Unterschied: Fast PWM - Phase Correct PWM

kann mir vorstellen,dass so etwas bei UPS sinnvoll ist um mit dem netz
synchron und in phase zu laufen....nuetzlich bei umschalten von netz
auf ups und umgekehrt.
kann aber auch was ganz anderes sein.

such mal im datenblatt eines avr deiner wahl (sollte schon pwm haben)
nach deinem begriff. da ist eine schöne erklärung mir bildchen drin

Hi,

Fast PWM the basic pulse width modulation , you surely know.
Phase Correct PWM is what we use with motor control systems. If we use
zigzag-wave and the sine-wave ( lower fequency ) and output is ON if
zigzag is higher than sine, we get PWM, where the pulse doesn't start
after constant time, but the middle of the pulse has nearly constant
time step. We can say it is in correct position with sine-wave eg. in
correct phase. If you make drawing of this, you will notice it.

Hello,

I have just a question. Where does the sine-wave came from?
Is it my line voltage (50Hz)?

thx

Hello,

Phase Correct PWM is mainly used for 3-phase ac-motor control ( also
called sine triangle PMW ). Sine wave is generated internally normally
in 3-phases internally.
Reason for using this PWM; output is very near sine-wave and then
efficiency is better and harmonics lower. So very specific use!
Google will tell more words: sine triangle PWM ac inverter etc..
http://www.kemt.fei.tuke.sk/predmety/KEMT350_EP/_materialy/ch030.pdf

SSt

Hello,

I thing i understand why i use this kind of PWM.
Today i found a interesting Homepage:

http://www.ipes.ethz.ch/ipes/Inverter/e_H_Bruecke.html

So i use this kind of mode to generate a AC-Voltage from a DC-Voltage
for inductors.

cu