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Self-powered sensor for use in closed-loop security system

  • US 4,745,398 A
  • Filed: 02/09/1987
  • Issued: 05/17/1988
  • Est. Priority Date: 02/09/1987
  • Status: Expired
First Claim
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1. A self-powered sensor for a closed-loop security system, comprising:

  • (a) self-powered sensor network means for providing a switch actuating signal upon the detection of a physical condition wherein said self-powered sensor network means comprises transducer means, said transducer means having a pair of plates separated by a piezoelectric element and having a transient alternating current output, and voltage doubling circuit means responsive to the output of said transducer means, said pair of plates forming a charge storage element of said voltage doubling circuit means, for approximately doubling the peak voltage output of said transducer means to provide said switch actuating signal for a predetermined period of time; and

    (b) electronic switch means, said electronic switch means having a semiconductor junction forming a diode included in said voltage doubling circuit means, said electronic switch means being in a normally closed position thereby allowing current in said closed-loop security system to flow therethrough, for opening said closed-loop security system in response to said switch actuating signal.

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