Classifications

• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
  • H02M3/00—Conversion of dc power input into dc power output
  • H02M3/22—Conversion of dc power input into dc power output with intermediate conversion into ac
  • H02M3/24—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters
  • H02M3/28—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac
  • H02M3/325—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal
  • H02M3/335—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only
  • H02M3/3353—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only having at least two simultaneously operating switches on the input side, e.g. "double forward" or "double (switched) flyback" converter
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
  • H02M3/00—Conversion of dc power input into dc power output
  • H02M3/22—Conversion of dc power input into dc power output with intermediate conversion into ac
  • H02M3/24—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters
  • H02M3/28—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac
  • H02M3/325—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal
  • H02M3/335—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only
  • H02M3/33507—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only with automatic control of the output voltage or current, e.g. flyback converters
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
  • H02M3/00—Conversion of dc power input into dc power output
  • H02M3/22—Conversion of dc power input into dc power output with intermediate conversion into ac
  • H02M3/24—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters
  • H02M3/28—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac
  • H02M3/325—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal
  • H02M3/335—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only
  • H02M3/33569—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only having several active switching elements
  • H02M3/33576—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only having several active switching elements having at least one active switching element at the secondary side of an isolation transformer
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
  • H02M3/00—Conversion of dc power input into dc power output
  • H02M3/22—Conversion of dc power input into dc power output with intermediate conversion into ac
  • H02M3/24—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters
  • H02M3/28—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac
  • H02M3/325—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal
  • H02M3/335—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only
  • H02M3/338—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only in a self-oscillating arrangement
  • H02M3/3385—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only in a self-oscillating arrangement with automatic control of output voltage or current
  • H02M3/3387—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only in a self-oscillating arrangement with automatic control of output voltage or current in a push-pull configuration
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10N30/00—Piezoelectric or electrostrictive devices
  • H10N30/80—Constructional details
  • H10N30/802—Circuitry or processes for operating piezoelectric or electrostrictive devices not otherwise provided for, e.g. drive circuits

Definitions

• the present invention relates to electronic methods and circuits for controlling general-purpose smart material based actuators.
• Actuator technologies are being developed for a wide range of applications.
• One example includes a mechanically leveraged smart material actuator that changes shape in response to electrical stimulus. Since this shape change is generally effectuated predominantly along a single axis, such actuators can be used to perform work on associated mechanical systems including a lever in combination with some main support structure. Changes in axial displacement are magnified by the lever to create an actuator with a useful amount of displacement and force.
• This displacement and force is useful for general-purpose industrial valves, beverage dispensers, compressors or pumps, brakes, door locks, electric relays, circuit breakers, and most applications employing a solenoid type actuator.
• Smart materials, however, piezoelectric specifically can require hundreds of volts to actuate and cause displacement. This type of voltage may not be readily available and may have to be derived from a lower voltage as one would find with a battery.
• piezoelectric materials are capacitive in nature. Moreover, a single actuator is often controlled using two separate signals: a main supply and a ground using watts of energy during the moment of actuation.
• the present invention provides a simple low power, and cost-effective means to drive a mechanically leveraged smart material actuator including a specialized power source operatively connected to switching circuitry.
• the specialized power source of the present invention includes a controllable power source, regulated direct current ⁇ DC ⁇ to ⁇ DC ⁇ converter, to apply a known voltage potential across a smart material and thereby converting a control voltage to a level suitable for the smart material.
• the control and main supply signals are combined into one conductor. This permits the proposed invention to be retrofit into present control systems, directly replacing existing actuators.
• the present invention further includes a smart material actuator coupled to one or both of a controllable power source for charging the smart material actuator and switching circuitry for discharging the smart material actuator.
• the controllable power source is a regulated DC to DC converter that includes a transformer having primary and secondary windings. The primary winding of the transformer, in turn, is coupled to controllable drive circuitry for generating drive signals 180° out of phase with one another.
• the controllable power source operates in a binary manner: either supplying a known stimulating voltage potential across the smart material, or shorting across the smart material.
• the drive circuitry of the controllable power source can further include feedback means such that the circuitry is self-oscillating.
• the feedback means can further include push-pull circuitry as well as an auxiliary winding associated with the transformer.
• the push-pull circuitry can further include a pair of negative positive negative (NPN ⁇ transistors.
• a rectifier may further be associated with the secondary winding of the transformer for generating a DC voltage from an alternating current ⁇ AC ⁇ signal associated with the secondary winding.
• Noise reduction circuitry can also be coupled to the secondary winding of the transformer for filtering noise that may be generated by the controllable drive circuitry.
• An apparatus for driving a smart material actuator according to the present invention thus includes a controllable power source for charging the smart material actuator and switching circuitry coupled between the controllable power source and the smart material actuator such that the switching circuitry discharges the smart material actuator upon removal of a power source.
• the rate of the discharge of the smart material actuator is determined by the impedance of the switching circuitry whereas the rate of charge of the controllable power source is determined by the impedance of the controllable power source.
• Fig. 1 is an electronic schematic of a controllable power source according to the present invention
• FIG. 2 is an electronic schematic of a first embodiment of switching circuitry according to the present invention.
• FIG. 3 is an electronic schematic of a second embodiment of switching circuitry according to the present invention.
• Fig. 4 is an electronic schematic of an apparatus for driving a smart material actuator implementing the controllable power source of Fig. 1 and the switching circuitry of Fig. 2;
• Fig. 5 is an electronic schematic of an apparatus for driving a smart material actuator implementing the switching circuit of Fig. 3 and the DC to DC converter of Fig 1.
• Fig. 1 is an electronic schematic diagram illustrating a controllable power source 10, where a known voltage source 12 of known potential is connected to a reverse protection diode 14 which feeds a bead inductor 16.
• the bead inductor 16 acts as a filter to remove noise generated by a collector of an NPN transistor 18 into the voltage source 12.
• the NPN transistor 18 and an NPN transistor 20 form a push-pull driver for a transformer 22.
• Resistors 24, 26, 28, 30 form a resistive voltage divider and set the basic bias points for the NPN transistors 18, 20.
• the transformer 22 is wound not only with primary and secondary windings 22a and 22b but also an auxiliary winding 22 c.
• the auxiliary winding 22c on the transformer 22, resistors 32, 34, 28, and capacitors 36, 38 form feedback means for creating oscillation on a base of the NPN transistors 18, 20.
• the oscillation is 180 degrees out of phase between the two NPN transistors 18, 20 forming a self-oscillating push-pull transformer driver.
• the secondary winding 22b of transformer 22 is connected to a rectifier 40, which is connected to a bead inductor 42 and a capacitive load 44, in this case a piezoelectric smart material actuator.
• the bead inductor 42 acts as a filter to remove noise generated by the oscillation of the circuit and feeds the capacitive load 44.
• a Zener diode 46 acts as feedback means through a current limiting resistor 48.
• a transistor 50 When the Zener voltage is exceeded, a transistor 50 is turned on causing the base of the transistor 20 to be grounded and stopping the self-oscillating mechanism.
• switching circuitry 11 for discharging a smart material actuator capacitive load 58 is shown.
• a switch 52 When a switch 52 is closed, current flows from a voltage source 54 through the switch 52 and through the bead inductor 56 for charging the capacitive load 58, in this case a piezoelectric smart material actuator. Also, current flows into a resistive divider network 60 driving an NPN transistor 62 on, which turns an NPN Darlington pair 64 off.
• the rate of charge is determined by the impedance of the bead inductor 56, the resistor 66 and the capacitive load 58.
• the switch 52 When the switch 52 is opened, the current stops flowing in the capacitive load 58 and the NPN transistor 62 is turned off and turning the NPN Darlington pair 64 on, causing current to flow through the resistor 66 for discharging the capacitive load 58.
• the rate of discharge is determined by the resistor 66 and the capacitive load 58.
• the resistor 68 and the base of NPN transistor 62 serve as a level translator between the switched voltage source 54 and a control signal; therefore the resistor 68 and the base of NPN transistor 62 do not have to have the same voltage levels or voltage swings.
• 111 for discharging a smart material actuator capacitive load 158 is shown.
• the switch 152 When the switch 152 is closed, current flows into the voltage divider network 160 turning the NPN transistor 162 on, causing current to flow through the resistor 70, turning the NPN Darlington transistor pair 164 off, and the positive negative positive ⁇ PNP ⁇ transistor 72 on, causing current to flow through the resistor 166 for discharging capacitive load 158.
• the rate of discharge is determined by the resistor 166 and the capacitive load 158.
• the base of the NPN transistor 162 turns the NPN transistor 162 off, allowing current to flow through the resistor 70 to the base of the PNP transistor 72, turning the PNP transistor off, and the NPN Darlington pair 164 sources current to the capacitive load 158 through the resistor 74.
• the rate of charge is determined by the resistor 74 and the capacitive load 158.
• the resistor 70 and the NPN transistor 162 serve as a level translator between the voltage source 154 and a control signal generated by the closure of switch 154, for example; therefore, the resistor 70 and the base of NPN transistor 162 do not have to have the same voltage levels or voltage swings.
• a preferred embodiment of a driver for a smart material actuator capacitive load 76 includes, a controllable power source 10a and switching circuitry 11a.
• An input voltage source 12a is applied to the controllable power source 10a and at the same time the switch circuit 1 la is disabled and the capacitive load 76 is charged.
• the controllable power source 10a is stopped and the switch circuit 1 la is enabled and the capacitive load 76 is discharged.
• the actual impedance of the controllable power source 10a controls the rate at which the capacitive load 76 is charged and the impedance of the switch circuit 11a controls the rate which the capacitive load 76 is discharged.
• a second embodiment of a driver for a smart material actuator includes a controllable power source 10b and switching circuitry 111 a, 111b, 111c, H id, 111 e, 11 If.
• An input voltage source 12b is applied to the controllable power source 10b. The voltage to be switched is generated continually.
• Figs. 1, 2, 3, 4 and 5 various components were included according to the current carrying ability, voltage rating, and type of the components.
• Other suitable components can include Field Effect Transistor ⁇ FET ⁇ and bipolar junction transistor ⁇ BJT ⁇ small signal and power transistors, wire wound, thin film and carbon comp resistors, ceramic, tantalum and film capacitors, wound, and Low Temperature cofired ceramic ⁇ LTCC ⁇ transformers, or any combination of suitable components commonly used for high volume production.
• FET ⁇ and bipolar junction transistor ⁇ BJT ⁇ small signal and power transistors wire wound, thin film and carbon comp resistors, ceramic, tantalum and film capacitors, wound, and Low Temperature cofired ceramic ⁇ LTCC ⁇ transformers, or any combination of suitable components commonly used for high volume production.
• these materials given as examples provide excellent performance, depending on the requirements of an application, use of other combinations of components can be appropriate.
• the embodiment illustrates components that are commercially available.

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• Engineering & Computer Science (AREA)
• Power Engineering (AREA)
• Dc-Dc Converters (AREA)
• Electrotherapy Devices (AREA)

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• 2003
  • 2003-07-17 WO PCT/US2003/022289 patent/WO2004023635A1/en active Application Filing
  • 2003-07-17 EP EP03794442A patent/EP1563597A1/en not_active Withdrawn
  • 2003-07-17 JP JP2004534247A patent/JP4274373B2/ja not_active Expired - Fee Related
  • 2003-07-17 CA CA002494873A patent/CA2494873C/en not_active Expired - Fee Related
  • 2003-07-17 CN CN03820974.8A patent/CN1679226A/zh active Pending
  • 2003-07-17 AU AU2003259143A patent/AU2003259143A1/en not_active Abandoned

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