GB2444295A

GB2444295A - Contactless electrical connector or power isolation means when members of a connector are separated.

Info

Publication number: GB2444295A
Application number: GB0623670A
Authority: GB
Inventors: Robert John Gray
Original assignee: Individual
Current assignee: Individual
Priority date: 2006-11-28
Filing date: 2006-11-28
Publication date: 2008-06-04
Also published as: GB0623670D0

Abstract

A contactless connector comprises first and second components 1, 2 which engage in a separable manner with one another. Each component 1, 2 has an induction coil 9, 12 positioned such that, when the components are engaged, the coils 9,12 are in close proximity and an alternating current in one coil 9 induces a corresponding alternating current in the other coil 12. Each component 1,2 is also provided with means 6, 7 for transmitting and receiving electromagnetic radiation, arranged such that radiation transmitted by one component can be received by the other component when the components are engaged with one another. An infra red or short-range radio link could be used. Another aspect of the invention provides a separable connector arranged to detect the proximity of the two components 1, 2 and to isolate exposed electrical contacts from electrical power when the components 1, 2 are separated. The proximity detector may be formed by a reed switch in one component 1 and a permanent magnet in the second component 2, which are arranged to interact when the components are engaged.

Description

ELECTRICAL CONNECTORS

Field of the Invention

This invention relates to electrical connectors, and in particular to the type of connector that supplies electrical power and audio signals, for example to a communications headset.

Background to the Invention

Communications headsets, comprising a microphone and earphones, for example incorporated into a military helmet, have conventionally been con-nected to communications apparatus such as an intercommunications appara-tus by means of a plug and socket connector, permitting rapid disconnection when circumstances require it. In addition to the audio signals carried by the connectors, electrical power can also be supplied through the connectors to power the attached communications equipment. For naval use in particular, such connectors can be subject to high levels of corrosion, requiring their fre-quent replacement, because of the electrolytic action of the sea water and the electrical potential on the exposed electrical contacts.

Although radio communications systems have been developed which might enable the wired connections to be dispensed with, there are several problems associated with them. Radio transmissions can be intercepted, and even if the communications cannot be received, the radio energy radiated can be sufficient to enable the source to be detected. In some military situations, this can be dangerous. If the radio transmissions are made very low-powered to try to reduce this risk, there is a risk that the received signal may be inade-quate, resulting in incomplete communication, which can again be dangerous in some military conditions. Self-contained radio devices require battery power, and battery failure could put the equipment out of action at a critical moment.

Seeking to make the transmissions more secure by digital encoding and the hke will incur a higher rate of power consumption because of the electronic process-ing required.

US-A-4 144 485 discloses a contactless connector for transmitting pulse signals through two sets of inductively coupled coils. There is no provision for the transfer of power and audio signals.

There is therefore a need to provide a wire connector for the transfer of audio signals and electrical power, which overcomes the problems of corrosion to provide a more reliable separable connector.

Summary of the Invention

According to a first aspect of the invention, there is provided a contact-less connector, comprising first and second components separably engageable one with the other, each component having an induction coil positioned such that, when the components are engaged together, the coils are in close prox- iniity one with the other whereby an alternating current in one coil induces a cor- responding alternating current in the other coil, each component also being pro- vided with means for transmitting and receiving electromagnetic radiation, ar-ranged such that radiation transmitted by one component can be received by the other component only when the components are engaged together.

Each means for transmitting and receiving radiation may comprise an in-fra red emitter and an infra-red receiver. These are preferably aligned with the corresponding receiver and emitter on the other component only when the two components are correctly assembled together.

Alternatively, the means for transmitting and receiving radiation may comprise a very low power radio transmitter and a receiver therefor, for exam-pIe of the type sold under the Trade Mark Bluetooth.

Preferably, the first component comprises a socket and the second com-ponent comprises a plug engageable in the socket, the coil in the second com-ponent being arranged within the plug and the coil in the first component being arranged around the socket. The plug may be temporarily retained in the socket by an elastic 0-ring seated in a groove in one of the components and frictionally engaging the other component.

According to another aspect of the invention, a separable electr!ca! power connector comprises a first component supplying electrical power from a power source via electrical contacts to a second component, the first compo- nent comprising means for detecting when the second component is discon-nected from the first component and for automatically electrically isolating the electrical contacts from the power source in response thereto.

Preferably, the first component comprises a socket and the second com-ponent comprises a plug engageable in the socket, the means for detecting be-ing adapted to isolate the electrical contacts when the plug is not fully engaged in the socket. The means for detecting may comprise a proximity switch in the first component and a magnet in the second component, the magnet causing the switch to change state when in close proximity thereto, i e. when the two components are securely fitted together.

Brief Description ot the Drawings

In the drawings, which illustrate exemplary embodiments of the invention: Figure 1 is a part-sectional elevation of the connector according to a first aspect of the invention; Figure 2 is a perspective view of the plug component of the connector shown in Figure 1; and Figure 3 is a circuit diagram illustrating the operation of a connector ac-cording to a second aspect of the invention.

Detailed Description of the Illustrated Embodiments Referring first to Figures 1 and 2, the connector comprises two principal components, a plug component 1 and a socket component 2 which fit together to connect a first electrical lead 3, for example extending from a communica-tions headset, to a second electrical lead 4, linked to an intercommunications system and power supply. Each component is in the form of a moulded plastics body sealed on to its respective electrical lead to prevent ingress of water, and each contains a space 5 for electronic circuitry connected to an infra-red light-emitting diode (LED) 6 and an infra-red phototransistor 7 The plug component 1 has a cylindrical plug 8, at the end of which the LED 6 and phototransistor 7 are mounted, protected from moisture by infra-red transparent windows. The plug 8 contains a first inductive coIl 9, also con- nected to the electronic circuitry in the plug component 1. A groove 1 0 is pro-vided around the plug 8 remote from the free end thereof, an elastic 0-ring 11 being seated in the groove to provide a water-resistant seal and to hold the components together. As an alternative to this, a circumferential ridge may be provided within the socket, hereinafter described, to engage with the groove 10 to hold the components together.

The socket component 2 has a cylindrical socket into which the plug 8 is a sliding fit. In the end wall of the socket, the LED 6 and phototransistor 7 face outwardly, again protected by infra-red transparent windows. An inductive coil 12 is embedded in the plastics body of the socket component, surrounding the socket and positioned so as to couple inductively with the coil 9 in the plug when this is fully engaged in the socket. In order to ensure correct alignment of the LEDs 6 with the phototransistors 7, means (not shown) may be provided on the plug and socket to ensure that they only fit together in one orientation rela-tive to each other.

When the components 1 and 2 are connected together, power may be supplied from the power supply to the headset through the inductive coupling, and audio signals may be transmitted via the LED/phototransistor pairs in both directions, without the need for any direct electrical contact. As the components are fully sealed from the atmosphere, even total immersion in sea water will not adversely affect the functioning of the components, and secure connections are therefore assured.

Figure 3 illustrates another aspect of the invention, which concerns im-proving the more conventional arrangement of physical electrical connections.

In this case, a separable connector has separate audio and power connections, but for the sake of simplicity, only the power connections are illustrated. The socket component 30 is connected to the intercommunications system and power supply, while the plug component 31 is connected to a headset. Each component has a pair of electrical contacts 32. Those which are connected to the power supply/intercommunications system are especially prone to electro-lytic corrosion because they would normally carry an electrical voltage when disconnected The present aspect of the invention provides an electrical detec-tor circuit in the socket component to detect the presence or absence of the plug component therein, and to disconnect the contacts 32 from the power sup- ply when the components are separated. A magnetic reed switch 33 is pro-vided in the socket component 30, while the plug component 31 is provided with a permanent magnet 34. When the magnet 34 is near to the reed switch 33, the switch is closed, in turn switching, through transistor circuit 35, power from the power supply to the contact 32. When the components are separated, the reed switch opens, in turn opening the circuit to the contacts. For simplicity of illustration, the power supply illustrated is a DC circuit, but one skilled in the art will readily appreciate that a corresponding arrangement can be provided for the switching of AC.

Claims

1 A contactiess connector, comprising first and second components separably engageable one with the other, each component having an induction coil positioned such that, when the components are engaged together, the coils are in close proximity one with the other whereby an alternating current in one coil induces a corresponding alternating current in the other coil, each compo- nent also being provided with means for transmitting and receiving electromag-netic radiation, arranged such that radiation transmitted by one component can be received by the other component only when the components are engaged together.

2. A contactless connector according to Claim 1, wherein each means for transmitting and receiving radiation comprises an infra red emitter and an infra-red receiver.

3. A contactless connector according to Claim 1, wherein each means for transmitting radiation comprises a very low power radio transmitter, and each means for receiving radiation comprises a radio receiver.

4. A contactless connector according to Claim 1, 2 or 3, wherein the first component comprises a socket and the second component comprises a plug engageable in the socket, the coil in the second component being ar-ranged within the plug and the coil in the first component being arranged around the socket.

5. A contactless component according to Claim 4, wherein the plug is temporarily retained in the socket by an elastic 0-ring seated in a groove in one of the components and frictionally engaging the other component.

6. A separable electrical power connector comprising a first compo-nent supplying electrical power from a power source via electrical contacts to a second component, the first component comprising means for detecting when the second component is disconnected from the first component and for auto-matically electrically isolating the electrical contacts from the power source in response thereto.

7. A separable electrical power connector according to Claim 6, wherein the first component comprises a socket and the second component comprises a plug engageable in the socket, the means for detecting being adapted to isolate the electrical contacts when the plug is not fully engaged in the socket.

8 A separable electrical power connector according to Claim 6 or 7, wherein the means for detecting comprises a proximity switch in the first com-ponent and a magnet in the second component, the magnet causing the switch to change state when in close proximity thereto.