Valve, controller, system and method providing closed loop current control of a voice coil using pulse width modulation drive elements
AssigneeEnfield Technoloties, LLC
InventorDaniel S. Cook
Life of this patent
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Abstract
A linear voice coil actuator is described, specifically applied to a fluid power valve. The valve includes at least one inlet port and at least one outlet port. A spool controls fluid flow between the inlet port and outlet port. At least one counter-acting spring asserts a force on the spool. The valve also includes a linear voice coil to regulate movement of the spool. The linear voice coil responds to a pulse width modulated signal, wherein the pulse width modulated signal is based on a determined current in the linear voice coil. Electromagnetic interference filtering may also be used. A controller, system and method are also described.
Claims20
A valve comprising:
- at least one inlet port;
- at least one outlet port;
- a spool configured to control fluid flow between the inlet port and outlet port;
- at least one counter-acting spring configured to assert a force on the spool;
- and
- a linear voice coil configured to regulate movement of the spool;
- wherein the linear voice coil is configured to respond to a pulse width modulated signal, wherein the pulse width modulated signal is based on at least a determined current in the linear voice coil.
A controller comprising:
- a receiver configured to receive a current signal based upon a determined current through a linear voice coil;
- and
- a processor configured to produce a control signal based on at least the received current signal, wherein the control signal is to be used by a pulse width modulation driver to generate a pulse width modulation drive signal to be applied to the linear voice coil.
A system comprising:
- a linear voice coil actuated valve comprising:
- a spool;
- at least one counter-acting spring configured to apply a force on the spool;
- and a linear voice coil configured to regulate a fluid flow through the valve by moving the spool;
- a sensor configured to determine a current in the linear voice coil;
- a processor configured to produce a control signal based at least on the determined current;
- and
- a pulse width modulation driver responsive to the control signal configured to generate a pulse width modulation drive signal to be applied to the linear voice coil.
The system of claim 13, wherein the difference amplifier circuit has a common mode rejection ratio of at least −40 dB.
A method comprising:
- providing a pulse width modulation drive signal to a linear voice coil of a linear voice coil actuated valve;
- determining a current through the linear voice coil;
- and
- adjusting the pulse width modulation drive signal based at least upon the determined current;
- wherein the linear voice coil is used to move a spool having a force applied to the spool by at least one counter-acting spring.
Dependencies are inferred from the claim text.