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US 4,271,384 AGranted
Synchronous motor drive
AssigneeSigma Instruments, Inc.
InventorsThomas E. Beling, Leopold Bric
Life of this patent
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AssigneeSigma Instruments, Inc.
InventorsThomas E. Beling, Leopold Bric
Estimating the term…
A synchronous motor is driven by applying cyclical or digital data through a phase locked loop whose loop filter integrates with a time constant equal to or greater than the inertial delay of the motor from start to its operating speed. According to one embodiment, the frequency output of the phase locked loop is further controlled with a digital rate multiplier whose phase effects are minimized by operating the VCO at a multiple of the input frequency and feeding the VCO voltage back through a frequency divider. According to another embodiment, the frequency control is obtained with a preliminary phase locked loop with a normal filter but a high frequency VCO whose feedback is divided by a value n, and then dividing the output of the main loop by m. Suitable counters may be used to stop and start the drive.
For a synchronous motor capable of reaching a given speed within a predetermined time, a motor drive operable from a voltage source repetitively variable at a frequency corresponding to the given speed, comprising:
A coil winding mechanism for winding wire on a form, comprising motor means for driving the form, sensing means coupled to the motor means for sensing rotation of the motor means, a synchronous motor, guide means coupled to the synchronous motor for guiding wire to be wound on the form laterally along the form, a motor control coupled to the sensing means for sensing the output of the sensing means and coupled to the synchronous motor for controlling rotation of the synchronous motor, said sensing means being constructed to produce a cyclical output whose frequency varies in response to speed of said motor means;
Dependencies are inferred from the claim text.