Raychem Limited

Other

Focas Limited

Richard J Penneck

Nicholas J Smith

Robin J Clabburn

Michael J Ludden

Paul Taylor

James M O'Brien

Stephen J Duckworth

Michael Booth

Takashi Sato

George B Park

Patrick J Horner

Per J Jensen

John M Senior

George Frederick Hopper

Stephen Michael Baigrie

Leslie J Allen

Richard S Skipper

Peter Nyholm

George M Gansbuehler

Robin James Clabburn

Robert L Hall

David H Thomas

Stephen Day

Edward B Atkinson

David R Fox

Shigefumi Torii

Alexander M Wood

Anthony G Moody

Allan J Cox

Peter N Barnett

Masanori Furuta

Kathleen A Hood

Michael C Booth

The present invention relates to an over-discharge preventing circuit, especially an over-discharge over-current preventing circuit, and more specifically relates to an over-discharge over-current preventing circuit comprising an over-discharge preventing circuit having a FET and an over-current preventing circuit for protecting the FET. The invention includes a primary or secondary battery containing such a circuit, and a battery pack containing such a circuit. The batteries comprising an over-discharge over-current preventing circuit according to the present invention have (1) an electrolyte, (2) a pair of electrode members forming a negative electrode member and a positive electrode member which electrically contact the electrolyte, (3) a pair of external connection terminals respectively electrically connected to corresponding electrode members and (4) a PTC element and FET with a source terminal and drain terminal serially connected between one of the electrode members and the corresponding external connection terminal, the gate terminal being connected to the other electrode member. The FET prevents over-discharge by stopping the supply of current to the external connection terminal when the voltage between the electrode members becomes lower than a predetermined value. The PTC element prevents over-current by stopping the supply of current to the external terminal when the current between the electrode members exceeds a predetermined value, thereby also protecting the FET from being destroyed by such an over-current.

Battery over-discharge protection

Laser-machining polymers

Polymeric composition

An article of manufacture, for example a conductor for an electrical wire or cable, is provided with a refractory coating preferably formed from a refractory metal or semi-metal oxide or nitride and preferably deposited on the surface of the article by a vacuum deposition process such as a sputter ion plating method. Adhesion of the refractory coating, especially at high temperatures may be improved, and migration of the substrate metal through the coating may be suppressed by varying the stoichiometry of the coating through its thickness and/or by the provision of a metallic or refractory intermediate layer. The articles are particularly suitable for use in circuit and signal integrity cables. The vacuum deposited refractory layer may constitute the sole refractory, or additional refractory layers may be deposited by other methods e.g. a sol-gel method.

Wire and cable

Laminar polymeric sheet

A tubular heat recoverable article comprises conductive polymeric material and is heated to effect recovery by the passage of electrical current therethrough. Elongate electrodes are attached on the surface or embedded in longitudinal flanges extending along the article. The flanges also comprise conductive polymeric material but are not heat recoverable, and therefore remain substantially undeformed on recovery other than bending to accommodate transitions. This means that the contact resistance between the electrode and the conductive material of the flange does not increase significantly on recovery.

Heat recoverable article

A support for an elongated piezoelectric pressure sensor, which is general cylindrical in shape is mounted on a hollow support member that has a thickness and strength selected to meet desired conditions. The elongated piezoelectric pressure sensor is wound in a helical depression on the exterior of the support member, and the support member in turn is filled with a potting material having a bulk modulus of elasticity selected to provide a sufficient flexibility so that the elongated piezoelectric sensing element generates signals that have a desired sign characteristic and improved acoustic response.

Support member for pressure sensor

A pressure sensing transducer comprises a central region which comprises a potting material and which is surrounded by a helix of piezo electric coaxial cable. The transducer includes a barrier that suppresses transmission of external pressure variations to the central region. In addition, the overall radial stiffness of the potting material and barrier is sufficiently low that the electrical signal generated by the coaxial cable have a d.sub.31 polarity (corresponding to axial stretching and contracting of the cable).

Acoustic transducer

A water stabilizer polymeric composition incorporating a hydrated alumina filler, which is characterized by the presence of an effective amount of an antimony V compound. The compositions have a reduced tendency to absorb water and specific compositions find applicaiton as electrical insulation and in the production of dimensionally recoverable article.

Stabilized-alumina filled thermoplastics

A piezoelectric coaxial cable comprises a central stretchable electrical conductor (1), preferably formed from a low melting point metal alloy, a piezoelectric intermediate layer (2), preferably formed from a vinylidene fluoride polymer which has been stretched and radially polarized to render it piezoelectric, and an outer electrical conductor (3). The intermediate layer has a ratio R of its internal radius to its external radius which is preferably not more than 0.5 and more preferably not more than 0.4. This construction enables coaxial cables to be formed without voiding or breaking of the internal conductor during stretching.

Method of making coaxial cable

A piezoelectric coaxial cable comprises a central stretchable electrical conductor (1), preferably formed from a low melting point metal alloy, a piezoelectric intermediate layer (2), preferably formed from a vinylidene fluoride polymer which has been stretched and radially polarized to render it piezoelectric, and an outer electrical conductor (3). The intermediate layer has a ratio R of its internal radius to its external radius which is preferably not more than 0.5 and especially not more than 0.4. This construction enables coaxial cables to be formed without voiding or breaking of the internal conductor during stretching.

Piezoelectric coaxial cable

Tracking is reduced in insulators comprising one or more polymers and an anti-tracking filler system comprising (a) a hydrate of alumina having a specific surface area of at least 2 m.sup.2 /g measured by the BET method, and (b) a compound selected from the group consisting of oxides, mixed oxides and mixtures of oxides wherein said compound contains at least one element selected from the group consisting of transition series elements, lanthanide series elements and nontransuranic actinide series elements.

High voltage insulating materials

Novel polymeric compositions having non-linear resistance characteristics, together with electrical equipment comprising such compositions. Any polymer may be used; the polymer contains substantial proportions of certain particulate fillers of a given structure, for example the perovskite and spinel structures.

Polymer compositions for electrical use

A dimensionally recoverable body, which is preferably heat-recoverable, has a body wall which is provided with a plurality of locking elements that are engageable with each other, or are engageable with corresponding elements located on a separate partition, to furcate the body into a plurality of channels. The body may be used for enclosing branch-offs in electrical cables in order to protect the enclosed branch-off from the environment.

Dimensionally recoverable articles

Growing community of inventors

Lechlade, United Kingdom

Richard J Penneck