Control circuit for feedback, motor-operated valve
AssigneeETI Systems
InventorBill Tice
Life of this patent
Estimating the term…
Abstract
A control circuit for limiting the current flow to a direct-current driven motor, to reduce current spikes at motor start up, including a voltage-regulated, current-passing device for passing current from a direct voltage source to the motor, the device having a default configuration such as to permit full current flow there-across when the voltage is initially applied, a voltage drop device interposed the voltage source and the voltage-regulated, current-passing device responsive to the current flow to the motor and a variable-voltage output device responsive to the voltage drop developed in the voltage-drop device for providing a subsequently changing voltage for input to the current-passing device for limiting the current flow therethrough following initial application of the voltage.
Claims9
A control circuit for instantaneously braking rotation of a direct-current driven motor upon termination of power from a voltage source comprising:
- a) means for storing a potential during circuit operation including a normally-open, voltage-actuated first switch means for isolating said stored potential from the rest of said circuit during motor operation;
- b) voltage-regulated, current-passing means for passing current from a direct-voltage source to the motor;
- and,
- c) a normally-open, voltage-actuated second switch means interconnected said first switch means, the motor, and ground during application of power to the motor;
- d) whereupon terminating drive voltage to said motor causes said first switch means to close and release said stored potential simultaneously to said current-passing means to deactivate said current-passing means and to said second switch means to ground the motor terminals to immediately drain all forward and reverse EMF to ground and stop rotation of the motor.
Dependencies are inferred from the claim text.