Pulse rate control motor speed control system with feedback

Claim 2

A pulse generating control system incorporating feedback control and comprising: a pulse generator circuit for generating constant width output pulses for use as ''''on'''' pulses for a motor; a motor circuit energized by said output ''''on'''' pulses and comprising means providing a feedback signal as a function of operation of said motor circuit; and a feedback circuit responsive to said feedback signal for controlling said pulse generator circuit so as to control the time of said output ''''on'''' pulses comprising: voltage integrating means; means operable during the ''''on'''' pulses for resetting said voltage integrating means to an initial voltage level from which it will decay at a predetermined rate; means for decaying said integrated voltage when each output ''''on'''' pulse ends; means responsive to the motor CEMF for altering said predeterMined rate during the ''''off'''' time or time between output ''''on'''' pulses; and voltage level detecting means responsive to said integrated voltage for controlling said pulse generator circuit to control the space between said constant width output ''''on'''' pulses thereby to control the motor speed.

Claim 3

The invention defined in claim 1, wherein said voltage level detecting means comprises: a solid state switching device responsive to said voltage above a predetermined value for applying a first control signal to cause said pulse generator circuit to delay generation of the next pulse, and being responsive to said voltage below said predetermined value for applying a second control signal to cause said pulse generator circuit to start generating the next pulse.

Claim 4

The invention defined in claim 1, wherein said voltage level detecting means comprises: adjustable means for selecting a variable portion of said integrated voltage for application to said voltage level detecting means thereby to select the amount of energization of the load.

Claim 5

The invention defined in claim 3, wherein said feedback circuit also comprises: means for applying an adjustable offset voltage to said voltage integrating means thereby to extend the low energization capabilities of the system.

Claim 6

The invention defined in claim 1, wherein said pulse generator circuit comprises: a solid state relaxation oscillator having a negative resistance solid state element and an RC circuit controlled thereby; and a high gain solid state switch responsive to current flow in said RC circuit to provide an output pulse and responsive to operation of said negative resistance solid state element for terminating said output pulse.

Claim 7

The invention defined in claim 5, wherein said voltage level detecting means comprises: a second high gain solid state switch operable when said integrated voltage decreases below said predetermined value for resetting said RC circuit to a state productive of another output pulse.

Claim 8

The invention defined in claim 5, wherein said voltage level detecting means comprises: a second high gain solid state switch connected to said RC circuit and responsive to said integrated voltage falling below said predetermined value for causing recovery of the pulse generating condition; and a blocking diode in said connecting preventing diversion of current from the first mentioned high gain solid state switch.

Claim 9

A pulse time controlled motor speed control system controlled by feedback comprising: a pulse generating circuit for generating constant width output pulses for use as ''''on'''' pulses for a motor; a motor circuit including means for applying said output pulses to the armature winding of a D.C. motor; a connection to the motor armature for obtaining a motor counter EMF signal; and a feedback circuit operable by said counter EMF signal for controlling said pulse generating circuit to adjust the space between said output ''''on'''' pulses whereby to regulate the motor speed to a preselected value comprising: a voltage integrator; means operable during the ''''on'''' pulses for setting said voltage integrator to an initial voltage level from which it will decay at a predetermined rate; means responsive to said counter EMF for altering said predetermined rate during the ''''off'''' time between ''''on'''' pulses; means for providing a control voltage as a function of said decaying voltage level; a speed setter for tapping an adjustable portion of said control voltage; and voltage level responsive switching means operable by said selected portion of said control voltage for controlling said pulse generator circuit to regulate the space between said output ''''on'''' pulses so as to maintain the motor speed at the value selected at said speed setter.

Claim 10

A pulse time controlled motor speed control system controlled by feedback comprising: a pulse generating circuit for generating constant width output pulses for use as ''''on'''' pulses for a motor; a motor circuit including means for applying said output pulses to the armature winding of a D.C. motor; a connection to the motor armature for obtaining a motor counter EMF signal; and a feedback circuit operable by said counter EMF signal for controlling said pulse generating circuit to adjust the space between said output ''''on'''' pulses whereby to regulate the motor speed to a preselected value comprising: a voltage integrator; means operable during the ''''on'''' pulses for setting said voltage integrator to an initial voltage level from which it will decay at a predetermined rate; means responsive to said counter EMF for altering said predetermined rate during the ''''off'''' time between ''''on'''' pulses; means for providing a control voltage as a function of said decaying voltage level; a speed setter for tapping an adjustable portion of said control voltage; and voltage level responsive switching means operable by said selected portion of said control voltage for controlling said pulse generator circuit to regulate the space between said output ''''on'''' pulses so as to maintain the motor speed at the value selected at said speed setter.

Claim 11

The invention defined in claim 8, wherein: said means operable during the ''''on'''' Pulses for setting said voltage integrator to an initial voltage level from which it will decay at a predetermined rate comprises a relatively short time constant circuit for integrating said ''''on'''' pulses; and said means for providing a control voltage as a function of said decaying voltage level comprises a relatively longer time constant circuit for decaying the integrated voltage whose decay rate is modified by said motor counter EMF; said predetermined rate providing a pedestal voltage and said alteration therein producing a ramp on said pedestal voltage to provide a high gain whereby small changes in the ramp slope provide large changes in time between ''''on'''' pulses; and a blocking diode in said short time constant circuit for preventing current flow back toward the motor armature.

Claim 12

The invention defined in claim 9, together with: means connected to said short time constant circuit for offsetting the counter EMF voltage in a direction to extend the low speed range of the motor.