David Y Chiang

US Patent:

44699956, Sep 4, 1984

Filed:

Jul 19, 1982

Appl. No.:

6/399207

Inventors:

David Chiang - Dix Hills NY
Mosi Chu - Setauket NY
Solomon Manber - Sands Point NY

Assignee:

MCC Associates - Short Hills NJ

International Classification:

H02K 2904

US Classification:

318685

Abstract:

A method of stopping a feedback-controlled stepping motor having a stator and a rotor wherein the drive of the stator field is leading the rotor by more than one step and the rotor is rotating with an angular velocity within a first range of values is performed by decreasing the drive lead of the stator field from its slewing value to another value whereby the angular velocity of the rotor decreases below the first range and sensing for the decrease of the angular velocity of the rotor to within a second range of values so that when the angular velocity of the rotor is within the second range of values the rotation of the stator field is stopped to brake the rotor.

US Patent:

43940765, Jul 19, 1983

Filed:

Jul 10, 1981

Appl. No.:

6/282279

Inventors:

Solomon Manber - Sands Point NY
David Chiang - Dix Hills NY
Mosi Chu - Setauket NY

Assignee:

Amtech Patent Licensing Corp. - No. Miami Beach FL

International Classification:

B41B 2108
G01D 938
H04I 1534

US Classification:

354 5

Abstract:

Apparatus for recording characters on a photographic record medium including spaced feed and takeup reels for carrying a roll of the medium. A support such as a cylinder is disposed between the reels supports the record medium. A carriage is controllably movable opposite the support and in a direction transverse to the direction of record medium movement. A recording head on the carriage has a radiation emitter device for emitting intensity modulated radiation toward the cylindrical support along a scan line which makes an angle with the direction of the transverse movement.

US Patent:

51858053, Feb 9, 1993

Filed:

Dec 17, 1990

Appl. No.:

7/628635

Inventors:

David Chiang - Dix Hills NY

International Classification:

H04R 300

US Classification:

381 96

Abstract:

A FIR (finite impulse response) type digital filter operates on digital audio signals in modern sound reproduction systems. It is shown that this operation forces the loudspeaker to produce a sound pressure wave having the original signal waveform. Given a multi-driver speaker, its response to a known broad band analog signal (impulsive) is sampled at least as fast as the Nyquist rate. The result is used to construct a deconvolution filter which compacts, in the least-squares sense, the blurred signal (speaker output) back into its original waveform. Since this anti-blurring process is linear and time invariant, it can be applied to the speaker driving signal as a blur preventive. A fine-tuning procedure utilizing Lagrange's Method of Multipliers modifies the deconvolution process such that the blur-free speaker output achieves a degree of flatness in frequency response beyond what could be attained with a simple deconvolution filter.

US Patent:

43102263, Jan 12, 1982

Filed:

Jul 31, 1980

Appl. No.:

6/173966

Inventors:

Solomon Manber - Sands Point NY
David Chiang - Dix Hills NY
Mosi Chu - Setauket NY

International Classification:

B41B 2108
G01D 938
H04I 1534

US Classification:

354 5

Abstract:

Apparatus for recording characters on a photographic record medium including spaced feed and takeup reels for carrying a roll of the medium. A cylindrical support disposed between the reels supports the record medium. A carriage is controllably movable opposite the cylindrical support and in a direction along the cylindrical axis of the latter. A recording head on the carriage has a radiation emitter device for emitting intensity modulated radiation toward the cylindrical support along a scan line which is in a plane intersecting such cylindrical axis.

US Patent:

42800846, Jul 21, 1981

Filed:

Oct 9, 1979

Appl. No.:

6/082742

Inventors:

David Chiang - Dix Hills NY

International Classification:

G05B 1940

US Classification:

318696

Abstract:

A method and apparatus for driving a stepping motor by angularly displacing the revolvable magnetic field with respect to the rotor by a first displacement angle in a given direction of revolution and then revolving the revolvable magnetic field, preferably with linearly increasing velocity and therefore maintaining constant displacement angle between the field and the rotor until the rotor rotates at a second velocity.

US Patent:

42976260, Oct 27, 1981

Filed:

Feb 7, 1980

Appl. No.:

6/119503

Inventors:

David Chiang - Dix Hills NY

International Classification:

G05B 1940

US Classification:

318696

Abstract:

A stepping motor system is shown wherein a method is employed for determining the optimum amplitude of the current supplied to the stator winding of the motor. A series of different currents are applied to the motor. First, the stator windings are energized with currents of certain base magnitudes. Then the current in one winding is increased by a small amount and the current in the adjacent winding is decreased by a small amount so that the rotor tends to move towards its new equilibrium position. When the rotor reaches its maximum displacement the current changes in the windings are reversed so that not only will the rotor "hunt" for its new equilibrium position but it overshoots with twice the magnitude. This process continues for a certain period of time during which the oscillation magnitudes rapidly grow. In one embodiment, after a maximum amplitude is reached, the current changes are applied out of phase with the oscillations to now try to decrease their amplitude.

US Patent:

44383797, Mar 20, 1984

Filed:

Jun 15, 1981

Appl. No.:

6/273625

Inventors:

David Chiang - Dix Hills NY
Mosi Chu - Setauket NY
Solomon Manber - Sands Point NY

Assignee:

MSS Associates - Short Hills NJ

International Classification:

G05B 1940

US Classification:

318685

Abstract:

For a stepping motor having a rotatable stator magnetic field for driving the rotor, there is disclosed a method of damping the oscillations of the rotor which occurs when the rotatable stator magnetic field is stopped upon arriving at a desired rotational position by measuring quantities related to the instantaneous velocity of the rotor due to the oscillations of the rotor about the desired rotational position, rotationally displacing the stator magnetic field from the desired rotational position in a direction opposite to the direction of the oscillation, and thereafter returning the stator magnetic field to the desired stopping position.

US Patent:

43307396, May 18, 1982

Filed:

Jan 29, 1981

Appl. No.:

6/229456

Inventors:

David Chiang - Dix Hills NY

Assignee:

MCC Associates - Short Hills NJ

International Classification:

G05B 1940

US Classification:

318696

Abstract:

A stepping motor system is shown wherein a method is employed for determining the optimum amplitude of the current supplied to the stator winding of the motor. A series of different currents are applied to the motor. First, the stator windings are energized with currents of certain base magnitudes. Then the current in one winding is increased by a small amount and the current in the adjacent winding is decreased by a small amount so that the rotor tends to move towards its new equilibrium position. When the rotor reaches its maximum displacement the current changes in the windings are reversed so that not only will the rotor "hunt" for its new equilibrium position but it overshoots with twice the magnitude. This process continues for certain period of time during which the oscillation magnitudes rapidly grow. In one embodiment, after a maximum amplitude is reached, the current changes are applied out of phase with the oscillations to now try to decrease their amplitude.