Sennheiser Electronic Gmbh & Co Kg

Fraunhofer-Gesellschaft Zur Foerderung Der Angewandten Forschung E.V.

Manfred Hibbing

Peter Schreiber

Axel Grell

André Michaelis

Tom-Fabian Frey

Wolfgang Niehoff

Vladimir Gorelik

Sergey Kudaev

Juergen Ihlemann

Jörg Riechers

Ruth Weichenhain-Schriever

An electrostatic transducer has two oppositely disposed counter-electrodes and a diaphragm which is disposed between the two counter-electrodes and which has a first weakly conductive coating. In its edge region the diaphragm has a second well-conductive coating on the first coating to protect the latter.

Electrostatic headphones

A headphone unit comprising a headphone, a headphone pre-amplifier for pre-amplification of an audio signal to be reproduced, and a cable between the headphone pre-amplifier and the headphone. The headphone has two symmetrically designed electrostatic transducers in the push-pull mode of operation. The pre-amplifier is adapted to output an audio signal to be reproduced by way of a first amplifier stage as a voltage-amplified audio signal at an output. The headphone has second amplifier stages which are in the form of high-voltage amplifier stages which are supplied by way of the cable with a pre-amplified audio signal to be reproduced and a high-voltage supply.

Headphone unit

The present invention concerns a feed device for feeding a microphone with a dc voltage. The feed device has first, second and third terminals (a, b, c), a resistor arrangement having at least a one resistor (R-R) and a dc voltage source () for providing a feed voltage. In that case the resistor arrangement is disposed between the dc voltage source () and the first and second terminals (a, b). In addition the feed device has a measuring device and a control device (). The measuring device detects a dc voltage between the first and second terminals and the third terminal, and the control device () reduces or increases the ohmic resistance of the resistor arrangement and the feed voltage of the dc voltage source ().

Power supply device for a microphone

A capacitive sound transducer provided with a perforated attenuation disk. The invention further relates to a capacitive sound transducer and a condenser microphone having such a sound transducer. The sound transducer comprises a diaphragm and a counterelectrode which is disposed at a short distance from the diaphragm and provided with first perforations. In order to attenuate natural oscillations of the diaphragm at high frequencies, a capacitive sound transducer is proposed in which a sound-permeable attenuation disk provided with second perforations is disposed at a short distance from the diaphragm and opposite the counterelectrode. In this arrangement, the first perforations and the second perforations are also offset in relation to each other.

Capacitive sound transducer having a perforated attenuation disk

The invention relates to an arrangement for optically determining the distance of a reflecting surface that can be used, in particular, for determining slight variations in distance such as can frequently occur in vibrating systems. Such an arrangement can also be used as optical microphone or hydrophone. The arrangement according to the invention is designed in this case such that light from a light source is directed onto a reflecting surface via a first optical fiber, and light reflected therefrom is directed onto at least one statically arranged optical detector via the first optical fiber or at least one further optical fiber. An optical element collimating in the direction of the reflecting surface is arranged between the reflecting surface and the one or more optical fibers. Furthermore, at least two optical elements focusing in the direction of the reflecting surface and whose optical axes are aligned parallel to the optical axis of the collimating optical element and are arranged at constant spacings from one another are arranged above the reflecting surface.

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Wedemark, Germany

Manfred Hibbing