Skip to main content
A
athurin1-Visitor
1-Visitor
February 4, 2015
Solved

Unit issue in solve block

  • February 4, 2015
  • 6 replies
  • 2369 views

Hi,

I have tried to solve equations of current ramping up and down in a power converter, including the series (parasitic) resistances in the circuit. Solve block works fine and finds sensible results, except ... one of the 2 parameters I am searching (aa) is a duty cycle, and therefore, should be unitless, and it comes out of the solve block with a unit (Amps, like the other variable). I just can't find what I've got wrong, since all the equations I input will only work if the variable is unitless, so why on earth would the solve block add a unit that doesn't work ? Unless I missed something ...

Thanks

Best answer by Werner_E

Seems to be a bug in Prime. You can avoid this effect if you provide a (unitless) guess value different to 0 (e.g. 0.01). As an alternative you could write aa:=0*UnitsOf(1) to use zero as guess and make it clear for Prime that its unitless.

6 replies

Werner_E
Werner_E25-Diamond IAnswer
25-Diamond I
February 4, 2015

Seems to be a bug in Prime. You can avoid this effect if you provide a (unitless) guess value different to 0 (e.g. 0.01). As an alternative you could write aa:=0*UnitsOf(1) to use zero as guess and make it clear for Prime that its unitless.

A
athurin1-VisitorAuthor
1-Visitor
February 4, 2015

Thanks Werner. I should have remembered I had unit issues with zeros before...

Terms & ConditionsAccessibility statement