulse also flows from the capacitor 10 which thereby discharges through the horn 17. The horn 17 is accordingly caused to sound, the surge of discharge current from the capacitor 10 bringing the volume of the sound emitted by the horn up from zero to a high volume in a relatively short time.

As the capacitor 11 discharges the current flow therefrom through the winding 16 diminishes and the total current flow through the winding 16 becomes insufficient to hold the contacts 15 in engagement with each other.

Accordingly the contacts 15 separate from each other, stopping the flow of current to the horn 17 and the horn accordingly stops sounding.

The capacitance of the capacitor 11 is selected such that the current flow through the winding 16 remains sufficiently high to keep the contacts 14 closed for between one hundred and five hundred milliseconds when the starter's switch 3 is closed. Thus the horn remains sounding at or near its maximum volume for between fifty and three hundred milliseconds. The overall effect of the sound provided by the horn is thus that of a short sharp noise which to the ear is similar to the report of a gun.

Referring now to Fig. 2, the apparatus comprises a starter's control unit 1 and a plurality of electric starting "guns" 2, only one of which is shown in the figure. The starter's control unit 1 comprises a manually operable starter's switch 3 and a direct current supply battery 4 having terminals 5 and 6. The switch 3 is connected by way of a line 7 to the terminal 5 of the supply 4. Each starting gun 2 is connected by way of lines 8 and 9 to terminals 5 and 6 of the supply battery 4.

Each starting gun comprises a capacitor 11 and a resistance 13 connected in series between the lines 8 and 9. A relatively large capacitor 10 is connected between the lines 8 and 9 by way of the normally closed changeover contacts 22 of an electromagnetic relay 14 and a resistance 24. The capacitor 10 is relatively high capacitance, for example, 5000 ,uF while the capacitor 11 is of relatively low capacitance, for example, 500 to 1000 AF.

The energising winding 16 of the relay 14 is connected to the line 12 between the capacitor 11 and the resistance 13 and through a line 18 to the starter's switch 3. An electrically operated sound producing device 17 in the form of a piezo-electric horn is connected between the line 8 and the normally open changeover contact 23 of the relay 14. The apparatus may also include a microphone 24 connected to a loudspeaker 25 by way of an amplifier 26 to enable the starter to give oral instructions to the competitors.

When the starter's switch 3 is open the battery 4 charges the capacitors 10 and 11 by way of lines 8 and 9, the winding 16 of the relay 14 being de-energised. When, subsequently, the starter closes the switch 3, ther relay winding 16 is connected to the charged capacitor 11 thus energising the winding 16 and causing the relay 14 to operate so that the normally open contacts 23 are now closed, isolating the capacitor 10 from the battery 4 and connecting it directly to the sound producing device 17. A surge of current in the form of a steep-fronted electrical pulse flows from the capacitor 10 which thereby discharges through the device 17. No current flows from the battery until the starter releases the switch 3. After about one quarter of a second the relay contacts change back to their original state as shown in the Figure and the capacitors 10 and 11 re-charge from the battery 4.

Referring to Fig. 3, for a staggered start to a race in which the athletes run in lanes 20, each starting gun 2 may be mounted on a respective lane 20 of a running track at a predetermined distance, e.g. three metres behind the starting position of an athlete who is to run in that lane 20. When the starter's switch 3 is operated each athlete hears first the sound of the gun 2 in his or her lane 20 and all athletes hear the sound of their respective guns 2 simultaneously. Thus no athlete has an advantage over any other athlete in hearing the starting signal earlier than any other athlete.

For a straight start with athletes in a row across a track, fewer starting guns 2 than the number of athletes are required in order that all athletes may be equidistant from their respective nearest starters guns. E.g. with eight athletes, four starting guns 2 may be provided, each behind a pair of the athletes and equidistant from those athletes.

The volume of sound received by each athlete three metres from his respective electric starting gun 2 may be approximately equal to that of a conventional starting pistol firing a blank cartridge twenty metres from the athlete, yet the total volume of sound emitted by eight such electric starting guns as described may be quite small as compared with a sound of the conventional pistol firing a blank cartridge.

The horns 17 may be commerically available horns such as electro-mechanical car horns or piezo-electric horns. In large sports stadia or other sporting complexes additional horns 17 may be provided in spectator areas to ensure that spectators are made aware of the starting sound at substantially the same time as the competing athletes. Alternatively the starting sound from an additional horn 17 may be fed into a public address system serving the spectator areas.

The circuits of the starters control unit 3 and the starting guns 2 shown are by way of example and may comprise other configurations using solid state semi-conductor devices such as silicon controlled thyristors and triacs and may include integrated circuits. Means may be included to allow control of the duration of the sound emitted by each horn 2 and of its volume by adjustment of the duration and magnitude of the current supplied to the horn.

It will be appreciated that the circuitry shown in Fig. 1 or 2 may be connected to and arranged to actuate an electric or electronic timing system and that the starter's control unit 1 may be arranged to provide an actuating signal for cinematographic apparatus or telerecording apparatus at a finishing line, which may be remote from the starting position, thereby to provide a visual record of the order in which competitors cross the finishing line. When competitors are required to compete within lanes 20 or other permitted zones, the starter's control unit 1 may be arranged to provide an actuating signal for cinematographic apparatus or telerecording apparatus arranged to provide a visual record of the progress of each of the competitors to monitor possible encroachment into the zones of the other competitors.

Reference numerals are included in the appended claims for the purpose of increasing the intelligibility of the claims and are not to be construed as limiting the claims.

Claims

1. Apparatus for producing a transient sound comprising: a) an electrically operated sound producing device (17); and b) a circuit (2) to be energised from an electrical power source (4) whereby a steepfronted electrical pulse can be supplied to the device (17) thereby to produce a transient sound.

2. Apparatus as claimed in Claim 1, wherein the circuit (2) includes a capacitor (10) arranged to be charged from the power source (4) and to be discharged through the sound producing device (17) to provide the steep-fronted electrical pulse.

3. Apparatus as claimed in either preceding claim, wherein the circuit (2) includes switch contacts (15) or (22, 23) operable to connect the steep-fronted electrical pulse to and to disconnect the steep-fronted electrical pulse from the device (17).

4. Apparatus as claimed in Claim 3, wherein the switch contacts comprise "changeover" contacts (22, 23) operable in response to the closure of a start switch (3).

5. Apparatus as claimed in Claim 3, wherein the switch contacts comprise "make" contacts operable in response to the closure of a start switch (3).

6. Apparatus as claimed in any one of Claims 3 to 5, wherein the switch contacts are the contacts of an electromagnetic relay (14).

7. Apparatus as claimed in Claim 6, wherein the electromagnetic relay (14) is arranged to be fast to operate and fast to release.

8. Apparatus as claimed in any one of Claims 3 to 5, wherein the switch contacts are contacts operable by a solid state semiconductor device.

9. Apparatus as claimed in any preceding claim, wherein the duration of the transient sound is between fifty and three hundred milliseconds.

10. Apparatus as claimed in any preceding claim, wherein the frequency of the transient sound is within the range 300 Hz to 3000 Hz.

11. Apparatus for producing a transient sound substantially as hereinbefore described with reference to and as illustrated in Fig. 1 or Fig. 2 of the accompanying drawings.

12. A system comprising apparatus according to any preceding claim and switch means (3) operable to cause the circuit (2) to supply the steep-fronted electrical pulse when the trasient sound is required to be produced.

13. A system comprising a plurality of apparatus according to any of claims 1 to 11 and common switch means (3) operable to cause the circuits (2) simultaneously to supply the steep-fronted electrical pulses when the transient sounds are required to be simultaneously produced.

14. A system according to claim 13, wherein each device (17) is disposed adjacent a respective lane, or a respective pair of lanes, of a multi-lane sports course, such as an athletics track.

15. A system according to any of claims 12 to 14, wherein operation of the switch means (3) actuates time-recording means or a timing device, such as a photo-finish camera.

16. A system according to any of claims 12 to 15, wherein operation of the switch means (3) actuates a visual signal, such as a light flash, for a time keeper.

17. A system according to claim 12 or 13, substantially as described herein with reference to and as illustrated in the accompanying drawings.