Abstract: A broadcasting arrangement includes a source of signals to be transmitted which is subject to distortion in the event that signals are reflected. An antenna is adapted for radiating all the signal applied to a polarization sensitive input part with a particular polarization. The antenna is mounted on a tower. A waveguide is coupled to the source of signals and to the input port of the antenna. If the waveguide is circular waveguide, the windload on the tower due to wind loading of the circular waveguide is low, but flexure which occurs results in polarization changes which causes signals applied to the antenna input port to be reflected, thereby reducing radiated power and causing distortion. If the waveguide is rectangular, the wind loading is high and the tower must be more sturdy and therefore more costly than for circualr waveguide. A truncated circular waveguide is used which has a wave propagation channel defined by a cylinder and a pair of parallel longitudinal plates in the cylinder.

Abstract: A bobbin construction that features a unique termination connection means or assembly at one end of the bobbin, including closely spaced apart recesses, one of the recesses being adapted to receive the crimped portion resulting from joining together a lead and one end of the reactor coil, the other recess having the lead threaded therethrough; consequently, the termination arrangement has excellent strain relief, that is, an assembler can pick up the unit by the leads without damage to the termination connection.

Abstract: A waveguide having reduced windloading yet a relatively wide bandwidth for the dominant mode of propagation comprises an elongated cylinder having substantially parallel plates forming an interior waveguide portion which in cross-section is a doubly-truncated circle. The plates are symmetrically disposed about the central axis of the elongated cylinder.

Abstract: An ionization smoke detector having a sensing chamber and including: a screen or mesh electrode enclosing and forming the outer limits of said sensing chamber, while fully exposing said sensing chamber to the ambient atmosphere; a baffle means covering said electrode and in close proximity thereto, said baffle means having a plurality of slit-like openings spaced around the periphery thereof for permitting the transfer of ambient atmosphere to said sensing chamber; said openings of said baffle means constituting deflectors oriented to deflect any air currents directed normal to the surface of said baffle means so the air currents will enter said sensing chamber at an angle other than said normal angle.

Abstract: A system for monitoring heater elements of electric furnaces so as to identify individual failures, such system comprising an arrangement for detecting the electrical open state of any one of the heater elements, including a current transformer for monitoring current flow; and the capability of monitoring element voltage, such that no element current in the presence of a minimum element voltage is defined as, or taken to be, a failure; further including the provision of a master alarm indication of a defined failure in any of the elements and also an individual alarm indication to indicate which element has failed.

Abstract: An ionization smoke detector device including means for insuring that adjustment can be made in the triggering potential for the alarm device so that should circumstances change, an operator can make a simple adjustment to take into account the changed circumstances. This means comprises a programmable Zener diode which is connected to a voltage dividing resistance network at the output of a field effect transistor, the other end of the Zener diode being connected to the input of a silicon controlled rectifier device which functions to trigger the alarm.Another primary feature of the present invention is the provision of a means for testing the operation of the system in such a way that all of the elements of the system will be tested rather than merely some of them.

Abstract: Apparatus for detecting the presence and position of individual wheels or wheel-axles of railroad cars. The apparatus involves no moving parts and basically senses the presence of a car wheel by sensing a shunt current flowing through the car wheel-axle set. The apparatus or system includes a transmitter which develops a high frequency AC signal which is impressed across the rails, and a sense or pick-up coil which is sensitive to the fields produced by currents flowing up through the radius of the wheel, whereas it is substantially unaffected by fields produced by the currents flowing in the rails. A pair of current-carrying loops is provided, the first loop including a pair of rails and a pair of boundary shunts connecting said rails; the first loop being subdivided for current flow into two substantially equal portions with respect to a detection zone center line; the second loop extending in close proximity to and inside said first loop, said second loop likewise being subdivided for current flow.

Abstract: A fail-safe active bandpass filter circuit is disclosed; that is, one having voltage gain and which is arranged to be fail-safe in the sense that opens, shorts and component value changes will not cause the circuit to self-oscillate and thereby produce a spurious signal that would cause unsafe effects.

Abstract: An electronic circuit for use with telephone instruments or the like in those cases where so-called "dial tap" is encountered, whereby a buzzer or bell included as part of the telephone instrument is adversely affected when the dial is rotated for purposes of dialing a particular call number. The circuit provides a discriminating function against the short term dial pulses by blocking them, but allows ringing current to pass substantially unaffected.

Abstract: A smoke detector of superior smoke sensitivity characterized by a compact unipolar ionization chamber in which the ionization area or zone is situated and defined between the source of alpha particles and an electrode which confronts the source; another electrode, which attracts the unipolar charge carriers, is situated on an indirect path from the source, preferably being behind such source with respect to the pattern of radiation emitted therefrom.

Abstract: Method and apparatus for detecting the presence of flat wheels on railroad cars, comprising an electro-acoustic transducer located on the track wayside so as to pick up the vibrations generated by a passing train. If a flat wheel is present it will generate a periodic clanging sound at a frequency proportional to train speed and wheel diameter. The invention capitalizes particularly on the measurement of train speed to control the response of an adaptive filter so as to enhance the periodic clanging frequency with respect to the background noise, thereby to improve the signal-to-noise ratio; the enhanced signal is further autocorrelated for ten wheel revolutions and if a periodic signal is present in the narrow frequency band of interest, a large periodic autocorrelation output will result and, as a consequence, any wheel flat will be readily detected and will act to trigger an alarm to alert the train crew of the condition.

Abstract: A solid state code transmitter adapted for use with a conventional local fire alarm system in connection with installations that include a McCulloh loop circuit for the transmission of signals to a central proprietary fire alarm surveillance point. The transmitter circuit generates an electronic data word 17 bits long, the first 14 bits being field programmable by way of miniature DIP switches, each data word representing an equivalent of one round of generated code.

Abstract: A locking system featuring a movable pin which is selectively operative to lock a blender jar into its holder when the entire jar assembly is positioned on a console or the like for performing a blending operation; otherwise the pin stays in an appropriate position such that the blender jar can be screwed into its holder without hindrance.

Abstract: A fail-safe solid state logic system based on the use of an AC input signal of one type, and a DC input which causes a logical gate to convert the AC input signal to a totally different AC output signal; that is, to one adapted to be received by a vital driver or the like, which is tuned to accept only that different AC output signal and no other. Accordingly, the failures which are most likely to occur, namely, shorts from input to output or failure to toggle, result in the AC signal frequency not being changed and as a consequence, the system fails safe.

Abstract: Apparatus for automatically calibrating smoke detectors within desired ranges of values of smoke obscuration, and thereafter retesting them for valid calibration; in accomplishing this the smoke obscuration is continuously increased at a predetermined uniform rate.

Abstract: A monitoring device which is directed to achieving a more reliable power supply for an electronic or electromechanical system; such monitoring device including a means for selecting, in response to detection of subtle failures in either of two power supplies, so as to connect one and only one of the power supplies, regardless of internal failure within the monitoring device itself.

Abstract: An overlay selective harmonic transducer device is installed on affected track circuits, that is, track circuits on which interference with normal functioning has occurred due to traction power harmonics.

Abstract: Apparatus for detecting the presence of flat wheels on railroad cars, comprising a high frequency transmitter or source connected so that the rail feed points are staggered or offset with respect to the detector apparatus. As a result, the transmitter cannot be completely shorted by a wheel axle; also, the stagger arrangement permits the overlap of two test sections so that no part of the wheel circumference is missed by the detector. Also the use of current detection of the transmitted signal minimizes loading effects on the received signal by adjacent wheel axle sets.

Abstract: Smoke detection apparatus including a pair of photoelectric cells which receive illumination in a predetermined ratio from a very low level light source. An improved simulating device is included for the purpose of testing the correct functioning of the alarm system connected to a sensing circuit formed by the photocells. The effects normally produced by smoke present in a chamber are simulated by selectively directing light from an auxiliary light source onto the sensing or "reflected" cell in the sensing circuit. In addition, a specially designed and constructed sensor head is provided for avoiding discrepancies in the placement of the critical elements; moreover, improved flow of any smoke present is promoted by the specific geometry of the sensor head.

Abstract: A flexible, expandable alarm control system in which varying combinations of functional circuit blocks or modules can be selected and connected in positions on a control panel by the customer or user of the system. Thus, the system can be modified to satisfy changing functional requirements by substitution of modules; furthermore, it can be expanded by adding functional modules to a given control panel or by extending the system to auxiliary control cabinets in which more circuitry can be mounted.