Abstract: A numerically-controlled phase-lock loop with input clock dependent ratio adjustment provides for narrower-bandwidth loops that lock to a wide range of frequencies and/or operation with an absent or degraded input timing reference. A timing reference characteristic detector determines an input frequency range of the input timing reference signal, the data type of the timing reference, and/or whether a timing reference signal of sufficient quality is present. A numerically controlled oscillator is controlled by a numeric ratio that is adjusted to provide the desired clock frequency output in conformity with the detected frequency range and/or data type. If the timing reference signal is absent or degraded, then the numeric ratio can be set to a fixed value or a local timing reference can be applied in order to generate the desired clock output frequency.

Abstract: A hybrid analog/digital phase-lock loop for low-jitter synchronization provides a mechanism for generating a low-jitter clock from a timing reference that has a high jitter level. A numerically-controlled analog oscillator provides a clock output and has an input for receiving a rational number. The rational number represents a ratio between the frequency of the clock output and the frequency of another stable clock provided to the circuit. A counter divides the frequency of either the clock output or the stable clock, providing feedback or feed-forward control of the analog oscillator, respectively. The circuit also includes a digital phase-frequency detector for detecting an on-going phase-frequency difference between an input timing reference and an output of the divider and a digital loop filter for filtering the output of the phase-frequency detector to provide the rational number that controls the frequency of the numerically-controlled analog oscillator.

Abstract: The invention is a direct replacement for conventional propellers on aquatic vehicles that utilize them. The cincture (26) (26A) being a integral part with the propeller makes a significant improvement over conventional propellers. Being so manufactured means that it can be conformed to virtually all types of propeller applications. Such as mounting requirements, the number of helical screws (20), their pitch and direction of rotation, and rear or forward mounted propellers. The cincture (26) (26A) being of one piece with the propeller means it is of the same material (plastic, aluminum, stainless steel, teflon, bronze, etc, etc.) as the propeller. Giving an enhanced performance and safety capability in a single article of manufacture for each desired application. Being beneficial not only for the owner, but the aquatic vehicle and its surroundings.