Synthesizer for multiphase waveforms
AssigneePertec Computer Corporation
InventorJack V. Fultz
Life of this patent
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Abstract
A synthesizer for multiphase waveforms is disclosed which is useful, for example, in open and closed loop control of a two-phase induction motor, such as for a magnetic recording disk spindle, utilizing a plurality of bistable elements, two for each phase, to control output power drivers. A single clock pulse counter is employed to time the setting and resetting of each bistable element according to some predetermined pattern controlled by combinational logic which presets the counter to proper values at appropriate times in response to external stimuli, such as speed feedback control and start-stop control.
Claims21
A synthesizer for at least one multiphase waveform comprising
- a stable source of clock pulses,
- an interval counter for counting predetermined numbers of said clock pulses to produce sequential phase timing signals, each phase timing signal being timed counting one of a plurality of predetermined numbers of clock pulses as preset into said counter,
- programming means for storing a set of numbers to be preset into said interval counter, one number for each unique interval to be timed by said interval timer in producting said phase timing signals for use in synthesizing at least one multiphase waveform,
- a source of at least one control signal,
- means responsive to said phase timing signals and said control signal for selecting a different one of said numbers stored by said programming means to be preset into said counter in response to each unique condition of said phase timing signals and said control signals, and
- synthesizing means responsive to said phase timing signals and including at least one bistable element for combining intervals timed by said interval counter, said bistable element being alternately clocked by said timing signals in a predetermined cyclic pattern, thus synthesizing at the output of said bistable element a multiphase waveform.
Apparatus for synthesizing a plurality of multiphase waveforms comprising
- a stable source of clock pulses,
- an interval counter connected to count said clock pulses and adapted to be preset to a selected one of a plurality of predetermined numbers for timing desired intervals, and producing a phase timing signal at the end of each interval,
- a plurality of bistable elements, each connected to receive said phase timing signals, and interconnecting means between elements to cause a different one of said elements to change state in a predetermined cyclic pattern in response to each phase timing signal,
- programming means for storing said plurality of predetermined numbers, and
- means responsive to at least one control signal and to each phase timing signal for selecting one of said numbers to be preset into said counter for timing the next interval, whereby each bistable element produces a multiphase waveform signal is said predetermined cyclic pattern.
Dependencies are inferred from the claim text.