FR690398A - Improvements to signaling devices using high frequency electromagnetic oscillations - Google Patents

Improvements to signaling devices using high frequency electromagnetic oscillations

Info

Publication number
FR690398A
FR690398A FR690398DA FR690398A FR 690398 A FR690398 A FR 690398A FR 690398D A FR690398D A FR 690398DA FR 690398 A FR690398 A FR 690398A
Authority
FR
France
Prior art keywords
high frequency
frequency electromagnetic
signaling devices
electromagnetic oscillations
oscillations
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)
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.)
THEREMIN PATENTS CORP
Original Assignee
THEREMIN PATENTS CORP
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 by THEREMIN PATENTS CORP filed Critical THEREMIN PATENTS CORP
Application granted granted Critical
Publication of FR690398A publication Critical patent/FR690398A/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
    • G08B13/22—Electrical actuation
    • G08B13/26—Electrical actuation by proximity of an intruder causing variation in capacitance or inductance of a circuit
FR690398D 1930-02-21 1930-02-21 Improvements to signaling devices using high frequency electromagnetic oscillations Expired FR690398A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
FR690398T 1930-02-21

Publications (1)

Publication Number Publication Date
FR690398A true FR690398A (en) 1930-09-19

Family

ID=9029236

Family Applications (1)

Application Number Title Priority Date Filing Date
FR690398D Expired FR690398A (en) 1930-02-21 1930-02-21 Improvements to signaling devices using high frequency electromagnetic oscillations

Country Status (1)

Country Link
FR (1) FR690398A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2472900A1 (en) * 1974-01-10 1981-07-03 Dynamit Nobel Ag Contact sensor for area surveillance - uses sensor wire connected to piezoelectric or electromagnetic transducer

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2472900A1 (en) * 1974-01-10 1981-07-03 Dynamit Nobel Ag Contact sensor for area surveillance - uses sensor wire connected to piezoelectric or electromagnetic transducer

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