Digital signal

About: Digital signal is a research topic. Over the lifetime, 44213 publications have been published within this topic receiving 345279 citations.

Portable pump for infusing medicine into a living body

Abstract: A portable infusion pump for delivering medicine to a living body has a roller pump for infusing solutions by use of a motor, a driving circuit for driving the motor in response to a control signal, and a flow rate control for generating the control signal. The flow rate control includes a manual operating unit for manually setting a value of a speed of the motor, a speed setting unit for generating a digital signal associated with the value set by the manual operating unit, and a control signal output unit for generating the control signal associated with the digital signal delivered from the speed setting unit. Accordingly, the flow rate thus set clearly corresponds to an actual flow rate, thus facilitating the control of the liquid flow rate.

Multi-Mode Operation and Control of a Resonant Converter

Abstract: In accordance with an embodiment, a method of controlling a switched-mode power includes generating a feedback signal proportional to an output of the switched-mode power supply, and operating the switched-mode power supply in a normal mode. If the feedback signal crosses a first threshold, the switched-mode power operates in a second operating mode. In the first operating mode the pulse modulated signal is adjusted to regulate a feedback signal to a first signal level, and in the second operating mode, a dead-time of the pulse modulated signal is adjusted to signal to regulate a feedback signal to a second signal level different from the first signal level. The method further includes driving a switch of the switched-mode power supply with the pulse modulated signal.

Narrow Pulse Elimination PWM for Multilevel Digital Audio Power Amplifiers Using Two Cascaded H-Bridges as a Nine-Level Converter

Abstract: This paper presents a methodology to reduce total harmonic distortion (THD) in digital audio power amplifiers, using two new approaches: 1) a multilevel converter made of two cascaded full-bridges, with suitable power supplies to operate as a nine-level hybrid type converter and 2) a new pulsewidth modulation (PWM) technique called narrow pulse elimination (NPE) PWM. The proposed nine-level converter uses only eight MOSFETs. Unlike conventional PWM, the NPE PWM does not generate excessively narrow pulses, so that power semiconductors nonideal delays and switching times are still negligible. Therefore, the nine-level output voltage THD, mostly introduced in the power stage, is strongly reduced. With the NPE technique, the resolution of the generated PWM is no longer limited by the switching speed of the output switches, but only by the frequency of digital processing circuit. Simulation and experimental results from a laboratory prototype are presented in order to show the effectiveness of the proposed approaches

Method and apparatus for transmitting a signal using thermal chirp management of a directly modulated transmitter

Abstract: A fiber optic transmitter comprising a digital driver adapted to adjust the crossing point of a digital base signal, an optical source adapted to receive the digital base signal and produce a frequency modulated optical signal, and an optical spectrum reshaper adapted to convert the frequency modulated optical signal to an amplitude modulated optical signal. A method for transmitting a signal, comprising: adjusting the crossing point of a digital base signal; providing the adjusted signal to an optical source to produce a frequency modulated optical signal; and providing the frequency modulated optical signal to an optical spectrum reshaper to convert the frequency modulated optical signal to an amplitude modulated optical signal.