Abstract: A vibration and shock-sensitive electrical switch comprising a disc mounted tube with a small snap switch such as a Microswitch centered above the tube end on the disc surface. A switch-actuating wire extends from the switch trigger mechanism through the tube so that when the tube is balanced on its bottom end, the switch is in its first switching position, and when tipped over by vibration or shock, the switch-actuating wire is released and the switch goes to its second switching position. Vibration sensitivity may be adjusted by attaching various diameter or irregular shaped collars on the bottom end of the tube.

Abstract: An electronic sensing device, operates to actuate a household lighting fixture in response to a sensed environmental condition such as sound or movement within a room. The device is provided with a receiver for sensing the particular environmental condition, a timer responsive to the output of the receiver, switching apparatus for switching on the household lighting fixture in response to the timer, and a power-providing circuit. The timer provides that the lighting fixture will remain on for a preselected time after sensing the environmental condition, and continually resets in the continued presence of the environmental condition. The switching apparatus switches the light fixture on in response to the timer output and further provides circuitry for varying the switched-on duty cycle of the lighting fixture in order to provide a dimmer control. The power-providing circuitry applies a portion of the leading edge of each half cycle of line current to power the circuitry of the sensing device.

Abstract: Seismic detection of a target is obtained with a geophone detecting earth vibrations caused by the actions of the target. The vibrations are wide band amplified and band-passed filtered with the pass bands being fed to the threshold detectors. The outputs of the threshold detectors are fed to a diode AND logic circuit, the output thereof indicating the presence of a target.

Abstract: An intrusion detection system includes a vibration sensor, and a gate circuit operable to provide an output signal only after the vibration sensor produces a first signal, and thereafter a second, separate signal within a preassigned "sensing window" period. To accomplish this, a timer circuit initiated by the sensor determines a timing interval, and a delay circuit coupled to the timing circuit prevents switching of the gate circuit until preset delay time has elapsed. After the delayed time, if a second sensor output signal is received before expiration of the timing interval, the gate circuit switches and passes a signal through an integrated circuit amplifier stage, and a driver circuit to energize an output unit. The sensitivity of the vibration sensor can be adjusted. The integrated circuit stage includes circuitry for maintaining the alarm signal even if the system is switched to off after it goes into alarm.

Abstract: A free-floating self-contained swimming pool alarm unit in which a hollow housing forms a float structure having an internal chamber within which an audible alarm device is mounted adjacent sound transmitting openings in a top wall of the housing. An upstanding flared chimney surrounds the openings and provides a sound amplifying horn, the outer end of the chimney being provided with a shielding cap. Electronic control is arranged to trigger and activate the alarm device by connecting it to an electric source in the housing in response to the operation of a liquid sensor switch as a result of tilting movements of the housing due to wave disturbances produced by an object or person falling into the pool. Once the alarm is triggered, it will continue to operate until deactivated by an appropriate switch such as a manual switch mounted in an accessible portion of the housing.

Abstract: A glass breakage detector includes a cantilever assembly incorporating a base member having a first beam coupled thereto. The base assembly is secured to a pane of glass with the beam extending along an axis determined by the plane contaning the glass. A piezoresistive device is positioned on the beam and adapted to change its resistance upon deflection of the beam due to the breakage of said glass and based upon the application of a vector component of force as deflecting the beam. Other embodiments employ at least another cantilever assembly also having a beam and sensor with the beam directed relatively transverse to the first beam and adapted to respond to force components normal to said vector component.

Abstract: A gravity operated intrusion sensing device comprises a mercury tilt switch having at least two operating modes and a stationary housing having means operative to support the tilt switch in a first position indicative of one operating mode and to provide a second position indicative of another operating mode. The switch is responsive to an external force applied to the housing and falls under the influence of gravity as constrained by the housing to the second position. The entire switch actually falls freely within the stationary housing as to the second position. The second position as dictated by the housing produces a tilted plane at which the switch, after falling, comes to rest, thus assuring the proper operating angle to cause the proper tilt so that in the second position the switch will be in a completely different state, as opened or closed, as compared to the state in the first position.

Abstract: An anti-theft alarm system for movable objects, particularly motorcycles, and actuated by mechanical disturbance, e.g., by using tools on a vehicle, moving it off its stand, or operating it. The primary disturbance sensors are steel balls or the like in small compartments inside which they are free to roll. Impacts of one or more balls against compartment walls generate pulses of high-frequency sound and vibration, which are in turn sensed by an adjacent high-frequency microphone or vibration pickup. The output of this transducer is then amplified and suitably processed to energize a horn or other alarm device.

Abstract: An optical fiber is used as a transducer to convert a low frequency mechanical disturbance into low frequency amplitude modulated optical energy. According to the preferred embodiment of the invention transduction occurs by means of a multi-path interference phenomena capable of responding to acoustic information ranging from less than one hundredth of a cycle per second to several hundred thousand cycles per second. This feature of the invention makes the general concept applicable to use in musical instruments or as a security sensing device. When the concept is applied to a musical instrument it would preferably include the following elements in series: a solid state laser, a multi-mode or single index optic fiber, a square law detector, such as a photodiode, an audio amplifier and a speaker. When the concept is applied in the embodiment of a security sensing apparatus it would preferably include the same active elements (i.e.

Abstract: The effects of wind noise signals from fence-mounted transducers are overcome by basing alarm indications on signal components in at least two narrow frequency bands centered on, say, 120 Hz and 240 Hz.

Abstract: A method and system for evaluating output signals from at least one sound pickup of a security alarm system and for generating an alarm signal by performing the following operations: before the system is placed into operation, determining a first signal frequency range containing the frequency of a signal to be determined and a second signal frequency range containing the frequency of an interference signal; then, during operation, filtering the two frequency range components out of the sound pickup output signals, each component containing a respective one of the frequency ranges, comparing the amplitudes of the two frequency components to one another and generating a difference signal representative of the difference therebetween, and generating an alarm signal whenever the difference signal traverses a threshold value.

Abstract: A personally worn or portable annunciator device for alerting, warning, training, communicating or diagnostic use for people especially those with hearing impairments. This device which can be activated locally or remotely has as one of its means of generating a tactile sensation a transducer or buzzer, as well as a visual light both of which are activated automatically upon the detection of an audio signal substantially above the local ambient noise, or by a RF signal remotely generated by an auxiliary unit.

Abstract: An intruder alarm for protecting the perimeter of an area utilizes a multimode optic fiber as the deformable sensing element, wherein a length of multimode optic fiber is buried in the ground of an area or perimeter to be protected. As coherent light from a laser is directed through a length of optic fiber, the output light pattern therefrom is speckled. When a deformation of the fiber occurs, even a small amount, the speckle pattern changes and is detected electronically indicating that a disturbance has taken place.

Abstract: The oscillations which are generated during an attempted instrusion at a protected area or surface, for instance a vault wall or fence, are received at a sonic receiver and processed by an evaluation circuit such that only the oscillations emanating from an intrusion attempt trip an alarm, not however spurious oscillations from the surroundings. The received oscillations are mixed with a carrier frequency whose frequency periodically and continuously passes through a certain frequency range. The mixed signals are filtered in a narrow band frequency range, so that at the output, during each frequency through pass period, there appears the entire frequency spectrum of the received sonic oscillations in the evaluated frequency range. The filtered signals are integrated and the integrated signal, after a brief period of time, is reset as a frequency throughpass if no further signal appears.

Abstract: A dual signature perimeter detection system utilizing an elongated solenoid ype transducer having a ferromagnetic core as a line sensor is buried in the ground around an area to be protected against intrusion. One end of the transducer is impressed with constant frequency oscillator signals from a signal generator, while a resistance load impedance is connected across the other end of the transducer at the input side of an amplifier used to pass amplified signals selectively to the inputs of either a bandpass type filter or an A.M. detector, or to both simultaneously, then to their related alarms. The line sensor is sensitive to both magnetic and strain stimuli, but the system hereof, which utilizes dual alarm devices, not only provides for determining the type of stimulus creating the signals, but also improves the sensitivity and response uniformity of the transducer.

Abstract: An alarm device responsive to vibration includes a unitary housing in which is disposed an SCR for connecting an alarm signal to an associated source of power, the gate of the SCR being connected to a pendulum and ring assembly with the pendulum being normally suspended within the ring out of engagement therewith but which moves into engagement with the ring when the housing is subjected to vibration to apply power to the SCR gate so that the SCR conducts to actuate the alarm signal for indicating the application of a vibration to the housing or a supporting structure on which the housing is mounted. The alarm device may also include timing circuitry which deactivates the SCR after a predetermined period of time.

Abstract: A signalling apparatus with pressure sensors, in particular for sensing intrusion into a closed surface area, with a yielding pipe embedded underground along the periphery of the surface area and filled with fluid; the pipe being divided into two separate sections by a deformable baffle plate to which are connected sensor means for supplying a signal depending on the deformation of said baffle plate, for initiating signalling means when said baffle plate is deformed.

Abstract: An intruder alarm apparatus is disclosed for protecting a building or a vehicle and consuming a minimal amount of energy when in "watch" condition. An acoustic transmitter is placed inside (or outside) a closed space being supervised, an acoustic receiver is placed outside (or inside) the closed space, and an amplifier has its input connected to the receiver output and its output connected to the transmitter input. If the integrity of the closed space is broken, for example, the enclosing wall is breached, then an acoustic feedback loop is completed by a path being thus established between transmitter and receiver, such that oscillation occurs, and only now are substantial amounts of electrical energy consumed.

Abstract: A sound receiver outputs a signal to a sound level detector and to a notification signal generator. The sound level detector outputs a signal to a first input of a switch, and the notification signal generator outputs a signal to a second input of the switch. Also input into the switch is the program from a program source. Under control of the sound level detector, the switch either outputs the program or the notification signal to an output element of the alarm system whereby the program is interrupted and the notification signal substituted therefor on detection of a sound level greater than a preselected level.

Abstract: An opaque box encloses a lamp, an integrated circuit light-change detector including a photo-diode and an amplifier, and an opto-mechanical means for modulating the light that is coupled from the lamp to the photodiode in response to a mechanical vibration of the box. This device serves as a vibration detector and more particularly as an intrusion alarm when mounted on a door or a window.

Abstract: Two receivers arranged inside and outside a closed space, respectively, are responsive to ambient or environmental noise and a comparator provides an alarm signal when the difference between the outputs of the two receivers falls below a threshold, thereby indicating that the wall to the space has been breached. Alternatively, the two receivers may be arranged in spaced relation within the space and the comparator provides the alarm signal when the difference between the two outputs rises above a threshold, thereby indicating that an intruder is present and closer to one receiver than the other. The apparatus consumes little energy during the watch period and does not depend on itself radiating energy.

Abstract: An intrusion alarm system utilizes an inertially responsive sensor preferably present as a pendulum actuated reed switch. Logic circuits provided within the system provide, an efficient pulsating alarm at dual frequencies optimized for human recognition. In both arrangements, a unique dual delay arrangement is provided, one delay commencing with the arming of the device to permit adequate time for the setting of a sensing switch. A second delay arrangement is provided at the option of the operator for purposes of delaying the activation of the alarm once the sensor switch has been tripped. This feature may be utilized to permit entrance through a door or the like upon which the unit is mounted wherein the device can be deactivated prior to assuming an alarm sounding condition.

Abstract: A method of, and apparatus for, monitoring sound-conducting media wherein sound vibrations are transmitted to and absorbed by the sound-conducting medium. The frequency of the transmitted sound vibrations periodically pass through a predetermined frequency range. During an evaluation period the course of any one of the amplitude or phase of the received sound vibrations are compared with the course of the amplitude or phase during one of the preceding evaluation periods, and when there occur predetermined deviations of both amplitude courses or both phase courses from one another there is triggered an alarm signal.

Abstract: Electric signals in two narrow frequency bands, centered on thirty-three and one hundred Hertz, arising from ground or airborne vibrations incident on one or more geophones are processed to give an alarm when signal components in the two bands exhibiting a rapid rise to greater than a predetermined amplitude level, characteristic of human footsteps within a protected area, occur at more than a predetermined repetition rate.

Abstract: An electro-mechanical transducer is disclosed for measuring physical parameters such as vibration, acceleration or the angular orientation of an object to which it is attached. A closed container partially filled with a fluid, has a light source and light detector mounted in optical communication with the container's interior. The arrangement of the detector and light source is such that light from the source must pass at least once through the surface (i.e., air-fluid interface) of the fluid before being detected. A constant incident light intensity is provided within the chamber and the resultant transmitted light is measured by the detector and an associated meter circuit. As the container is vibrated, or the angular relationship of the surface of the liquid with respect to the detected light rays is varied, the light transmissive and refractive properties of the liquid surface are altered, thereby altering the output of the light detector.

Abstract: A fence surveillance and security system includes a plurality of sections of relatively rigid electrical conduit which are supported by a fence. A plurality of housings are provided at spaced intervals between two adjacent sections of the conduit. Within each housing is mounted both a vibration sensor and an ultrasonic intrusion sensor. The vibration sensor produces a vibratory electrical signal in response to vibration transmitted to the housing by the conduit. The ultrasonic intrusion sensor transmits ultrasonic waves and senses changes in the ultrasonic waves resulting from movement of an object in a zone proximate the fence. The system, therefore, provides detection of persons climbing, lifting, or cutting the fence itself, as well as setting up a zone of protection to detect any movement within a predetermined distance of the fence.

Abstract: A device for indicating a disturbance in a liquid medium, which is especially useful for providing an alarm when a child falls into a swimming pool, comprises a buoyant member carrying a first conductive member, a second conductive member spaced and normally unconnected to the first conductive member, and an alarm circuit. The conductive members are connected to the alarm circuit such that when the liquid in which the buoyant member is floating is disturbed by a predetermined amount, the conductive members are brought into contact through the disturbed liquid, thereby to activate the alarm.

Abstract: A specially configured cable, which, in use, has a cross section which is mmetrical to a vertical line, but asymmetrical to a horizontal line, is used for an intrusion detection system. It comprises an external sheath, which may be round or rectangular in cross section. An inner conductor is positioned below the center of the cable. It is supported in place by a thin, substantially flat, sheet of insulating material, which is attached to the inner surface of the outer sheath. This particular configuration maximizes the change in capacitance caused by an intruder passing over the cable. The cable is connected to a time-domain reflectometer, which can display on a screen the location of the intrusion with respect to an end of the cable as well as the probable type of intrusion.

Abstract: An array of interdigitally related elements are interstitially spaced from one another, with alternate elements in the array connected to a first conductor and the remaining elements in the array connected to a second conductor. A conductive member, such as a metallic ball, is freely movable in two dimensions over the area of the array, electrically coupling and decoupling adjacent elements in the array as it moves. A circuit is connected between the first and second conductors and detects the coupling of and/or decoupling of electrical contact between adjacent elements as the ball moves over the elements, with the frequency of the coupling and/or decoupling being detected to indicate a predetermined motion or absence of motion. The elements may take different configurations for different desired results.

Abstract: An intrusion detector is provided for detecting a forcible entry into a secured structure while minimizing false alarms. The detector uses a piezoelectric crystal transducer to sense acoustic emissions. The transducer output is amplified by a selectable gain amplifier to control the sensitivity. The rectified output of the amplifier is applied to a Schmitt trigger circuit having a preselected threshold level to provide amplitude discrimination. Timing circuitry is provided which is activated by successive pulses from the Schmitt trigger which lie within a selected time frame for frequency discrimination. Detected signals having proper amplitude and frequency trigger an alarm within the first complete cycle time of a detected acoustical disturbance signal.

Abstract: An intrusion sensor uses thin film piezoelectric transducers to sense nea mechanical vibrations. A hose-like sheath contains a pair of insulating strips which carry conductive leaves on their outer surfaces. A series of longitudinally arranged segments of a thin film piezoelectric material are coupled to the leaves to provide signals representative of impinging mechanical vibrations. Since adjacent ones of the thin film segments are alternately polarized, signals are created only when the vibrations are nearby. Greater sensitivity to nearby vibrations is assured when each of the segments is fabricated from several layers of the thin film piezoelectric material.

Abstract: The trigger mechanism is an electronic switch comprised of an LED and a photosensitive transistor. The active surfaces of the LED and photosensitive transistor are normally aligned, the LED being suspended by a wire from a support above the transistor. Vibration or movement above a given magnitude results in misalignment of the active surfaces which causes the transistor to generate a trigger signal. The sensitivity of the electronic switch is adjustable by varying the spacing between the active surfaces. A delay circuit is interposed between the electronic switch and the remainder of the alarm circuitry such that generation of the alarm signal is prevented for a preset time interval after the arming of the device in order to permit the electronic switch to achieve mechanical equilibrium.

Abstract: A swimming pool alarm system of the pressure transducer type employs an omnidirectional hydrophone which is held immersed in the swimming pool by means that mechanically decouples the hydrophone.

Abstract: A detecting device for destructive vibration of structures wherein detected vibration is converted into electric signal and an alarm is actuated when signal amount reaches at least one of a predetermined counting value and integration value is provided. The converted vibration signals are amplified, a high level signal in such amplified signals is detected and amplified by a high level detector, a high level output of this detector is counted by a counter to generate a counter output when the predetermined counting value is reached, a low level signal in the amplified signals is detected and amplified by a low level detector, a low level output of this detector is integrated by an integrating circuit to generate an integration output when the predetermined integration value is reached, and the alarm is actuated whenever at least one of the counter output and integration output is provided.

Abstract: An intrusion alarm circuit including a single electroacoustical transducer, such as a diaphragm-supported piezoelectric element, connected to an amplifier in a positive feedback loop configuration. The transducer functions as both a sound pickup and sound generator. When the ambient sound level exceeds a preselected threshold level, the resulting vibration of the transducer generates a voltage which activates the amplifier, whereupon the transducer vibrations are sustained and amplified in the manner of an oscillator, thereby producing an audible alarm.

Abstract: A tamper-proof security alarm system comprising basically a radio transmitter unit to be located at equipment which is to be protected, and a radio receiver unit with alarm and control circuits located at a point remote from the transmitter. The transmitter unit comprises a unique, wholly self-contained, small portable sensing and triggering assemblage constructed in a novel manner by which it is completely, 100 percent tamper-proof. The sensing and triggering assemblage employs an ultra-sensitive, gravity-responsive electrical switch connected to energize the transmitter, said switch incorporating a suspension system with reset means whereby the switch can be properly oriented to take care of various angularities of the supporting surface on which the assemblage is placed. The reset means clamps the switch in any of an infinite number of oriented positions. Whenever the unit is moved, however slightly, the switch closes and energizes the transmitter.

Abstract: The invention comprises a plurality of intrusion detection transducers connected together wherein each transducer has a central core extending along an axis and having a length along that axis defined as XL where X is an even number of at least two and L is a given length. At least one sensing winding wire is wound around the core to provide a first-hand winding of L/2 length, X-1 number of windings of length L, and a second end winding of L/2 length, each adjacent winding being a reverse polarity to the next adjacent winding. Means are provided to connect each transducer to the adjacent transducers such that the first end of one transducer connects to the second end of the adjacent transducer.

Abstract: 10. A vehicle identifying circuit comprising: means for detecting seismic brations created by passing vehicles and converting them into electrical impulses; frequency-sensing circuit means coupled to said detecting means for producing electrical signals in accordance with the frequency characteristics of said impulses, said frequency-sensing circuit means comprising an amplifier, a clipper circuit, a differentiator circuit, a rectifier and an integrator coupled in sequence to produce said electrical signals; and vehicle discriminating circuit means coupled to said frequency-sensing means to convert said signals into output pulses having voltage levels indicative of the character of the suspension system of the passing vehicle.

Abstract: An alarm device for detecting movement of parked automobiles provides a support for mounting on an automobile. An outer member defines a ring having an inner surface of conducting material. A helical spring is attached to the support to suspend the ring in an attitude where the ring defines an aperture in cross-section. An inner member having an outer surface of conducting material is connected by a flexible connection to the support to be suspended in said outer member and spaced from the inner surface thereof.

Abstract: A single composite cable is deployed between adjacent monitoring stations r sensing an intruder. A number of piezoelectric elements disposed in the cable provide electrical intrusion signals when they are disturbed. Power and triggering pulses for the stations are fed through the cable by a pair of electrical conductors and optical signals representative of the intrusion signals are fed through at least one optical fiber. As a result, the composite cable is relatively lightweight and compact to simplify deployment and it avoids the problems normally associated with crosstalk.

Abstract: An alarm system for detecting the pattern of acoustic signals resulting from the breaking of glass utilizes transducers to convert the acoustic waves to electrical signals and then analyzes the signal strength, the frequency content and the pattern of the signal and no signal intervals to discriminate the breaking of glass from background or spurious noises. The system also determines the level of background noise and compensates therefor in determining whether an alarm signal is to be generated.

Abstract: A system is described which detects the sound of barking of a watchdog and generates an electric signal in response to that barking. The electric signal, suitably processed by electronic circuitry, is used to operate an appropriate intrusion reaction device, such as an audible alarm, floodlights, or a remote indicator device located at a guard or police station.

Abstract: A device for giving a visual or audible indication of motion such as impact, vibration or the like, which has a contact element supported on a base. When motion occurs, due to earthquake or other causes, a contact element is displaced completing an electrical circuit. In a preferred embodiment, the contact element comprises an elongate pin which topples in response to motion. In another embodiment the contact element may be a spherical element. The device may also be used as an intrusion alarm having an auxiliary member co-operable with the device so that the device can be attached to a door or a window as a trip alarm.

Abstract: An intrusion alarm system of a variety utilizing an inertially responsive sensor preferably present as a pendulum actuated reed switch. Logic circuits provided within the system provide, in one embodiment, an efficient pulsating alarm at dual frequencies optimized for human recognition. In another arrangement, a unique dual delay arrangement is provided, one delay commencing with the arming of the device to permit adequate time for the setting of a sensing switch. A second delay arrangement is provided at the option of the operator for purposes of delaying the activation of the alarm once the sensor switch has been tripped. This feature may be utilized to permit entrance through a door or the like upon which the unit is mounted wherein the device can be deactivated prior to assuming an alarm sounding condition. In each of the circuit embodiments, an arrangement is provided wherein, once tripped, the alarm will continue to sound for designated intervals even though turned "off".

Abstract: The detector is primarily for detecting glass breakage and is constructed as a sensing element for detecting the breakage and generating an alarm signal. The detector generally comprises a thin cylindrical casing including a first leaf spring and a second leaf spring having a plurality identations or bends thereon for absorbing noise signals below a breakage frequency signal when a glass panel is actually broken or cut.

Abstract: This invention relates to a system and method for determining velocity, direction, position, profile and confidence information of a target such as an intruder from alarms generated by the intruder passing by an array of spaced sensors. The system comprises a processor, the primary element of which is a velocity-position matrix comprising a plurality of information storage cells in the form of counters. The cells are arranged in a plurality of adjacent rows and adjacent columns corresponding to target velocity and position, respectively. Each sensor alarm is entered as a count into cells in those columns which correspond to sensor deployment and the count in each cell is shifted to the adjacent cell in the same row by auxiliary equipment at different rates for the different rows to provide a velocity determination capability. Counts are subtracted from the cells in the columns corresponding to sensor locations when no alarm is given by the particular sensor.

Abstract: A swimming pool alarm system for activating an alarm indicator responsive to the presence of a person in a pool being monitored. The system includes a frequency selective detector responsive to water disturbance created by a person in a swimming pool. The detector enables a transmitter at poolside. A receiver remotely mounted with respect to the poolside transmitter responds to the transmissions therefrom activating the alarm indicator.

Abstract: A tamper-resistant box for protecting the hooters of burglar and fire alarm systems. The box has a fixed frame to be attached to a support, such as a building, and a moveable cover separated slightly from the frame by interposed springs. Microinterrupters are sensitive to any movement of the moveable cover relative to the frame to energize the hooter when the moveable cover is touched.

Abstract: A piezoelectric transducer is secured to the surface of a glass sheet to translate mechanical vibrations generated in the glass sheet into an electrical signal when a crack is produced. A detection circuit is connected to the transducer to determine whether the frequency of the signal is above or below a predetermined value. If the frequency is higher than the predetermined value, a warning signal is derived to indicate a crack and therefore probably a burglary. Alternatively, the piezoelectric transducer in the transmit mode is excited electrically by an impulse to introduce an elastic wave into the glass sheet. A gate circuit is connected to the transducer to pass signals resulting from reflection of the elastic wave from discontinuities in the glass sheet which result from a crack. The reflected crack indicating signals are passed through the gate to the transducer when it is in the receive mode.

Abstract: A rate sensitive system for a seismic sensing pedestrian range containment evice monitors the shift in relative energy of a footstep as a function of footstep rate. A rate sensitive relative energy measurement circuit operates in conjunction with the detection of human footsteps and classification of personnel to limit the detection range of a seismic sensor to specific distance range.