Abstract: A system for wirelessly supplying electric energy to a rotating device includes a flange disk, a disk-shaped ring, an annular plastic filling, a receiving coil which is embedded in the annular plastic filling, a U-shaped ferrite core having a short section, the end face of which is directed to the plastic filling, a long section which is oriented parallel to the short section and which extends parallel along the outer surface of the annular plastic filling, with the sections connected to one another via a section, a coil system and a receiving coil made of revolving wire windings. A distance of the end face of the long section from the rotation axis of the flange disk is smaller than a distance of the receiving coil from the rotation axis of the flange disk.

Abstract: The invention relates to an optical strain gauge (1) using a glass fibre as a strain sensor. The strain gauge comprises a glass fibre comprising a sheath. The sheath has the following composition: a mixture of polyether ether ketone and an admixture of at least 10 weight percent and a maximum of 40 weight percent of an inorganic filler, with a particle size of between 0.08 ?m and 12 ?m. The outer diameter of the sheath is between 0.2 mm and 1.2 mm. The ratio D/d between the outer diameter D of the sheath and the diameter d of the glass fibre is between 2 and 6. A pressure of the sheath on the glass fibre is such that essentially no relative movement can occur between the glass fibre and the sheath.

Abstract: The invention relates to an optical strain gauge using a glass fiber (1) comprising a Bragg grating (2). The glass fiber is coated with a sheath (3) of polyether ether ketone with an admixture of at least 10 weight percent and a maximum of 40 weight percent of an inorganic filler, with a particle size of between 0.08 ?m and 12 ?m. The outer diameter of the sheath (3) is between 0.2 mm and 1.2 mm. The ratio D/d between the outer diameter D of the sheath (3) and the diameter d of the glass fiber (1) is between 2 and 6. A pressure of the sheath (3) on the glass fiber (1) is such that essentially no relative movement can occur between the glass fiber (1) and the sheath (3).

Abstract: An optical strain gage incorporates an optical waveguide or fiber that includes a sensing section with a fiber Bragg grating, which serves for detecting a strain in a strainable member on which the strain gage is mounted. At locations displaced away from the fiber Bragg grating section, on both sides thereof, the optical waveguide is covered by two fastening elements, which secure the optical waveguide in a force-transmitting manner on the strainable member or a bottom support. Between the two fastening elements, a relatively soft elastic fixing material surrounds the optical waveguide and fixes the fiber Bragg grating section on the strainable member or bottom support in a form-fitting and force-isolating manner.

Abstract: The invention relates to a solid core optic fiber (1) as used in optical fiber technology to transfer optical signals, but also to transmit light for illuminating purposes. The solid core optic fiber (1) comprises a glass fiber (2) with a coating (3). The coating (3) comprises the following composition: a mixture of polyetheretherketone and an inorganic filler material in an admixture of at least 10 and a maximum of 40 wt. % having a particle size of 0.08 ?m to 12 ?m. The outer diameter of the coating (3) is 0.2 mm to 1.2 mm. The ratio D/d between the outer diameter D of the coating (3) and the diameter d of the glass fiber (2) is 2 to 6. A pressure of the coating (3) on the glass fiber (2) is such that essentially no relative motion can occur between the glass fiber (2) and the coating (3).

Abstract: The invention relates to an optical strain gauge (1) using a glass fibre as a strain sensor. The strain gauge comprises a glass fibre comprising a sheath. The sheath has the following composition: a mixture of polyether ether ketone and an admixture of at least 10 weight percent and a maximum of 40 weight percent of an inorganic filler, with a particle size of between 0.08 [mu]m and 12 [mu]m. The outer diameter of the sheath is between 0.2 mm and 1.2 mm. The ratio D/d between the outer diameter D of the sheath and the diameter d of the glass fibre is between 2 and 6. A pressure of the sheath on the glass fibre is such that essentially no relative movement can occur between the glass fibre and the sheath.

Abstract: The invention relates to an optical strain gauge using a glass fiber (1) comprising a Bragg grating (2). The glass fiber is coated with a sheath (3) of polyether ether ketone with an admixture of at least 10 weight percent and a maximum of 40 weight percent of an inorganic filler, with a particle size of between 0.08 ?m and 12 ?m. The outer diameter of the sheath (3) is between 0.2 mm and 1.2 mm. The ratio D/d between the outer diameter D of the sheath (3) and the diameter d of the glass fiber (1) is between 2 and 6. A pressure of the sheath (3) on the glass fiber (1) is such that essentially no relative movement can occur between the glass fiber (1) and the sheath (3).

Abstract: The invention relates to a strain gauge, comprising at least one optical waveguide (5) fastened to a thin support (1). The optical waveguide (5) has at least one section (10) with a fiber Bragg grating (6), which serves the detection of strain. The invention is characterized in that the optical waveguide (5) outside of the fiber Bragg grating section (10) is covered on both sides of said section by two fastening elements (3, 4). In this way, the optical waveguide (5) outside of the fiber Bragg grating section (10) is fastened to the support (1) with force fit. Between the two lateral fastening elements (3, 4), a relatively soft elastic fixing element (2) is fastened around the optical waveguide (2), the element fixing at least the fiber Bragg grating section (10) with positive fit to the support (1).

Abstract: The invention relates to an arrangement for the torque measurement of rotating machine parts with a strain measuring bridge (2) arranged on the rotor, which bridge consists of circuit-connected strain gages. The output signals of the strain measuring bridge (2) are amplified with an amplifier circuit (3) and are converted into frequency-proportional signals in a subsequent or downstream voltage-frequency converter (4). The invention is characterized in that the voltage-frequency converter is embodied as a so-called synchronous voltage-frequency converter (4), which is fed with a quartz-controlled frequency. For the suppression of the so-called frequency jitter, a follow-up synchronization circuit (PLL) (6) is provided after the synchronous voltage-frequency converter (4), which circuit suppresses the alternating frequency of the synchronous voltage-frequency converter (4), so that a frequency signal that is proportional to the analog strain measurement signal is produced at the output.

Abstract: A measured voltage is converted into a digital value according to the follow-up principle. A compensation signal is added to the measuring signal so that the mean value of both signals becomes zero. The compensation signal is formed from at least two auxiliary compensation values which are each a square wave signal having a fixed frequency and a keying ratio which is adjustable independently of the other square wave voltage. The keying ratios are varied or adjusted so that the compensation signal compensates the measured signal. In order to achieve this the value deviating from zero of the sum of the measured signal and the compensation signal is integrated, converted into digital values, and supplied to a PI-or PID-control circuit which controls in a closed loop manner the keying ratios of the square wave signals. The I-value of the PI- or PID-control circuit serves as a measure of the measured voltage.

Abstract: An electrical bridge circuit arrangement for multi-position measuring includes an auxiliary or standard resistance half bridge and measuring resistances (M.sub.1, M.sub.2, M.sub.3) arranged in respective bridge arm circuits. An auxiliary or standard resistance (E) common to all measuring resistances is part of the bridge circuit. The measuring resistances (M.sub.1, M.sub.2, M.sub.3) and the auxiliary resistance (E) can be connected to a supply voltage by means of supply voltage switches (S.sub.12, S.sub.22, S.sub.32 ; S.sub.E3). The voltages present at the ends of the supply voltage diagonal of the bridge circuit are tapped by conductors (L'.sub.12, L'.sub.22, L'.sub.32 ; L'.sub.E3) and are supplied to the inputs of operational amplifiers (1, 2) which adjust or control the voltage level at the tapping point to a reference level. Voltage drops across the measuring diagonal are tapped by additional conductors (L.sub.31, L.sub.21, L.sub.11 ; L.sub.