Abstract: An electronic device for a vehicle detects the number of rotations of a wheel of a vehicle, calculates the distance covered by the vehicle, measures the atmospheric pressure to provide data on the atmospheric pressure, obtains a height corresponding to the measured atmospheric pressure from a height-atmospheric pressure conversion table stored in a RAM on the basis of the measured atmospheric pressure data, calculates an tilt of a road where the vehicle travels on the basis of the height and the measured covered distance, detects a gear corresponding to the calculated tilt from a gear change conversion table, drives a transmission to put the gear in the meshed state. In order to apply a barometer to a weather forecast, an actual height where the vehicle travels is calculated on the basis of data on a tilt of the road measured by an inclinometer attached to the vehicle and the calculated covered distance.

Abstract: An AGC for a laser amplifier uses a control tone modulated onto the optical signals. During use the modulation on the optical signals is superimposed on the drive current for the laser. The AGC derives a control signal by detecting the modulation in the drive current, multiplying it by the drive current. The drive current for the laser is adjusted to keep the control signal constant. In a preferred embodiment a low level sensor detects when the control tone falls below a threshold level and switches the circuit to a default configuration. The default configuration provides a distress signal to indicate a fault and to identify the affected amplifier. This preferred embodiment is particularly suitable for submarine telecommunications capable which include a plurality of inaccessible amplifiers.

Abstract: An aircraft collision avoidance instrument system has a display located in the aircraft glareshield in the peripheral field of view of the pilot when the pilot is looking forwardly through the aircraft window. The display has a matrix array of LCD elements which is controlled to provide a continually changing image that is visible in the peripheral field of view of the pilot when a possible collision with another aircraft is likely. The changing image may be arrows moving up or down the display to indicate climb or decend, or a flashing horizontal line to indicate that present height must be maintained. An alphanumeric legend indicative of the collision avoidance action to be taken is also provided by the display. When no collision is likely, the display is used to present other information to the pilot.

Abstract: A multi-zone alarm system operative with a two-wire alarm loop and having a simple network at each alarm sensor for providing a coded signal indicative of sensor identity and relatively simple circuitry at a central location for interrogation of the remote sensors and determination of those sensors providing an alarm signal.

Abstract: A retractable roof top sign for automotive vehicles including a generally rectangular low profile frame for attachment to the roof of the vehicle and a sign structure transversely spanning the frame in pivotal attachment at a lower end between a pair of longitudinal side rails of the frame, a small gear motor being provided in driving connection to the sign in a manner so as to permit the sign to be selectively moved between a retracted position within the confines of the frame and a vertically erect position by operation of appropriate electric control switches mounted in the operator's compartment of the vehicle. For use in police cruisers or the like, an attention getting light flasher bar extends across the top width of the sign, and front an rear lights mounted within the confines of the frame are directed respectively on front and back messages displayed on the sign.