Barbershop

[m-Kresol]

thread necro

can this run on 18v?
Im worried about the 16v rated 220uF cap.

Well, I think you answered your question right there.

From a professional point of view, I can only say that if you apply 18V you should do it slowly the first time so not to blow the cap. Usually there is a safety margin, so it should be ok without a problem, while the lifespan will be a bit reduced. However, we usually do not overly stress electrolytics in filtering caps with strong ripple (amplitude nor frequency).
The way it works when you apply more than the rated voltage is that the dielectric anodically grows in the electrolyte (with hydrogen evolving, which can blow the vent) so that the voltage rating actually increases. However due to the increase in thickness, the capacity will decrease according to  C=eps*A/d (capacity=permittivity*Surface area/dielectric thickness).
So overall, increase voltage slowly, if you can, to not have too much hydrogen at once and expect voltage to be slightly lower.
hope that helps

[LaceSensor]

thread necro

can this run on 18v?
Im worried about the 16v rated 220uF cap.

Well, I think you answered your question right there.

From a professional point of view, I can only say that if you apply 18V you should do it slowly the first time so not to blow the cap. Usually there is a safety margin, so it should be ok without a problem, while the lifespan will be a bit reduced. However, we usually do not overly stress electrolytics in filtering caps with strong ripple (amplitude nor frequency).
The way it works when you apply more than the rated voltage is that the dielectric anodically grows in the electrolyte (with hydrogen evolving, which can blow the vent) so that the voltage rating actually increases. However due to the increase in thickness, the capacity will decrease according to  C=eps*A/d (capacity=permittivity*Surface area/dielectric thickness).
So overall, increase voltage slowly, if you can, to not have too much hydrogen at once and expect voltage to be slightly lower.
hope that helps

thanks for the reply
Yeah figures, I know its a risk. I built one years ago and having a clearout. I never bothered to run it at anything but 9v and yet the chap purchased it and is now wanting to try. Ive said it might pop the cap, at his risk basically. its an easy thing to fix mind you.

cheers
Ian