Abstract: An arrangement for testing an alarm system, requiring only a single individual. The alarm system itself includes an alarm activation circuit, a main alarm, for example an audio alarm, and a plurality of remote sensors all connected together such that activation of at least one of the remote sensors activates the alarm circuit which, in turn, activates the alarm. The testing arrangement senses whether the alarm activation circuit has been activated in response to the activation of one of the sensors. If it has, the testing arrangement automatically deactivates the alarm circuit and the alarm, preferably in an adjustably fixed period of time after activation of the circuit. Thereafter, preferably after a second adjustably fixed period of time, the arrangement automatically causes the alarm activation circuit to be reset. In addition, the testing arrangement preferably includes its own alarm preferably an audio alarm, which is activated during this second adjustably fixed period of time.

Abstract: A warning device is energized when speed signals integrated in an integrator exceed a predetermined level. However if a steering wheel and/or an accelerator pedal is operated, the integrator is reset.

Abstract: An anti-theft alarm system is provided for detecting a desired disturbance to an associated structure wherein a momentary disturbance of the structure causes the alarm to emit a short audible warning blast and if the disturbance continues, thereafterwards, the alarm will remain on until the alarm system is deactivated.

Abstract: Theft of electrical appliances and the like is counteracted through provision of an alarm activated by removal of an electrical power line plug from an outlet by opening a normally closed or closing a normally open pair of contacts to gate a thyristor or relay and provide power through the thyristor or relay to a light, audible alarm or the like, the contacts being entirely hidden within the outlet. The alarm may also be activated by cutting a power line.

Abstract: A plurality of watch stations are installed in protected premises that must be tripped in proper sequence once each hour and embodies means whereby when the watchman comes on duty and starts his rounds of duty, a signal will be transmitted to the central station and when he has completed the rounds of stations a second signal will be transmitted to the central station indicating that all is well. In the event the proper sequence of operation of the watchman's stations is broken, an alarm will be indicated in the central station. Thus the central station receives only two signals regardless of the number of stations on the watchman's route unless there is something wrong with the watchman and he is in need of help. The present system is designed to prevent tampering with the system, to prevent the system being turned off prior to the end of the watchman's tour of duty, and to permit the watchman to signal for outside help from anyone of the stations on his tour.

Abstract: A reflective type module for remotely controlled sign displays providing a plurality of linear elements adapted for form the Latin alphabet and Arabic numerals, each element controlled by a two position electromechanical motor to be rotatably moved to a visual or non-visual state in response to an electrical signal. Each module is self-contained and individually encased.

Abstract: A remote temperature change warning system for a refrigeration vehicle comprised of a temperature sensing circuit located in the refrigeration compartment of the refrigeration vehicle and a detection circuit located on the vehicle remote from the temperature sensing circuit and having means for indicating to the vehicle operator the temperature condition in the refrigeration compartment, the output of the temperature sensing circuit and the input of the remote detection circuit being electrically connected through the existing electrical wiring of said refrigeration vehicle.

Abstract: An improved early warning fire detector of the ionization type is provided wherein detection circuitry having adjustable sensitivity is connected to an ionization chamber responsive to products of combustion. A supervisory circuit monitors the unit to assure that power is applied to the unit, that the detecting circuitry is operative and that the unit is operating at the proper sensitivity.

Abstract: An adapter unit is provided which may be easily and quickly fitted into existing pedestrian traffic control signals to adapt such signals to an assembly in which luminous gaseous tube signal elements are mounted in an enclosed capsule, or module, which, in turn, is supported within the original housing of the signal. The adapter unit of the invention comprises a signal illuminating capsule which has a tray-like configuration, and which is mounted in the cover of the traffic control signal by means of a pair of cross bars which are releasably clipped into brackets fixed to the upper and lower rear edges of the cover.

Abstract: The invention relates to a device for checking the angular position and the starting position of a roller supporting a plurality of indicating pallets, which roller is driven in stepwise rotation. The device comprises magnetic members adapted to sense the position of magnetic poles provided on the roller or on a member mechanically linked to the roller, whereby the number of steps taken by the roller, starting from a predetermined position, can be counted taking advantage of a circumferentially arranged Hall effect and without contact between the sensing members and the roller or the member mechanically linked thereto.

Abstract: A switch comprises a housing and a shaft movable into and out of the housing with two circuit paths carried by the housing and adapted to be interconnected only during movement of one of the paths across the other path. Means are provided for moving the one path across the other path; in one embodiment, this means comprises a cam and bevel arrangement carried by the shaft.

Abstract: A speed alarm system which is actuated by the pointer of a speedometer. The device is completely self-contained and self-powered. It is adapted for attachment to the existing speedometer of an automobile or the like with a minimum of modification. It includes a battery powered audible oscillator which, when the battery circuit is closed to the oscillator, drives a transducer which generates an audible warning sound loud enough to be heard by the driver. Closure of the circuit is effected by a special type of switch in the shape of a small cylinder which may be inserted from the outside through a hole drilled in the plastic cover plate of the speedometer at the point at which the speed warning is to be sounded. The switch includes a hair-fine wire extending axially of the cylinder beyond the end thereof so that it may be moved by the speedometer pointer to contact a metallic sleeve of the activation switch, thus completing the circuit to energize the transducer.

Abstract: An electronic theft detection system includes antenna clusters connected to electromagnetic wave transmitter and receiver means. Each antenna cluster comprises a group of spaced apart parallel loops connected in phase opposition or bucking relationship. Electromagnetic waves emitted from the transmitting cluster are detectable close by, i.e., at distances substantially less than one wavelength, but not at far distances due to cancellation effects; and, conversely, electromagnetic waves incident upon the receiving antenna cluster are sensed by it only if they originate from sources close to the cluster, i.e., substantially less than one wavelength.

Abstract: An electronic control center comprising part of an intrusion (burglar) alarm system, the control center being hermetically encapsulated in a mass of hard plastic (in lieu of the conventional steel cabinet enclosure) for purposes of economy and, significantly, to protect the control center from tampering and attack by an intruder. The control center is very small and presents a single multi-conductor cable directed way from the control center to the remainder of the alarm system including the sensors. The multi-conductor cable leading to the control unit includes a positive supply conductor, a negative supply conductor, four input conductors, one output conductor and one output monitor conductor for monitoring the continuity, during the day time, of the foil on the windows and the trap wiring (lacing) across skylights, air conditioning ducts etc. If any of the input conductors, the output conductors or the positive supply conductor is cut, while the system is activated, an alarm will occur.

Abstract: A displacement - electricity transducer contains a movable magnetic core and a fixed magnetic core oppositely arranged so as to have predetermined gaps or clearances in at least two places. Two substantially closed magnetic circuits, each including one of the gaps, are formed by both magnetic cores, so that when the movable magnetic core is displaced relative to the fixed magnetic core while maintaining a predetermined spacing therefrom, the substantially opposite area of the gap portion in one of the magnetic circuits increases, while the substantially opposite area of the gap portion in the other magnetic circuit decreases. A first coil is wound around a part common to the two magnetic circuits, while a second coil is wound around a part not common thereto. By applying an alternating current to the first coil, an output responsive to the displacement of the movable magnetic core is derived from the second coil.

Abstract: An A.M. signal generator having an r.f. level control arrangement includes a modulator whose output gain is controllable, a detector for detecting the A.M. wave produced by the modulator and means for sampling and storing the output of the detector at times occurring when the modulating wave passes through a predetermined amplitude level. The sampled and stored signal is then compared with a D.C. voltage and the resultant of the comparison is applied back to the modulator in opposite fashion to variation in the level of the A.M. wave.

Abstract: The improved burglar alarm system of the present invention includes a housing which is secured around a doorknob rotatably mounted on a door. The doorknob shaft extends out through an opening in the housing. A magnet is positioned on the shaft and aligned with a magnetic field-responsive switch in the housing so that the switch is held open only when the shaft is in the fully unrotated resting position. The switch is part of a circuit which includes a power source, such as a battery, and an annunciator, such as a buzzer or horn. The power source is connected to the circuit through an "on-off" switch accessible through the housing to activate the system.A pointer or the like indicates the resting, fully unrotated position of the shaft, preferably by reference to the magnet, and preferably conceals the magnet.

Abstract: A temperature sensor for a food freezer alarm or the like comprises a sensing element such as a thermistor enclosed in a capsule filled with a material (e.g., water-alcohol mixture) that melts and freezes at a predetermined temperature (e.g., 25.degree. F.), with such change of state occurring as a result of change of latent heat content of the material.

Abstract: A changeable display apparatus and method is disclosed which is made up of a group of similar individual character modules, disposed in a substantially continuous viewing surface, each module comprising support panel or base and a set of identical and changeable elements so it can represent any desired one of a character group, e.g., any letter of the alphabet. Each display element comprises a molded two-piece housing body designed to pivotally support a rotatable magnetic display piece having a relatively visible light-showing or light-reflective face and a dark or non-visible face which can be moved selectively to a viewing position. Solenoid means individual for rotating each element show a desired face selectively, so that selected elements in any module as desired may be shifted either in unison, or preferably sequentially, to show individual display characters or symbols, such as a letter of the alphabet or an arabic numeral, etc.

Abstract: A buzzer structure, of the type comprising a housing having a coil unit therein and an armature mounted for vibratory movement adjacent the coil unit, includes in one embodiment an integral portion of the housing which is bent inwardly into engagement with the coil unit to fix the spacing between the coil unit and housing, thereby to determine the dimensions of the gap between the coil unit and armature. In a further embodiment, the coil unit is mounted directly to a deformable, integral part of the housing which is bent inwardly to fix the spacing between the coil unit and an adjacent diaphragm.