What is the difference between excitation frequency and switching frequency?

Question

Specifically, how this relates to the use of pulse width modulation (PWM) technique.

Answer 1

You may not have to correct terms but i think that the excitation frequency that your talking about is a dc voltage that is turn into a square wave so its on, off, on off, for certain peroids of time. This is a good way to control the speed of a DC motor. PWM is an AC voltage and how it works is that it "crops" off certain parts of the wave form by using a triac and diac. how much is croped is controled by a potentiometer. This is used to control AC motors, commenly called varible frequecy drives, it also is a dimmer switch but much less power. Hope this helps

Answer 2

I'm not familiar with those terms. i would guess that excitation frequency refers to the modulation frequency, and the switching frequency refers to the pulse (carrier) frequency.

To elaborate: the unmodulated pulse train would have a carrier frequency (the switching frequency), so many pulses per second. When modulation is applied, the pulses vary in width according to the level of the modulation signal. If the modulation signal is a sine wave (or composite of sine waves), then the frequency of those waves would be the excitation frequency.

Answer 3

That is just the different ways they create the change.