Self-powered switching device

• US 6,630,894 B1
• Filed: 07/14/2000
• Issued: 10/07/2003
• Est. Priority Date: 07/14/2000
• Status: Active Grant

• Current Assignee: Face International Corp.
• Original Assignee: Face International Corp.
• Inventors: Boyd, Clark Davis, Face, Bradbury R., Face, Samuel A. Jr.
• Primary Examiner(s): EDWARDS JR, TIMOTHY
• Application Number:
  US09/616,978
• Time in Patent Office: 1,180 Days
• Field of Search: 341/22, 341/176, 341/825.69, 310/311, 310/314, 310/318, 367/157, 367/160
• US Class Current: 341/22
• CPC Class Codes: H01H 2239/076 Key stroke generating power
• CPC Class Codes: H01H 2300/03 Application domotique, e.g. for house automation, bus connected switches, sensors, loads or intelligent wiring
• CPC Class Codes: H03K 17/964 Piezoelectric touch switches
• CPC Class Codes: H03K 17/965 Switches controlled by moving an element forming part of the switch
• CPC Class Codes: H03K 2217/94089 Wireless transmission
• CPC Class Codes: Y02B 90/20 Smart grids as enabling technology in buildings sector smart grids supporting the management or operation of end-user stationary applications in general, or like technologies with no associated climate change mitigation effect Y04S20/00
• CPC Class Codes: Y04S 20/14 Protecting elements, switches, relays or circuit breakers

Abstract

A self-powered switching device using a prestressed flextensional electroactive member generates a signal for activation of a latching relay. The electroactive member has a piezoelectric element with a convex and a concave face that may be compressed to generate an electrical pulse. The flextensional electroactive member and associated signal generation circuitry can be hardwired directly to the latching relay or may be coupled to a transmitter for sending an RF signal to a receiver which actuates the latching relay.

Claims

1. A self-powered switching device comprising:

flextensional transducer, said flextensional transducer comprising;

a first electroactive member having opposing first and second electrode major faces;

said first opposing major face being substantially convex and said second opposing major face being substantially concave;

a prestress layer bonded to said second major face of said first electroactive member;

wherein said flextensional transducer is adapted to deform from a first position to a second position upon application of a force to said flextensional transducer;

and wherein upon said deformation to said second position, said flextensional transducer is adapted to generate a first voltage potential between said first electroded major face and said second electroded major face;

a first conductor electrically connected to said first electroded major face of said first electroactive member;

a second conductor electrically connected to said second electroded major face of said first electroactive member;

signal transmission means electrically connected to said first and second conductors, said signal transmission means being adapted to generate a first signal in response to said first voltage potential; and

a switch having a first position and a second position;

said switch being in communication with said signal transmission means;

said switch being adapted to change from said first position to said second position in response to said first signal;

said switch being adapted to change from said second position to said first position in response to said first signal;

a voltage regulator having an input side and an output side;

said input side of said voltage regulator being electrically connected to said first and second conductors;

said output side of said voltage regulator being electrically connected to said signal transmission means;

a diode having an anode and a cathode connected in parallel with said flextensional;

said cathode of said diode being electrically connected to said first conductor and said input side of said voltage regulator;

said anode of said diode being electrically connected to said second conductor and said input side of said voltage regulator;

whereby said diode is connected in parallel with first and second electroded major faces of said first electroactive member.

2. The switching device according to claim 1, wherein said signal transmission means comprises:

a third conductor connecting said first conductor to a first pole of said switch; and

a fourth conductor connecting said second conductor to a second pole of said switch.

3. The switching device according to claim 1, further comprising:

pressure application means for application of a force to said flextensional transducer, said pressure application means being adapted to apply a force sufficient to deform said flextensional transducer from said first position to said second position, thereby generating said first voltage potential.

4. The switching device according to claim 1, wherein said signal transmission means comprises a radio frequency generator subcircuit.

5. The switching device according to claim 4, wherein said radio frequency generator subcircuit comprises:

an oscillator array having an input side and an output side;

said input side of said oscillator array being connected to said output side of said voltage regulator;

a BJT having a base connected to said output side of said oscillator array and a grounded emitter; and

a resonant subcircuit having a first and a second junction;

said first junction of said resonant subcircuit being connected to said voltage regulator;

said second junction of said resonant subcircuit being connected to a collector of said BJT.

6. The switching device according to claim 5, wherein said radio frequency generator subcircuit further comprises:

a radio frequency choke connected in series between said output side of said voltage regulator and said first junction of said resonant subcircuit.

7. The switching device according to claim 6, wherein said resonant subcircuit comprises:

a first capacitor having a first and a second plate; and

an inductive loop of a fifth conductor having first and second ends;

said first plate of said first capacitor being connected to said first end of said fifth conductor, thereby forming said first junction of said resonant subcircuit;

said second plate of said first capacitor being connected to said second end of said fifth conductor, thereby forming said second junction of said resonant subcircuit 1.

8. The switching device according to claim 7, wherein said oscillator array comprises:

a first inverter having an input side and an output side;

said output side of said first inverter being electrically connected to said base of said BJT;

a first resistor electrically connected to said output side of said first inverter; and

a second capacitor connected in series between said first resistor and said input side of said first inverter.

9. The switching device according to claim 8, wherein said oscillator array further comprises:

a second inverter having an input side and an output side;

said output side of said second inverter being electrically connected to input side of said first inverter; and

a second resistor electrically connected in parallel with said second capacitor and said second inverter.

10. The switching device according to claim 9, wherein said radio frequency choke comprises an inductor.

11. The switching device according to claim 10, further comprising:

a third capacitor connected to said first and second conductors in parallel with said diode.

12. The switching device according to claim 11, wherein said resonant subcircuit further comprises:

a tuning jumper comprising a sixth conductor having first and second ends each connected to said fifth conductor;

said tuning jumper being adapted to pivot at said first and second ends, thereby rotating relative to said fifth conductor.

13. The switching device according to claim 12, wherein said flextensional transducer further comprises:

a second electroactive member having opposing first and second electroded major faces;

said first opposing major face being substantially convex and said second opposing major face being substantially concave;

said second major face of said second electroactive member being bonded to said first major face of said first electroactive member.

14. The switching device according to claim 13, wherein said first and second electroactive members each comprise a piezoelectric material.

15. The switching device according to claim 10, wherein said signal transmission means further comprises:

a receiver for intercepting a signal generated by said radio frequency generator subcircuit; and

electrical signal generation means for generating an electrical signal in response to said signal intercepted by said receiver, said electrical signal generation means being electrically connected to said receiver;

wherein said switch is adapted to change from said first position to said second position in response to said electrical signal generated by said electrical signal generation means;

and wherein said switch is adapted to change from said second position to said first position in response to said electrical signal generated by said electrical signal generation means.

16. The switching device according to claim 15, wherein said electrical signal generation means comprises a microprocessor for differentiating between a first radio frequency signal and said signal generated by said radio frequency generator subcircuit.