SE8400826L - PROCEDURAL EQUIPMENT TO DETECT THE PRESENCE OF AN INDICATING DEVICE IN A LIMITED INVESTIGATION ZONE - Google Patents

PROCEDURAL EQUIPMENT TO DETECT THE PRESENCE OF AN INDICATING DEVICE IN A LIMITED INVESTIGATION ZONE

Info

Publication number
SE8400826L
SE8400826L SE8400826A SE8400826A SE8400826L SE 8400826 L SE8400826 L SE 8400826L SE 8400826 A SE8400826 A SE 8400826A SE 8400826 A SE8400826 A SE 8400826A SE 8400826 L SE8400826 L SE 8400826L
Authority
SE
Sweden
Prior art keywords
frequency
field
indicated device
detect
low
Prior art date
Application number
SE8400826A
Other languages
Swedish (sv)
Other versions
SE8400826D0 (en
Inventor
Leif Asbrink
Original Assignee
Leif Asbrink
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 Leif Asbrink filed Critical Leif Asbrink
Priority to SE8400826A priority Critical patent/SE8400826L/en
Publication of SE8400826D0 publication Critical patent/SE8400826D0/en
Priority to SE8404691A priority patent/SE440833B/en
Priority to EP85850041A priority patent/EP0153286B1/en
Priority to BR8505670A priority patent/BR8505670A/en
Priority to AU39329/85A priority patent/AU567604B2/en
Priority to AT85850041T priority patent/ATE53675T1/en
Priority to US06/787,789 priority patent/US4704602A/en
Priority to PCT/SE1985/000054 priority patent/WO1985003793A1/en
Priority to DE8585850041T priority patent/DE3578228D1/en
Priority to JP60500674A priority patent/JPS61501229A/en
Priority to ZA85897A priority patent/ZA85897B/en
Priority to CA000473804A priority patent/CA1231152A/en
Priority to ES540975A priority patent/ES8702683A1/en
Publication of SE8400826L publication Critical patent/SE8400826L/en
Priority to NO85853981A priority patent/NO166509C/en
Priority to DK469685A priority patent/DK163695C/en
Priority to FI854012A priority patent/FI81920C/en

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
    • G08B13/24—Electrical actuation by interference with electromagnetic field distribution

Landscapes

  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • General Physics & Mathematics (AREA)
  • Geophysics And Detection Of Objects (AREA)

Abstract

Process in order to detect the presence of an indicated device in a limited investigation zone, including the detection of an indicated device (31) in a highly permeable material through transmitting and receiving of a magnetic field, where two coils (1, 2) are made to transmit a high-frequency magnetic alternating field, where the first of the coils (1) transmits an alternating field with a frequency (f1), differentiating itself from the frequency (f2) of the transmitted field of the other coil (2), and where at least one, through intermodulation while the indicated device (31), occurring differentiating and/ or summation frequency n x f1 + m x f2 , where n and m are positive or negative integers, are received by one or more coils (9). According to the invention, a third low-frequency magnetic alternating field is brought to transmission in the given zone, which has a frequency (f3) essentially below the given frequencies (f1, f2), where the low-frequency field is brought to a field strength that is sufficiently high enough in order to, independent of the field with the frequencies f1 and f2 continue the indicated device (31) in its saturated condition in tact with the frequency of the low frequency field. A retransmitted field is brought from the indicated device (31) to detect that with the low-frequency field's frequency periodically occurring intermodulation between the frequencies f1 and f2 by means of a detection device.<IMAGE>
SE8400826A 1984-02-15 1984-02-15 PROCEDURAL EQUIPMENT TO DETECT THE PRESENCE OF AN INDICATING DEVICE IN A LIMITED INVESTIGATION ZONE SE8400826L (en)

Priority Applications (16)

Application Number Priority Date Filing Date Title
SE8400826A SE8400826L (en) 1984-02-15 1984-02-15 PROCEDURAL EQUIPMENT TO DETECT THE PRESENCE OF AN INDICATING DEVICE IN A LIMITED INVESTIGATION ZONE
SE8404691A SE440833B (en) 1984-02-15 1984-09-19 Process and device for detection of an indicated device in a limited investigation zone
BR8505670A BR8505670A (en) 1984-02-15 1985-02-05 METHOD AND SYSTEM FOR DETECTING THE PRESENCE OF DEVICES INDICATED IN A LIMITED RESEARCH AREA
US06/787,789 US4704602A (en) 1984-02-15 1985-02-05 Method and system for detecting an indicating device
JP60500674A JPS61501229A (en) 1984-02-15 1985-02-05 Method and apparatus for detecting an indicating device
AU39329/85A AU567604B2 (en) 1984-02-15 1985-02-05 Method and system for detecting an indicating device
AT85850041T ATE53675T1 (en) 1984-02-15 1985-02-05 METHOD AND ARRANGEMENT FOR DETECTING AN INDICATOR.
EP85850041A EP0153286B1 (en) 1984-02-15 1985-02-05 Method and system for detecting an indicating device
PCT/SE1985/000054 WO1985003793A1 (en) 1984-02-15 1985-02-05 Method and system for detecting an indicating device
DE8585850041T DE3578228D1 (en) 1984-02-15 1985-02-05 METHOD AND ARRANGEMENT FOR DETECTING A DISPLAY DEVICE.
ZA85897A ZA85897B (en) 1984-02-15 1985-02-06 Method and system for detecting an indicating device
CA000473804A CA1231152A (en) 1984-02-15 1985-02-07 Method and system for detecting an indicating device
ES540975A ES8702683A1 (en) 1984-02-15 1985-02-15 Method and system for detecting an indicating device.
NO85853981A NO166509C (en) 1984-02-15 1985-10-08 PROCEDURE AND EQUIPMENT FOR AA DETECTED ATTENTION OF THE INDICATOR DEVICE IN A LIMITED INVESTIGATION ZONE.
DK469685A DK163695C (en) 1984-02-15 1985-10-14 METHOD AND DEVICE FOR DETECTING AN INDICATING DEVICE
FI854012A FI81920C (en) 1984-02-15 1985-10-15 FOERFARANDE FOER ATT DETEKTERA EN INDIKERINGSANORDNING, JAEMTE ANORDNING.

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
SE8400826A SE8400826L (en) 1984-02-15 1984-02-15 PROCEDURAL EQUIPMENT TO DETECT THE PRESENCE OF AN INDICATING DEVICE IN A LIMITED INVESTIGATION ZONE

Publications (2)

Publication Number Publication Date
SE8400826D0 SE8400826D0 (en) 1984-02-15
SE8400826L true SE8400826L (en) 1985-08-16

Family

ID=20354765

Family Applications (2)

Application Number Title Priority Date Filing Date
SE8400826A SE8400826L (en) 1984-02-15 1984-02-15 PROCEDURAL EQUIPMENT TO DETECT THE PRESENCE OF AN INDICATING DEVICE IN A LIMITED INVESTIGATION ZONE
SE8404691A SE440833B (en) 1984-02-15 1984-09-19 Process and device for detection of an indicated device in a limited investigation zone

Family Applications After (1)

Application Number Title Priority Date Filing Date
SE8404691A SE440833B (en) 1984-02-15 1984-09-19 Process and device for detection of an indicated device in a limited investigation zone

Country Status (3)

Country Link
JP (1) JPS61501229A (en)
SE (2) SE8400826L (en)
ZA (1) ZA85897B (en)

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3990065A (en) * 1975-02-20 1976-11-02 The Magnavox Company Theft detection system
NL7702946A (en) * 1976-04-03 1977-10-05 Bizerba Werke Kraut Kg Wilh METHOD AND ARRANGEMENT FOR DETERMINING THE PRESENCE OF OBJECTS IN A PARTICULAR CONTROL AREA, IN PARTICULAR FOR PREVENTION OF SHOP THEFT.
JPS5853395A (en) * 1981-09-27 1983-03-29 Tazawa Makoto Cam press which has jointly utilized hydraulic and air pressure

Also Published As

Publication number Publication date
JPH0355878B2 (en) 1991-08-26
SE440833B (en) 1985-08-19
SE8404691D0 (en) 1984-09-19
ZA85897B (en) 1985-09-25
JPS61501229A (en) 1986-06-19
SE8400826D0 (en) 1984-02-15
SE8404691L (en) 1985-08-16

Similar Documents

Publication Publication Date Title
DK469685A (en) METHOD AND DEVICE FOR DETECTING AN INDICATING DEVICE
SE8403564D0 (en) PROCEDURE FOR THE DETERMINATION OF MEDICINE, AS APPLICABLE HEREIN
EP0765059A3 (en) Method for transmitting an orthogonal frequency division multiplex (OFDM) signal and transmitter/receiver therefor
FI884549A (en) ANORDNING FOER FJAERRTRANSMISSION AV SIGNALER SAERSKILT VIDEOSIGNALER.
WO1990014497A3 (en) Process and device for transmitting data signals and/or control signals in a pipe train
SG4593G (en) Self-tuning low frequency phase shift coin examination method and apparatus
SE8400826D0 (en) PROCEDURAL EQUIPMENT TO DETECT THE PRESENCE OF AN INDICATING DEVICE IN A LIMITED INVESTIGATION ZONE
JPS56114450A (en) Signal transmission system
ATE113015T1 (en) METHOD OF SIGNAL AND INFORMATION TRANSMISSION BETWEEN TRANSMITTER AND RECEIVER EQUIPMENT OF PUBLIC TRANSPORT VEHICLES.
ES2033665T1 (en) PROCEDURE AND DEVICE FOR TRANSMISSION OF VIDEO SIGNALS IN A CONFINED MEDIA.
JPS55137729A (en) Multiple signal receiver
JPS57211539A (en) Nuclear magnetic resonance device
US1141453A (en) Apparatus for the transmission and receipt of electrical energy.
JPS5787264A (en) Line monitoring system for high-level transmission control procedure
JPS53129671A (en) Position detector
SU964696A1 (en) Device for remote transmission of angular displacement
JPS6437164A (en) Facsimile transmission equipment for radio line
JPS5723349A (en) Information transmitting circuit changeover device
GB2273407A (en) Monitoring of optical communications fibres
Luiz HF/VHF spectrum surveillance ESM receiver
FR2394937A1 (en) Telephone channel terminal adaptor - is used for earth return continuous current signal transmission with oscillator and transformer, transmitter and photocoupler receiver
JPS5639638A (en) Radio communication system tolerant of transmission mutual modulation disturbance
JPS547392A (en) Eddy current flaw detecting apparatus of rotary probe type
JPS54109235A (en) Control and monitoring apparatus in air conditioning system
ES8501587A1 (en) Method of receiving a transmission transmitted in single sideband by a receiver operating under amplitude modulation and device permitting the implementation of this method.

Legal Events

Date Code Title Description
NAV Patent application has lapsed

Ref document number: 8400826-7

Effective date: 19920607