US 6,271,456 B1 · Transducer and musical instrument employing the same

Abstract

An electrical pickup for use with a stringed musical instrument is disclosed, as well as a stringed musical instrument employing such a pickup. The pickup is formed of a plurality of magnetoresistive elements, whose electrical resistance decreases as the magnitude of a surrounding magnetic field increases. A first pair of the magnetoresistive elements form two opposite legs of a Wheatstone bridge, and a second pair forms the remaining legs. The magnetoresistive elements forming the two pairs are electrically opposite one another, but are physically located side by side. The first pair is located on a first side of the vibrating string, and the second pair is located on the other side. A magnetic field is established which interacts with the magnetoresistive elements. The pickup is positioned so that the vibration of the string causes perturbations in the magnetic field, which in turn alter the resistance of the magnetoresistive elements. When a DC voltage is applied across the input terminals of the Wheatstone bridge, an output voltage signal is developed across the output terminals that varies with the changing resistance of the magnetoresistive elements. Because the resistance of the magnetoresistive elements changes with the instantaneous position of the vibrating string, the output voltage is representative of the vibration of the string.

Claims30

Dependent claims

A transducer for use with a stringed instrument, said transducer generating an electrical signal corresponding to movement of a vibrating string as the instrument is played, the transducer comprising:

a plurality of magnetoresistive elements, each having an electrical resistance that varies in response to a parameter of a magnetic field;
said plurality of magnetoresistive elements electrically connected in a Wheatstone bridge configuration having a pair of input terminals and a pair of output terminals;
a first pair of said magnetoresistive elements corresponding to a first pair of opposite legs of said Wheatstone bridge and being physically located on a first side of said string, and a second pair of said magnetoresistive elements corresponding to a second pair of opposite legs of said Wheatstone bridge and being physically located on a second side of the string;
and means for generating a magnetic field adapted to interact with said magnetoresistive elements such that perturbations in the magnetic field caused by movement of the string alter the resistance of at least some of said magnetoresistive elements whereby, when a voltage is applied across the input terminals of said Wheatstone bridge, an output signal that varies with the changing resistance of said magnetoresistive elements is developed across the output terminals.

1 more element

An electrical musical instrument comprising:

a support having an electrically conductive string stretched taut thereacross, said string being adapted to vibrate when acted upon by a musician;
and
an electrical pickup for sensing the vibration of the string, said pickup comprising;
first and second magnetoresistive elements located on a first side of said string, and third and fourth magnetoresistive elements located on a second side of said string, said magnetoresistive elements being electrically connected in a Wheatstone bridge configuration;
a first DC input terminal formed at a junction between said first and second magnetoresistive elements and a second DC input terminal formed at a junction between said third and fourth magnetoresistive elements;
a first output terminal formed at a junction between said first and third magnetoresistive elements and a second output terminal formed at a junction between said second and fourth magnetoresistive elements;
a DC voltage source providing a DC voltage across said first and second DC input terminals;
means for creating a magnetic field oriented to interact with said magnetoresistive elements, such that vibration of said string causes perturbations in said magnetic field, said perturbations causing the resistance of said magnetoresistive elements to change, thereby generating an output signal across said output terminals corresponding to the position of the vibrating string;
and
an output amplifier for amplifying said output signal.

7 more elements

Dependencies are inferred from the claim text.

Transducer and musical instrument employing the same

Life of this patent

Transducer and musical instrument employing the same

Life of this patent

Abstract

Claims30