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In telecommunications, PWM is a form of signal modulation where the widths of the pulses correspond to specific data values encoded at one end and decoded at the other. Pulses of various lengths (the information itself) will be sent at regular intervals (the carrier frequency of the modulation).
The carrier-based PWM technique compares the AC output waveform, v c, to a carrier voltage signal, v Δ. When v c is greater than v Δ , S+ is on, and when v c is less than v Δ , S− is on. When the AC output is at frequency fc with its amplitude at v c , and the triangular carrier signal is at frequency f Δ with its amplitude at v Δ , the ...
A compressor map is a chart which shows the performance of a turbomachinery compressor. This type of compressor is used in gas turbine engines, for supercharging reciprocating engines and for industrial processes, where it is known as a dynamic compressor. A map is created from compressor rig test results or predicted by a special computer program.
Pulse compression is a signal processing technique commonly used by radar, sonar and echography to either increase the range resolution when pulse length is constrained or increase the signal to noise ratio when the peak power and the bandwidth (or equivalently range resolution) of the transmitted signal are constrained.
Electromagnetic interference (EMI) filters have been widely used for filtering out the conducted emissions generated by power converters since their advent. However, when size is of great concern like in aircraft and automobile applications, one of the practical solutions to suppress conducted emissions is to use random pulse-width modulation (RPWM).
Figure 2 shows the top and bottom views of an air-cooled 10 kW-Vienna Rectifier (400 kHz PWM), with sinusoidal input current s and controlled output voltage. Dimensions are 250mm x 120mm x 40mm, resulting in a power density of 8.5 kW/dm 3. The total weight of the converter is 2.1 kg [10]
Second Edition electrical equivalent circuit for connection of LIN nodes to the control pilot circuit with improved PWM compatibility. Basic AC charging is defined in SAE J1772 and IEC 61851-1 Annex A with an analog control pilot, and is used with a variety of single-phase AC grid voltages lower than 250 VAC.
PWM is considered the most common deterministic technique. Considering the example of a DC-DC converter, a controlled switch is designed to “cut-off” the DC waveform into a pulse-shaped waveform. Therefore, the voltage of this signal alternates at the switching frequency between a maximum value and zero.