Abstract: A motion responsive alarm system including a motion sensor having a housing with a rotatable disk therein, a slot in the disk and a ball bearing in the slot and being loosely confined within an annular chamber in the housing surrounding the disk. The disk contains a plurality of orifices which pass between an LED on one side of the disk and a phototransistor on the other. A signal from the phototransistor is sent to a triggering circuit by interrupting light transfer between the LED and the phototransistor. The circuit includes a novel oscillator having a duty cycle of 10% which drives the LED in the sensor. An alternate state device is coupled to the sensor and the oscillator for generating alternate state outputs only during sensing of motion. A one-shot circuit generates a motion pulse each time motion is sensed. A pulse interval timer and gate determine if the pulses are to be gated to a timer or blocked.

Abstract: A security system (10), operable to produce an ALARM signal indicative of glass breakage in a region (16) in which a human being (24) may legitimately be present, has a human presence detector (12), a glass breakage detector (14), and an alarm signal activator (30) that includes a one-shot timer (52). A HUMAN PRESENCE DETECT signal (36, 38) output from the human presence detector triggers or retriggers the timer to produce an active output for a predetermined holdoff time interval T.sub.H. The active output causes a gate (58) to prevent a glass breakage alarm or GB DETECT pulse (46) from the glass breakage detector from reaching a control panel (34) and thus from triggering the ALARM signal if the GB DETECT signal occurs within the holdoff time interval after a HUMAN PRESENCE DETECT signal. Another gate (64) prevents a GB DETECT pulse (48) from reaching the control panel if that pulse occurs while the human presence detector is detecting human presence in the region (38).

Abstract: A method and apparatus are provided for warning when the amplitude of conversations exceeds certain values. The apparatus includes a microphone and related circuitry which continuously produce a signal related to the amplitude of the conversation while the apparatus is operational. A comparator continuously compares the signal to a pre-set first value and produces an output as long as the signal indicates that the conversation exceeds a certain amplitude. There is a discriminator responsive to the comparator output which provides a discriminator output when the duration of the comparator output exceeds a pre-determined value. The discriminator is connected to an alarm which produces a warning signal when the discriminator provides the discriminator output. There may also be a second comparator which produces a visual signal when the amplitude of the conversation is above an amplitude which may be below the amplitude which activates the alarm.

Abstract: An apparatus for detecting of the loss of motion in a transporting system regardless of the position in which the system stops. The apparatus incorporates one or more detection switches coupled with two timers operating in series or parallel and determines when motion has ceased.

Abstract: The system includes optical detectors, a control microprocessor, and an alarm. The detectors optically detect the presence of cartons within the shelf exit openings and emit carton-present signals upon such detection. The microprocessor is responsive to the signals and activates an alarm when a preselected detector signal pattern is observed. In the preferred embodiment, the alarm patterns include four signals within 15 seconds or one signal having a duration of 6.5 seconds.

Abstract: An alarm unit for a ski has a battery powered circuit which energizes an audible alarm in response to the output from a movement detector on the indication of absence of movement for a predetermined time. This allows a buried ski or a buried skier to be detected. A remotely controlled mode switch enables the unit to be switched to a theft mode in which the alarm is energized on detection of movement by the movement responsive unit.

Abstract: A system is disclosed for deterring theft of portable electronic equipment that operates in accordance with an industry standard known as EIA-232-D. A theft deterrent unit monitors signal current transmitted between interconnected electronic units. When one or more of the interconnected electronic units is disconnected, the theft deterrent unit detects the cessation of signal current and activates an alarm. The alarm may be used to generate a local alarm such as, for example, an audible alarm, and the alarm signal may be transmitted to a central alarm system for further processing.

Abstract: The system includes optical detectors, a control microprocessor, and an alarm. The detectors optically detect the presence of cartons within the shelf exit openings and emit carton-present signals upon such detection The microprocessor is responsive to the signals and activates an alarm when a preselected detector signal pattern is observed. In the preferred embodiment, the alarm patterns include four signals within 15 seconds or one signal having a duration of 6.5 seconds.

Abstract: A resettable fire detection device comprises in combination a rate of temperature rise sensor, an electronic fixed temperature sensor, and electronic circuitry connected to both circuits for producing an alarm signal if either sensor is activated and for maintaining the alarm signal once the device has been activated. This resettable fire detection device has many uses: specifically, it can be used as a replacement device for a smoke detector device commonly used on ships. In this case, the device draws a very low amperage for use on a parallel circuit common wih smoke detectors. In addition, a time delay circuit can be associated with each of the sensors to avoid false alarms and to accommodate certain environmental conditions. The resettable nature of both the fixed temperature and rate of rise temperatue sensor allows full testing of each device while allowing a remote reset signal to be used to reset the device. In a preferred form, the rate of temperature rise sensor is a mechanical arrangement.

Abstract: In a glass smashing alarm system for generating an alarm when a glass smashing sound is detected, the present invention is directed to reduce the possibility of occurrence of an erroneous alarm, and includes a normal alarm mode in which a preliminary alarm is raised for a short time when a glass smashing sound is detected, and a special alarm mode in which a main alarm is raised for a long time when the glass smashing sound is detected, and is constituted in such a manner that mode switching is effected so as to shift the mode to the special alarm mode at the end of the preliminary alarm, and to return it to the normal alarm mode after the passage of a predetermined time if the glass smashing sound is not detected at the end of the main alarm or during the special alarming mode. In another aspect of the invention, generation of an alarm is inhibited if a key unlock switch is turned ON before passage of a predetermined time from detection of the glass smashing sound.

Abstract: An object to be protected is placed on a compressible pad having upper and lower conductive plates, separated by a compressible dielectric. A sensing device is connected to the upper and lower plates to sense a first capacitance when the upper plate is compressed by presence of the object, and a change in capacitance when the object is removed so as to permit the dielectric layer to expand and change the capacitance. There is a time delay circuitry and other circuitry to alleviate the possibility of false alarms.

Abstract: An anti-pilferage alarm system for a cigarette carton display case. The system includes optical detectors, a control microprocessor, and an alarm. The detectors optically detect the presence of cartons within the shelf exit openings and emit carton-present signals upon such detection. The microprocessor is responsive to the signals and activates an alarm when a preselected detector signal pattern is observed. In the preferred embodiment, the alarm patterns include four signals within 15 seconds or one signal having a duration of 6.5 seconds.

Abstract: An alarm system for use in store showcases. The alarm system includes a door switch, a timer, a user actuable shunt switch, a lock switch and door alarm logic. Prior to opening a showcase door, the shunt switch is actuated causing the time to produce a signal which disables the door alarm logic for a first predetermined time period. The sales person then has a first predetermined time period to enter the showcase, remove the desired merchandise, and close the showcase. Failure to close the showcase door in time, or opening the showcase door without actuating the shunt switch, causes the door alarm logic to activate, and the salesperson is notified of the open door. The lock switch can be actuated to disable the alarm logic for a second time period.

Abstract: A general purpose time delay weight activated switch is disclosed. A foam seat cushion contains wire mesh electrical switch closing contacts. Sitting or rising from the cushion opens and closes the switch. A solid state adjustable timer is also imbedded in the cushion, or adjacent to the cushion. Its purpose is to delay the opening of the switch several seconds. An ideal application for the device is to automaticlly lock an emergency brake in a delivery van. The driver leaving the parked vehicle automatically locks the parking brake or vehicle brakes when leaving the vehicle when the present invention is combined with a parking brake or vehicle brake locking means. The invention's delay circuit allows the driver to bounce up and down on a bumpy road without setting off the switch. Other uses for this special purpose seat cushion include railroad, farm equipment, industrial and power boat safety systems.

Abstract: A swimmer protection and pool safety warning device comprises a portable sonic signal generating member worn by a swimmer in a pool, the signal generating member having a switch or similar device which is activated at a predetermined depth. Also included is a timer for detecting immersion at said predetermined depth for a predetermined time. On immersion occurring at the predetermined depth for the predetermined time, a sonic signal is generated, and detected by a receiver mounted in the pool. An alarm signal is generated to operate an alarm device. Calibration of the source signal generating member can be provided.

Abstract: An error-free control circuit for burglar alarm detectors which eliminates false alarms and facilitates setting the sensitivity of the detectors by providing an audible pre-warning signal via some alarm warning device to indicate false alarms and impending violation by a burglar an alarm signal from an alarm upon actual violation by a burglar. When the detector detects a false alarm condition, a pre-warning audible signal is sounded by the alarm warning device for easy sensitivity setting during installation. When the detector detects the sounds of tampering to the car, a pre-warning audible signal is sounded by the alarm warning device to warn the would-be burglar that the premises are protected by an armed alarm. Finally, when the detector detects actual violation of the protected premises, the alarm sounds to scare the burglar away. By this means, an alarm detector can be set to give optimum performance under any condition.

Abstract: A document retainer (10) having receptacles (14) is provided. The retainer is equipped with clip switch contact sensors (46,50) in the retainer receptacles. Documents (12) held in the receptacles maintain the clip switch contact faces in a spaced relationship by being interposed therebetween. When a document is withdrawn, the contact faces spring into engagement, closing the contacts and thereby energizing an alarm circuit that has audible and inaudible alarms (20,18) to facilitate indication of the document withdrawal. A resetable timing device is provided to suppress the audible alarm for a period considered sufficient for a card transaction. Preferably, the retainer is in the form of a compact module that can be inserted into a receptacle in a wallet or can be attached to another object by use of a provided releasable attachment device.

Abstract: A locating system and method in which a network of communication stations are spread over a surveillance area. Each moveable element is provided with a transponder having an associated identification code. A paging signal sent out over the surveillance area is picked up by the transponders and the one with the identification code provided in the page responds. The response is made at a frequency different from the page. The response is picked up by the nearest communication stations. A master station communicates with the communication stations at a frequency different from that used by the paging signal or the transponder. The master station which interrogates all the communication stations locates the paged transponder to within a sector bordered by the communication stations that received the response from the transponder. The communication stations can be subdivided into three or more interspersed arrays.

Abstract: A pool safety alarm system includes a water-activated sonar transmitter adapted to be worn on the body of a non-swimmer for continuously transmitting low frequency audio signals upon immersion of the transmitter. An underwater microphone or hydrophone is located within the pool and is connected to a receiver circuit having a band pass filter connected to a monostable multivibrator for supplying signals to an alarm. Whenever signals within the pass band of the filter are received by the hydrophone, these signals trigger the monostable multivibrator from its stable state to its astable state. The astable state of the multivibrator operates the alarm. When signals within the pass band frequency of the filters are received by the hydrophone from sources other than the water-activated transmitter, such signals typically are momentary or intermittent.

Abstract: The location on an escalator where the handrail reenters the balustrade is provided with an electrical field projector which will establish a limited extent electrical field around the handrail reentry housing. The field is established with a pair of antennae disposed adjacent to the handrail reentry. The antennae are preferably connected to the main AC power source for the escalator, and can be angularly adjusted to focus the field that they project. Shrouds are positioned adjacent to each antenna to confine the lateral extent of the field. An object entering the field will cause a field disturbance which creates a signal setting off an audible alarm. Subsequent stopping of the escalator can ensue if the disturbance is not removed in a predetermined amount of time.

Abstract: A remote confinement system provides a plurality of different unsupervised tests to determine the presence, identity or conduct of the prisoner. The tests preferably include an RF test performed continuously with an RF transmitter attached to the prisoner and a receiver at the remote location, a schedulable voice test performed to identify a person as the specified prisoner, and a breath alcohol test to determine the prisoner's sobriety. The tests are performed with equipment at the remote location in accordance with test selections and schedules selected in a prior automated communication with a central office computer. Events which include test results are communicated to the central office upon a selectively established communications link to the central office, in reply to which communication information selecting subsequent tests procedures or scheduling is communicated from the host to and stored at the remote location.

Abstract: A door status detection system is provided for use in a refrigerator having a cabinet defining first and second food storage compartments and corresponding first and second doors hingely mounted to the cabinet for selectively closing the compartments. The doors each include a magnetic sealing strip secured thereto for sealing the doors to the cabinet and for maintaining the doors in closed position. First and second switch arrays are installed into the cabinet generally adjacent a section of the magnetic sealing strips of the first and second doors, respectively, when the doors are in closed position for signaling the opened/closed status of the doors. The first and second switch arrays are electrically connected in series and operated by the magnetic sealing strips of the doors. Circuitry is connected to the first and second switch arrays for signaling a user of the refrigerator if either of the doors remains in an opened position for a defined period of time.

Abstract: An alarm apparatus includes a plurality of sensors connected in parallel with each other between sensor lines extending from a receiver and sounding devices connected between the sensor lines in correspondence to at least one of the sensors. The receiver includes a unit for changing a voltage supply condition of the sensor lines. A control circuit is provided to each audio device so as to selectively control the audio devices when the voltage supply condition is changed, so that a audio device corresponding to an activated sensor, or all of the audio devices, can be arbitrarily controlled to generate audio alarm signals.

Abstract: A personal security communication system is disclosed. It is comprised of a motion and position sensor adapted to detect motion and lack of motion. The sensor has a motion and position sensing switch having means indicative of the motion of a contact making element in the switch and is adapted to provide at least a first and second electrical state according to the motion and lack of motion of the contact making element. Means is provided for detecting the first and second electrical state. The detecting means being adapted to provide a signal indicative of the electrical state of said switch. The system also includes user input means, processor means for receiving information from said motion sensing means and said user input means and adapted to format a digital data message indicative of said information, a transmitter means for transmitting said message, an alarm means activatable by said processor means and a power supply means for powering said processor means, transmitter and alarm means.

Abstract: An intrusion detector and method of operating the detector is disclosed. The detector comprises a means including an antenna for transmitting spaced pulses of radiation energy of a given frequency throughout a region to be protected. Means are also provided for receiving the radiation energy reflected from the protected region. The reflected radiation energy is received between adjacent spaced transmitted pulses in the form of an AC analog signal at the given frequency, the peaks and valleys of which signal vary in amplitude with time. Means are also provided for allocating a portion of the time occurring between transmitted pulses into a plurality of time segments, each of which segments is long enough to correspond to a plurality of cycles of the analog signal.

Abstract: A data entry system comprising a one-handed keyboard having five data keys and five control keys which are used in combinations for entering data and control characters in the system. The system also comprises a cursor control assembly for controlling a cursor on a screen and controls for permitting a single keyboard to be operated with either the left or right hand.

Abstract: An alarm for sending out distress information when the user is in an abnormal position or when the user wishes to alert others of a distress condition. The alarm includes an omni-directional tilt switch and a transmitter. When the tilt switch has passed a critical angle, a signal is sent to a delay circuit. The delay circuit waits for a predetermined period of time, such as ten seconds, before enabling a transmitter. The transmitter then sends information over a communication link, signaling others that the user is in need of assistance. The invention further includes an alarm for alerting the user that the predetermined position of the tilt switch has been satisfied and that, after the predetermined delay, the distress information will be transmitted over the communication link unless deactivated by the user.

Abstract: A tire pressure monitoring system for a tractor-trailer type vehicle includes a series of sensors on each of the wheels of the vehicle. When a low pressure condition occurs, the sensor activates a radio frequency transmitter for delivering a low power FM signal to a receiver on the tractor. A delay circuit is incorporated in the receiver to require that the signal from the transmitter last for a predetermined duration prior to energizing an indicator in the tractor. The receiver antenna is preferably mounted on the bottom of the tractor in a plane including the trailer wheels.

Abstract: It will thus be seen that the method for measuring the level of a liquid contained in a reservoir which is subjected to varying accelerations is carried out by means of a level sensor which signals when the level of the liquid drops below a predetermined level, and a warning device which is activated if the sensor signal is applied thereto uninterruptedly for a predetermined minimum period of time and results in maximizing functional reliability of the warning signal issuing means during all types of movement situations of the reservoir, while false alarms are virtually eliminated. This is accomlished in that each occurrence involving the uninterrupted application of a sensor signal for a period which is longer than the predetermined time period (t.sub.1) is registered as an event, and in that the warning device is activated after a predetermined number (n) of events have been registered within a predetermined period of time (m).

Abstract: An intruder detection system is provided with circuitry for reducing the risk of false alarms from spurious sources. Such circuitry comprises a pulse generator for producing current pulses of predetermined pulsewidth and amplitude each time the output of an intrusion detecting element exceeds or falls belows a preset threshold level, an integrating circuit for integrating the output of the pulse generator, threshold sensing means for activating an alarm when the integrator output exceeds a preset level, and a timing circuit for establishing a predetermined time interval and for discharging the integrating circuit in the event the integrator output fails to exceed such preset level within such predetermined time interval. According to a preferred embodiment, means are provided for resetting the time interval each time the detector output exceeds or falls below the selected threshold level.

Abstract: A space surveillance apparatus includes at least one source of sonic radiation driven by a driver circuit as well as a processing or evaluation circuit. Upon movement of an object, or presence of a foreign object within a monitored space, the processing circuit triggers an alarm signal. Each sonic source defines the volume of its own monitored space, according to the equation:L=D.sup.2 /(4.lambda.),wherein:L=Length of main direction of radiation of the monitored space;D=Diameter of diaphragm of sonic source; and.lambda.=Wavelength of acoustic wave.The driver circuit drives the sonic source either in continuous mode, or in pulsed mode, and either at a constant wavelength or at a variable wavelength, i.e. in frequency modulation.

Abstract: An automatic lighting device having a circuit for operating an electric light, a switch for manually actuating the circuit, a detector circuit for determining whether movement above a prescribed threshold level has occurred within the area covered by the electric light within a first preselected period, a circuit responsive to the detector circuit for disabling the circuit for providing electricity if movement has not occurred in the area during the first preselected period, and a circuit for reactivating the circuit for providing electricity in response to the detection of movement in the area within a second preselected period.

Abstract: An alarm system comprising a sensor which detects a human body in a fixed detection area and outputs signals, a delay timer circuit which outputs signals after passing a fixed delay time by turning on an alarm switch, a two input AND circuit in which output signals of the delay timer circuit and the sensor are entered, a latch circuit with a delay timer which outputs signals after passing a fixed delay time from when output signals of the two input AND circuit are entered and keeps the signals being outputed until entry of reset signals.

Abstract: The present invention relates to a system for the vehicular transportation of a lock-equipped cassette (1) for valuable documents between a first station, e.g. a bank or a post office, to a second station. The cassette (1) is intended to be kept in a cassette holder or rack (2) in the first station and the second station, and also in the transporting vehicle. The cassette is provided with an electronic circuit (R1,22) which is characteristic to the cassette concerned and which is arranged to co-act with a controlling activating circuit (M1). When the cassette (1) is lifted from its cassette holder or rack a clock circuit located in the cassette is activated and, unless the cassette is replaced in a cassette holder within a predetermined time, causes an alarm to be activated, this alarm being an acoustic alarm, a device for generating smoke within the cassette, releasing a dye onto the valuable documents contained in the cassette, etc.

Abstract: A device for generating an alarm signal in the event of an abnormality in the environment of a detector includes a pair of signal/power supply lines, a number of detectors for detecting an abnormality, e.g., fire, gas leakage, or burglary, and an alarm receiver including a signal processing circuit for receiving a signal from a detector indicating the presence of an abnormality. The signal process circuit includes a signal storage circuit, and a converting circuit for changing one or a combination of at least two of a polarity, voltage, current, or impedance of a power source if the abnormality persists for a predetermined time. The change in the power source parameter is supplied via the supply lines to a signal holding circuit in the vicinity of the detector. The signal holding circuit is responsive to the changed parameter and changes state, thus providing an indication at the detector that the abnormality has persisted for the predetermined time.

Abstract: Fire detection apparatus includes a fire detector panel and an accumulation-type control panel in which the fire detection element is non-latching but the fire voltage detection circuit includes a fire indicator which is latched when a fire signal is detected for longer than a predetermined time. The circuit for latching is controlled by an accumulation circuit in the control panel that controls a relay closing that generates a fixed voltage suitable for the fire indicator.

Abstract: A fire alarm system employing multiple sensors can accurately and quickly respond to real fires with an alarm signal and prevent issuance of a false alarm due to noise or the like. A pair of decision circuits in a fire signal receiver receive fire detection signals from respective sensors and produce fire occurrence signals representing a first level of probability that a fire has occurred and decision signals representing a second lower level of probability that a fire has occurred. A fire alarm is issued when a fire occurrence signal has been outputted by any one of the decision circuits or when a decision signal is simultaneously outputted by both decision circuits.

Abstract: An intrusion alarming apparatus according to this invention detects the human body present in a sensing zone thereof and sends out warning information by means of sound and light. Detection of the human body depends on a human body sensor which emits detection signals in response to variation in the strength of heat rays or interception of radiated infrared rays. Information by the use of sound and light is effected by driving a sound-using alarm such as a speaker and a light-using alarm such as a stroboscope with a sound emission driving circuit and a light emission driving circuit which operate on the basis of detection signals output by the human body sensor. The driving circuits for sound and light emission are connected to each other so as to be operated by means of a single timer circuit.

Abstract: An object detecting apparatus has a plurality of light emitters which are sequentially actuated for projecting sequential light beams. A first structure is provided for receiving beams not reflected off any external body. A second structure is provided for receiving any part of the light beams reflected from an object in the area. A reference phase signal corresponding to the projected light beams is generated. A detection phase signal corresponding to the received reflected beam is also generated. The light emitters corresponding to the reflected light beams are continuously activated. The detection area is restricted by inhibition of output from an alarm phase difference discriminating circuit to a circuit when a difference between the reference and detection phases is not within a predetermined range. Consequently, the detection area can be restricted to a desired range, and the alarm circuit can be retained non-operative unless the object remains continuously in the area.

Abstract: A self test circuit for a combustion products detector automatically periodically tests whether the sensitivity of the sensor is in a predetermined range between minimum and maximum sensitivities. Transistor switches selectively connect different test impedances across the sensor for respectively simulating two amounts of combustion products, one of which is slightly less than the amount corresponding to the maximum sensitivity level and the other of which is slightly greater than the amount corresponding to the minimum sensitivity level. If the sensor either produces a smoke output signal in response to the first test or fails to produce an output signal in response to the second test, then the smoke alarm is actuated after the tests are completed to produce a unique fault signal, the alarm annunciator being inhibited during the test.

Abstract: In the apparatus for signalling an alarm, for example, in a gas or fire detecting installation, a detector is reset after a first response and the time duration until the next-following detector response is determined and classified with respect to three classes of time periods. When the time duration until the further detector response is beyond a predetermined upper or outer time limit, no alarm signal is released and the apparatus returns into its original state. When the further detector response occurs between two time limits, the alarm is immediately signalled. When the further detector response occurs prior to a lower one of the two time limits, there is carried out still one further test during which the detector is once again reset. The alarm signal will only be released if an additional further detector response is still observed prior to the upper time limit.

Abstract: A box formed with an aperture in which a photosensitive cell is secured includes an electronic circuit connected to be fed by the electrical signal produced by the photosensitive cell when the latter is irradiated by ambient radiation. Said electronic circuit comprises a delay circuit adapted to receive the signal and arranged to produce a control signal when the cell has been irradiated for a predetermined time interval; an audible signal generator received in the box opposite apertures and connected to produce an audible signal in response to the control signal; and a circuit adapted to interrupt the audible signal after a predetermined time interval so that the audible signal is of predetermined duration.The box has means for securing it to an object which is required not to be lost accidentally, e.g. keys, a wallet, a diary, etc. A cover can be provided for being placed over the cell to protect it and keep away external radiations when the reminder device is not required to be operative.

Abstract: A monitoring system (10) for a fluid waste disposal system is provided. Fluid waste is transported from a source (12) through a valve (16) to a reservoir (14) under access control provided by access switches (40). The monitoring system (10) includes density circuitry (64) for monitoring the density of fluid being deposited into the reservoir (14). Level detector circuitry (90) is provided for monitoring the level of fluid which has been deposited in the reservoir (14). The monitoring system (10) further includes a counter (56) for counting the number of times the valve (16) has been actuated. Counter delay circuitry (54) provides an output to counter (56) to positively indicate that an access switch (40) has been actuated.

Abstract: A control system for an illumination lamp installed in a building equipped with a door operation control apparatus. The system comprises a door opening and closing instructor, a control circuit responsive to an instruction signal from the instructor to produce a door control signal and a lamp control signal, a door driver responsive to the door control signal to drive the opening and closing of a door, an illumination lamp for illumination of the interior of the building, a detector for detecting the movement of a human body and producing an electric signal representative of the movement, and a circuit which is responsive to the lamp control signal and the electric signal to turn on the illumination lamp and keeps the illumination lamp turned on for a predetermined time extending from the termination of the lamp control signal and the electric signal.

Abstract: Circuitry for qualifying a series of randomly occurring alarm events to avoid erroneous indications. Alarm events occurring in a surveillance system or the like are counted over a selected time interval, and final alarm output is effected only if a selected 1+n number of events has been counted within the interval. Both the repetitive time intervals and the event number are variable in accordance with the exigencies of the alarm application.

Abstract: An intrusion detection system which reliably detects intrusions while minimizing false alarms by time-analyzing significant signals indicative of intrusions. The time length of each significant signal is measured, the time lengths of successive significant signals are accumulated, and an intrusion signal is generated if the accumulated time length reaches a first preselected time length. The time length between successive significant signals is also measured, and the accumulated time length is reset to zero if the time length between successive significant signals reaches a second preselected time length.

Abstract: A burglar alarm system of the non-wired perimeter protective type for detecting and indicating break-ins at an entrance or opening, such as a window or door, of a building, employs as a sonic signal generator a transducer that is both triggered and powered by the break-in. The sonic signal is of a specific selected supersonic frequency and is received by a remotely located local receiver within the building which in turn may actuate an alarm. Protection against false activation by sonic noise is provided by altering the gain of the receiver in response to received sonic noise adjacent to but different from the selected frequency, so that noise containing even a strong signal at the selected frequency, as well as at adjacent frequencies, does not result in an alarm being raised, but a weaker signal at the selected frequency, without signals at adjacent frequencies, such as is produced by the transducer, does result in an alarm being activated.

Abstract: A sound level alarm device sequentially listens to the sound level of an enclosure or area for a first predetermined interval of time, and thereafter does not listen to the sound level of the area for another predetermined interval of time. The circuit sounds an alarm upon detection of a sound level of a predetermined magnitude measured during the first time interval. The circuitry is designed for omitting quick, sharp noises such as a cough, hand clap, book dropping, or the like. The apparatus is advantageously used in class rooms, laboratories, libraries, and play rooms as a teaching aid wherein people with loud noisy habits are electronically assisted in overcoming these undesirable aspects of their life style.

Abstract: A microcomputer based monitor and display system for a refrigerator in which visual indicia are provided to indicate to the user the degree of door usage on a rolling average time basis. Threshold time limits are established to correspond to heavy, normal and light usage. The actual door-open time is sensed and accumulated in successive time segments. The rolling average door open time over a predetermined number of time segments is calculated at the end of each time segment and the appropriate lamp is lit depending on how the calculated average door-open time compares to the established threshold values.

Abstract: A door status detection system is provided for use in a refrigerator having a cabinet defining first and second food storage compartments and corresponding first and second doors hingely mounted to the cabinet for selectively closing the compartments. The doors each include a magnetic sealing strip secured thereto for sealing the doors to the cabinet and for maintaining the doors in closed position. First and second switch arrays are installed into the cabinet generally adjacent a section of the magnetic sealing strips of the first and second doors, respectively, when the doors are in closed position for signaling the opened/closed status of the doors. The first and second switch arrays are electrically connected in series and operated by the magnetic sealing strips of the doors. Circuitry is connected to the first and second switch arrays for signaling a user of the refrigerator if either of the doors remains in an opened position for a defined period of time.