Question

Hello Could I please have some guidance on the following question.

If an astable waveform (rectangular wave) has a mark/space ratio of 0.33, what would be the Duty Cycle for the same waveform expressed in %?

So this is what I know

Duty Cycle (DC) = TH / T x 100

Period (T) = TH + TL

Mark/Space (MS) = TH / TL

So I have managed to get this far with substitution

DC = TH/ (TH + TH/ MS)

which is equal to DC = (TH/1) / ((TH/1) + (TH/MS)), however I am missing the point from here. I thought I could use the ear rule (a/b) / (c/d) = ad/bc which gives the following

DC = THMS / (TH + TH) so therefore DC = THMS / 2TH

If I now cancel common terms I have DC = MS/TH

This cannot be correct as I do not have a value for TH so I believe it must be cancelled somewhere up the chain only I am not sure where. I'm guessing there is a problem with how I have implemented the ear rule or the equation should not be handled that way in that section. I really not sure where I need to go from that point.

Any assistance/guidance would be most appreciated.

Regards

Daniel

Answer 1

hope this helps daniel ..