Matches 301 - 335 out of 335 < 1 2 3 4 5 6 7
Match Document Document Title
4195234 Infrared intrusion alarm system with temperature responsive threshold level  
Intrusion detector of the type in which the presence of an intruder is detected by infrared heat energy emitted by his body. An alarm signal is delivered when the level of radiation detected rises...
4179691 Infrared intrusion detector circuit  
A circuit for an infrared intrusion detector comprising a plurality of receiving directions or regions which are separated from one another and a radiation receiver, at the output of which there...
4173016 Interpersonal-introduction signalling system  
An interpersonal-introduction signalling system includes a receiving and transmitting transceiver having a relatively short range response and of such size as to permit convenient carrying by a...
4159473 Charge sensitive switch  
A charge-sensitive switch is described sensitive to the adjacency of, or transfer of charge from a person, for controlling lamps, appliances, motors, etc. The switch contains an over-current sensor...
4057805 Radio-controlled machine power cut-off  
A pair of battery-powered radio transmitters are individually worn on the wrists of a machine operator, and two radio receivers are tuned to receive the signals broadcast by the radio transmitters,...
4052716 Fire and intruder detection and alarm apparatus  
Improved apparatus is provided for monitoring a space under surveillance, for detecting the existence of a fire, the presence of an intruder or the occurrence of other abnormal conditions, and for...
4038633 Detection system for automobiles and other motor-driven objects  
A system for detecting the presence of motor-driven vehicles or other objects which are motor-driven includes a sensor for detecting the presence of a changing magnetic field generated by operation...
3988726 Infrared intrusion detection apparatus  
The infrared system employs an optical focusing arrangement for collecting radiation from a moving object such as an intruder and directing the energy to a sensing element which may be a thermistor...
3972598 Multifaceted mirror structure for infrared radiation detector  
Infrared radiation can be gathered from a number of discrete, spaced apart fields of view and focused on a single sensing element with a multifaceted mirror. Each facet of the mirror is a concave...
3958118 Intrusion detection devices employing multiple scan zones  
This invention relates to intrusion detection devices, and in one embodiment includes an array of infra-red detectors with associated means for selectively increasing the number of scan zones which...
3955184 Passive infrared room intrusion detector  
An intrusion system detects changes in background radiation received from a plurality of orthogonally arranged fields of view (FOV) which preferably are defined by thin polyhedrons coextensive with...
3928849 Intrusion detector self-test system  
An intrusion detection system which automatically makes periodic tests of the operability of the system and provides an alarm in the event of a malfunction during the supervisory self-check regimen...
3928843 Dual channel infrared intrusion alarm system  
An infrared intrusion alarm system utilizes two sensing elements and two signal processing channels arranged such that an intruder produces signals of opposite polarities in the two channels. An...
3924130 Body exposure indicator  
An infra-red detector is caused to scan a field of view periodically to dct warm bodied intruders or other personnel. Signals from the detector are compared with signals from a scene recorder...
3812483 POINT SOURCE DISCRIMINATOR THERMAL ALARM  
An alarm system is provided for a scanning type far infrared system. The eo signal is processed by a gated pulse blanking system which permits automatic surveillance of one or more windows within...
3766539 AUTOMATIC PERSONNEL INTRUSION ALARM  
The invention is concerned with infrared viewing systems, particularly th operating in the spectral wavelength regions between 3 to 5 and 8 to 14 microns. An alarm is provided for these systems to...
3760399 INTRUSION DETECTOR  
A simple optical system collects and applies radiation from a predetermined field of view onto a thermopile detector. The thermopile detector has a plurality of rows of thermocouples having all...
3703718 INFRARED INTRUSION DETECTOR SYSTEM  
Infrared intrusion detector system utilizing a single sensing element and optical means for focusing radiation from one or more discrete fields of view onto the sensing element. An amplifier tuned...
3656161 MAINTAINING A CIRCULARLY POLARIZED MAGNETIC FIELD AT A MOVING POINT  
A circularly polarized magnetic field is maintained at the location of a subsoil penetrator traveling beneath a dipole-quadrupole field propagating antenna which serves as a reference frame with...
3631434 PASSIVE INTRUSION DETECTOR  
A passive intrusion detector is described with two stationary detectors or detector elements arranged side by side and stationary optics which image a target onto the plane of the detector. The...
3597680 METHOD AND APPARATUS UTILIZING A TRANSMITTER AND RECEIVER FOR DETECTING THE PRESENCE OF A METALLIC OBJECT WITHIN A PIPE  
A method and apparatus for exploring an installed, concealed pipe to obtain information such as the location and coarse thereof, and the presence and position of a metallic object lodged therein....
3577079 WATCHMAN'S RADIO LOCATION INDICATING SYSTEM  
In a location system a radio transmitter carried by a security guard or watchman has a modulator and an oscillator, but without the frequency determining components. At various points which the...
3573620 SECURITY SYSTEM WITH INDUCTIVE TO RF COMMUNICATIONS LINKS  
In a location system a radio transmitter carried by a security guard or watchman includes a loop aerial and a loop demodulator, and loop carrier frequency generators each generating a loop carrier...
3524180 PASSIVE INTRUSION DETECTING SYSTEM  
3480775 RADIATION SENSITIVE OMNIDIRECTIONAL MOTION DETECTOR SYSTEM  
3278932 Infrared system audio augmentation circuit  
3264646 Passive perimeter intrusion detection system  
3192506 Electronic indicator system more particularly for use in mines  
3056106 Infrared detectors  
2991458 Ignition interference alarm  
2908897 Intrusion detecting system  
2814032 Protective apparatus for materialhandling equipment  
2810902 Fire and intrusion detector system  
2795778 Tow target  
3560950 Title is not available  
Matches 301 - 335 out of 335 < 1 2 3 4 5 6 7