Abstract: A circuit arrangement for testing operating functions in motor vehicles by means of parallel circuits which contain at least one switching element conductive during a normal operating function and one control lamp and which are adapted to be closed by a test switch, and with one transmitter each coordinated to the operating functions which automatically triggers a warning indication with abnormal operating functions; at least one warning lamp for the warning indication which is independent of the control lamps is thereby provided in the circuit arrangement.

Abstract: A passive infrared intrusion detection system is provided in which one or more Fresnel lenses are employed to focus received infrared energy onto a detector element which provides an electrical output signal indicative of the level of received radiation. The Fresnel lens is preferably formed of a plastic material which is translucent to visible light such that visible light is not focussed onto the detecting element while infrared radiation is.

Abstract: An automobile alarm comprising a pair of self latching relay devices one or the other of which, but not both, must operate within a predetermined time after turning the ignition switch on or hot wiring around the switch. The depression of the horn ring within the predetermined time disables the alarm and connects the normal circuits of the car for normal operation. The failure to depress the horn ring within the predetermined time latches the horn or an auxiliary alarm device on and prevents starting of the car. A timing device for unlatching the horn after a predetermined alarm time is also shown.

Abstract: Apparatus and method of processing in an ultrasonic alarm system to detect the doppler-shifted components which indicate the presence of an intruder. A master control applies to each of the transmitter transducers a signal which alternates between two frequencies at a modulation frequency. The output signal from the receiving transducer is synchronously detected and low pass filtered. The filtered signal is applied to electronics which respond to the presence of modulation frequency components in the filter output signal. A first embodiment utilizes a high-Q bandpass filter having a resonance frequency equal to the modulation frequency. In a second embodiment, the modulation frequency is used to effectively perform a correlation between the received signal and the modulation frequency.

Abstract: A position detector providing an electrical position feedback signal proportional to relative mechanical movement between two elements employs a hall effect device to sense changes in magnetic flux density resulting from relative movement of the hall effect device with respect to an adjacent magnetic field, the hall effect device producing an electrical signal proportional to magnetic flux density which signal comprises the electrical position feedback signal. The hall effect device and magnet are supported in respective relatively movable members in cooperative relationship such that the magnet is adjacent the hall effect device so as to permit relative movement of the hall effect device with respect to the magnetic field, the members being preferably adapted for mounting respectively on two relatively movable mechanical elements.

Abstract: An improved infrared detector system includes a pair of thin film thermopile sensing elements that receives reflected energy from aspheric reflectors that are designed to provide optimum energy resolution. An absorbing coating can be placed above the sensors and extending beyond the periphery to improve the signal to noise ratio. A high gain low noise D.C. amplifier is coupled to the output of the infrared sensing elements while a high pass amplifier and low pass amplifier are designed to pass an amplified signal in the frequency range from approximately 0.2 Hz to 15 Hz. Finally, a combined peak detector and time dependent integrator summing amplifier circuit provides an enabling predetermined threshhold detection gate that requires either a predetermined large signal level or a multiple of small electrical signals within a preselected interval to produce an alarm enabling signal.

Abstract: According to the invention, an accelerometer (G) is attached on the spring suspension (U) of the wheel (H) in question and capable upon passing of the vehicle over road irregularities to emit a decaying A.C. signal (S) with information on the oscillations of the axle (A) and the damping of the tire. After integration in an integrator (I) the signal is a measure of the difference between the damping of the shock absorber at expansion and at compression. This signal is compared in a comparator (K) with a reference signal (V.sub.ref) for the permissible damping difference and results in alarm (L) upon achieving said difference.

Abstract: A digital indicating installation for vehicles which selectively reproduces several function values within an indicating field; by actuating one of several switches, the reproduction of a first function value is interrupted for a predetermined time and a further function value coordinated to the switch is reproduced in the meantime within the indicating field.

Abstract: Tire pressure monitors are incorporated in vehicles having penumatic tires (14) to continuously or periodically measure the air pressure within the tires and to alert the driver should the pressure in one of the tires fall below a predetermined value. A self-contained battery powered rf transmitter unit (10) is affixed within the drop center (22) of each wheel (12) and includes a pressure sensing switch (84). The battery is contained within a housing (20) mounted to the external surface of the wheel adjacent a fill valve (30) through which electrical wires (50) are routed to the transmitter (11). The transmitter emits a pulse every 33 seconds when the air pressure within the tire is above a prescribed value. A receiver (13), located in the passenger compartment of the vehicle, receives the signal(s) from the transmitters and counts the number of signals received over a given time period established by an internal pulse generator.

Abstract: In a method for advance indication of the possibility of damage occurring to wheel bearings of vehicles, particularly railroad vehicles, the temperatures of the wheel bearing sets of a plurality of wheels are monitored by temperature detectors fixedly mounted on the vehicle. A determined value is derived from the measured values of temperature, and this determined value is compared with the temperature of a further temperature detector, in order to produce a warning signal. The warning system is incorporated in the vehicle itself, and provides a warning to the vehicle personnel.

Abstract: A directional detector of changes in a local electrostatic field comprising two parallel flat coils of copper wire, separated by an electrically grounded plane rectangular conductor that is coated on both sides with an insulator, and associated signal conditioning electronics has been constructed. The combination of coils and plane rectangular conductors forms two independent wideband antennas which, when placed in an unobstructed electromagnetic radiation field, have induced in them electric currents of equal peak-to-peak values. When the combination was brought near an ungrounded body, such as a person standing on an insulator to earth, a coupling of high frequency potentials of the ungrounded body and the nearest coil occurred, while the coil farthest away from the body, due to the presence of the electrically grounded plane rectangular conductor, was unaffected.

Abstract: This invention relates to an automatic alarm system for the discouragement of theft or unauthorized tampering with a so equipped motorcycle or other vehicle. This device consists of the motorcycle or vehicle's horn, lights, a source of electrical power (such as the vehicle's battery), an activating or "on" switch, a short circuit preventing fuse, an alarm limiting timer, and a circuit breaking triggering device held open by a non-conducting element of the motorcycle or vehicle which must be moved outside of the circuit breaking triggering device if the motorcycle or vehicle or its equipment is stolen or tampered with. A transmitter of limited range may be incorporated within the activated circuit for broadcasting a tone of identifiable character to interested persons should the circuit breaking triggering device be activated.

Abstract: The Unused Fuel Indicator (UFI) comprises a reliable thermo-electric/electronic circuit employing thermocouples attached to the catalytic converter of an emission control system for an automobile engine for providing easy readout of the condition of the automobile engine and the emission control system. A preferred kind of readout is provided by the sequential glowing of light indicators such as light emitting diodes (LEDs) wherein the sequence in which the LEDs are caused to glow, and their color is indicative of the proper functioning (or malfunctioning) of the automobile engine and catalytic converter emission control system. The UFI incrementally indicates the potential heat of pollutants in an automobile engine exhaust, which pollutants are converted by oxidation to heat produced by the catalytic converter. The heat is sensed by thermocouples which are differentially connected with the output of one opposing the output of the other.

Abstract: A submersible pump alarm includes an adapter in a well casing for receiving the well water pipe. An extension is threaded into the adapter and a switch inserted therein. A rod cooperates with a switch actuator and a cover on the casing, whereby when the cover is removed, bias which the rod exerts on the actuator is released and the switch energizes an alarm.

Abstract: A device (1) for sensing the presence of a dielectric liquid at a predetermined level in a tank is described. The main feature of device (1) is that it comprises a first and a second bimetallic strip (23, 44) disposed facing each other and a resistor (48) disposed in proximity to said second strip (14) at a level in said tank equal to said predetermined level.

Abstract: Tire pressure indicator having a wheel mounted transponder unit and a hand-held interrogator unit which can be positioned for coupling with the transponder unit. The transponder unit is a passive device which returns signals to the interrogator unit in accordance with the pressure in the tire mounted on the wheel. When the tire pressure is above a predetermined safe level, a "safe" light on the interrogator unit is illuminated, and when the pressure is below the safe level, a "low" light is illuminated. Operating power for the interrogator unit is supplied by a battery in the unit, and the lights are flashed at a visible rate when the battery voltage drops below a predetermined level.

Abstract: A device is disclosed which detects the knocking phenomena in a controlled-ignition internal combustion engine, the device essentially comprising two ionization probes arranged in a zone of the explosion chamber remote from the sparking plug: the probes deliver signals when the state of ionization changes and the time interval between the signals of the two probes is measured and compared with an appropriate reference value.

Abstract: In a security system in which at least one fibre-optic wave guide, which is carried in a strand, extends along a boundary, light is directed into one end of the guide and the light leaving the guide is detected by an optical detector. An indication is given when the intensity of the detected light falls below a predetermined threshold, so as to warn when the wave guide is disturbed significantly or cut through.In order to manufacture the strand, a fibre-optic wave guide is positioned against an elongate carrier and secured to the latter by bonding agent and/or adhesive tape.A dummy strip, having identical external appearance to the strand but not including a fibre-optic wave guide, can also run along the boundary in question.

Abstract: A device mountable on top of a truck cab so to automatically warn a truck driver if the truck body can clear underneath a bridge or other overhead structure; the device consisting of an upwardly telescopic rod that is adjustable to the height of the truck body or box and which, upon contact with any overhead object, will flex and bend over so to act as a switch arm of a switch for closing an electric circuit to either a light on the dashboard or other signalling device to the driver.

Abstract: A seed monitoring apparatus for use with a seed planting machine includes a seed sensor comprising a housing forming a substantially tubular passageway and mounting a light source and three photosensitive elements arranged substantially in a triangular configuration. The arrangement of the light source and the triangular photosensor configuration is such that a seed passing through the tubular passageway will momentarily obscure the passage of light to the photosensor the apex of the triangle, if at all, before obscuring the passage of light to either of the photosensors forming the base of the triangle. The monitoring circuit includes two signal paths in which different methods of counting are used to produce different numbers of pulses in response to signals from the three photosensors. One or the other of these signal paths is selected automatically in accordance with the rate at which seeds are detected.