US 4,086,519 A · Hall effect shaft angle position encoder

Abstract

A Hall effect shaft angle position encoder is constructed using a plurality of magnetic elements independent of any magnetic rotor of the electrical device which may be a brushless motor or brushless tachometer. The plurality of magnetic elements has serially alternating polarities of magnetic north and south with at least one Hall effect sensor mounted in spaced and confronting relation with the magnetic elements for sensing the alternating polarities and producing output signals representative of the magnetic polarities where the signals include a ramp voltage passing through zero value. The magnetic elements are secured to the rotor outside the normal rotor elements of the device. The output signals from at least one Hall effect sensor are applied to amplifying means which may be an operational amplifier and through the use of a variable reference voltage varying in magnitude and polarity, the output voltage is shiftable to provide signals differing in phase from the Hall effect sensor output signals in accordance with the variable reference voltage polarity and magnitude.

Claims19

Dependent claims

A Hall effect shaft angle position encoder for use with a rotatable electrical device, comprising:

a. a plurality of magnetic elements independent of any magnetic rotor of the electrical device, said magnetic elements having serially alternating polarities of magnetic north and south;
b. at least one Hall effect sensor mounted in spaced and confronting relation with said magnetic elements for sensing said alternating polarities of magnetic north and south and producing output signals representative thereof, said signals including a ramp voltage passing through zero value;
c. rotor means including a shaft having said plurality of magnetic elements secured thereto and rotating said magnetic elements with respect to at least said one Hall effect sensor;
d. amplifier means connected to, and amplifying the output signals of, at least one said Hall effect sensor;
e. variable reference voltage means providing a voltage variable in magnitude and polarity;
f. and voltage shifting means connected to said amplifier means and to said variable reference voltage means providing an output signal differing in phase from said Hall effect sensor output signals in accordance with said variable reference voltage polarity and magnitude.

3 more elements

Dependencies are inferred from the claim text.

Hall effect shaft angle position encoder

Life of this patent

Hall effect shaft angle position encoder

Life of this patent

Abstract

Claims19