ELEC1310 Lecture 11: ELEC1310 Week 6.11
9 Oct 2018
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Document Summary
Shown as a cosine function: amplitude is the coefficient of the function, frequency is a value within cosine, the phase shift is theta. Power systems are built around ac voltages. The common waveform in signal processing and communications. A magnetic field with a coil in between. Spin the coil to create an ac voltage due to change in flux within the coil. Transmission lines (power lines) are not ideal conductors: have a small amount of resistance, transmissions losses: p = i2r, transmission power: p = vi. Ac switches are easier to build: arc quenching, dc current is hard to break. Also critical as a communications mechanism: am, fm. Downsides include: more interference, more complicated to analyse, extra problems in transmission due to (cid:498)reactive(cid:499) power. Cosine is the preferred function for analysis. Elec1310: when calculating the sine value, care needs to be taken that the value is completely in radians.
