Abstract: A muffler providing a compact and low-profile form factor for small two-stroke engines is described, particularly useful for aerodynamic radio controlled aircraft. The muffler comprises a tuned internal header eliminating the need for an external header to mount the inventive muffler to the exhaust port of a two-stroke engine while maintaining enhanced engine performance, obviating the need for a conventional tuned-pipe exhaust.

Abstract: Examples of a system and method for sigma-delta analog-to-digital conversion of an electrical input signal are disclosed. An electrical input signal is received. A filtered analog signal is provided based on the electrical input signal and an analog feedback signal. A digital representation of the filtered analog signal is provided, the digital representation being one of K quantization levels, wherein K is a positive integer between 2L and 2L+1, L being a positive integer. The analog feedback signal is obtained based on the digital representation.

Abstract: An interpolation circuit for comparing an input voltage signal with an interpolated reference signal derived from a first reference voltage signal and a second reference voltage signal may include a transconductive circuit configured to generate a first differential current signal proportional to a difference between the first reference voltage signal and the input voltage signal and a second differential current signal proportional to a difference between the second reference voltage signal and the input voltage signal, an intermediate circuit configured to generate a third differential current signal, and a transinductive circuit configured to generate an output voltage signal having a first polarity if a value of the input voltage signal is greater than a value of the interpolated reference signal and a second polarity if the value of the input signal is less than the value of the interpolated reference signal.

Abstract: Examples of systems and methods are provided for tracking-and-holding an input signal. The system may produce a pair of differential voltage outputs responsive to a pair of differential voltage inputs. The system may couple, in response to a clock signal, an input amplifier circuit to an output circuit or decouple the input amplifier circuit from the output circuit. The system may couple the input amplifier to an electrical ground. The system may track values of a pair of differential voltage outputs when a switching circuit is in a closed position and to hold the values of the pair of differential voltage outputs constant when the switching circuit is in an open position.

Abstract: Examples of systems and methods are provided for generating an output signal having an output code having less number of bits compared to an input signal having a thermometer code representation. The system may partition the input code bits into non-overlapping clusters. The system may generate a control signal for each of the clusters based on, at least in part, a logical OR operation over all bits in a corresponding one of the clusters. The system may determine a transition cluster comprising a 1/0 transition in the input code bits. The system may determine output code bits based on, at least in part, an input code bit pattern in the transition cluster and an identity of the transition cluster.

Abstract: Examples of a system and method for sigma-delta analog-to-digital conversion of an electrical input signal are disclosed. A bandpass-filtered signal based on an electrical input signal and an analog feedback signal may be provided. A multi-bit digital representation of the bandpass-filtered signal may be provided. An analog representation of the multi-bit digital representation may be provided. A return-to-zero (RTZ) carving operation may be performed on the analog representation to obtain the analog feedback signal.

Abstract: An interpolation circuit for comparing an input voltage signal with an interpolated reference signal derived from a first reference voltage signal and a second reference voltage signal may include a transconductive circuit configured to generate a first differential current signal proportional to a difference between the first reference voltage signal and the input voltage signal and a second differential current signal proportional to a difference between the second reference voltage signal and the input voltage signal, an intermediate circuit configured to generate a third differential current signal, and a transinductive circuit configured to generate an output voltage signal having a first polarity if a value of the input voltage signal is greater than a value of the interpolated reference signal and a second polarity if the value of the input signal is less than the value of the interpolated reference signal.

Abstract: Examples of systems and methods are provided for generating an output signal having an output code having less number of bits compared to an input signal having a thermometer code representation. The system may partition the input code bits into non-overlapping clusters. The system may generate a control signal for each of the clusters based on, at least in part, a logical OR operation over all bits in a corresponding one of the clusters. The system may determine a transition cluster comprising a 1/0 transition in the input code bits. The system may determine output code bits based on, at least in part, an input code bit pattern in the transition cluster and an identity of the transition cluster.

Abstract: Examples of systems and methods are provided for tracking-and-holding an input signal. The system may produce a pair of differential voltage outputs responsive to a pair of differential voltage inputs. The system may couple, in response to a clock signal, an input amplifier circuit to an output circuit or decouple the input amplifier circuit from the output circuit. The system may couple the input amplifier to an electrical ground. The system may track values of a pair of differential voltage outputs when a switching circuit is in a closed position and to hold the values of the pair of differential voltage outputs constant when the switching circuit is in an open position.

Abstract: Methods for treating pathological pulmonary conditions and bleomycin associated pulmonary fibrosis administer IL-16 antagonists, for example, anti-IL-16 antibodies, to subjects.

Abstract: Examples of a system and method for sigma-delta analog-to-digital conversion of an electrical input signal are disclosed. A bandpass-filtered signal based on an electrical input signal and an analog feedback signal may be provided. A multi-bit digital representation of the bandpass-filtered signal may be provided. An analog representation of the multi-bit digital representation may be provided. A return-to-zero (RTZ) carving operation may be performed on the analog representation to obtain the analog feedback signal.

Abstract: Methods for treating pathological pulmonary conditions and bleomycin associated pulmonary fibrosis administer IL-16 antagonists, for example, anti-IL-16 antibodies, to subjects.

Abstract: A circuit for transmitting and receiving communications. The circuit includes a transmit block, a receive block, and an echo canceller, coupled to the transmit block and to the receive block, for determining an echo signal and subtracting it from the received signal, the determination of the echo signal involving a predetermined number N of coefficients calculated at the beginning of each of the communications in an initialization phase. The circuit periodically updates during communication a restricted group of coefficients chosen from among the most significant coefficients. The present invention also relates to an echo cancellation method.

Abstract: A circuit for transmitting and receiving communications. The circuit includes a transmit block, a receive block, and an echo canceller, coupled to the transmit block and to the receive block, for determining an echo signal and subtracting it from the received signal, the determination of the echo signal involving a predetermined number N of coefficients calculated at the beginning of each of the communications in an initialization phase. The circuit periodically updates during communication a restricted group of coefficients chosen from among the most significant coefficients. The present invention also relates to an echo cancellation method.

Abstract: A device for identifying a determined repetitive sequence of predetermined signals arriving on a modem. The device includes a delay circuit so that all the words of a sequence are simultaneously present; a combination circuit for providing a combined word; a circuit for calculating the modulus of each combined word and for comparing this modulus with a threshold; a circuit for counting clock pulses corresponding to the rate at which words arrive; a circuit for inhibiting the counting circuit when the modulus of the combined word is lower than the threshold; and a circuit for providing an identification signal when a predetermined number of clock signals is counted.

Abstract: A detector of a carrier loss in a modem receiver of a fax transmission of a document, of the type includes a first calculator of the receive signal and a first comparator of this energy with respect to a threshold. The detector further includes means for adapting said threshold between each page of the transmitted document.

Abstract: The invention relates to a device for identifying a predetermined sequence of signals arriving on a modem, the sequence having a frequency spectrum of two determined frequencies, the device including a notch filter, associated with a first magnitude calculator having an output sent on a first input of a comparator, a second input of the comparator receiving the output of a second magnitude calculator, the input of which directly receives the signals received by the modem.

Abstract: A device for identifying a determined repetitive sequence of predetermined signals arriving on a modem. The device includes a delay circuit so that all the words of a sequence are simultaneously present; a combination circuit for providing a combined word; a circuit for calculating the modulus of each combined word and for comparing this modulus with a threshold; a circuit for counting clock pulses corresponding to the rate at which words arrive; a circuit for inhibiting the counting circuit when the modulus of the combined word is lower than the threshold; and a circuit for providing an identification signal when a predetermined number of clock signals is counted.

Abstract: A detector of the presence of a transmission in a modem, including a circuit for determining the absolute value of a receive signal, a first averaging block of the absolute value and two first comparators with respect to two predetermined detection and loss thresholds of a transmission, and further including a second averager which is associated with two second comparators with respect to predetermined extreme thresholds which englobe the two detection and loss thresholds, the first averager having a high time constant with respect to the time constant of the second averager.

Abstract: A device for identifying a determined repetitive sequence of predetermined signals arriving on a modem. The device includes a delay circuit so that all the words of a sequence are simultaneously present; a combination circuit for providing a combined word; a circuit for calculating the modulus of each combined word and for comparing this modulus with a threshold; a circuit for counting clock pulses corresponding to the rate at which words arrive; a circuit for inhibiting the counting circuit when the modulus of the combined word is lower than the threshold; and a circuit for providing an identification signal when a predetermined number of clock signals is counted.