US3654540A - Magnetostrictive drive circuit feedback coil - Google Patents
Magnetostrictive drive circuit feedback coil Download PDFInfo
- Publication number
- US3654540A US3654540A US106675A US3654540DA US3654540A US 3654540 A US3654540 A US 3654540A US 106675 A US106675 A US 106675A US 3654540D A US3654540D A US 3654540DA US 3654540 A US3654540 A US 3654540A
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- US
- United States
- Prior art keywords
- magnetostrictive member
- coil
- pickup coil
- wound
- induced
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
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Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B06—GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS IN GENERAL
- B06B—METHODS OR APPARATUS FOR GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS OF INFRASONIC, SONIC, OR ULTRASONIC FREQUENCY, e.g. FOR PERFORMING MECHANICAL WORK IN GENERAL
- B06B1/00—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency
- B06B1/02—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy
- B06B1/0207—Driving circuits
- B06B1/0223—Driving circuits for generating signals continuous in time
- B06B1/0238—Driving circuits for generating signals continuous in time of a single frequency, e.g. a sine-wave
- B06B1/0246—Driving circuits for generating signals continuous in time of a single frequency, e.g. a sine-wave with a feedback signal
- B06B1/0261—Driving circuits for generating signals continuous in time of a single frequency, e.g. a sine-wave with a feedback signal taken from a transducer or electrode connected to the driving transducer
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B06—GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS IN GENERAL
- B06B—METHODS OR APPARATUS FOR GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS OF INFRASONIC, SONIC, OR ULTRASONIC FREQUENCY, e.g. FOR PERFORMING MECHANICAL WORK IN GENERAL
- B06B2201/00—Indexing scheme associated with B06B1/0207 for details covered by B06B1/0207 but not provided for in any of its subgroups
- B06B2201/50—Application to a particular transducer type
- B06B2201/58—Magnetostrictive transducer
Definitions
- ABSTRACT A feedback coil is placed in surrounding relation to a magnetostrictive member which is vibrating under the influence of there is no transformer coupling between the feedback and drive coils.
- the feedback coil can be positioned along the length of the device in one of two ways, so as to maximize the induced voltage. Each way relies on a different magnetostrictive effect.
- electro-mechanical resonant systems are driven into acoustic vibration by means of a drive coil which is energized by an electrical AC power from an oscillation generator.
- This AC power produces a magnetic field in the region of the coil in which is placed a magnetostrictive member. Compresup in the magnetostrictive member causing it and other parts connected thereto to vibrate.
- a tool is connected to the magnetostrictive member by way of a tool holder whereby the high frequency longitudinal vibrations set up in the tool may be employed in performing ultrasonic machining, forming, welding, cleaning or other operations.
- the maximum amplitude of vibration at the working end of the tool is obtained when the frequency of the electrical power applied to the drive coil is equal to one of the resonant frequencies of the combined magnetostrictive member, tool holder and tool.
- the desired resonant frequency can change due to various factors such as the use of different tools, tool wear and variations in temperature and loading. In order for such a system to be useful and practical, the frequency applied to the drive coil should be capable of being varied so as to maintain the appropriate drive frequency.
- a feedback signal may be obtained from a pickup device such as a piezo-electric crystal or a resonant pin which is coupled to the mechanically vibrating part of the resonant system as in U.S. Pat. No. 3,304,479 issued Feb. 14, 1967 to C. Kleesattel et al. and assigned to the assignee of this application and U.S. Pat. No. 3,419,776 issued Dec.
- Another more desirable approach of the automatic frequency control type is to use a feedback coil in surrounding relation to the magnetostrictive member to act as a sensor. The voltage induced in said feedback coil is then used to control the frequency of the power amplifier which is used to energize the drive coil. This approach is usually referred to as a feed back stablized oscillator.
- transformer coupling effect some of the power applied to the drive coil is coupled directly to the feedback coil by pure magnetic coupling, hereinafter to be called the transformer coupling effect.
- the feedback signal is influenced in part by power that has not acoustically acted upon the magnetostrictive member. Therefore the transformer coupling effect should be minimized or eliminated as much as possible.
- One way to solve the transformer coupling effect problem is to magnetically shield the two coils by some type of physical barrier.
- the disadvantage of such an approach is that it increases the overall bulk of the completed device and the effect and/or sensitivity of at least one of the coils is diminished.
- Another way to solve the transformer coupling effect problem is to windthe drive coil about one portion of the mag netostrictive member and the feedback coil about the remaining portion of the member with some type of shielding mechanism therebetween.
- An example of such a shielding mechanism is to have the drive coil to include a few reverse windings positioned over the feedback coil or between the feedback and drive coils, cancelling any type of transformer effect between the two coils.
- Such a design is disclosed and claimed in U.S. Pat. No. 3,151,284 issued Sept. 29, 1964 to C. Kleesattel and assigned to the assignee of this application.
- the problem with such designs is that shielding occurs at only one frequency setting of the drive power and incomplete shielding will occur at drive powers both higher and lower than this.
- the maximum number of ampere turns cannot be used to drive the magnetostrictive member.
- the principal object of this invention is to provide a new and improved feedback coil for use with an electromechanical resonant system to insure that the mechanically vibrating part of said system continues to vibrate at one of its natu al resonant frequencies.
- An'other 013166! of this invention is to provide a new and 1mprove'd feedback coil for use with an electro-mechanical resonant system which is designed so that there is no transformer effect between said feedback coil and the drive coil of the system.
- a still further object of this invention is to provide a new and improved feedback coil for use with an electro-mechanical resonant system, said coil being designed to minimize any transformer effect with the drive coil and said coil being positioned so as to maximize the voltage induced therein.
- An even further object of this invention is to provide a new and improved feedback coil for use with an electro-mechanical resonant system for eliminating many of the spurious frequency modes at which said system may have a tendency to vibrate.
- the drive coil is in surrounding relation to the entire length of the magnetostrictive member and the feedback coil is in surrounding relation to a portion of or to the entire length of the member.
- half of the windings of the feedback coil are wound in one direction (such as clockwise) and the other half of the windings of the feedback coil are wound in the reverse direction, (such as counterclockwise), with the transition region to be hereinafter referred to as the reversal point.
- the magnetostrictive member Since the magnetostrictive member is being vibrated by a drive coil, it may be considered the equivalent of a moving magnet which gives rise to an induced voltage in any surrounding coil.
- the feedback coil should be positioned so that its reversal point is at the node of longitudinal motion of the member, such that when half of the turns of the feedback coil sense a voltage due to motion in one direction, the other half of the turns sense a voltage due to motion in the other motion. Since the two halves are wound in opposite direction, relative to each other, the induced voltage reinforce each other.
- Another effect resulting in an induced voltage in the feedback coil is that as the magnetostrictive member is vibrated, there is a changing stress pattern along the length of member resulting in a changing permeability of the magnetostrictive member, along its length.
- the maximum rate of change of permeability occurs in the vicinity of the node of longitudinal motion of the magnetostrictive member and is symmetrical thereabout.
- the coil should be displaced from the node a certain distance, such that that portion of the member experiencing the maximum rate of change of permeability should be surrounded by one half of the feedback coil. In such a position, the motional velocity effect still induces some voltage but a portion thereof is cancelled out since the reversal point of the feedback coil is not at the node of longitudinal motion.
- this configuration is most advantageous whenever the permeability effect is the most significant.
- FIG. 3 is a schematic diagram of a portion of FIG. 1 illustrating the portion of the feedback coil relative to the node of longitudinal motion of the magnetostrictive member in another embodiment of the invention.
- an electro-mechanical resonant system embodying the invention may include a mechanical portion made up in part by a magnetostrictive member 10.
- the magnetostrictive member may either be made from any ferromagnetic, magnetic or ferrite material having a high tensile strength and highly magnetostrictive in character, such as permanickel, nickel or permendur.
- a drive coil which is energized by alternating current from a power circuit (to be discussed in more detail below) establish an alternating electromagnetic field setting up compressional waves in the magnetostrictive member 10 causing it to vibrate.
- the coil 15 is wound around the magnetostrictive member 10, but for ease in explanation it is shown removed therefrom in FIG. 1.
- the vibration of the magnetostrictive member is sinusoidal such that the amplitude of vibration varies in magnitude along the length of the member in a sinusoidal fashion. Points at which there is no amplitude are referred to as nodes of longitudinal motion and points at which the amplitude is a maximum for any particular frequency are referred to as antinodes of longitudinal motion.
- a DC bias supply is coupled to the drive coil 15 via an inductor 22 for polarizing the magnetostrictive member 10.
- the inductor 22 is used to prevent the AC power which is energizing the drive coil 15, from flowing into the DC bias supply 20.
- a feedback coil 25 is wound around the magnetostrictive member 10, but for ease in explanation it is shown removed therefrom in FIG. 1.
- the feedback coil 25 develops a voltage proportional to the vibration of the magnetostrictive member because of two different effects, to be described in more detail hereinafter.
- the output of the feedback coil is delivered to a phasing circuit 30, then to a pre-amplifier 35 where the signal is amplified and then to the power amplifier 40, the latter two components comprising the power circuit.
- This signal controls the frequency of the output of the power amplifier 40 which is then applied to the drive coil 15 via a capacitor 42 to insure that the magnetostrictive member vibrates at one of its resonant frequencies.
- the capacitor 42 is used to prevent the DC power from the DC bias supply 20 from flowing into the power amplifier 40.
- the power circuit comprising the preamplifier 35 and the power amplifier '40, is energized by the power supply 45.
- the purpose of the phasing circuit 30 is to compensate for phase shifts in the pre-amplifier 35 and power amplifier 40 and for phase shifts between the drive coil 15, the magnetostrictive member 10 and the feedback coil 25.
- the feedback coil 25 may be considered to have two portions 25a and 25b. There are the same number of windings in each portion 25a and 25b. However each portion is wound in an opposite direction, that is, one portion is wound in a clockwise manner and the other portion is wound in a counterclockwise manner with a reversal point 250 somewhere in the transition region between the two portions. Due to this oppositely wound feature, any induced voltage caused by the magnetic field of the drive coil 15, (the transformer effect) is cancelled out within the feedback coil 25.
- FIG. 2 a magnetostrictive member 10a having a longitudinal axis 11a is shown having a feedback coil 25 of the nature described above in surrounding relation thereto.
- the magnetostrictive member 10a is under the influence of a drive coil (not shown) of the nature described with respect to FIG. 1.
- the magnetostrictive member 10a is vibrated such that there is a node of longitudinal motion somewhere along its length, designated as the NODE on FIG. 2.
- the feedback coil 25 is positioned along the length of the magnetostrictive member 10a, such that the reversal point 25c between the portions 25a and 25b occurs at the NODE.
- FIG. 2 includes a graph showing the sinusoidal nature of the amplitude of vibration of a resonating member.
- FIG. 3 a magnetostrictive member 10b having a longitudinal axis 11b is shown to have a feedback coil 25 of the nature described above in surrounding relation thereto.
- the magnetostrictive member 10b is under the influence of a drive coil (not shown) of the nature described with respect to FIG. 1.
- the magnetostrictive member 10b is vibrated such that there is a node of longitudinal motion somewhere along its length, designated as NODE on FIG. 3.
- FIG. 3 includes a graph showing the change in permeability (An) of the magnetostrictive member 10b .as it is subjected to the varying current of the drive coil (not shown) versus the length of the member 10b.
- the feedback coil 25 is positioned so that the NODE is approximately near the center of one portion 25b of the feedback coil 25. It is true that the voltage induced in the other portion 25a of the feedback coil 25, due to this permeability effect, will be in the opposite direction. However, as can be seen from the graph in FIG. 3, the change in permeability declines rapidly at points removed from the NODE', induced voltage in portion 25a portion 25b will be very slight.
- An electro-mechanical resonant system comprising a work performing, variably loaded mechanical part including a magnetostrictive member and having a drive coil in surrounding relation thereto, a power circuit operative to supply alternating current to said drive coil so that the latter establishes an alternating electromagnetic field which sets up compressional waves in said magnetostrictive member at a resonant frequency of said mechanical part, a pickup coil in surrounding relation to the magnetostrictive member so that a voltage is induced in said pickup coil directly related to the actual frequency of the compressional waves, said pickup coil having two portions each with an equal number of winding, with the first portion being wound in a clockwise direction about the magnetostrictive member and the second portion being wound in a counterclockwise direction about the magnetostrictive member, and a circuit means connecting said pickup coil to said power circuit so that the power supplied to said drive coil is controlled by said alternating feedback voltage,
- a pickup coil for use with a magnetostrictive member hence the subtraction of the from the induced voltage in being vibrated by a drive coil energized by a power circuit
- said pickup coil is in surrounding relation to the magnetostrictive member whereby a voltage is induced in said pickup coil directly related to the actual frequency of vibration of the magnetostrictive member, said pickup coil includes two portions, each with an equal number of windings, with the first portion being wound in a clockwise direction about the magnetostrictive member and the second portion being wound in a counterclockwise direction about the magnetostrictive member, and a circuit means connects said pickup coil to the power circuit so that the power supplied to the drive coil is controlled by the induced feedback voltage.
- An electro-mechanical resonant system comprising a work performing, variably loading mechanical part including a magnetostrictive member having a longitudinal axis and having a drive coil in surrounding relation thereto, a power circuit operative to supply alternating current to said drive coil so that the latter establishes an alternating electromagnetic field which sets up longitudinal compressional waves in said magnetostrictive member at a resonant frequency of said mechanical part, a pickup coil in surrounding relation to the magnetostrictive member so that a voltage is induced in said pickup coil directly related to the actual frequency of the compressional waves, said pickup coil having two portions, each with an equal number of windings, with the first portion being wound in a clockwise direction about the magnetostrictive member, the second portion being wound in a counterclockwise direction about the magnetostrictive member and the reversal point positioned at a node of longitudinal motion, and a circuit means connecting said pickup coil to said power circuit so that the power supplied to said drive coil is controlled by said alternating feedback voltage.
- a pickup coil for use with a magnetostrictive member having a longitudinal axis and being vibrated by a drive coil energized by a power circuit, wherein said pickup coil is in surrounding relation to the ma netostrictive member whereb a voltage is induced in said pic up coil directly related to the actual frequency of vibration of the magnetostrictive member, said pickup coil includes two portions, each with an equal number of windings, with the first portion being wound in a clockwise direction about the magnetostrictive member, the second portion being wound in a counterclockwise direction about the magnetostrictive member and the reversal point being positioned at a node of longitudinal motion, and a circuit means connects said pickup coil to the power circuit so that the power supplied to the drive coil is controlled by the induced feedback voltage.
- An electro-mechanical resonant system comprising a work performing, variably loaded mechanical part including a polarized magnetostrictive member having a longitudinal axis and having a drive coil in surrounding relation thereto, a power circuit operative to supply alternating current to said drive coil so that the latter establishes an alternating electromagnetic field which sets up longitudinal compressional waves in said magnetostrictive member at a resonant frequency of said mechanical part, a pickup coil in surrounding relation to the magnetostrictive member so that a voltage is induced in said pickup coil directly related to the actual frequency of the compressional waves, said pickup coil having two portions, each with an equal number of windings, with the first portion being wound in a clockwise direction about the magnetostrictive member, the second portion being wound in a counterclockwise direction about the magnetostrictive member and a node of longitudinal motion of said member approximately at the center of one of the portions of the pickup coil, and a circuit means connecting said pickup coil to said power circuit so that the power supplied to said drive coil is controlled by said alternating feedback voltage
- a pickup coil for use with a polarized magnetostrictive member having a longitudinal axis and being vibrated by a drive coil energized by a power circuit, wherein said pickup coil is in surrounding relation to the magnetostrictive member whereby a voltage is induced in said pickup coil directly related to the actual frequency of vibration of the magnetostrictive member, said pickup coil includes two portions, each with an equal number of windings, with the first portion being wound in a clockwise direction about the magnetostrictive member, the second portion being wound in a counterclockwise direction about the magnetostrictive member and a node of longitudinal motion of said member approximately at the center of one of the portions of the pickup coil, and a circuit means connects said pickup coil to the power circuit so that the power supplied to the drive coil is controlled by the induced feedback voltage.
Abstract
Description
Claims (6)
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
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US10667571A | 1971-01-15 | 1971-01-15 |
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US3654540A true US3654540A (en) | 1972-04-04 |
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US106675A Expired - Lifetime US3654540A (en) | 1971-01-15 | 1971-01-15 | Magnetostrictive drive circuit feedback coil |
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Cited By (16)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3743868A (en) * | 1970-10-12 | 1973-07-03 | Denki Onkyo Co Ltd | Driving apparatus for piezoelectric ceramic elements |
US3748553A (en) * | 1971-10-08 | 1973-07-24 | Cleveland Machine Controls | Self-tuned vibratory feeder |
US4127889A (en) * | 1975-10-31 | 1978-11-28 | Mitsubishi Jukogyo Kabushiki Kaisha | Electromagnetic damping mechanism for force motor |
US4663574A (en) * | 1983-09-27 | 1987-05-05 | Dresser Industries, Inc. | Reactive position detector for electromagnetic vibrators |
US4677353A (en) * | 1983-09-27 | 1987-06-30 | Dresser Industries, Inc. | Electro-inductive vibratory monitoring system |
US5776155A (en) * | 1996-12-23 | 1998-07-07 | Ethicon Endo-Surgery, Inc. | Methods and devices for attaching and detaching transmission components |
US5775901A (en) * | 1996-03-07 | 1998-07-07 | Hu-Friedy Mfg. Co., Ltd. | Insert for ultrasonic scaler |
US5810859A (en) * | 1997-02-28 | 1998-09-22 | Ethicon Endo-Surgery, Inc. | Apparatus for applying torque to an ultrasonic transmission component |
US5957943A (en) * | 1997-03-05 | 1999-09-28 | Ethicon Endo-Surgery, Inc. | Method and devices for increasing ultrasonic effects |
US5968060A (en) * | 1997-02-28 | 1999-10-19 | Ethicon Endo-Surgery, Inc. | Ultrasonic interlock and method of using the same |
US5989275A (en) * | 1997-02-28 | 1999-11-23 | Ethicon Endo-Surgery, Inc. | Damping ultrasonic transmission components |
US5989274A (en) * | 1996-10-17 | 1999-11-23 | Ethicon Endo-Surgery, Inc. | Methods and devices for improving blood flow to a heart of a patient |
US6051010A (en) * | 1996-12-23 | 2000-04-18 | Ethicon Endo-Surgery, Inc. | Methods and devices for joining transmission components |
US6093021A (en) * | 1997-06-25 | 2000-07-25 | Rainey; J. Tim | Parallel air stream dental air-abrasion system |
US6720684B2 (en) | 2000-03-22 | 2004-04-13 | Siemens Automotive Corporation | Method of control for a self-sensing magnetostrictive actuator |
US20110241576A1 (en) * | 2010-04-01 | 2011-10-06 | Paschke Consulting Group Inc. (PCG INC.) | Ultrasonic system controls, tool recognition means and feedback methods |
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US2296754A (en) * | 1939-04-29 | 1942-09-22 | Texas Co | Astatic electromagnetic vibration detector |
US2848672A (en) * | 1955-07-26 | 1958-08-19 | Harris Transducer Corp | Self-excited transducer |
US3133214A (en) * | 1960-01-04 | 1964-05-12 | John D Lawson | Linear motion sensing generator |
GB1132125A (en) * | 1965-06-10 | 1968-10-30 | Vuma Vyskumny Ustav Machanizac | Improvements in or relating to ultrasonic transducers |
US3470399A (en) * | 1968-06-17 | 1969-09-30 | Ibm | Linear motor velocity detection apparatus |
US3505544A (en) * | 1968-02-09 | 1970-04-07 | Data Products Corp | Linear motor |
-
1971
- 1971-01-15 US US106675A patent/US3654540A/en not_active Expired - Lifetime
Patent Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
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US2296754A (en) * | 1939-04-29 | 1942-09-22 | Texas Co | Astatic electromagnetic vibration detector |
US2848672A (en) * | 1955-07-26 | 1958-08-19 | Harris Transducer Corp | Self-excited transducer |
US3133214A (en) * | 1960-01-04 | 1964-05-12 | John D Lawson | Linear motion sensing generator |
GB1132125A (en) * | 1965-06-10 | 1968-10-30 | Vuma Vyskumny Ustav Machanizac | Improvements in or relating to ultrasonic transducers |
US3505544A (en) * | 1968-02-09 | 1970-04-07 | Data Products Corp | Linear motor |
US3470399A (en) * | 1968-06-17 | 1969-09-30 | Ibm | Linear motor velocity detection apparatus |
Cited By (18)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3743868A (en) * | 1970-10-12 | 1973-07-03 | Denki Onkyo Co Ltd | Driving apparatus for piezoelectric ceramic elements |
US3748553A (en) * | 1971-10-08 | 1973-07-24 | Cleveland Machine Controls | Self-tuned vibratory feeder |
US4127889A (en) * | 1975-10-31 | 1978-11-28 | Mitsubishi Jukogyo Kabushiki Kaisha | Electromagnetic damping mechanism for force motor |
US4663574A (en) * | 1983-09-27 | 1987-05-05 | Dresser Industries, Inc. | Reactive position detector for electromagnetic vibrators |
US4677353A (en) * | 1983-09-27 | 1987-06-30 | Dresser Industries, Inc. | Electro-inductive vibratory monitoring system |
US5775901A (en) * | 1996-03-07 | 1998-07-07 | Hu-Friedy Mfg. Co., Ltd. | Insert for ultrasonic scaler |
US5989274A (en) * | 1996-10-17 | 1999-11-23 | Ethicon Endo-Surgery, Inc. | Methods and devices for improving blood flow to a heart of a patient |
US6387109B1 (en) | 1996-10-17 | 2002-05-14 | Ethicon Endo-Surgery, Inc. | Methods and device for improving blood flow to heart of a patient |
US6051010A (en) * | 1996-12-23 | 2000-04-18 | Ethicon Endo-Surgery, Inc. | Methods and devices for joining transmission components |
US5776155A (en) * | 1996-12-23 | 1998-07-07 | Ethicon Endo-Surgery, Inc. | Methods and devices for attaching and detaching transmission components |
US5968060A (en) * | 1997-02-28 | 1999-10-19 | Ethicon Endo-Surgery, Inc. | Ultrasonic interlock and method of using the same |
US5989275A (en) * | 1997-02-28 | 1999-11-23 | Ethicon Endo-Surgery, Inc. | Damping ultrasonic transmission components |
US5810859A (en) * | 1997-02-28 | 1998-09-22 | Ethicon Endo-Surgery, Inc. | Apparatus for applying torque to an ultrasonic transmission component |
US5957943A (en) * | 1997-03-05 | 1999-09-28 | Ethicon Endo-Surgery, Inc. | Method and devices for increasing ultrasonic effects |
US6093021A (en) * | 1997-06-25 | 2000-07-25 | Rainey; J. Tim | Parallel air stream dental air-abrasion system |
US6720684B2 (en) | 2000-03-22 | 2004-04-13 | Siemens Automotive Corporation | Method of control for a self-sensing magnetostrictive actuator |
US20110241576A1 (en) * | 2010-04-01 | 2011-10-06 | Paschke Consulting Group Inc. (PCG INC.) | Ultrasonic system controls, tool recognition means and feedback methods |
US9018887B2 (en) * | 2010-04-01 | 2015-04-28 | Westdale Holdings, Inc. | Ultrasonic system controls, tool recognition means and feedback methods |
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