Abstract: A digital demodulator provides efficient demodulation of frequency modulated, pulse-width modulated, and other temporally modulated signals. Without employing an analog-to-digital converter, modulating signal information is extracted from a modulated signal as numerical information. For frequency demodulation, a high gain stage is applied to an incoming FM signal to produce a corresponding sequence of square waves. The period between zero-crossings of the square waves is accurately measured to within one clock pulse using a high-speed clock and at least one counter to produce a demodulated signal.

Abstract: A digital demodulator provides efficient demodulation of frequency modulated, pulse-width modulated, and other temporally modulated signals. Without employing an analog-to-digital converter, modulating signal information is extracted from a modulated signal as numerical information. For frequency demodulation, a high gain stage is applied to an incoming FM signal to produce a corresponding sequence of square waves. The period between zero-crossings of the square waves is accurately measured to within one clock pulse using a high-speed clock and at least one counter. Period information is then provided to a signal processor that serves to convert the sequence of period measurement values into a demodulated signal with a high signal-to-noise ratio.

Abstract: A digital demodulator provides efficient demodulation of frequency modulated, pulse-width modulated, and other temporally modulated signals. Without employing an analog-to-digital converter, modulating signal information is extracted from a modulated signal as numerical information. For frequency demodulation, a high gain stage is applied to an incoming FM signal to produce a corresponding sequence of square waves. The period between zero-crossings of the square waves is accurately measured to within one clock pulse using a high-speed clock and at least one counter. Period information is then provided to a numerical processor, wherein it is at least scaled and low-pass filtered to produce a high-quality demodulated signal with a high signal-to-noise ratio.

Abstract: Many seat belt configurations have incorporated a belt retraction device into the design of the seat belt apparatus. When the retraction device includes a recoil spool that is housed within the buckle member the function of the buckle member becomes compounded. In order to release the seat belt buckle the operator is often required to move the release handle in a manner that necessitates the use of both his hands. The seat belt apparatus of the present invention provides a buckle member that is moved toward a tongue member to achieve a latching engagement between the two. A latch release member is provided within the buckle housing and is movable in a direction away from the tongue member to release the connection therebetween. This direction of movement is the same as the direction of separation between the buckle member and the tongue. Both operations may be accomplished in one motion and require the use of only one hand.