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Old 01-19-2009, 12:04 PM   #1
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Default what are the pros annd cons of using capacitors??

i've seen some in pictures and such and was wondering what size is best to use and if there's any down sides besides shorter run times
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Old 01-19-2009, 12:26 PM   #2
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I take it you mean the capacitors on the ESC - what we call "power capacitors".

There is no real downside - certainly they will not shorten runtime as all the energy they store is used by the car. They are their to smooth out the power supply and make the ESC work more effectively - generally if the capacitor is recommended by the manufacturer, you should use one, if not, then there is no need.
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Old 01-20-2009, 11:04 AM   #3
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The only downside is that you have something else to find room for on the chassis!

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Old 01-20-2009, 11:16 AM   #4
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ACTUALLY there is a problem with not running a power capacitor from an electronics standpoint... and if you want your electronics to keep running for a long time I would recommend running them ... even though they take up valuble realestate in your vehicle or might look unsightly.

Sosidge is about half right:

The caps are there to smooth out ripple current caused by the transistors in the ESC turning on and off supplying power to the motor.

If you do not have an adequate power capacitor to suppress the ripple current, your transistors will run hotter and are much more prone to failure due to the fluctuating power.

So if you're lucky and run your ESC without a capacitor and the ESC doesn't fail, you're still losing overall efficiency, which CAN effect your runtime and power.

Just run a power cap
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Old 01-20-2009, 11:28 AM   #5
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Here's another benefit to running power caps...

I recently (and carelessly) installed my lipo battery plugs backwards into my car (polarity reversed). It was only for a split second, as the connection immediately sparked and the power cap emitted a quick puff of smoke. Thankfully, after replacing the power cap, my Novak GTB speedo was completely UNHARMED and operated normally without damage. In conclusion, the power capacitor protected my ESC from damage!
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Old 01-20-2009, 11:34 AM   #6
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Capacitors help keep the temperature of the ESC and Motor LOWER by storing energy to maintain voltage during peak periods of increased demand/load.

"I think" without a capacitor during peak demands, if the battery cannot supply the voltage quickly enough, amp draw will increase, from increased resistance, thus increasing temperature.

"I think" with a capacitor, voltage spikes/demand to the motor will become more stable, reducing peak amperage draw. Reduced amps will keep temps lower.

BUT, what do I know - I'm not a rocket scientest.



edit - Darn Steve Weiss said it better. I was typing and he was already posting...
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Old 01-20-2009, 11:58 AM   #7
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Would it be safe to say that capacitors function similarly to boost bottles on R/C Nitro engines?

That is what I am gathering so far...
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Old 01-20-2009, 12:03 PM   #8
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Quote:
Originally Posted by J.Filipow View Post
Here's another benefit to running power caps...

I recently (and carelessly) installed my lipo battery plugs backwards into my car (polarity reversed). It was only for a split second, as the connection immediately sparked and the power cap emitted a quick puff of smoke. Thankfully, after replacing the power cap, my Novak GTB speedo was completely UNHARMED and operated normally without damage. In conclusion, the power capacitor protected my ESC from damage!
Come on GTB is bulletproof. I`ve seen one being reversed for 10seconds, drowned, overloaded, killed fan, heavily abused, smoked with stink. It was all on 3.5 Novak motor and it is still alive.
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Old 01-20-2009, 12:32 PM   #9
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what would be an appropriate size to get? or does it not really matter?
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Old 01-20-2009, 01:02 PM   #10
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Quote:
Originally Posted by ringo3632 View Post
what would be an appropriate size to get? or does it not really matter?

What type of ESC do you have?
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Old 01-20-2009, 01:24 PM   #11
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Quote:
Originally Posted by HarryN View Post
Would it be safe to say that capacitors function similarly to boost bottles on R/C Nitro engines?

That is what I am gathering so far...
the same idea, but faster and it actually works
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Old 01-20-2009, 01:25 PM   #12
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right now i just have the stock lrp A.i. Automatic Super Reverse ESC that comes in the tc4. i wanted to get somethin new but i've had a lack in funding..
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Old 01-20-2009, 01:40 PM   #13
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You could try using the 5682 power cap with your ESC and it should work fine.

http://www.teamnovak.com/products/po...ors/index.html
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Old 01-20-2009, 01:55 PM   #14
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awesome! thanks i'll be getting one of those asap!
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Old 01-20-2009, 04:19 PM   #15
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Hi guys... so Power Caps ........ I only remember seeing these in BL Speedos and Motors... but I suppose they work for brushed motors too..... if so, for 540 class might have a little improvement i guess.. well anyway I want to try them.....

How do I buy tose suckers??? References??

And where do I install it?? Where to solder??

Thanks for the advice guys........
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