FR642758A - Electrical device for theft protection - Google Patents

Electrical device for theft protection

Info

Publication number
FR642758A
FR642758A FR642758DA FR642758A FR 642758 A FR642758 A FR 642758A FR 642758D A FR642758D A FR 642758DA FR 642758 A FR642758 A FR 642758A
Authority
FR
France
Prior art keywords
electrical device
theft protection
theft
protection
electrical
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
Other languages
French (fr)
Inventor
Maurice Lormier
Henry Hallam
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed filed Critical
Application granted granted Critical
Publication of FR642758A publication Critical patent/FR642758A/en
Expired legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G08—SIGNALLING
    • G08B—SIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
    • G08B13/00—Burglar, theft or intruder alarms
    • G08B13/16—Actuation by interference with mechanical vibrations in air or other fluid
    • G08B13/1654—Actuation by interference with mechanical vibrations in air or other fluid using passive vibration detection systems
    • G08B13/1672—Actuation by interference with mechanical vibrations in air or other fluid using passive vibration detection systems using sonic detecting means, e.g. a microphone operating in the audio frequency range

Landscapes

  • Engineering & Computer Science (AREA)
  • Multimedia (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
FR642758D 1927-03-29 1927-03-29 Electrical device for theft protection Expired FR642758A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
FR642758T 1927-03-29

Publications (1)

Publication Number Publication Date
FR642758A true FR642758A (en) 1928-09-04

Family

ID=8999028

Family Applications (1)

Application Number Title Priority Date Filing Date
FR642758D Expired FR642758A (en) 1927-03-29 1927-03-29 Electrical device for theft protection

Country Status (1)

Country Link
FR (1) FR642758A (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE758380C (en) * 1939-08-31 1953-08-31 Normalzeit G M B H Quiescent current safety system
US3167755A (en) * 1963-02-11 1965-01-26 Howard M Larrick Monitor circuits for detection and alarm systems
US4383250A (en) * 1981-03-09 1983-05-10 American District Telegraph Company System for intrusion detection

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE758380C (en) * 1939-08-31 1953-08-31 Normalzeit G M B H Quiescent current safety system
US3167755A (en) * 1963-02-11 1965-01-26 Howard M Larrick Monitor circuits for detection and alarm systems
US4383250A (en) * 1981-03-09 1983-05-10 American District Telegraph Company System for intrusion detection

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