EP0217599B1
Expired / Lapsed
EP
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Brushless motor drive circuits
Assignee: Sony Corp
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Filing: 1986-09-18
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Granted: 1992-02-12
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Expires: 2006-09-18
Abstract
Abstract A brushless motor drive circuit includes a plurality of Hall elements (1) for detecting magnetic flux changes of a rotating rotor magnet A drive signal generating circuit (6, 7, 12, 13, 20, 21) generates drive signals applied to the stator windings (L) of the motor. The waveform of each of the drive signals has a pair of slanted edge portions and a relatively flat portion interposed between the slanted edge portions which are directly formed from said detected flux changes.
Inventors
- 👤 Yuuichi C/O Patents Div. Sony Corporation Nanae
- 👤 Hideo C/O Patents Div. Niikura
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-30 13:12
CPC Classifications
H; H02; H02P; H02P6/00; H02P6/04; H02P6/14; H02P2209/00; H02P2209/07
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
125 words
A brushless motor drive circuit comprising: a plurality of Hall elements (1) for detecting magnetic flux changes of a rotating rotor magnet of a brushless motor; and a drive signal generating circuit (6, 7, 12, 13, 20, 21) connected to said Hall elements (1) for generating drive signals to be supplied to stator windings (L) of said motor, each of said drive signals having a pair of slanted edge portions with a relatively flat portion therebetween; characterized in that; each of said edge portions has an angle in the range 2° el. to 30° el, formed by shifting the level or amplifying the edge portions of trapezoidal output signals of said Hall elements (1); and said flat portion is formed by a clamping circuit (6,7).
Claim 2
Dependent Claim
28 words
A circuit according to claim 1 wherein portions of each of said slanted edge portions of an adjacent two of said drive signals form an overlapping drive area.
Claim 3
Dependent Claim
54 words
A circuit according to claim 1 wherein said drive signal generating circuit (6, 7, 12, 13, 20, 21) includes operational amplifier circuits (10, 11) connected to said Hall elements (1), clamping circuits (6, 7), non-adding mixing circuits (12, 13), analogue switching circuits (20, 21), and output amplifiers (26 to 29) respectively connected in series.
Claim 4
Dependent Claim
47 words
A circuit according to claim 3 wherein said drive signal generating circuit (6, 7, 12, 13, 20, 21) further includes switching pulse generating circuits (Figure 4) for generating switching pulses to be supplied to said analogue switching circuits (20, 21) based on said detected magnetic flux changes.
Claim 5
Dependent Claim
48 words
A circuit according to claim 1 wherein said drive signal generating circuit (6, 7, 12, 13, 20, 21) includes operational amplifier circuits (10, 11) connected to said Hall elements (1), signal mixing circuits (12, 13), analogue switching circuits (20, 21) and output amplifiers (26 to 29) in series.
Claim 6
Dependent Claim
46 words
A circuit according to claim 5 wherein said drive signal generating circuit (6, 7, 12, 13, 20, 21) includes means (Figure 4) for generating switching signals to be supplied to said analogue switching circuits (20, 21) based on outputs from said signal mixing circuits (12, 13).
References Cited (Backward Citations)
No citation records indexed.
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