Abstract: A transaction system includes a portable electronic token and an external read/write unit which communicate by inductive coupling. The read/write unit transmits short pulses of an r.f. carrier when in its dormant or stand-by mode and, upon detecting the presence of a token, switches its r.f. on continuously to power up the token and conduct a transaction. Thus, the system conserves power but can react rapidly when a transaction is necessary.

Abstract: A portable electronic card or token has a plurality of discrete electronic components mounted on a flexible substrate, the substrate and the components are encapsulated in a plastics material, and at least one respective high tensile member is associated with each component and disposed such that a region of the card or token encompassing the component is restrained from flexing. The flexing substrate forms resilient hinge portions between adjacent components.

Abstract: A vibrating force sensor comprising a metallic strip having three metallic coplanar beams (20, 21, 22). The sensor also includes capacitive transducers (30, 31) for driving the beam or beams into flexural vibration in a plane normal to their common plane and for detecting changes in the frequency of vibrations in response to changes in tension applied to the sensor. Drive and detect electrodes (50, 51) are formed on the surface of an intermediate insulating layer (70) in turn located on the surface of a shielding layer (71) of conductive material.

Abstract: A transducer designed to give an output which is dependent upon the relative displacement of two bodies comprises two sets of spaced plates interleaved one with the other to form a capacitor, the two sets of plates being movable relative to each other in a direction which maintains the spacing between them, the shape and or disposition of the plates being such that when an oscillating voltage is applied across the capacitor an output signal derived from an intermediate plate varies with changes in the position of the two sets of plates.Such an arrangement gives an output which is substantially linearly dependent on displacement, and by attaching one set of plates to some form of spring the device can be used as a force transducer.

Abstract: A price computing weighing scale has a platform 10 and a m in housing 14 and also incorporates a printer unit 16 located between the platform 10 and the main housing 14 so as to be removable as a unit whereby the scale can be supplied with or without a printing facility. Location of the printer unit 16 within the area beneath the platform 10 minimises the counter space occupied by the weighing scale and printer.

Abstract: A force transducer comprises a block of material which is formed with a generally U-shaped or pi-shaped throughaperture 24 and a generally T-shaped throughaperture 26 in such a way as to form two loading members 10, 12 coupled together by first flexure elements 14, 16 which constrain the loading members to move in a predetermined direction under load and a second pair of flexure elements 18, 20 united by a connecting portion 22. In use, one loading member is connected to a fixture and the other is connected to a force receiver so that when one loading member is displaced relative to the other in said predetermined direction, the second flexure strips 18, 20 undergo a lateral deflection which is a measure of the applied force. This arrangement is particularly suitable for use with strain gauges as the flexures 18, 20 are subjected to a substantially uniform stress along their lengths when loaded.