Tellabs Operations, Inc.

American Telephone and Telegraph, Co.

Coriant Operations, Inc.

American Telephone and Telegraph Company; At&t Information Systems

Cecil W Deisch

A voltage rectifier circuit having a storage element and a switching stage that is switchable to enable the storage element to capture a peak voltage of an alternating power source. The switching stage includes transistors arranged in a back-to-back configuration. In one example, the storage element is a capacitor and the transistors are PNP bipolar junction transistors. The configuration of the circuit enables reduced loading on the power source, as well as reduced sensitivity to temperature.

Diode substitute with low drop and minimal loading

An electrical circuit and a procedure for tracking at least one input pulse width applied to the electrical circuit. The electrical circuit includes a threshold component (e.g., a comparator) arranged to provide an output pulse width based on whether an input to the threshold component exceeds a threshold. The circuit also includes a controller arranged to control the threshold of the threshold component, based on the at least one input pulse width applied to the electrical circuit, such that the output pulse width of the threshold component tracks the at least one input pulse width applied to the electrical circuit. The controller includes at least a switch, and the output pulse width tracks the at least one input pulse width by following or anticipating the pulse width. In one example embodiment the tracking is performed for a series of pulses of varied widths.

Pulse width anticipator

A method for reducing distortion in a nonlinear device whereby n-order intermodulation products are canceled. A test signal is applied to the input of the nonlinear device and amplitudes of n- and m-order intermodulation products are measured. Transfer function coefficients and an optimum value of a baseband resistance are calculated. A baseband resistance is applied to an output of the device. An input signal is applied to the input of the device and a m-order intermodulation product is passed through the baseband resistance and added back to the input. A system for practicing the same includes a signal source that generates the test signal, a unit that measures the intermodulation products, a unit that calculates the transfer function coefficients and the optimum value of a baseband resistance, and a unit that applies the baseband resistance to the output of the device.

[object Object]

A system provides overload protection in power-switching circuitry, whereby current through a switch is controlled by adaptive circuitry. The switch, configured to deliver a current and a voltage, is connected to two current-limiting feedback circuits. The first current-limiting feedback circuit is coupled to the switch and limits the current through the switch based on current measured through the switch. The second current-limiting feedback circuit is configured to shunt current around the first current-limiting feedback circuit as a function of the voltage delivered to the load, which changes the amount of current the switch can deliver to the load.

Power switch with simple overload protection

A signal shaping circuit for shaping amplitude shift keyed digital pulses of a digital data stream is set forth. The digital data stream is comprised of a plurality of symbols from which the signal shaping circuit generates an output signal having sinusoidally shaped transition regions between logic level transitions of the digital data stream. The signal shaping circuit comprises an input lead receiving each of the digital pulses of the digital data stream. A delay circuit receives each of the digital pulses of the digital data stream at the input lead and, after a predefined time delay, outputs delayed digital pulses corresponding to each of the digital pulses received at the input lead. A ringing filter circuit having a linear response receives each of the digital pulses of the digital data stream provided from the input lead and each of the digital pulses provided at the output of the delay circuit. The ringing filter circuit has a ringing period about equal to or less than twice the symbol period of the digital data stream which, in turn, sets the value of the predefined delay. More particularly, the predefined delay of the delay circuit is about equal to half of the ringing period. As a result, the ringing filter circuit generates an output amplitude shift keyed digital data stream directly corresponding to the digital data stream provided at the input lead which has sinusoidally shaped transition regions between its logic level transitions. The resulting waveform has a lower bandwidth than the corresponding input signal and, further, has no intersymbol interference associated with it.

Pulse shaping and filtering circuit for digital pulse data transmissions

A power factor compensator (18) for a power converter (17) comprises an L-C circuit connected in series between the power converter and the converter's A.C. power source (13). The values of the inductor (30) and the capacitor (31) of the compensator circuit are selected to cause the L-C circuit to resonate at a frequency higher than the power source frequency, preferably at a frequency ranging between 1.4 and 3.5 times the power source frequency, in order to achieve a power factor within the range of about 0.65 to 0.95. A resonant frequency of about twice the power source frequency has been experimentally found to give particularly good performance.

Power factor improving arrangement

Apparatus for terminating conductors on circuit boards. The apparatus comses an insulator member having electrical conducting contacts embedded therein each with a bifurcate portion extending from the insulator member. The bifurcate portion consists of a pair of prongs arranged for engaging a conductor and a complaint section having an end formed both for piercing insulation of the conductor and insertion into a circuit board plated-through hole to establish an electrical connection between the engaged conductor and circuit board.

Growing community of inventors

Warrenville, IL, United States of America

Cecil W Deisch