Digital motor speed control
First Claim
1. Apparatus for controlling the speed of a motor to a desired value, comprising;
- encoding means for generating a succession of indicator pulses, each pulse having a period T related to the rotational speed of the motor;
a pulse burst generator responsive to each of said indicator pulses for generating a predetermined pattern of n pulses such that the sum of their widths t1 =t2 . . . tn is directly related to a given value for T0 corresponding to a desired speed of said motor;
means for integrating said n pulses over said given period T relative to a reference signal to generate an output signal, including a differential integrator having the output of said pulse burst generator as its first input and the logically inverted output of the pulse burst generator as its second input, said output signal being the output of said differential integrator; and
a motor drive circuit responsive to said output signal of said integrating means for controlling the speed of the motor to the predetermined speed.
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Accused Products
Abstract
A motor speed control circuit produces indexing pulses during each revolution of the motor. Each indexing pulse triggers the production of a predetermined pattern of timing pulses. The timing pulses are integrated. The result of the integration is a relatively constant level signal that controls the motor current. At the end of a predetermined pattern of pulses in the binary signal, the integrator input signal goes to one of two binary states and causes the integrator output voltage to ramp up or down, as the case may be, until another indexing pulse is received from the motor. The output of the integrator upon receipt of the indexing pulse controls the speed of the motor while another set of binary pulses are being integrated.
17 Citations
4 Claims
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1. Apparatus for controlling the speed of a motor to a desired value, comprising;
- encoding means for generating a succession of indicator pulses, each pulse having a period T related to the rotational speed of the motor;
a pulse burst generator responsive to each of said indicator pulses for generating a predetermined pattern of n pulses such that the sum of their widths t1 =t2 . . . tn is directly related to a given value for T0 corresponding to a desired speed of said motor;
means for integrating said n pulses over said given period T relative to a reference signal to generate an output signal, including a differential integrator having the output of said pulse burst generator as its first input and the logically inverted output of the pulse burst generator as its second input, said output signal being the output of said differential integrator; and
a motor drive circuit responsive to said output signal of said integrating means for controlling the speed of the motor to the predetermined speed.
- encoding means for generating a succession of indicator pulses, each pulse having a period T related to the rotational speed of the motor;
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2. Apparatus for driving a motor at a predetermined speed, comprising;
- encoding means for generating indicator pulses related to the rotational speed of the motor, said indicator pulses havinga period T0 when the motor is running at said predetermined speed;
timing means responsive to each of said indicator pulses for generating n timing pulses having widths t1 through tn, wherein n is an integer and the sum of t1 through tn equals T0 /2;
means for integrating said n timing pulses to generate an output signal, including a differential integrator having the output of the timing means as its first input and the logically inverted output of the timing means as its second input, said output signal being the output of said differential integrator, and a motor driving circuit responsive to said output signal of said integrating means for controlling the speed of the motor to the predetermined speed. - View Dependent Claims (3, 4)
- encoding means for generating indicator pulses related to the rotational speed of the motor, said indicator pulses havinga period T0 when the motor is running at said predetermined speed;
Specification