Intrusion Alarm Patents

Background

Seismic

Cites:
3246285 Method of and apparatus for signal-information detection, Karl D Kryter, Bolt Beranek and Newman, 1966-04-12, -
3296587 by TI.  See the PSR-1 web page.

Fence

Around 1960 I worked for a glass window company in Mountain View just off the Central Expressway and behind us there was a company that made outdoor intrusion equipment, one aspect of which was a fence sensor.  Every now and then they would bring out a dozen folding chairs and high ranking military men would watch a demonstration.  An intruder dressed all in black would try and get over each section of the fence but an alarm would sound.  He would stand still just inside the fence then try to move away from it, but the alarm sounded.  There was a plywood box on wheels that he would try to move from inside, but with no luck.

2424677 Approach protective apparatus, Allan L Brownlee, App: 1942-10-26, Pub:1947-07-29 - prior capacitive systems were troubled by weather, this system which depends on balanced electrodes.
2450166 Electrical detection apparatus, Nicholas S Rich, App: 1944-08-18, Pub: 1948-09-28 - vehicle detection for traffic lights - secret during W.W.II? - senses the vehicles magnetic field, not the Earth's field or the field from a permanent magnet. sensor is 88,000 turns 38AWG wire on high mu (2,000 to 4,000) core.  Note the vehicle makes a single cycle (+ to -, or - to +) at a frequency depending on it's speed.  This looks very similar to the inductive exploder on a W.W.II torpedo.
2991458 Ignition interference alarm, Cooke Engineering Co Va., App: 1956-07-27, Pub: 1961-07-04 - tubes, - Vietnam Ho Chi Minh trail (Wiki) sensor? EDIT III ignition sensor

Have book on order: Wiring Vietnam: The Electronic Wall, Tambini, Anthony J., 2007, ISBN-13: 978-0810858442 -

2956269 Electronic barrier, MOSLER RES PRODUCTS Inc Conn., 1960-10-11
3031643 Transmission line fence burglar alarm, National Co Inc, 1962-04-24 - uses a terminated balanced transmission line consisting of a pair of parallel wires.  The intruder changes the impedance and causes a reflection.
3047849 Electronic intrusion protection array system, MOSLER RES PRODUCTS Inc, 1962-07-31 - looks like a 3-wire electric cattle fence, transistors, stable & sensitive unlike prior art capacitive type systems, 10 to 30 kHz, the top and bottom wires transmit and are 180 deg out of phase so that the center wire sees almost no signal.
3074053 Electrical system and method for protecting premises subject to varying ambient conditions, ADT Security Systems Inc, 1963-01-15
3110891 Security fence alarm system, TRW (Northrop Grumman), 1963-11-12 - 3-phase field
3237105 Personnel intrusion detecting device, Henry P Kalmus, 1966-02-22 - simple transistor ckt, uses between 5 & 100 kHz signal to detect man size or larger objects while allowing smaller objects, like a cat, to pass.
3375511 Transmission line intruder detection system, (Bay area inventors) GTE Sylvania Inc, 1968-03-26 -
3696369 Signal processor, GTE Sylvania Inc Mtn. View, - analog processing of geophone seismic output
3947835 Fence Protection System, General Dynamics Government Systems Corp, GTE Sylvania, Mtn. View - electret cable to sense fence vibrations, transistors,
4213122 Intrusion detection system, U.S. AF, 1980-07-15 - near RF field detection man: large signal, dog: small signal, surround a 40' shipping container or aircraft, 72 to 76 MHz desired correspond to wavelengths of about 4 meters or a half wave of about 2 meters (6') the height of a man.
5969608 Magneto-inductive seismic fence, Oct 19, 1999
6456198 Fence sensor Sep 24, 2002

People Sniffer (Wiki)

2021 Sep 18 - ordered the book: The End of the Line: The Siege of Khe Sanh, Robert Pisor, 1982 where pg 57 has a little about the XM-2 Personnel Detector (Forgotten Weapons).

Doppler

RF Metal Detector

Radar

RE25100 Object Detectors, R.S. Chapin, Chapin Electronics Corp (Pinkertons Inc), Dec 19, 1961 - detects changes in standing wave pattern effecting the impedance of the antenna, so less sensitive to false alarms.  But this system also responds to Doppler shifts and these are a source of false alarms, fixed in patent 3237191

Calls:
2238041 Power Control System - radio beam
2333688 Distance measuring system 1943-11-09 - time of flight = radar
2617983 Moving target detecting system - radar MTI
2622140 Hi-frequency control system for traffic signals - dipoles over head detect cars
2659077 Moving target radio pulse echo system 1953-11-10 - MTI for radar
2677126 Wave signaling system -Doppler based moving target system

3210752 Moving object detection system, Bojko George, Pinkertons Inc, 1965-10-05 -
Harvard Scientific Instruments: "Radar-Eye" burglar alarm transmitter/receiver -
3237191 Object detection system, Bojko George, Pinkertons Inc, 1966-02-22 - Doppler - whip antenna hangs from ceiling (ME400?) Cites 10 patents, called by 10
3599196 Plural chambered, oscillator-coaxial line resonator-detector assembly for moving object detection systems, Bojko George, Pinkertons Inc, 1971-08-10

Electrostatic Field

Brooke's Home Page  Brooke's Military Information page -

  page created July 13 2008.