Power Capacitor For LRP Sphere

[jonny123]

What is the best power capacitor for a lrp sphere compettition tc spec esc as my original has broken.
E.g what power rating e.g uf and what voltage.
Any help would be apriciated.

[jonny123]

surely someone knows ???
Please help me !

[DaveG28]

I broke one on a sphere (not tc) and replaced it with the Novak one, which worked fine!

[Dagger Thrasher]

Any 16V, 4700uF (or thereabouts) electrolytic cap should do the job just fine. The Novak cap will work perfectly, but personally, I'd just buy a cap from somewhere like Maplin. Much cheaper and every bit as good, but you'd just need to solder wires on yourself and it doesn't have the Novak badge. You could buy a whole load for the same price as a single Novak cap. Preferably, the capacitor needs to be "low-ESR"...but I won't get into that lol. If you get one from an electronics supplier like Maplin, then as long as rated to 105 degrees, it's probably low-ESR (even if it doesn't say).

Sorry if I'm a bit late on this, but just thought I'd give my 2 pence if you hadn't already sorted it.

[jonny123]

i have a temporary one that i made in electronics in school roughly to the same rating as my teacher thought i needed. But he only had small ones so i had to solder 5 in parralel to get a rating that he thought wouldnt be far off from the original.
thanks for your help
much appriciated

Ive heard that a bigger capacitor would give me more punch. Is this true or just an old wives tale lol.

[jonny123]

think i found one on maplin 4700 uf low esr
up to 63v

http://www.maplin.co.uk/Module.aspx?ModuleNo=23074

would that do the job ?

And would the 6800 uf one work or favour me in any other way ?

[Dagger Thrasher]

Nooo, that thing is waaaay too big (physically); thing is with electrolytic capacitors is that, generally, the higher the voltage they can handle, the bigger they are even at the same capacity. That thing's a bit of a whopper unfortunately!

You should find one of these will suit you just fine:
http://www.maplin.co.uk/Module.aspx?ModuleNo=13472 (You want the 4700uf 16V one).

You could certainly increase capacitance with no ill effects, but with diminishing returns. On 2S LiPo, in your application, 4700uf will be just fine. :-)

[jonny123]

ok thanks ive ordered one.
Its not that exaxt one from maplin. But from what youve said its perfect.
4700 uf, 16v, to 105c, low ESR. and pretty small in size.
Thanks m8. I got 4 of them for 3 quid posted on the bay !
Bargain

[madmax]

hi m8 i have a spair cap for one of these speedos if that is eny help

[jonny123]

got 1 now m8 thanks for the offer. I got a few spairs aswell

[DaveG28]

Originally Posted by Dagger Thrasher

Nooo, that thing is waaaay too big (physically); thing is with electrolytic capacitors is that, generally, the higher the voltage they can handle, the bigger they are even at the same capacity. That thing's a bit of a whopper unfortunately!

You should find one of these will suit you just fine:
http://www.maplin.co.uk/Module.aspx?ModuleNo=13472 (You want the 4700uf 16V one).

You could certainly increase capacitance with no ill effects, but with diminishing returns. On 2S LiPo, in your application, 4700uf will be just fine. :-)

Is that one Low ESR though (whatever that means!?)

[Northy]

Equivalent Series Resistance

G

[DaveG28]

Originally Posted by Northy

Equivalent Series Resistance

G

Don't suppose you also know where one can be got??

[Northy]

I can look tomorrow

G

[jonny123]

here you go guys heres the link where i got mine off ebay yes there low esr aswell !

Brilliant service, fast delivery, and polite people to deal with.


http://cgi.ebay.co.uk/ws/eBayISAPI.d...m=120229578605

[Northy]

They are physically a little large though

G

[jonny123]

fits nicely in my touring car i think it completes the good image with a beefy capacitor !

[Mike Hudson]

Originally Posted by jonny123

fits nicely in my touring car i think it completes the good image with a beefy capacitor !

can you post a pic up of it so give an idea of size? there not bigger than the NOvak caps are they?

[Dagger Thrasher]

Is that one Low ESR though (whatever that means!?)

I'm not sure whether those particular caps are low-ESR, but it's more of a preference than a necessity, so I just linked to those as I didn't have time to find some low-ESR jobbies - sorry! Low-ESR caps will help your ESC run cooler than non-low-ESR caps as they'll be slightly more effective at smoothing out voltage ripples (less resistance, so the cap will absorb/release more voltage when it's needed). Northy's right with the definition there.

But yup, ideally you want low-ESR caps; especially if you're running a demanding setup (higher current draw means more voltage ripple from the cells). If you're not running a particularly hot motor though, it doesn't *need* to be low-ESR.

[Northy]

Originally Posted by Mike Hudson

can you post a pic up of it so give an idea of size? there not bigger than the NOvak caps are they?

Same diameter but a bit longer.

G