1uf electrolytic

km-r · February 13, 2007, 01:28:21 AM

i have seen lots of schematics with 1uf non-polarized cap...
i tried building them with two 0.47uf mylars in parallel but its very bulky so i wanna know whats the disadvantage of using electrolytic 1uf in lieu of 1uf nonpolar?

and what considerations should i make if im going to use this susbstitution?
thanks,

RaceDriver205 · February 13, 2007, 01:36:54 AM

If you use a normal 1uF electro in place of a 1uF NP, odds are it won't work. You should be able to get non-polars, which are also called bi-polars.

tcobretti · February 13, 2007, 01:59:46 AM

I would try it using the electro. Race, is that something you read somewhere? I didn't think it made a difference.

RaceDriver205 · February 13, 2007, 02:51:13 AM

Well, if it doesn't make a difference theres no point specifying it!

The idea is that an electro can't/shouldn't be charged in the opposite direction, and in applications were it would be, one uses a NP. Of course, if one doesn't know if it will be reverse charged or not, one might say use NP anyway.

tcobretti · February 13, 2007, 03:26:49 AM

I had just thought there was a time when large NP caps were more common. I guess I was wrong!

jcwillow777 · February 14, 2007, 08:49:26 AM

I'm sure you know where to get 1uf caps from, but I like digikey.com for these - the part number is P4675-ND. I bought a few others when I was just starting out that were to big for my liking and short leads from Smallbear. Not that I have been doing this for that long.

Just my 2 cents

km-r · February 14, 2007, 08:44:33 PM

there no 1uf NP in my locale...
this might suggest that im stuck with two 0.47 mylars in parallel... would this be effecttive not considering the bulkiness of the replacement?

my rule for replacement using 1uf elec is to determine which side is more positive and thats where i solder the + side.

RaceDriver205 · February 14, 2007, 11:25:44 PM

What effect is it your making?

km-r · February 16, 2007, 10:22:57 PM

^ almost anything... well for one, my tubescreamer clone.

ive heard the 2pcs electrolytic connected back-to-back with their neg leads work... and well, double the capacitance of each cap.

oldrocker · February 28, 2007, 10:01:52 AM

If the layout specifies an NP cap then use one for sure. If it doesn't specify NP then either cap will work. Check out that huge 1uF cap at the bottom of the Nyquist Aliaser I just built. Talk about bulky.

As for the two electro caps tied by the negatives.. If both caps are the same size then even though you have two connected together one cancels out the other. So two electro 1uF caps will equal one 1uF NP cap. R.G.?...
http://www.logmonster.com/images/full/?pic=aliaser4_1169985910-422-14673.jpg

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1uf electrolytic