539 results about "Voltage response" patented technology

An electronic device with a force sensing key (200) has a switch (280), a first force sensing region (290) for acquiring a first force value, a second force sensing region (290) for acquiring a second force value, and a processor for determining a selected function for the key (200) based upon the first force value and the second force value when the switch (280) is activated. The first force sensing pad (290) and the second force sensing pad (290) use a partially resistive material (250) that exhibits a force-to-voltage response value. By forming the switch (280) as a dome (225) switch, the force sensing key (200) provides crisp tactile feedback to a user. The force sensing key (200) can be configured for a variety of applications and user preferences by varying the architecture of the actuator (270).

The present invention provides an inexpensive security sensor cable, a method for manufacturing of same and an overall security system for using that sensor cable. The sensor cable consists of a central conductor, an air separator, a polyethylene dielectric tube, an outer conductor and an outer protective jacket. The central conductor is loosely centered in the coaxial cable and thus freely movable relative to the dielectric tube. The sensor cable has application either in a passive sensing system or in an active ranging sensing system to determine the location of an intrusion along the cable. For the passive sensing function, when the center conductor moves, it contacts a suitable dielectric material from the triboelectric series, such as polyethylene, which can be processed to produce a charge transfer by triboelectric effect that is measurable as a terminal voltage. In an active system, the central conductor moves within the dielectric in response to a vibration to provide an impedance change that can be sensed. Conventional radio grade cable may be modified in its construction by removing its dielectric thread to manufacture the sensor cable, thus enabling the center conductor to move freely in the air gap within the dielectric tube. An inexpensive method of manufacturing sensor cable is provided as the cable parts are readily available. Such a sensor cable is advantageous in that the passive triboelectric properties of the cable, in response to a disturbance, can provide a larger voltage response over prior art cables.

Formulations for voltage switchable dielectric materials include two or more different types of semiconductive materials uniformly dispersed within a dielectric matrix material. The semiconductive materials are selected to have different bandgap energies in order to provide the voltage switchable dielectric material with a stepped voltage response. The semiconductive materials can comprise inorganic particles, organic particles, or an organic material that is soluble in, or miscible with, the dielectric matrix material. Formulations optionally can also include electrically conductive materials. At least one of the conductive or semiconductive materials in a formulation can comprise particles characterized by an aspect ratio of at least 3 or greater.