Abstract: A vehicle-mounted, rear-directed message display apparatus includes a housing which includes a transparent rear wall, a front wall, side walls, a bottom wall, and a cover. Support assemblies are connected to the side walls and extend downward. Illumination lamps are supported inside the housing near the front wall. A display sign is supported inside the housing between the illumination lamps and the transparent rear wall. The display sign includes an opaque background and transparent message lettering. An illumination control switch is electrically connected to the illumination lamps. With the invention installed in a front vehicle, when the driver of the front vehicle thinks that a following vehicle is following too closely, the driver of the front vehicle can operate the illumination control switch to light the illumination lamps to illuminate the display sign to warn the driver of the following vehicle that the following vehicle is following too closely.

Abstract: A high resolution digital phase detector adapted to receive a threshold value and a sequence of digital samples of a substantially linear portion of an analog video signal. A first output signal is provided when a digital sample is detected as having crossed the threshold value. An interpolation is done between the value of the digital sample to first cross the threshold value and the immediately preceding digital sample on the opposite side of the threshold value. In such manner, the time of the crossing within the sample interval is resolved to a subpixel level. A second output signal represents a fractional phase error between the actual crossing and a desired crossing point within the sample interval. The first and second signals are added in a phase locked loop to adjust the output of a voltage controlled oscillator to be synchronized to the incoming analog video signal in both integer and subpixel phase.

Abstract: A digital linked compressor-expander telecommunications system (Lincompex), is implemented using a general purpose digital signal processor wherein the compression and expansion functions are performed by blocks of programmed code. Input audio analog signals are converted to parallel data digital signals thereupon the digitial signals are input for processing. After processing, the resultant signals are passed to a 16-bit digital-to-analog converter where either the compressed or expanded digital voice data signal is converted back into an audio frequency analog signal for either transmission or communication on an output device.