Reduced-energy-consumption actuator

• US 6,305,662 B1
• Filed: 02/29/2000
• Issued: 10/23/2001
• Est. Priority Date: 02/29/2000
• Status: Expired due to Term

• Current Assignee: Arichell Technologies Inc. (Sloan Valve Company)
• Original Assignee: Arichell Technologies Inc. (Sloan Valve Company)
• Inventors: Mo, Xiaoxiong, Parsons, Natan E.
• Primary Examiner(s): Shaver, Kevin
• Assistant Examiner(s): BONDERER, DAVID A
• Application Number:
  US09/514,491
• Time in Patent Office: 602 Days
• Field of Search: 251/129.04
• US Class Current: 251/129.04
• CPC Class Codes: F16K 31/0675 Electromagnet aspects, e.g. electric supply therefor
• CPC Class Codes: F16K 37/00 Special means in or on valves or other cut-off apparatus for indicating or recording operation thereof, or for enabling an alarm to be given
• CPC Class Codes: Y10T 137/8242 Electrical

Abstract

A valve system (10) includes a piezoelectric transducer (44) mounted on its housing (16). To change the valve'"'"'s state, a microcontroller (54) causes a valve driver (58) to drive current through the actuator'"'"'s coil (12) at a relatively high level. It continues driving current through the coil (12) at the high level until the transducer'"'"'s output reaches a magnitude characteristic of the disturbance that typically results when the actuator'"'"'s armature (22) reaches the end of its travel. At that point, the microcontroller (54) reduces coil drive.

Claims

1. An actuator system comprising:

A) an actuator including an armature and a coil operable by application of a coil drive thereto to conduct current and thereby tend to drive the armature to an end position from a rest position, to which the armature is biased to return in the absence of coil current;

B) a sound sensor so coupled to the actuator as to sense sound made by the armature in reaching the end position, the sound sensor generating a sensor output indicative of the sound that it senses; and

C) a control circuit operable to begin applying coil drive to the coil at a first level and responsive (i) to the sensor output'"'"'s meeting a predetermined end-position-indicating criterion to change the coil drive to a different level great enough to keep the armature from returning to the rest position and (ii) to the sensor output'"'"'s failure to meet the end-position-indicating criterion within a predetermined drive duration after the control circuit begins application of coil drive to the coil to apply coil drive to the coil at a level higher than that at which it began application of coil drive to the coil.

2. An actuator system as defined in claim 1 wherein the sound sensor includes a piezoelectric transducer.

3. An actuator system as defined in claim 2 wherein the different level is lower than the first level.

4. An actuator system as defined in claim 2 wherein:

A) the actuator system includes a housing that contains the armature and coil; and

B) the piezoelectric transducer is secured to the housing.

5. An actuator system as defined in claim 2 wherein the different level is lower than the first level.

6. An actuator system as defined in claim 1 wherein the control circuit stops applying the coil drive after the predetermined drive duration before driving the coil at the level higher than that at which it began application of coil drive to the coil.

7. An actuator system as defined in claim 1 wherein the different level is lower than the first level.

8. A flow-control system comprising:

A) a valve operable between open and closed states;

B) an actuator including an armature operatively connected to the valve and further including a coil operable by application of a coil drive thereto to conduct current and thereby tend to drive the armature to an end position, in which the armature holds the valve in one of said open and closed states, from a rest position, to which the armature is biased to return in the absence of coil current and thereby hold the valve in the other of said open and closed states;

C) an endpoint detector that detects the armature'"'"'s reaching the end position and responds thereto by generating a detector output indicative thereof; and

D) a control circuit operable to begin applying coil drive to the coil at a first level and responsive (i) to the detector output indicative of the armature'"'"'s reaching the end position to change the coil drive to a different level great enough to keep the armature from returning to the rest position and (ii) to the failure to receive the detector output indicative of the armature'"'"'s reaching the end position within a predetermined drive duration after the control circuit begins application of coil drive to the coil to apply coil drive to the coil at a level higher than that at which it began application of coil drive to the coil.

9. A flow-control system as defined in claim 8 wherein the different level is lower than the first level.

10. A flow-control system as defined in claim 8 wherein:

A) the flow-control system additionally includes an object sensor that produces an object sensor output; and

B) the control circuit'"'"'s application of the coil drive to the coil is dependent on the object-sensor output.

11. A flow-control system as defined in claim 10 wherein:

A) the endpoint detector includes a sound sensor that is so coupled to the actuator as to sense sound made by the armature in reaching the end position and generates a sensor output indicative of the sound that it senses; and

B) the detector output indicates that the armature has reached the end position if the sensor output meets a predetermined current-termination criterion.

12. A flow-control system as defined in claim 11 wherein the sound sensor includes a piezoelectric transducer.

13. A flow-control system as defined in claim 10 wherein the different level is lower than the first level.

14. A flow-control system as defined in claim 8 wherein:

A) the endpoint detector includes a sound sensor that is so coupled to the actuator as to sense sound made by the armature in reaching the end position and generates a sensor output indicative of the sound that it senses; and

B) the detector output indicates that the armature has reached the end position if the sensor output meets a predetermined current-termination criterion.

15. A flow-control system as defined in claim 14 wherein the different level is lower than the first level.

16. A flow-control system as defined in claim 14 wherein the sound sensor includes a piezoelectric transducer.

17. For controlling a actuator including an armature and a coil operable by application of a coil drive thereto to conduct current and thereby tend to drive the armature to an end position from a rest position, to which the armature is biased to return in the absence of coil current, a method comprising:

A) applying coil drive to the coil at a first level;

B) determining whether the armature has reached the end position;

C) if so, changing the coil drive to a level lower than the first level but great enough to keep the armature from returning to the rest position; and

D) if not within a predetermined duration after application of coil drive to the coil to apply coil drive has begun, driving the coil at a level higher than that at which it began application of coil drive to the coil.

18. An actuator system comprising:

A) an actuator including an armature and a coil operable by application of a coil drive thereto through first and second drive terminals to conduct current and thereby tend to drive the armature to an end position from a rest position, to which the armature is biased to return in the absence of coil current;

B) a sound sensor so coupled to the actuator as to sense sound made by the armature in reaching the end position, the sound sensor generating at first and second sensor terminal a sensor output indicative of the sound that it senses, the second sensor terminal being the same as the second coil terminal; and

C) a control circuit operable to begin applying coil drive to the coil at a first level and responsive to the sensor output'"'"'s meeting a predetermined end-position-indicating criterion to change the coil drive to a different level great enough to keep the armature from returning to the rest position.