Transcript EAS 5407: Mechatronic Systems

AC CURRENT
EAS 5407: Mechatronic Systems
Arthur
AC Line Waveform
AC Line Feature
Amplitude = 110 V
Frequency = 60 Hz
Period = 1/f = 16.67 ms
RMS of Voltage = 110/sqrt(2) = 77.79 V
Typical RMS Current of Household = 30~5 A
AC v.s. DC
More Efficient to Transmit
More Easier to Drive Motor
Can Be a 60Hz Signal
More Efficient Transmit
All the power transmit lines have internal resistance.
This resistance is in serial with the household electrical
applicants. Because the power wasted on the transmit
lines is equal to I*I*R. To reduce the wasted power, we
must try to reduce the current of the transmit lines.
Because the total power is constant, P=U*I. So we can
make the voltage very high to reduce the current
amplitude.
But only AC can use transformer to change voltage.
Although DC can also change voltage with the help of
Inverter, but it is less stable and robust.