Abstract:
A magnetic switch can be configured to have or provide a variable, user-selectable radial flux pattern. In an example, the switch comprises a magnetized outer structure and a magnetized inner structure provided at least partially inside of the magnetized outer structure. In an example, at least one of the magnetized inner and outer structures is rotatable relative to the other one of the magnetized inner and outer structures about an axis of rotation that is common to the magnetized outer structure and magnetized inner structure. The radial flux pattern can extend away from the common axis of rotation and can vary in strength according to a relative position of the magnetized inner and outer structures. In other examples, the switch can comprise multiple layers of magnetized structures.
Abstract:
A method and apparatus for adaptively adjusting the parameters of a timing loop based upon frequency errors between a data signal and a receiver's clock that is being used to sample the data signal are provided by the present invention. In accordance with the invention, the timing loop parameters are first set to an initial set of parameter values. A current frequency error between the data signal and the receiver's clock is calculated. The approximate average value of the frequency error is then determined. After a predetermined amount of time, the absolute value of the difference between the average frequency error and the current frequency error is examined. If the absolute value of the difference is less than a specified threshold, the timing loop parameters are reset to a second set of parameter values contained in a memory. The timing loop parameters are then reset to a third set of parameter values after a second interval of time. By adaptively adjusting the parameters of the timing loop based upon frequency errors, the present invention decreases the amount of time required for a receiver to train its timing loop to, and acquire timing from, a received data signal without introducing jitter into the signal.
Abstract:
A method and apparatus for removing glitches, interference or noise from a clock signal are provided by the present invention. In accordance with the invention, a glitch-ridden clock signal is monitored to determine when a transition in the glitch ridden clock signal occurs. When a transition occurs, a counter is initiated in accordance with a second high-speed clock signal. The value of this counter is compared to a compare value. The compare value is selected to approximately equal the expected period of the glitch-ridden clock signal. If the counter value equals the compare value, it is assumed that the transition was a valid transition and the transition is carried through and output as a glitch-free clock signal. However, if a transition occurs before the count value equals the counter compare value, it is assumed that the transition is invalid and no transition is carried to the glitch-free clock output. Thus, the present invention removes glitches from a received clock signal and outputs a glitch-free clock signal.
Abstract:
Data communication stations 10, 12, 14 are connected by way of a shared bus 15 common to all the communication stations. When two stations attempt to access the shared bus simultaneously, a conflict resolution method if used to determine which of the two stations is allowed access to the bus 15. Each station seeking access to the bus 15 serially transmits its address. The priority of the stations is determined, and the station with priority is given access to the bus 15.
Abstract:
A dual-diaphragm loudspeaker driver assembly can include a multiple pole magnet structure, and first and second pole piece assemblies can be provided on opposite first and second sides of the multiple pole magnet structure. In an example, each pole piece assembly defines an airgap over a polarity transition region on a respective side of the magnet structure. First and second voice coils can be provided in respective ones of the airgaps, wherein each of the voice coils is coupled to a respective diaphragm assembly, and at least one acoustic tuning port can be configured to provide a damped acoustic communication path between first and opposite second sides of each diaphragm assembly.
Abstract:
A system and method for transmitting data over a twisted pair with or without load coils using a transmitter and receiver is disclosed. The system detects load coils by generating and transmitting a test signal having signal power concentrated in two different frequency bands across the twisted pair and comparing the signal power of the received signal to determine whether the twisted pair is loaded or unloaded. If load coils are detected, an adjustment circuit is used to configure the receiver for reception of data over a twisted pair having load coils. Otherwise, the adjustment circuit configures the receiver for reception of data over a twisted pair without load coils.
Abstract:
A loop loss measurement and reporting mechanism for a digital data services unit obviates interaction with a test unit at a far end of the loop, by relying upon a priori knowledge of the signal power and spectral content of a data port at the far end of the loop to conduct threshold detection and power level measurements. A received signal is amplified by amplifier circuitry, the gain of which is controllably adjusted by the microcontroller based upon the outputs of threshold detectors and power level measurement circuitry that monitor the amplified received signal. A front panel display is controlled by the microcontroller to display loop loss parameter information. To measure and report loop loss, the digital data services unit turns off its transmitter for a prescribed period of time and monitors an in-band signal of known power and spectral content sourced from the far end of the loop. In response to this measurement it iteratively adjusts, as necessary, the amplifier gains, and illuminates the LED display device in accordance with the power measurement.
Abstract:
A loop loss measurement and reporting mechanism for a digital data services unit obviates interaction with a test unit at a far end of the loop, by relying upon a priori knowledge of the signal power and spectral content of a data port at the far end of the loop to conduct threshold detection and power level measurements. A received signal is amplified by amplifier circuitry, the gain of which is controllably adjusted by the microcontroller based upon the outputs of threshold detectors and power level measurement circuitry that monitor the amplified received signal. A front panel display is controlled by the microcontroller to display loop loss parameter information. To measure and report loop loss, the digital data services unit turns off its transmitter for a prescribed period of time and monitors an in-band signal of known power and spectral content sourced from the far end of the loop. In response to this measurement it iteratively adjusts, as necessary, the amplifier gains, and illuminates the LED display device in accordance with the power measurement.
Abstract:
An alarm indication translation mechanism in a digital access and cross-connect system monitors all incoming tributary DS1 streams for the presence of an alarm indication. Whenever an alarm indication is detected in a fractional tributary DS1 data stream, all DS0 bytes within the T1 stream containing that tributary DS1 data stream include the detected alarm indication. For a Yellow alarm, this means that for the case of D4 superframe format (SF), the second most significant bit of each of the twenty-four bytes of a T1 frame containing at least one fractional DS1 carrying alarm information is set to a ‘0’, irrespective of whether the bytes are valid DS0s or idle bytes. For extended superframe format (ESF), Yellow alarm is transmitted by sending a repetitive sixteen bit pattern consisting of eight marks or ‘1’s, followed by eight spaces or ‘0’s in the data link.
Abstract:
A (DS3) network interface unit (NIU) by-pass architecture places the NIU on its own circuit card and exclusive of by-pass switching (and relay) components, which are installed in the equipment shelf, proper, so that physical removal of the NIU card will leave the by-pass circuitry intact. The by-pass circuit responds to an abnormality of the NIU card, such as malfunction or physical removal of the NIU from its card slot, and also to a power supply failure. It also contains an indicator to draw attention to a failed NIU, increasing the likelihood that someone will notice a damaged card.