Society of Robots - Robot Forum
Electronics => Electronics => Topic started by: krich on October 30, 2007, 05:08:18 PM
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I've got a number of capacitors laying around from a previous project. The catch is that they are rated for 250V, for example. I know the recommendation is to use a cap rated at about twice the voltage you are expecting to run through it, but is there any issue with using a capacitor that is rated at 20 or more times the voltage? ???
These guys are left over from a monitor repair I did a while back, thus the larger voltage ratings.
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i've actually read that you need to be over the rating by at least %50, too high a rating will cause it not to work
i can't say for sure
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What about a 240V capacitor on a 5V circuit, assuming the proper number of uF's?
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Why not just make a simple circuit with a switch ,LED, and capacitor?
Should take like 5 minutes... ;)
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There should really be no problem in using a higher v rated capacitor, ive used a 25 kilovolt cap on a 24 volt circuit (although i did change it eventually once i got a suitable one), the load might alter slightly though
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That 250V rating is actually for AC current (its a non-polarized cap, like ceramic, right?) . . . I don't remember what the conversion is, but I think its like 100V for DC.
For crude applications (like for motors) it won't matter.
The only real disadvantage to a voltage rating that high is that the capacitor is unnecessarily large.
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That makes sense. I just got around to looking at some of the ratings and what you say about the size is definitely true. A good example is this 350V 22uF capacitor. Its a tenth the uF's as the one used in the $50 dollar robot, but its at least 5 to 6 times larger (wow).
Edit: These are polarized caps. I guess there's some high DC voltage flying around inside a monitor.