Abstract: A composite circuit protection device includes a laminar insulating member and first and second laminar circuit protection devices.

Abstract: A laminar sensor (1) for detecting changes on a laminar substrate (35). The sensor includes a laminar sheet (3) which has a first surface (5) and a second opposite surface (7), and is made from a conductive polymer composition which exhibits temperature dependent resistance behavior, preferably PTC behavior. A plurality of sensing elements (12) are electrically connected, preferably in series, on the sensor. Each sensing element is formed as an electrode pair containing a first electrode and a second electrode. The first and second electrodes (9,11) may be on the same surface of the laminar sheet or on opposite surfaces of the sheet. Two electrical leads (17,19) are present for connecting the sensing elements into a circuit, which may be used to detect changes in resistance which occur when a sensing element is exposed to an elevated temperature, a change in pressure, or a solvent.

Abstract: A composite circuit protection device includes a laminar insulating member and first and second laminar circuit protection devices.

Abstract: A composite circuit protection device includes a laminar insulating member and first and second laminar circuit protection devices.

Abstract: A laminar sensor (1) for detecting changes on a laminar substrate (35). The sensor includes a laminar sheet (3) which has a first surface (5) and a second opposite surface (7), and is made from a conductive polymer composition which exhibits temperature dependent resistance behavior, preferably PTC behavior. A plurality of sensing elements (12) are electrically connected, preferably in series, on the sensor. Each sensing element is formed as an electrode pair containing a first electrode and a second electrode. The first and second electrodes (9, 11) may be on the same surface of the laminar sheet or on opposite surfaces of the sheet. Two electrical leads (17, 19) are present for connecting the sensing elements into a circuit, which may be used to detect changes in resistance which occur when a sensing element is exposed to an elevated temperature, a change in pressure, or a solvent.

Abstract: A composite circuit protection device includes a laminar insulating member and first and second laminar circuit protection devices.

Abstract: A laminar sensor for detecting changes on a laminar substrate. The sensor includes a laminar sheet which has a first surface and a second opposite surface, and is made from a conductive polymer composition which exhibits PTC behavior. A plurality of sensing elements are electrically connected in series on the sensor. Each sensing element is formed as an electrode pair containing a first electrode and a second electrode. The first and second electrodes may be on the same surface of the laminar sheet or on opposite surfaces of the sheet. Two electrical leads are present for connecting the sensing elements into a circuit, which may be used to detect changes in resistance which occur when a sensing element is exposed to an elevated temperature, a change in pressure, or a solvent.

Abstract: A circuit protection device in which a PTC element made from a PTC composition includes or has at a boundary thereof a mechanical stress riser. The device will be tripped by, and provide reversible protection against, a first set of fault conditions, and will also provide protection at least one time against a second, more severe, set of fault conditions which cause physical disruption of the device and which cause the device to have a substantially infinite resistance. Devices of the invention are useful in protecting against relatively high voltages.