CA2294587A1 - Vibrational transducer - Google Patents

Vibrational transducer Download PDF

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Publication number
CA2294587A1
CA2294587A1 CA 2294587 CA2294587A CA2294587A1 CA 2294587 A1 CA2294587 A1 CA 2294587A1 CA 2294587 CA2294587 CA 2294587 CA 2294587 A CA2294587 A CA 2294587A CA 2294587 A1 CA2294587 A1 CA 2294587A1
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CA
Canada
Prior art keywords
coil
magnet
switching power
rotor assembly
vibrational transducer
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.)
Abandoned
Application number
CA 2294587
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French (fr)
Inventor
John L. Myers
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Projects Unlimited Inc
Original Assignee
Individual
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Filing date
Publication date
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Publication of CA2294587A1 publication Critical patent/CA2294587A1/en
Abandoned legal-status Critical Current

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Classifications

    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04RLOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R1/00Details of transducers, loudspeakers or microphones
    • GPHYSICS
    • G08SIGNALLING
    • G08BSIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
    • G08B6/00Tactile signalling systems, e.g. personal calling systems
    • HELECTRICITY
    • H02GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02KDYNAMO-ELECTRIC MACHINES
    • H02K21/00Synchronous motors having permanent magnets; Synchronous generators having permanent magnets
    • H02K21/12Synchronous motors having permanent magnets; Synchronous generators having permanent magnets with stationary armatures and rotating magnets
    • H02K21/14Synchronous motors having permanent magnets; Synchronous generators having permanent magnets with stationary armatures and rotating magnets with magnets rotating within the armatures
    • H02K21/20Synchronous motors having permanent magnets; Synchronous generators having permanent magnets with stationary armatures and rotating magnets with magnets rotating within the armatures having windings each turn of which co-operates only with poles of one polarity, e.g. homopolar machine
    • HELECTRICITY
    • H02GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02KDYNAMO-ELECTRIC MACHINES
    • H02K3/00Details of windings
    • H02K3/46Fastening of windings on the stator or rotor structure
    • H02K3/47Air-gap windings, i.e. iron-free windings
    • HELECTRICITY
    • H02GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02KDYNAMO-ELECTRIC MACHINES
    • H02K7/00Arrangements for handling mechanical energy structurally associated with dynamo-electric machines, e.g. structural association with mechanical driving motors or auxiliary dynamo-electric machines
    • H02K7/06Means for converting reciprocating motion into rotary motion or vice versa
    • H02K7/061Means for converting reciprocating motion into rotary motion or vice versa using rotary unbalanced masses
    • H02K7/063Means for converting reciprocating motion into rotary motion or vice versa using rotary unbalanced masses integrally combined with motor parts, e.g. motors with eccentric rotors
    • HELECTRICITY
    • H02GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02KDYNAMO-ELECTRIC MACHINES
    • H02K2211/00Specific aspects not provided for in the other groups of this subclass relating to measuring or protective devices or electric components
    • H02K2211/03Machines characterised by circuit boards, e.g. pcb
    • HELECTRICITY
    • H02GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02KDYNAMO-ELECTRIC MACHINES
    • H02K5/00Casings; Enclosures; Supports
    • HELECTRICITY
    • H02GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02KDYNAMO-ELECTRIC MACHINES
    • H02K5/00Casings; Enclosures; Supports
    • H02K5/04Casings or enclosures characterised by the shape, form or construction thereof
    • H02K5/22Auxiliary parts of casings not covered by groups H02K5/06-H02K5/20, e.g. shaped to form connection boxes or terminal boxes
    • H02K5/225Terminal boxes or connection arrangements

Abstract

A vibrating tranducer or alarm for a pager, cellular telephone and the like, includes a single coil wound in a longitudinal direction to enclose a chamber extending in the longitudinal direction; a planar substrate, bonded to an outer wall formed by the coil; a switching power source, operatively coupled to the coil, for producing an oscillating magnetic field within the chamber, and an eccentric weight rotor assembly extending within the chamber, where the rotor assembly includes a permanent magnet that provides a rotational force to the rotor assembly when acted upon by the oscillating magnetic field.

Description

VIBRATIONAL TRANSDUCER
CROSS REFERENCE TO RELATED APPLICATIONS
This application claims priority under 35 U.S.C. ~119 from Provisional Application Ser. No. 60/051,737 filed July 3, 1997, the entire disclosure of which is incorporated herein by reference.
COPYRIGHTED MATERIAL
A portion of the disclosure of this patent document contains material which is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the PTO patent files or records, but otherwise reserves all copyright rights whatsoever.
BACKGROUND
The present invention relates to personal communication devices, and more particularly, to a vibrational transducer or vibrating alarm for use with personal communication devices.
Vibrating alarms for use with personal communication devices are well known in the art. Many of these alarms comprise conventional motors having an eccentric weight attached to the rotor shaft. Accordingly, when the motor is activated, the rotation of the rotor shaft and corresponding rotation of the eccentric weight causes vibration within the persona! communication device that is detected by the holder of the device.
A disadvantage with conventional eccentric weight motors is that they are not specifically designed for mass production. In particular, several manual labor steps are required to assemble the device. For example, the most popular conventional vibrating motors require three coils, each of which must be soldered to the associated leads by manual labor.
Additional disadvantages with conventional vibrating motors is that they are not surface mountable, i.e., that they are not specifically adapted to be surface mounted onto a circuit board of a personal communication device. For example, the most popular conventional vibrating motors require a specialized bracket which must first be mounted to the personal communication device, a male connector component which must be attached to the ends of the motor's lead wires, and a corresponding female connector which is mounted to the communication device's circuit board. First, the bracket must be mounted within the communication device, then the female connector is mounted to the circuit board, then the male connector is coupled to the wires of the motor, and finally, in an assembly process, the motor is installed into the bracket and the female and male connectors. are mated.
Accordingly, a need exists for a vibrating alarm for use with a personal communication device which substantially reduces manual assembly requirements, which is specifically designed to be surface mounted onto a printed circuit board of a personal communication device, and which minimizes the energy requirements for operating the device.
SUMMARY
The present invention is a small vibrating motor for use with a personal communication device that comprises a rotor assembly mounted within a single coil wound to form a chamber therewithin for receiving the rotor assembly. The rotor assembly is mounted within the chamber by upper and Power bearing assemblies.
A
semi-cylindrical, or half donut shaped magnet is coupled to the rotor assembly so that when an alternating magnetic field is supplied by the coil, the magnet is caused to move and rotate within the coil. The half donut-shaped magnet provides an eccentric weight, such that rotation of the rotor assembly within the coil causes the motor to vibrate. Of course, other eccentrically shaped magnets may also be utilized in place of the half donut-shaped magnet. The coil and rotor assembly is contained within a housing that is specifically designed to be surface mounted or PC mounted to a circuit board.
In a first embodiment, an H-bridge circuit is used to provide switched power to the motor, and a comparator circuit is used to sense the direction of motor generated Voltage (back-EMF). A microprocessor or microcontroller, operatively coupled to the H-bridge and comparator circuits, preferably uses the back-EMF signal to determine the appropriate driver input signals to apply to the H-bridge circuit. Therefore, the EMF
comparator circuit is used to control the commutation in the motor.
Accordingly, one aspect of the present invention provides a vibrating transducer comprising a coil wound in a longitudinal direction to enclose a chamber extending in the longitudinal direction; a switching power source, operatively coupled to the coil, for producing an oscillating magnetic field within the chamber; and a rotor assembly extending within the chamber, where the rotor assembly includes a permanent magnet and where the rotor assembly has center of mass located radially distal from its rotational axis. Another aspect of the present invention provides a communication device comprising a receiver component for receiving messages transmitted to the communications device, a processor operatively coupled to the receiver component for processing messages received by the receiver component, and a vibrating alarm operatively coupled to the processor where the vibrating alarm includes the small vibrating transducer described above.
Yet another aspect of the present invention provides a vibrating alarm for a pager, cellular telephone and the like, comprising a single coil wound in a longitudinal direction to enclose a chamber extending in the longitudinal direction; a planar substrate, bonded to an outer wall formed by the coil; a power source, operatively coupled to the coil, for producing an oscillating magnetic field within the chamber; and an eccentric weight rotor assembly mounted within the chamber, where the rotor assembly includes a permanent magnet that provides a rotational force to the rotor assembly when acted upon by the oscillating magnetic field.
Accordingly, it is an object of the present invention to provide a vibrating transducer for use with a personal communication device that significantly reduces manual labor requirements in manufacturing the transducer; it is a further object of the present invention to provide a vibrating transducer for use with a personal communication device that uses a single coil as opposed to several coils; it is a further object of the present invention to provide a vibrating transducer for use with a personal communication device that can be surface mounted to a printed circuit board;
and it is a further object of the present invention to provide a vibrating transducer for a personal communication device that can transfer vibrational energy in any direction needed by simply mounting the transducer in a particular orientation.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 is a schematic, block-diagram representation of a personal communication device incorporating the vibrating transducer of present invention;
Fig. 2A is an elevational, cross-sectional view of the vibrating transducer of the present invention (taken along line 2A-2A of Fig. 2B);
Fig. 2B is a top, cross-sectional view of the vibrating transducer taken along line 2B-2B of Fig. 2A;
Fig. 3A is a bottom, perspective view of the vibrating transducer of the present invention including pins, facilitating PC mounting;
Fig. 3B is a bottom, perspective view of the vibrating transducer of the present invention including surface-mount pads, facilitating surface mounting;
Fig. 3C is a bottom, perspective view of the vibrating transducer of the present invention including break-out wires, facilitating optional mounting methods;

Fig. 4 is a schematic representation of H-bridge and comparator circuits for use with the present invention;
Fig. 5 is a time versus Voltage diagram illustrating operation of the H-bridge and comparator circuits of Fig. 4;
Fig. 6 is a flow diagram illustrating operation of the microcontroller or microprocessor of the present invention;
Fig. 7 is a block-diagram representation of an alternate embodiment of the vibrating transducer;
Fig. 8 is a schematic representation of an oscillator circuit for use with the embodiment of Fig. 7;
Fig. 9 is a schematic representation of an NT one-shot multivibrator circuit for use with the embodiment of Fig. 7;
Fig. 10 is a schematic representation of a PT one-shot multivibrator circuit for use with the embodiment of Fig. 7;
Fig. 11 is a schematic representation of an oscillator charge-control circuit for use with the embodiment of Fig. 7;
Fig. 12 is a schematic representation of an oscillator discharge-control circuit for use with the embodiment of Fig. 7;
Fig. 13 is a time versus Voltage diagram illustrating operation of the motor control circuitry of Figs. 7-12;
Fig. 14 is a block-diagram representation of a motor control unit in yet another embodiment of the present invention;
Fig. 15 is a block-diagram representation of a motor control unit in yet another embodiment of the present invention;
Fig. 16 is a block-diagram representation of a motor control unit in yet another embodiment of the present invention, incorporating a center tapped coil;
Fig. 17 is an elevational, cross-sectional view of a vibrating transducer incorporating the center-tapped coil of Fig. 16;

Fig. 18 is a time versus Voltage diagram illustrating operation of the motor control circuitry of Figs. 14 and 1fi;
Fig. 19 is a circuit diagram for the microcontrollers of Figs. 14 and 16;
Fig. 20 is a circuit diagram for a single-input, swept-frequency H-bridge driver for use with the present invention;
Fig. 21 is a circuit diagram for a single-input, swept-frequency dual-transistor driver for use with the present invention;
Fig. 22 is a time versus Voltage diagram illustrating operation of swept-frequency driver circuitry for use with the circuits of Figs. 20 and 21;
Fig. 23 is a circuit diagram for a microcontroller for generating the driver signal of Fig. 22;
Fig. 24A is a cross-sectional top plan view of yet another embodiment of the vibrating transducer, taken along lines 24A-24A of Fig. 24B;
Fig. 24B is a cross-sectional elevational view of the embodiment of Fig. 24A, taken along lines 24B-24B of Fig. 24A;
Fig. 25A is a perspective, cut-away view of yet another embodiment of the vibrating transducer; and Fig. 25B is an elevational, cross-sectional view of a longitudinal portion of the embodiment of Fig. 25A.
DETAILED DESCRIPTION
As shown in Fig. 1, a cellular telephone, pager or other type of personal communication device will typically include a central processor 20 such as a microprocessor, microcontroller or other similar processing device; a receiver 22 such as an RF antenna, an infrared sensor, or other related reception device; an output device 24 such as an LCD or LED display component and/or a speaker component;
and a power supply 26, such as a battery, a solar cell, or any other known means for providing power to the various components of the personal communication device.
Such components are known to those of ordinary skill in the art and will therefore not be discussed in significant detail herein. Generally, the processor 20 receives information transmitted to the personal communication device from the receiver 22 and relays that information to the user of the personal communication device by controlling the output device 24.
The personal communication device will also include a vibrating transducer 28 of the present invention for alerting a user of the device of an incoming message, for example. The vibrating transducer 28 of the present invention includes a motor 30, and a switched power source 32. As will be described in further detail below, the motor 30 includes a coil 33 and a rotor assembly 34 extending near the coil and having a center of mass located radially distal from its rotational axis. Furthermore, the vibrating transducer 28 also preferably includes a component or a circuit, such as a comparator 36, operatively coupled to the coil 33 for detecting the direction of travel of the rotor assembly 34.
As shown in Figs. 2A and 2B, the coil 33 is wound in a longitudinal direction L to enclose a chamber 38 extending in the longitudinal direction L. Preferably, the coil 33 is layer-wound in the longitudinal direction L. The coil 33 is mounted to a substrate 40 and is also encased by a low-cost, molded plastic housing 42, which is also mounted to the substrate 40. The rotor assembly 34 includes a center hub 44, including a shaft 46 extending through the center of the rotor hub 44. The center shaft 46 extends between an upper end bearing 48 and a lower end bearing 50, which are in tum mounted, preferably by epoxy, to the coil 33 within the chamber 38. Rotor assembly 34 also includes an eccentric shaped magnet 52 mounted, preferably by epoxy, to the center hub 44. As shown in Figs. 2A and 2B, the magnet 52 is preferably semi-cylindrical, i.e., shaped as a half-donut, where its inner circumferential surface (hole) 55 is mounted to the center hub. As will be described in detail below, when a suitable magnetic field is produced by the coil 33, the rotor assembly 34 will rotate within the upper and lower end bearings 48, 50. The eccentric shape of the magnet 52 provides an eccentric weight, such that rotation of the rotor assembly 34 within the coil causes the motor 30 to vibrate.
Preferably, the magnet 52 is a neodiumlironlboron-magnet stabilized with electroless nickel plate. The magnet 52 is magnetized in a direction parallel to its axis of symmetry (in the H direction). The end bearings 48, 50 are preferably grade poly (amide-imide), the shaft 46 is preferably a high-speed steel polished drill rod, the center hub 44 is preferably free machining brass, and the substrate 40 is preferably FR404 epoxy glass.
Accordingly, the motor design is extremely simple, consisting of a rectangular coil 33 with a rotating, off-center magnet 52 therewithin. Since no external shaft is necessary, rotor assembly 34 can be completely contained within the confines of the coil 33. Operating force is transmitted to the outside housing 42 through the shaft 46 and bearing structures 48, 50.
The substrate 40 is preferably a glass-epoxy printed-circuit-board material, which facilitates the mounting of associated driver circuitry thereon and also facilitates the inclusion of PC-mount pins 57 (see Fig. 3A), surface-mount pads 59 (see Fig.
3B), or wire leads 61 (see Fig. 3C) thereto. Driver circuitry for use with the present invention is described in detail below.
The motor torque varies approximately as the sine of the angle between the longitudinal axis of the coil (which defines the direction of flux inside the coil) and the axis of symmetry of the magnet (the direction of magnetization H); thus, if the magnet is at rest and these axes are aligned, the torque is zero (0), and the motor cannot start.
Torque is maximum when the magnet's axis of symmetry and the longitudinal axis of the coil are at 90°. As shown in Figs. 2A and 2B, a small, 0.001 inch thick strip 53 of nickel-iron alloy is therefore attached to the casing on one side of the coil 33 to position the magnet 52 so that, when power is off, the magnet's axis of symmetry and the longitudinal axis of the coil are at 90°, thereby facilitating maximum torque at startup.
_g_ The strip 53 is preferably placed near or on a side of the coil which is in a plane parallel to the magnet axis of rotation, in such a manner as to minimize bearing ioadinglfriction.
As will be further described below, the power to the coil 33 is switched (reversed) when the magnet 52 reaches the extremity of travel (the extremity of travel will be the end of the coil when running, but during start-up, may or may not be the end of the coil), and a preferred method of determining when to switch the power is by detecting motion-generated or "back EMF" in the coil 33 using the comparator circuit 3fi.
As shown in Fig. 4, in one embodiment, the switching power source 32 utilizes a conventional H-bridge circuit. Directional inputs A and B are provided by the central processor 20. As those of ordinary skill in the art will recognize, when input A is active, NPN transistor T3 is activated, causing PNP transistor T2 to activate, which in turn allows positive current to flow through T2, through the coil 33, through NPN
transistor T3, to ground. Accordingly, activating input A, provides positive Voltage across the motor 30. Likewise, when input B is activated by the central processor, NPN
transistor T4 is activated, causing PNP transistor T1 to be pulled to active. Therefore, positive current flows through PNP transistor T1, then through the coil 33, through NPN
transistor T4, and then to ground. Accordingly, activating input B causes negative Voltage to be applied across the motor 30. Resistor R1 is coupled to the emitters of NPN transistors T3 and T4 and is used to lower the transitionaUshoot through current spikes in the circuit. The individual values of the components of the H-bridge circuit of the first embodiment are given in the table below:

Ref. Type ValuefType T1 PNP Transistor MPS751 T2 PNP Transistor MPS751 T3 NPN Transistor MPS651 T4 NPN Transistor MPS651 R1 Resistor 1 Ohm R2 Resistor 300 Ohm R3 Resistor 200 Ohm R4 Resistor 100 Ohm C1 Capacitor 47 micro-Farads D1 Schottky Diode SD103A

Comparator circuit 36 is a conventional comparator circuit which will activate the output ("COMP OUT") 37 when the Voltage on motor lead ("MOTOR +") 41 is greater than the Voltage on motor lead (°MOTOR =') 43, and will likewise deactivate the COMP
OUT 37 when MOTOR - 43 has a higher Voltage than MOTOR + 41. When the Voltage on MOTOR + is greater than the Voltage on MOTOR -, NPN transistor T5 will activate and NPN transistor T6 will deactivate, causing PNP transistor T7 to deactivate.
Lack of Voltage out of divider circuit R9, R12 deactivates NPN transistor T8, which allows R11 to pull COMP OUT Voltage high. When the MOTOR - Voltage is greater than the MOTOR + Voltage, T6 will be active and NPN transistor T5 will deactivate.
When T6 is active, PNP transistor T7 is in turn activated, allowing the divider circuit R9, R12 to activate NPN transistor T8, which pulls COMP OUT low. NPN transistors and T10 and resistors R13 and R14 comprise a 100 micro-amp current source. The values of the first embodiment of the comparator circuit 36 are given in the table below (R.LR,M trims the comparator input offset Voltage to 0, and is typically 115 K-Ohms):

Ref. Type ValueIType T5 NPN Transistor 2N5089 T6 NPN Transistor 2N5089 T7 PNP Transistor 2N3906 T8 NPN Transistor 2N3904 T9 NPN Transistor 2N5089 T10 NPN Transistor 2N5089 R5 Resistor 1 K-Ohm R6 Resistor 3.0 K-Ohm R7 Resistor 10 K-Ohm R8 Resistor 100 K-Ohm R9 Resistor 1 K-Ohm R11 Resistor 10 K-Ohm R12 Resistor 10 K-Ohm R13 Resistor 5.1 K-Ohm R14 Resistor 2 K-Ohm RTRIM Resistor See above Operation of the H-bridge circuit 32 and the comparator circuit 36 is illustrated by reference to the Voltage versus timing diagram as shown in Fig. 5. The Voltage versus timing diagram of Fig. 5 depicts three signals, COMP OUT, MOTOR+ and MOTOR- in comparison to each other with respect to time. Activation of the A input into H-bridge circuit 32 by the central processor 20 can be seen by the substantially square peaks 45 in the MOTOR+ Voltage signal. Activation of the B input into the H-bridge circuit 32 by the central processor 20 can be seen as square peaks 47 in the MOTOR- Voltage signal. The sinusoidal portions 49 of each of the MOTOR+ and the MOTOR-Voltage signals, represent the back EMF in the coil 33 caused by the moving (rotating) magnet 52 when neither of the A or B inputs into H-bridge circuit are activated. TW
denotes the software delay time to allow for UR decay (see functional block 60 of Fig. 6).
Signifiicant transitions of the comparator circuit 36 output, COMP OUT, are indicated by arrows at times T1, T2, and T3 {13 msec, 28 msec and 49 msec). The edges of the "don't care" areas are not significant. TS is the total time from a COMP OUT
edge to output transistor activation, and includes software latency {time for the microcontroller to execute the software and respond) and time for the electronics (transistors, etc.) to switch on.
Because the magnet 52 will be rotating within the coil 33; during one 180°
segment of its rotation, the magnet will have a velocity component in a first longitudinal direction with respect to the coil, and during the other 180° segment of its rotation, the magnet will have a velocity component in an opposite longitudinal direction with respect to the coil. As will be known to one of ordinary skill in the art, the back EMF signal in the coil 33 is directly dependent upon the product of magnet flux density and the magnet's velocity component due to the magnet's rotation within the coil 33.
The central processor 20 is thus able to determine which longitudinal direction the magnet is traveling, with respect to the coil, by sampling the COMP OUT signal 37 from the comparator circuit.
As discussed above, the central processor 20 uses the COMP OUT signal 37 to determine which of the appropriate driver input signals, A or B, to apply to the H-bridge circuit 32. Fig. 6 depicts a control algorithm for use by the central processor 20. At functional block 56, the motor is not operating, and to start the motor, the central processor 20, in functional block 58, will direct the H-bridge circuit to pulse the motor in a first direction, for a predetermined pulse time, either by activating the A
input fine or the B input line for the predetermined pulse time. In the present embodiment, the predetermined pulse time is 10 milliseconds. Advancing to functional block 60, the central processor will then delay for an appropriate UR decay time. UR decay time is the time required for the current in a circuit containing inductance (L) and resistance (R) to decay to an acceptable value. The UR decay time for the present embodiment is 1 millisecond. In the loop formed by functional blocks 62 and 64, the central processor will sample the COMP OUT signal 37 from the comparator circuit 36 for a predetermined period of time or until the COMP OUT signal changes. In the present embodiment, the predetermined time to sample the COMP OUT signal in blocks 62 and 64 is 24 milliseconds. lf, in functional block 62, the central processor determines that the COMP OUT signal had changed, the central processor will advance to functional block 66. But if a time-out occurred in functional block 64, before the COMP
OUT
signal changes, the central processor will advance to functional block 68.~
Typically a time-out will occur only in a situation where the first pulse delivered in functional block 58 failed to move the magnet; and therefore, the motor will need to be pulsed in the opposite direction. Accordingly, in functional block 68 the central processor toggles the pulse direction and returns to functional block 58 to cause the H-bridge circuit to pulse the motor in the opposite direction (i.e., if the A input line was originally activated, now the B input line will be activated). From functional block 58, the central processor returns to functional block 60.
If, in functional block 62 the central processor had determined that the COMP
OUT signal had changed, then in functional block 66, the central processor will determine, based upon the new value of the COMP OUT signal, which longitudinal direction (relative to the coil) that the magnet was traveling. If the COMP
OUT signal indicates that the magnet was traveling in the reverse direction, the central processor will set the pulse direction to the forward direction and then return to functional block 58 to pulse the motor in the forward direction. However, if the COMP OUT signal indicates that the magnet was traveling in the forward direction, the central processor will advance to functional block 70 to set the pulse direction to the reverse direction. From functional block 70, the central processor returns to functional block 58 reverse direction. As will be apparent from the above, steps 58, 60, 62, 64.and 68 will repeat until the motor is started; and steps 58, 60, 62, 66, and 70 will repeat once the motor has started and until the central processor deactivates the motor.
As shown in Fig. 7, another embodiment of the present invention uses a motor driver circuit having all transistors and no microcontrollers, making the circuit suitable for realization in the form of a single monolithic bipolar integrated circuit.
The circuit utilizes an H-bridge driver 32' and a comparator 36' similar to the first embodiment above, however, the control algorithm as depicted in Fig. 6 is implemented in a form of an oscillator circuit 74, two monostable (one-shot) multivibrator circuits 76, 78, and oscillator control circuitry, 80, 82. The power supply is a single nickel cadmium (NiCd) cell with an output Voltage of 1.3VDC. The primary difference between the comparator 36' of the alternate embodiment of Fig. 7 and the comparator 36 of Fig. 4, is that the comparator 36' of the bipolar IC circuit uses a 1 K resistor for R11, pulled up to 1.3 VDC.
Also R6 is changed from 3.3 K-Ohm to 3.0 K-Ohm.
As shown in Fig. 8, the oscillator circuit 74 generates the basic pulse outputs OSC A-out 86 and OSC B-out 88. These outputs, respectively, have well defined negative transition and positive transition. Low Voltage operation is accomplished by using a current source and sink to charge and discharge a 100 nanoFarad timing capacitor C2. The individual values of the components of the oscillator circuit 74 are given in the table below:
Ref. Type ValuelType T13 PNP Transistor 2N5087 T14 NPN Transistor 2N5089 T15 PNP Transistor 2N5087 T16 NPN Transistor 2N5089 T17 PNP Transistor 2N5087 T18 NPN Transistor 2N5089 R15 Resistor 1 K-Ohm R16 Resistor 51 K-Ohm R17 Resistor 2 M-Ohm R18 Resistor 200 K-Ohm C2 Capacitor 100 nF

As shown in Fig. 9, the NT one-shot multivibrator circuit 76 translates the positive pulse of the OSC A-out 86 into a 7 millisecond square wave pulse at A-out 90.
The NT
one-shot multivibrator circuit 76 utilizes a 1.0 nanoFarad capacitor C4 and a one megaOhm resistor R20 to differentiate the OSC A-out signal 86 to sense the negative edge. When the negative transition occurs, the 68 nanoFarad capacitor C5 is discharged, and the output A-out 90 goes high. The output A-out 90 remains high while the current source, realized by transistors T21, T22 and resistors R20, R22,.
charges capacitor C5. When capacitor C5, becomes charged, the current mirror.transistor T22 turns off, and the output A-out 90 returns low. As shown in Fig. 10, operation of the PT
one-shot multivibrator circuit 78 is identical to the NT one-shot multivibrator circuit 76 except an inverter T26 on the input, OSC B-out 88, makes the circuit 78 sensitive to the positive edge. The individual component values for the NT one-shot multivibrator circuit 76 and the PT one-shot multivibrator circuit 78 are given in the table below:
Ref. Type ValuelType T19 NPN Transistor 2N5089 T20 NPN Transistor 2N5089 T21 PNP Transistor 2N5087 T22 PNP Transistor 2N5087 T23 NPN Transistor 2N5089 T24 NPN Transistor 2N3904 T25 NPN Transistor 2N5089 T26 NPN Transistor 2N5089 R20 Resistor 1 M-Ohm R21 Resistor 200 K-Ohm R22 Resistor 20 K-Ohm R23 Resistor 3.9 K-Ohm R24 Resistor 100 Ohm R25 Resistor 5.1 K-Ohm R26 Resistor 100 K-Ohm R27 Resistor 10 Ohm R28 Resistor 1 K-Ohm R29 Resistor 2 M-Ohm R30 Resistor 200 K-Ohm C4 Capacitor 1 nF

C5 Capacitor 68 nF

Figs. 11 and 12, respectively show the oscillator charge control and discharge control circuits 80, 82. The oscillator control circuits respectively charge or discharge the 100 nF oscillator capacitor C2 when the comparator circuit 36' senses the direction change in back-EMF of the motor. Since back-EMF is sensed only when the H-bridge circuit outputs are off, response is inhibited during drive pulses by INH A
and INH B (see Figs. 9 and 10). Also the 2.2 nF delay timing capacitors C7, C9 increase inhibit time, to allow the motor winding current to decay to a negligible value.
The individual values of the oscillator charge control circuit 80 are as follows:
Ref. Type VafuelType T27 PNP Transistor 2N5087 T28 PNP Transistor 2N5087 T29 NPN Transistor 2N5089 T31 NPN Transistor 2N5089 T11 (see Fig. PNP Transistor 2N5087 7) R31 Resistor 1 M-Ohm R32 Resistor 100 K-Ohm R33 Resistor 30 K-Ohm R34 Resistor 200 K-Ohm R35 Resistor 5.1 M-Ohm C6 Capacitor 1 nF

C7 Capacitor 2.2 nF

The individual values of the oscillator discharge control circuit 82 are as follows:
Ref. Type VafuelType T33 NPN Transistor 2N5089 T34 NPN Transistor 2N5089 T35 NPN Transistor 2N5089 T36 NPN Transistor 2N5089 T12 (see Fig. NPN Transistor 2N5089 7) T38 NPN Transistor 2N5089 R36 Resistor 100 K-Ohm R37 Resistor 2 M-Ohm R38 Resistor 30 K-Ohm R39 Resistor 1 M-Ohm R40 Resistor 200 K-Ohm C8 Capacitor 1 nF

C9 Capacitor 2.2 nF

Operation of the motor driver circuitry shown in Figs. 7-12 is described in reference to the operational waveforms shown in Fig. 13. When the H-bridge 32' is off, the 1 K, 3.3K input dividers establish the zero-input Voltage to the comparator 36' at the common-mode Voltage VIM. Thus, the back-EMF generated Voltage (at MOTOR+ or MOTOR-) is measured as positive or negative with respect to VIM, which is 1.00 VDC
for a 1.30 VDC supply. The differential-input comparator 36' (by definition) responds to the difference in Voltage between MOTOR+ and~MOTOR-.
Referring to the MOTOR+ waveform and progressing left to right, a negative-going lobe 94 of motor back-EMF is observed. This is the small, nearly sinusoidal waveform with a peak-to-peak magnitude of approximately 600 mV, and appears when the forward (A-Out) and reverse (B-Outs pulses are off. At this time, T0, the OSC CONTROL CHARGE waveform shows the oscillator timing capacitor C2 Voltage vamping as it is charging from the constant-current source. At time T1 (7 msec) the back-EMF becomes 0, the COMP OUT waveform switches high and the oscillator capacitor C2 charges rapidly turning on the forward H-bridge legs, as evidenced by the peak 96 on the MOTOR+ waveform. The forward pulse lasts for the NT one-shot time of about 7 msec, and turns of at time T2. The back-EMF pulse may again be observed on the MOTOR+ waveform as lobe 98. At time T3, the back-EMF goes through zero, causing the COMP OUT waveform to switch back to zero, which causes the oscillator control circuits to discharge the oscillator timing capacitor, and to turn the reverse pulse, B-Out, on. The reverse pulse lasts until time T4, where the back~EMF 100 is again apparent on the MOTOR+ waveform, first positive going, and then passing through 0 at time T5. Therefore, at time T5, the oscillator timing capacitor discharges rapidly.
However, since the output (of the oscillator) is already in the negative state, a second reverse pulse is not generated (no positive transition is generated and the PT
one-shot circuit does not put out a pulse). The actual motor speed is, however, detem~ined by pulse. For the purposes of this disclosure, the wave-forms of Fig. 13 are shown in the proper time sequence for only the first cycle.
As shown in Fig. 14, another alternate embodiment of the present invention 102 uses a swept-frequency motor driver circuit. The circuit utilizes a oscillator controller 104 to provide a switched input to the H-bridge circuit 32" at a frequency which is continuously swept from low to high. The low end of the frequency is low enough to start the motor when it is at rest. The frequency is thereafter swept up to increase the velocity of the motor. The unit is then turned off, allowing the rotor to coast. Then, the frequency is swept upward again, and the cycle repeats until power is removed.
The use of this type of circuit eliminates the need for sensing the motor velocity (i.e., by using a comparator circuit or Hall Effect sensors}. Turning off the unit between sweeps conserves energy and lowers battery drain.
As shown in Fig. 15, another alternate embodiment of the present invention 106 utilizes Hall Effect switches 108 to sense the position of the rotor assembly 34, and a motor controller 110 to generate inputs to the H-bridge circuit 32" according, in part, to signals received back from the Hall Effect switches 108. A control algorithm is implemented by the controller that first starts rotation of the rotor assembly and then switches pulses to the drive coil 33 (commutates) in the proper sequence. The location of the Hall Effect switches 108 can be determined theoretically andlor by measurement.
At a proper radius, axial flux of magnet 52 can produce a distinct positive peak in flux to activate the Hall-Effect switch 108. In practice, the best location was determined by moving a functioning Hall switch until proper operation was obtained.
An example Hall Effect switch is an HAL 506UA, commercially available from ITT
Semiconductors. The controller 110 preferably implements the following algorithm:

1. Apply forward Voltage to the coil 33.
2. Poll the Hall inputs for switch closure.
3. If no switch closure in 35 msec, turn off for a short time to eliminate crossover currents, and then apply a pulse in an opposite direction. Go to step 2, above.
4. ff a Half switch closes, turn off the pulse and wait for the switch to open.
Then apply a pulse of proper polarity (determined by which switch was activated). Then go to step 2, above.
As shown in Fig. 16, in another embodiment of the present invention 112, a center-tapped coil 114 can be utilized instead of the single coil of the prior embodiments. One side 114a of the coil will be coupled to a first switch 116a, while the other side 114b of the coil will be coupled to a second switch 116b. The center point of the coif 114 will be coupled to ground 120. When the switch 116a is activated by a controller 118, the first side 114a of the coil will be energized at a first polarity, and when the switch 116b is activated by the controller 118, the other side 114b of the coil will be energized at an opposite polarity. A control algorithm, such as a swept frequency algorithm, may be utilized to control the activation of the switches 116a, 116b.
Referring to Fig. 18, the controller 104 of the circuit shown in Fig. 14 or the controller 118 of the circuit shown in Fig. 16 is programmed to switch outputs Drive A
and Drive B on and off (active low) in a swept frequency. The outputs sweep from a half-period of 50 msec (10 Hz) to half-period of 6.8 msec (74 Hz). Motor pulsing time is 412 msec .and off time is 308msec, totaling 720 msec for a sweep repetition rate of 1.4 times per second.
The controllers 104, 118 are preferably a Microchip PIC12C508 microcontrofler, with a circuit diagram as shown in Fig. 19. Source code for operating the controllers to provide the swept frequency output is appended hereto. The source code has a jump table which determines half period times, approximately 200 usec per count (counts go from 1 to 256, 256 being indicated as 0). Thus, OFAH (the first value) is 250 * 0.2, or 50 msec and 22H (the last value) is 34 * 0.2, or 6.8 msec. The values between these two limits are chosen to give an exponential sweep envelope. The jump table has a total number of entries (40) defined by NUM PULSES, and the number of half pulses (34) is defined as ON PULSES. A fixed off time between pulses of approximately 37usec is implemented in the software code to eliminate transition/shoot-through currents.
As shown in Fig. 17, the functionality of the center-tapped coil 114 of Fig.
16 can be met utilizing a single bifilar wound coil '! 14', which is two insulated wires 114a', 114b' bonded together in parallel to form a discrete bifilar wire, which is then layer-wound in a longitudinal direction to enclose a chamber 38'. Within the chamber 38', the rotor assembly 34 is mounted for rotation. At one end of the bifilar coil 114', a first wire 114a' is operatively coupled to the first switch 116a and the second wire 114b' is operatively coupled to ground 120. At the other end of the bifilar coil 114', the other end of wire 114a' is coupled to ground 120 while the other end of wire 114b' is coupled to the second switch 116b. A suitable bifilar wire for use with the present invention is commercially available from MWS Wire Industries.
As discussed above, the embodiments of Figs. 14 and 16 utilize dual-input swept frequency driver circuits. It is also within the scope of the invention to utilize a single-input swept frequency driver circuit as shown in Figs 20 and 21. Fig. 20 represents an H-bridge, single-input swept frequency driver circuit. The magnet preferably has a 5mm radius and the coif is preferably 3 layers of #33 AWG wire, having a resistance of 4.3 Ohms. The individual values of the H-bridge, single-input swept frequency driver circuit are as follows:
Ref. Type ValueIType T39 NPN Transistor BCX70 T40 PNP Transistor BCX17 T41 NPN Transistor BCX19 R41 Resistor 10 K-Ohms R42 Resistor 22 K-Ohms R43 Resistor 100 Ohms Fig. 21 represents a dual-switch, single-input swept frequency driver circuit.
The magnet preferably has a 5mm radius and the coil is preferably 4 layers of #35 AWG
bifilar wire and having a resistance of 5.8 Ohms per coil. The individual values of the dual-switch, single-input swept frequency driver circuit are as follows:
Ref. Type ValuelType T42 NPN Transistor BCX70 T43 PNP Transistor BCX17 R44 Resistor 10 K-Ohms R45 Resistor 22 K-Ohms R46 Resistor 100 Ohms Referring to Fig. 22, the controller of the circuits shown in Figs. 20 and 21 is programmed to switch output Drive A (active low) in a swept frequency. The output starts with 10 half-cycles at 16.6 msec (30Hz), then sweeps to a half-period of 6.8 msec (74 Hz). Motor pulsing time is 418 msec and off time is 310msec, totaling 728 msec for a sweep repetition rate of 1.4 times per second. As shown in Fig. 23, the controller is virtually identical to that of Fig. 19, except that the GP1 output line is not used. The design of software for producing the swept frequency signal shown in Fig. 22 will be apparent to one of ordinary skill in the art.
Figs 24A, 24B and 25A, 25B illustrate that there are many ways to fashion a rotor assembly of the present invention that includes a permanent magnet and a center of mass positioned distal from the rotational axis. As shown in Figs. 24A and 24B, in another alternate embodiment of the present invention 122, the alternate rotor assembly 124 utilizes a rectangular magnet 126 mounted with epoxy to a shaft 128.
The coil 33 is mounted to a substrate 40 of glass-epoxy printed-circuit-board material.
The magnet 126 provides the eccentricity of the motor by having its center of mass positioned radially distal from the shaft 128.

As shown in Figs. 25A and 25B, in yet another alternate embodiment of the present invention 130, a substantially cylindrical magnet 132 is mounted for rotation within a coil 134 wound to form a cavity 136 therein. The rotor bearings 138 are mounted to the magnet on a rotational axis 140 which is off-center with respect to the magnet 132, and therefore, the magnet's center of mass will be positioned radially distal from the rotational axis 140 provided by the rotor bearings 138.
Source code for operating the controNer of Fig. 19, discussed above is as follows:

c:\mpiab\up12c508.inc Copyright 1998 John L. Myers Printed 20:41 24 Mar 98 .******x*************************
;* filename up12c508.inc ;* header file for PIC 12C508 ;* by John L. Myers 9706281148 .******************************x*
register definitions .***x***********x****************
W EQU H'0000' ; working register F EQU H'0001' ; file register .********************************
;* special registers *
.*********************
I~F EQU H'0000' , indirect file register SRO EQU H'0001' ; timer 0 PCL EQU H'0002' , program counter low byte STATUS EQU H'0003' , status register STATUS bits .x*******************************
; RW-0 RW-0 RW-0 R-1 R-1 RW-x RW-x RW-x IGPWUFI ___ I-PAO I-TO_- II~PD=_I__Z__I_DC__'__C__II
. I_________________ -II-GPWUF EQU H'0007' , GPIO reset bit (1 = wake up from sleep) pp,0 EQU H'0005' ; page select (0 for 12C508) TO_ EQU H'0009' ; WDT time-out pD EQU H'0003' ; power-down EQU H'0002' , zero DC EQU H'0001' , digit carry C EQU H'0000' carry .*t****************x*************
FSR EQU H'0004' , file-select register/indirect mem pointer FSR bits .********************************
1 1 1 RW-x RW-x RW-x RW-x RW-x ___ I __--I_----IFSR4 I FSR3_IFSR2_IFSR1_IFSRO_~
I_____ ___ ___ ____ - _ .********************************

WO 99!01849 PCT/US98/13815 c:\mplab\up12c508.inc Copyright 1998 John L. Myers Printed 20:41 24 Mar 98 OSCCAL EQU H'0005' ; oscillator calibration register OSCCAL bits .x*x*****************************
RW-x RW-x RW-x RW-x 'CAL7 ~CAL6 ~CALS ~CAL4 _______________________II____________________ CAL7 EQU H'0007' , CAL6 EQU H'0006' , CAL5 EQU H'0005' ;
CAL4 EQU H'0004' ;
.********************************
GPIO EQU H'0006' , general purpose I/O register GPIO
bits .************ ********************

RW-x RW-x RW-x RW-x RW-x RW-x _____ ___ _______________________II____ I ___' ___ ~ GP5 ~ _______ ___________GP4 ~ ~ GP3 ~ GP2 ~ GP1 ____________I~ GPO
I___________________ GP5 EQU H'0005' , GP4 EQU H'0004' ;

GP3 EQU H'0003' , GP2 EQU H'0002' , GP1 EQU H'0001' , GPO EQU H'0000' , TRIS
bits .**********

w-1 w-1 w-1 w-1 w-1 w-1 ~_______________________~~___________________ -- - ~ ~TRIS5~TRIS4~~TRIS3~TRIS2~TRIS1~TRISO~
___--- _____________II___________________ _______ control 1 = input, for 0 = output, GPIO, write with TRIS
f .*********** *********************

;* end special registers .**************************

c: \mplab\up12c508. inc Copyright 1998 John L. Myers Printed 20:41 24 Mar 98 OPTION bits .x*******************************

~GpWU_~GPPU_~TOCS NOSE I~ PSA , PS2 ~ PSl ~ PSO
I_______________________I,_______________________ Gp~ EQU H'0007' ; wake up on pin (GPO, GP3) change GP1, - EQU H'0006' ; enable weak pull-ups(GPO. GP3) 'GPPU GP1, _ EQU H'0005' ; TO clock source (0 for clock) TOCS int TOSS EQU H'0004' ; TO source edge (0 for on L>H) inc EQU H'0003' ; prescaler assignment(0 assignsto TO) PSA EQU H'0002' ; prescaler setting(011 for iv by d 16) PS2 EQU H'0001' ; current design MHz INTRC
uses 4 PS1 U H'0000' divide by 2~(n+1)TMRO, for for 2~n WDT

PSO EQ

.****************************x***

RAM definition .*******************x************
_MAXRAM H'OO1F' ;
.********************************
r Configuration Bits .******************************x*
_,MCLRE_ON EQU H'OFFF' , _MCLRE_OFF EQU H'OFEF' ;
_CP_ON EQU H'OFF?' ;
_CP_OFF EQU H'OFFF' 7 ON EQU H'OFFF' t WDT_OFF EQU H'OFFB' ;
_LP_OSC EQU H'OFFC' XT OSC EQU H'OFFD' , _IntRC OSC EQU H'OFFE' , _ExtRC OSC EQU H'OFFF' ;
********x******************x****
define reset vector .********************************
RESET EQU H'01FF' ; roll over to H'0000' with OSCCAL
.********************************
.***********x*********x***
;* end PIC 12C508 header .************x************

WO 99/01849 PCTlUS98/13815 c:\mplab\ddzvh0yy.asm Copyright 1998 John L. Myers Printed 20:42 24 Mar 98 .***************w************t***
;* filename ddrvhOyy.asm ;* header file for ddrivexx.asm ;* by John L. Myers 9803172240 *
.***************r****************
option register initialization .*******************************
OPTION bits .**rr**********w******************
w-1 w-1 w-1 w-1 w-1 w-1 W-1 w-1 ~_______________________~~_______________________ iGPWU=~GPPU=jTOCS_ NOSE-li-PSA_~_PS2-~-PSl-~-PSO-I

GPWU_ EQU H'0007' , wake up on pin change (GPO, GP1, GP3) GPPU_ EQU H'0006' , enable weak pull-ups (GPO, GP1, GP3) TOCS EQU H'0005' , TO clock source (0 for int clock) TOSE EQU H'0004' , TO source edge (0 for inc on L>H) PSA EQU H'0003' , prescaler assignment (0 assigns to TO) PS2 EQU H'0002' , prescaier setting (011 for div by 16) PS1 EQU H'0001' , current design uses 4 MHz INTRO
PSO EQU H'0000' , divide by 2~(n+1) for TMRO, 2~n for WDT
OPT_INI EQU H'0083' .r**wr****r***r*w*******rr*******
GPIO configuration .**rr*********r*****************r RW-x RW-x RW-x RW-x RW-x RW-x ___ ~ ___ ~ GP5 ~ GP4 ~~ GP3 ! GP2 ~ GP1 ~ GPO
I_______________________~I_______________________ , DRVR_ DRVF_ > > < > > >
DRVR_ EQU H'0001' , driver output reverse, active low DRVF_ EQU H'0000' ; driver output forward, active low GPIO_CFG EQU H'0008' ; general purpose port I/0 configuration .**r******x**********************

c:\mplab\ ddrvh0yy.asm Copyright 1998 John L. Myers Printed 20:42 24 Mar 98 '* user registers .*********x********
CTRO EQU H'0007' ; program counter 0 CTR1 EQU H'0008' ; program counter 1 T_OFFSET EQU H'0009' ; look-up table offset ON_COUNT EQU H'OOOA' ; counter for on pulses *x******************x***********
configuration register initialization .**************************************
CONFIGURATION bits {12) .************************x*******
"- I "' I "' II "' I -'- I "' IMCLRE'I CP_ IWDTE IFOSC1IFOSCO~
____________________II_______________________1I_______________________I
MCLRE EQU H'0004' ; MCLR_ pin enable CP_ EQU H'0003' , code protect negative enable WDTE EQU H'0002' watch dog timer enable FOSC1 EQU H'0001' ,' 00 = LP oscillator O1 = XT oscillator FOSCO EQU H'0000' 10 = int RC osc 11 = ext RC osc .*******************************.
miscellaneous .******************************** ' NUM_PULSES EQU H'0028' ; number of look-up table entries, even ON_PULSES EQU H'0022' number of on pulses < above .*x*x*****************x**********
.*********.***************
;* end of hdrive header .************************
_27_ c: \mplab\ddrvs0yy.asm - Copyright 1998 John L. N(yers Printed 21:09 24 Mar 98 .***********************************
;* ddrivexx.asm page 0 subroutines .***********************************
ORG H'0000' rollover from 12C508 reset vector .*********************x************
MOVWF OSCCAL ; use oscillator trim GOTO MAIN begin program .******************************** ' sweep half-period delay time .********************************
DELAY
get delay value from table .************************
MOVF T_OFFSET, W , CALL DELAY TABLE ;
implement the delay .************************.
load counter MOVWF CTR1 , load counter high byte LOAD_CTR1 MOVLW 41H ; load counter low byte MOVWF CTRO , cycles = THIGH * (T_LOW * 3 + 5), use T_LOW = 41H for 200 usec COUNT
DECFSZ CTRO, F , GOTO COUNT , NOP , to make last cycles = 3 also DECFSZ CTR1, F
GOTO LOAD_CTR1 ;
DECF T_OFFSET, F ; point to nert table value DECF ON_COUNT, F ; count on pulses return to main program RETLW OOH t .********************************
-zs-c: \mplab\ddrvs0yy.asm Copyright 1998 John L. Myers Printed 21:'09 24 Mar 98 table of half-period delays .************************
DELAY_TABLE ; number of entries must be even ADDWF PCL, F ; jump to table entry NOP ; add NOP for automatic increment by 1 RETLW OOH ; 40, off times, OOH = 256 RETLW OOH ; 39 RETLW OOH ; 38 RETLW OOH ; 37 RETLW OOH ; 36 RETLW OOH ; 35 RETLW 22H ; 34, forward and reverse on times RETLW 22H , 33 RETLW 22H , 32 RETLW 23H , 31 RETLW 23H ; 30 RETLW 23H :'29 RETLW 24H : 28 RETLW 24H ; 27 RETLW 25H , 26 RETLW 25H ; 25 RETLW 26H : 24 RETLW 27H ; 23 RETLW 27H ; 22 RETLW 28H ;~21 RETLW 29H , 20 RETLW 2AH . 19 RETLV1 2BH 7 1 g RETLW 2CH , 17 RETLW 2FH ; 15 RETLW 31H ; 14 RETLtn1 3 3 H ; 13 RETLW 35H ; 12 RETLW 38H ; 11 RETLW 3BH ; 10 RETLW 3FH ; 9 RETLW SBH ; 5 RETLW 69H : 4 RETLW 7EH : 3 RETLW OA3H ; 2 RETLW OFAH : 1 .************************
fill remaining space with NOP'S
.*********************x**********
FILL (NOP), (OFF-$) ;
GOTO MAIN
.~********************************
end of subroutine page 0 ~;~mplab\ddrvp0yy.asm Copyright 1998 John L. Myers Printed 20:53 24 Mar 98 .'*******************************
;* filename ddrvpOxx.asm ;* hdrivexx.asm program page 0 ;* by John L. Myers 9803032225 .*******************************
start program page 0 ORG H'0100' MAIN

.********************************

initialize .*************************
s -> option register ttin MOVLW OPT_INI ; g option se OPTION %
'00000011' initialize GPIO

, MOVLW B

MOVWF GPIO
configure GPIO

MOVLW GPIO CFG , TRIS GPIO %

.*************************

drive vibrator, sweep the frequency .*************************

; start a sweep LOAD CTRS load table pointer MOVLW NLJM_PULSES

MOVWF T_OFFSET
load on-pulse counter MOVLW ON_PULSES-1 , MOVWF ON COUNT

DRIVE , start a cycle OUTPUT

_ turn forward pulse on MOVLW B'00000010' , '7 turn off if > number of pulses BTFSC ON COUNT, ;

MOVLW B'00000011' MOVWF GPIO
delay for forward pulse CALL DELAY , ' output driver off-time MOVLW B'00000011 , MOVWF GPIO

MOVLW 0AH , load CTRO

MOVWF CTRO

DECFSZ CTRO, F

GOTO COUNT_OFF1 add 4 NOP's for = off times NOP , NOP

NOP

NOP
MOVLW B'00000001' , turn reverse pulse on 7 turn off if > number of pulses BTFSC ON_COUNT, , MOVLW B'00000011' c:\mplab\ddrvp0yy.asm Printed 20:53 24 Mar 98 Copyright 1998 John L. Myers MOVWF GPIO ;
CALL DELAY ; delay for reverse pulse MOVLW 8'00000011' ; output driver off-time MOVWF GPIO ;
MOVLW OAH , load CTRO
MOVWF CTRO

DECFSZ CTRO, F ;
GOTO COUNT_OFF2 ;
MOVE T_OFFSET, F , test for end of sweep BTFSS STATUS, Z ;
GOTO OUTPUT_DRIVE ; repeat the cycle GOTO LOAD_CTRS repeat the sweep .*************************
.********************************
end MAIN
fill remaining space with NOP'S
.*********************************
FILL (NOP), (H'O1FF'-$);
.x********************************
PIC12C508 reset vector .********************************
MOVLW H'OCDO' , unit #1 OSCAL trim value MOVLW H'OCCO' , unit #2 OSCAL trim value MOVLW H'OCAO' , unit #3 OSCAL trim value MOVLW H'OCCO' ; unit #4 OSCAL trim value .********************************
end program page 0 -3i-Following from the above description, it should be apparent to those of ordinary skill in the art that, while the designs and operations herein described constitute several embodiments of the present invention, it is to be understood that the invention is not limited to these precise designs and operations, and that changes may be made therein without departing from the scope of the invention as recited in the following claims.
What is claimed is:

Claims (22)

1. A vibrational transducer comprising:
a coil wound in a longitudinal direction to enclose a chamber extending in the longitudinal direction;
a switching power source, operatively coupled to the coil, for producing an oscillating magnetic field within the chamber; and a rotor assembly extending within the chamber, the rotor assembly including a permanent magnet, the rotor assembly having a rotational axis and a center of mass, the center of mass being located radially distal from the rotational axis.
2. The vibrational transducer of claim 1, wherein:
the rotor assembly includes a rotor;
the magnet is mounted to the rotor; and the magnet has a center of mass located radially distal from the rotational axis.
3. The vibrational transducer of claim 2, wherein the magnet is substantially semi-cylindrical, the magnet having a hub, and the magnet is mounted to the rotor substantially along its hub.
4. The vibrational transducer of claim 3, wherein the magnet has an axis of symmetry and is magnetized in a direction parallel to the axis of symmetry.
5. The vibrational transducer of claim 4, wherein the rotor assembly is mounted to the coil within the chamber and the rotational axis is substantially perpendicular to the longitudinal direction.
6. The vibrational transducer of claim 5, further comprising:
a magnetically susceptible object positioned in close proximity to the coil, so as to mis-align the magnet's axis of symmetry with a longitudinal axis of the coil when the switching power source is not active.
7. The vibrational transducer of claim 1, wherein the switching power source includes:
a controller for controlling production of switching power; and a comparator operatively coupled to the coil for detecting a longitudinal component of the magnet's travel, and for generating a directional signal indicative of the longitudinal component detected, the directional signal being sent to the controller;
wherein the controller controls the production of switching power responsive to the directional signal.
8. The vibrational transducer of claim 7, wherein the controller is a microprocessor.
9. The vibrational transducer of claim 1, wherein the rotor is journaled on a pair of sleeve bearings mounted within the chamber to opposing walls formed by the coil.
10. The vibrational transducer of claim 1, further comprising a planar substrate material bonded to an outer wall formed by the coil.
11. The vibrational transducer of claim 10, wherein the substrate is an epoxy-glass substrate.
12. The vibrational transducer of claim 10, wherein the substrate is adapted to be surface mounted to a printed circuit board.
13. The vibrational transducer of claim 12, wherein the switching power source includes:
a controller for controlling production of switching power; and a comparator operatively coupled to the coil for detecting a longitudinal component of the magnet's travel, and for generating a directional signal indicative of the longitudinal component detected, the directional signal being sent to the controller;
wherein the controller controls the production of switching power responsive to the directional signal;
wherein the controller and the comparator are mounted to the printed circuit board.
14. The vibrational transducer of claim 1, wherein the switching power source includes:
a controller for controlling the production of switching power; and a Hall Effect switch positioned near the magnet for detecting a position of the magnet within the coil and for generating a positional signal indicative of the magnet's position within the coil, the positional signal being sent to the controller;
wherein the controller controls the production of switching power responsive to the positional signal.
15. The vibrational transducer of claim 1, wherein the coil is a bifilar wound coil.
16. The vibrational transducer of claim 1, wherein the switching power source includes a swept frequency driver circuit operatively coupled to the coil.
17. The vibrational transducer of claim 16, wherein the swept frequency driver circuit is a dual-input swept frequency driver circuit.
18. The vibrational transducer of claim 16, wherein the swept frequency driver circuit is a single-input swept frequency driver circuit.
19. The vibrational transducer of claim 1, wherein the switching power source includes an H-bridge circuit operatively coupled to the coil and a controller operatively coupled to the H-bridge circuit.
20. A vibrating transducer for a pager, cellular telephone and the like, comprising:
a single coil layer-wound in a longitudinal direction to enclose a chamber extending in the longitudinal direction;
a planar substrate, bonded to an outer wall formed by the coil;
a switching power source, operatively coupled to the coil, for producing an oscillating magnetic field within the chamber; and an eccentric weight rotor assembly extending within the chamber, the rotor assembly including a permanent magnet that provides a rotational force to the rotor assembly when acted upon by the oscillating magnetic field.
21. A communications device comprising:
a receiver component for receiving messages transmitted to the communications device;
a processor operatively coupled to the receiver component for processing messages received by the receiver component; and a vibrating alarm operatively coupled to the processor, the vibrating alarm including:

a coil wound in a longitudinal direction to enclose a chamber extending in the longitudinal direction;
a switching power source, operatively coupled to the processor and to the coil, for producing an oscillating magnetic field within the chamber responsive to a signal from the processor; and a rotor assembly extending within the chamber, the rotor assembly including a permanent magnet, the rotor assembly having a rotational axis and a center of mass, the center of mass being located radially distal from the rotational axis.
22. The communications device of claim 27 , further comprising a printed circuit board, wherein the processor and vibrating alarm are mounted to the printed circuit board.
CA 2294587 1997-07-03 1998-07-02 Vibrational transducer Abandoned CA2294587A1 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
US5173797P 1997-07-03 1997-07-03
US60/051,737 1997-07-03
PCT/US1998/013815 WO1999001849A1 (en) 1997-07-03 1998-07-02 Vibrational transducer

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CA2294587A1 true CA2294587A1 (en) 1999-01-14

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ID=21973088

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CA 2294587 Abandoned CA2294587A1 (en) 1997-07-03 1998-07-02 Vibrational transducer

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JP (1) JP2002509485A (en)
KR (1) KR20010021492A (en)
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CA (1) CA2294587A1 (en)
TW (1) TW411658B (en)
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Families Citing this family (40)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH11165128A (en) * 1997-12-04 1999-06-22 Namiki Precision Jewel Co Ltd Driving device of vibration actuator
DE69839114T2 (en) 1998-02-20 2009-02-05 Asulab S.A. Inaudible alarm device
EP0938034B1 (en) * 1998-02-20 2008-02-13 Asulab S.A. Non-sonic alarm device
US6697043B1 (en) * 1999-12-21 2004-02-24 Immersion Corporation Haptic interface device and actuator assembly providing linear haptic sensations
US6996228B1 (en) * 1999-03-10 2006-02-07 Nokia Mobile Phones, Ltd. Motor for generating vibrational signal
US6570994B1 (en) * 1999-03-25 2003-05-27 Agere Systems Inc. Field layer speaker for consumer products
DE20022244U1 (en) * 1999-07-01 2001-11-08 Immersion Corp Control of vibrotactile sensations for haptic feedback devices
US8169402B2 (en) * 1999-07-01 2012-05-01 Immersion Corporation Vibrotactile haptic feedback devices
US7561142B2 (en) * 1999-07-01 2009-07-14 Immersion Corporation Vibrotactile haptic feedback devices
JP3416584B2 (en) * 1999-08-27 2003-06-16 三洋電機株式会社 Electronic equipment with built-in vibration generator
DE20080209U1 (en) 1999-09-28 2001-08-09 Immersion Corp Control of haptic sensations for interface devices with vibrotactile feedback
KR100360126B1 (en) * 2000-01-04 2002-11-08 주식회사 삼부커뮤닉스 Vibrator
US6384498B1 (en) * 2000-05-22 2002-05-07 Tokyo Parts Industrial Co., Ltd. Compact vibration motor
US7182691B1 (en) * 2000-09-28 2007-02-27 Immersion Corporation Directional inertial tactile feedback using rotating masses
US7084854B1 (en) 2000-09-28 2006-08-01 Immersion Corporation Actuator for providing tactile sensations and device for directional tactile sensations
US6789347B1 (en) 2000-12-19 2004-09-14 Daron K. West Vibrating fishing lure with frictionally fixed conductor pins
US6581319B2 (en) * 2000-12-19 2003-06-24 Daron K. West Battery powered vibrating fishing lure
US6665976B2 (en) 2000-12-19 2003-12-23 Daron K. West Method and fishing lure for producing oscillatory movement
EP1220177B1 (en) * 2000-12-27 2005-11-09 SANYO ELECTRIC Co., Ltd. Vibrator controlling circuit
US6636007B2 (en) * 2001-03-12 2003-10-21 Sunonwealth Electric Machine Industry Co., Ltd. DC brushless vibration motor
JP2003061387A (en) * 2001-08-14 2003-02-28 Sony Corp Brushless motor drive circuit and portable terminal mounting it
CN1168192C (en) * 2001-09-10 2004-09-22 阿尔卑斯电气株式会社 Variable vibration generator and electronic machine equiped with the same vibration generating device
US7623114B2 (en) 2001-10-09 2009-11-24 Immersion Corporation Haptic feedback sensations based on audio output from computer devices
US7161580B2 (en) * 2002-04-25 2007-01-09 Immersion Corporation Haptic feedback using rotary harmonic moving mass
US7369115B2 (en) * 2002-04-25 2008-05-06 Immersion Corporation Haptic devices having multiple operational modes including at least one resonant mode
US20040104631A1 (en) * 2002-12-03 2004-06-03 Tokyo Parts Industrial Co., Ltd. Brushless vibration motor
US20040200125A1 (en) * 2003-03-31 2004-10-14 Albanito Thomas K. Vibrating fishing lure
US8232969B2 (en) * 2004-10-08 2012-07-31 Immersion Corporation Haptic feedback for button and scrolling action simulation in touch input devices
WO2006070369A2 (en) * 2004-12-30 2006-07-06 Given Imaging Ltd. Device, system and method for orienting a sensor in-vivo
JP2006222826A (en) * 2005-02-14 2006-08-24 Fujitsu Ltd Personal digital assistant with speech function
US7825903B2 (en) * 2005-05-12 2010-11-02 Immersion Corporation Method and apparatus for providing haptic effects to a touch panel
CN101662531A (en) * 2008-08-26 2010-03-03 深圳富泰宏精密工业有限公司 Vibration device
US9489046B2 (en) 2009-05-04 2016-11-08 Immersion Corporation Method and apparatus for providing haptic feedback to non-input locations
CN101621570A (en) * 2009-08-10 2010-01-06 上海闻泰电子科技有限公司 Mobile terminal with vibration sense regulating function
US8542105B2 (en) * 2009-11-24 2013-09-24 Immersion Corporation Handheld computer interface with haptic feedback
US9032660B2 (en) 2011-06-16 2015-05-19 William George Vanacore, JR. Fishing system to attract fish
JP6125852B2 (en) * 2012-02-01 2017-05-10 イマージョン コーポレーションImmersion Corporation Optimization of eccentric rotating mass actuators for haptic effects
US10837844B2 (en) * 2017-09-18 2020-11-17 Apple Inc. Haptic engine having a single sensing magnet and multiple hall-effect sensors
US11150731B2 (en) * 2018-09-28 2021-10-19 Apple Inc. Multi-modal haptic feedback for an electronic device using a single haptic actuator
CN116233667B (en) * 2023-05-10 2023-07-18 东莞市金文华数码科技有限公司 High-performance sound box module and electronic equipment

Family Cites Families (33)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3538756A (en) * 1968-10-07 1970-11-10 Verner D Coombs Eccentric mass-rotor-motor mechanical testing device
US3623064A (en) * 1968-10-11 1971-11-23 Bell & Howell Co Paging receiver having cycling eccentric mass
US3911416A (en) * 1974-08-05 1975-10-07 Motorola Inc Silent call pager
US4093944A (en) * 1977-02-16 1978-06-06 Muncheryan Hrand M Silent awakening system with means adapted to induce sleep
US4403176A (en) * 1978-05-08 1983-09-06 California Technics, Ltd. Circuit for driving an ultrasonic dental tool at its resonant frequency
JPS5853782Y2 (en) * 1979-01-08 1983-12-07 日本電気株式会社 Personal selection call receiver
JPS57158141A (en) * 1981-03-25 1982-09-29 Aisin Seiki Co Ltd Safety device for vibrator attached to car seat
US4446741A (en) * 1981-06-01 1984-05-08 Prvni Brnenska Strojirna, Narodni Podnik Vibration transducer
FR2531363A1 (en) * 1982-08-03 1984-02-10 Martelec METHOD AND DEVICE FOR SELF-SYNCHRONIZED CONTROL OF AN ELECTRO-MAGNETIC HAMMER
GB2183371B (en) * 1985-10-09 1989-09-27 Canon Kk Vibration wave motor and drive circuit therefor
JPH0763193B2 (en) * 1986-05-30 1995-07-05 日本電気株式会社 Individual selective call receiver
US5287099A (en) * 1986-09-16 1994-02-15 Nec Corporation Multi-alert radio paging system
US4811835A (en) * 1986-10-07 1989-03-14 K-Tron International, Inc. Vibratory material feeder
US4794392A (en) * 1987-02-20 1988-12-27 Motorola, Inc. Vibrator alert device for a communication receiver
US5007105A (en) * 1987-08-14 1991-04-09 Nec Corporation Watch type paging receiver
US4864276C1 (en) * 1988-06-03 2001-01-09 Motorola Inc Very low-profile motor arrangement for radio pager silent alerting
JP2530518B2 (en) * 1990-11-16 1996-09-04 東京パーツ工業株式会社 Cylindrical coreless vibration motor
US5229744A (en) * 1990-11-27 1993-07-20 Ngk Spark Plug Co., Ltd. Piezoelectric type pager
US5153473A (en) * 1991-06-07 1992-10-06 Russell Camille C Eccentric-rotor electromagnetic energy converter
US5175459A (en) * 1991-08-19 1992-12-29 Motorola, Inc. Low profile vibratory alerting device
US5440185A (en) * 1991-10-28 1995-08-08 Allwine, Jr.; Elmer C. Composite magnet brushless DC motor
JP2818508B2 (en) * 1991-10-29 1998-10-30 日本電気株式会社 Small portable electronic devices
US5164668A (en) * 1991-12-06 1992-11-17 Honeywell, Inc. Angular position sensor with decreased sensitivity to shaft position variability
JPH05168196A (en) * 1991-12-17 1993-07-02 Nec Corp Motor for generation of oscillation
US5379032A (en) * 1992-11-02 1995-01-03 Motorola, Inc. Impulse transducer enunciator
US5397949A (en) * 1993-06-10 1995-03-14 Westinghouse Electric Corporation Vibration cancellation apparatus with line frequency components
CN1046613C (en) * 1993-06-21 1999-11-17 日本电气株式会社 Selective calling receiver capable of stopping a notifying operation by touching a chain clip
US5436622A (en) * 1993-07-06 1995-07-25 Motorola, Inc. Variable frequency vibratory alert method and structure
US5469133A (en) * 1993-11-29 1995-11-21 Hensler; Scott E. Telephone pager alarm enhancement and method therefor
US5646589A (en) * 1994-12-19 1997-07-08 Lucent Technologies Inc. Electronic device having selectable alert modes
US5708726A (en) * 1995-08-16 1998-01-13 Motorola, Inc. Taut armature resonant impulse transducer
US5798623A (en) * 1996-02-12 1998-08-25 Quantum Corporation Switch mode sine wave driver for polyphase brushless permanent magnet motor
US5668423A (en) * 1996-03-21 1997-09-16 You; Dong-Ok Exciter for generating vibration in a pager

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JP2002509485A (en) 2002-03-26
WO1999001849A1 (en) 1999-01-14

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