Electronics Forum -> Rms Of Discontinuous Sine Wave

Electronics Forum

Help

Members

Calendar

Welcome Guest ( Log In | Register )

Resend Validation Email

Electronics Forum -> Analog Electronics -> Theoretical Analog Electronics

Forum Rules (please read before posting)

Rms Of Discontinuous Sine Wave

Topic Options

pbdavis	Posted: January 23, 2013 05:34 am
Newbie Group: Members+ Posts: 2 Member No.: 37,726 Joined: January 23, 2013	Hi, How to find the rms value of a discontinuous sine wave of the form shown in the figure.

Sch3mat1c	Posted: January 23, 2013 05:54 am
Forum Addict ++ Group: Moderators Posts: 18,144 Member No.: 73 Joined: July 24, 2002	The RMS of any waveform which is pulsed at some duty cycle D == [0...1] happens to be 1/sqrt(D) times the continuous wave's RMS value. So a sine wave of, say, 300V peak, has an RMS of 300/sqrt(2) for the sine wave, and if it has a duty cycle of 50%, another 1/sqrt(2), or 150Vrms. A "pulsed DC" square wave can be thought of as DC with a duty cycle; since the RMS of DC is equal to its value, which is same as the peak value of a "pulsed DC" waveform, the RMS is simply peak/sqrt(D). Or you can zoom way out and tell your scope to calculate RMS. Tim -------------------- Answering questions is a tricky subject to practice. Not due to the difficulty of formulating or locating answers, but due to the human inability of asking the right questions; a skill that, were one to possess, would put them in the "answering" category.

pbdavis	Posted: January 23, 2013 06:01 am
Newbie Group: Members+ Posts: 2 Member No.: 37,726 Joined: January 23, 2013	1/sqrt(2)???? How did you get "2"....D=[0...1]...isn't it? This post has been edited by pbdavis on January 23, 2013 06:03 am

Sch3mat1c	Posted: January 25, 2013 04:05 am
Forum Addict ++ Group: Moderators Posts: 18,144 Member No.: 73 Joined: July 24, 2002	Oops, that should be sqrt(D), or 1/sqrt(2) for D=1/2 -------------------- Answering questions is a tricky subject to practice. Not due to the difficulty of formulating or locating answers, but due to the human inability of asking the right questions; a skill that, were one to possess, would put them in the "answering" category.

circuitfella11

Posted: May 08, 2013 09:30 am

Newbie

Group: Members+
Posts: 22
Member No.: 38,101
Joined: May 08, 2013

QUOTE (pbdavis @ January 23, 2013 01:34 pm)

Hi,
How to find the rms value of a discontinuous sine wave of the form shown in the figure.

user posted image

hi,

from your figure, first get the RMS for your active signal ( those are the waves looking like pulses from far away)

after that, get the duty cycle..

dutycycle=duration of the active signal/period of the function

you multiply both the rms of the active signal and the dutycycle to get the RMS of the figure.

---regards

1 User(s) are reading this topic (1 Guests and 0 Anonymous Users)

0 Members:

« Next Oldest | Theoretical Analog Electronics | Next Newest »

:: support us ::

ElectronicsSkin by DutchDork & The-Force