Finding RMS value of discontinuous current waveform

[treez]

Hello,

Do you know of a mathematical expression that give the RMS value of this Discontinuous current waveform?

https://i49.tinypic.com/152gryo.jpg

(i.e. supposing I know the peak value, the rise time, fall time and dead time)

 

[Raza]

May be this one helpful for you.

https://www.google.com.pk/url?sa=t&...sg=AFQjCNHwADtHgdmDT3Mp9eCIrse_w5vPkA&cad=rja

 

[_Eduardo_]

Have you problems with the RMS definition?

==> Vrms = Vpk sqrt((trise+tfall)/(3*(trise+tfall+tdead)) = Vpk sqrt(duty_cycle/3)

 

[treez]

Thankyou, i guiltily avoid the integration......because its easier to simply use a standard formula and then check it on the simulator.....and this is a more failsafe method.

....In fact, i have found that the formula for a trapezoid waveform can be used......do it twice and then take root of some of squares.

(ie break the triangles into two right angled ones and treat each as a trapezoid with one side = zero)

..then get rms for each train of "trapezoids"..then take root of sum of squares for overall RMS value.

 

[Ratch]

treez,

So easy to integrate the two linear functions, why bother with a "cookbook" method?

Ratch

 

[treez]

standard formula is one cell in an excel spreadsheet....integration is several cells, and this mess's up the smps design document....there are so few different waveforms in hard switched smps that you may as well just use the standard formulae

 

[Ratch]

treez,

Are you going to find the rms of this answer and the one posted here **broken link removed** ?

Ratch