Means for adjustment of speed of prime mover

• US 4,127,800 A
• Filed: 12/30/1976
• Issued: 11/28/1978
• Est. Priority Date: 12/30/1976
• Status: Expired due to Term

• Current Assignee: NCR Corporation
• Original Assignee: NCR Corporation
• Inventors: Rushby, Robert J., Long, Donald E., Toraskar, Krantikumar V.
• Primary Examiner(s): Schaefer, Robert K.
• Assistant Examiner(s): Mutter, M. K.
• Application Number:
  US05/755,779
• Time in Patent Office: 698 Days
• Field of Search: 318/696, 318/685
• US Class Current: 318/685
• CPC Class Codes: H02P 23/22 Controlling the speed digitally using a reference oscillator, a speed proportional pulse rate feedback and a digital comparator

Abstract

A microprocessor is programmed to generate reference envelopes of a specified time duration and synchronized with clock pulses, and circuit means is associated with such microprocessor for indicating desired speed of a prime mover through comparison of prime mover actual speed with said reference envelope, and means is provided for adjusting prime mover speed to correspond with such reference envelope.

Claims

1. A method of controlling the speed of a prime mover comprising the steps of

generating a programmed reference signal of predetermined time duration;

generating a speed signal indicative of the actual speed of the prime mover in successive relationship with said reference signal;

generating a delay signal after initiation of the generation of each speed signal for determining the time duration of each of said speed signals;

repeating said reference signal in duplicating manner for a desired number of times;

repeating said speed signal sequentially in alternate relationship with said reference signal for said desired number of times;

utilizing programmed memory for tracking the number of repeated speed signals and reference signals;

synchronizing said reference signals and said speed signals by clocking predetermined time periods therewith;

setting the programmed memory to indicate mode index of the prime mover,

connecting voltage indicating means with the output of said prime mover for receiving said speed signals and with said programmed memory for receiving said reference signals after completion of said desired number of times, observing differences in time periods between said reference signals and said speed signals by reading the range of voltage indication; and

adjusting the width of said speed signals to equal the width of said reference signals until a steady voltage indication is observed.

2. A control system for adjusting the speed of a prime mover to conform with predetermined parameters, including:

microprocessor means for generating repeated cycles of reference signals of fixed time duration;

memory means associated with said microprocessor means for reading the number of cycles of fixed time duration of said reference signals;

multivibrator means for generating signals indicative of the speed of said prime mover in alternate relationship with said reference signals and in sequential manner therewith;

delay means associated with said microprocessor means for determining the time duration of said speed signals;

clock means for synchronizing said reference signals and said speed signals;

voltage responsive means connected with said microprocessor means to receive said reference signals and with said multivibrator means to receive said speed signals for indicating differences in time duration between said reference signals and said speed signals by range of voltage observed; and

potentiometer means connected with said multivibrator means for adjusting the width of said speed signals to correspond with the width of said reference signals at a steady voltage indication.

3. The system of claim 2 wherein said reference signal generating means comprises a microprocessor programmed to repeat cycles of reference signals to said indicating means.

4. The system of claim 2 wherein said speed signal generating means comprises a one-shot multivibrator associated with said prime mover for generating alternate speed signals.

5. The system of claim 2 wherein said indicating means comprises a voltage responsive device for indicating a voltage differential proportional to the pulse width of said reference signals and to the pulse width of said speed signals.

6. The system of claim 2 wherein said adjusting means comprises a potentiometer device associated with said speed signal generating means.

7. The system of claim 2 wherein said prime mover is a stepping motor.

8. The system of claim 2 wherein said prime mover is an induction motor.

9. The system of claim 2 wherein said prime mover is an internal combustion engine.

10. The system of claim 4 wherein said adjusting means comprises a potentiometer device associated with said one-shot multivibrator permitting adjustment of the width of said speed signals generated thereby.

11. In a printer having a rotatable type character carrying member, drive means for rotating said member, hammer means for impacting against the type characters, and means for adjusting the speed of rotation of said drive means to be compatible with the impacting of said hammer means comprising:

processor means programmed for generating repeated cycles of reference pulses of fixed time duration;

multivibrator trigger means associated with said drive means for generating pulses indicative of the speed of rotation of said drive means;

said speed pulses occurring in alternate relationship with said reference pulses and in sequential manner therewith;

memory means associated with said processor means for reading a number of cycles of alternate reference pulses and speed pulses;

delay means associated with said processor means for determining the time duration of said speed pulses;

clock means for synchronizing said reference pulses and said speed pulses at the time of initation of each respective pulse;

voltage responsive means connected with said processor means and with said multivibrator trigger means to receive said reference pulses and said speed pulses for indicating difference in pulse width between said reference pulses and said speed pulses by observing range of voltage indicated; and

potentiometer means connected with said multivibrator trigger means for adjusting the width of said speed pulses to correspond with the width of said reference pulses at a steady voltage indication observed.

12. In the printer of claim 11 wherein said drive means comprises a stepping motor for incrementally rotating said type character carrying member.