Digital servomotor drive apparatus
AssigneeSperry Corporation
InventorsDavid J. Cooley, Theodore C. Ebbinga
Life of this patent
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Abstract
An apparatus for converting digital signals into analog pulse width modulated signals without a D/A Converter includes an up-down counter, programmed by the digital signal, which provides a signal to logic circuitry at the conclusion of each count. The logic circuitry responds to the counter signal and clock signals coupled thereto to provide an analog pulse width modulated signal corresponding to the digital signal.
Claims6
An apparatus for converting digital words having a sign bit and a plurality of magnitude bits into analog signals having pulse widths corresponding to the magnitude bits and polarity corresponding to the sign bit, comprising:
- waveform generator means for providing a first signal having a predetermined pulse rate and a second signal having a predetermined clock rate;
- digital counting means, responsive to said first signal, for providing a count corresponding to said magnitude bits and said polarity bit of said digital words;
- logic means responsive to said digital counting means and said second signal, for providing analog output signals having pulse widths proportional to said count and said clock rate of said second signal.
Dependencies are inferred from the claim text.