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Old 05-27-2009 | 12:40 AM
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Default ESC with Capacitor

Hi guys. I recently bought a used ESC. It has a capacitor soldered to it. It is non-standard as the ESC originally didn't have it. The guy selling this to me saying that a capacitor would increase punch and reduce the temperature of the ESC. Is it true? Thanks.
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Old 05-27-2009 | 12:48 AM
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Didn't you ask this question recently in another thread?

If the capacitor is polarised and soldered on the battery wires correctly (plus to battery plus) it is used to store a bit of charge which is released abruptly to compensate the battery voltage if it is momentarily depleted during hard acceleration or brake. Otherwise, no idea.
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Old 05-27-2009 | 01:08 AM
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A capacitor does help the esc perform more efficiently which makes it run cooler.
In most cases it does improve response.
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Old 05-27-2009 | 01:21 AM
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It must be someone else. This is the first time I am posting about capacitor with ESC.

So it makes ESC cooler. The effect of a better acceleration, is it certain? Any other benefits? So capacitor can also be connected to battery too?

Thanks very much for all the advice.
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Old 05-27-2009 | 04:50 AM
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Look.

What the capacitor does is in my response above. Wether or not it actually keeps the esc cooler or improve acceleration dependes on other variables.

And as I said above, the capacitor I am guessing you talk about (since you didn't specify) is always connected to the battery.
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Old 05-27-2009 | 06:36 PM
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Originally Posted by niznai
Look.

What the capacitor does is in my response above. Wether or not it actually keeps the esc cooler or improve acceleration dependes on other variables.

And as I said above, the capacitor I am guessing you talk about (since you didn't specify) is always connected to the battery.
Sorry the capacitor is actually soldered to ESC. There are 4 cables coming out of the ESC. 2 are on their own and the other 2 appear to be connected as the solder coil melt and link the 2. One of the capacitor's leg is soldered to these 2 linked cables and the other leg is soldered to 1 of the independent cables.
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Old 05-27-2009 | 07:03 PM
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post a picture and we can help you decipher it.
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Old 05-27-2009 | 07:37 PM
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I can't take pictures as I am at work. But attached is the picture I got from the Internet. As you can see there are 4 cables, yellow, red, black, and blue. The capacitor is soldered to yellow and black.
Attached Thumbnails ESC with Capacitor-bg_esc_lrp_8460.jpg  
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Old 05-27-2009 | 08:42 PM
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Lucky you didn't plug in the battery on that one. You MUST remove the solder bridge between those two wires otherwise upon plugging in the battery your speedy is toast instantly.

You also need to identify the cables the capacitor is soldered to and the polarity of the capacitor just in case it is not attached properly.
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Old 05-27-2009 | 10:07 PM
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Originally Posted by niznai
Lucky you didn't plug in the battery on that one. You MUST remove the solder bridge between those two wires otherwise upon plugging in the battery your speedy is toast instantly.

You also need to identify the cables the capacitor is soldered to and the polarity of the capacitor just in case it is not attached properly.
Sorry but I am not quite with you. Pardon me for my "noobness" in this.

I bought this ESC from someone and I haven't done anything with it. He tested it for me before I paid him and the ESC worked alright. So when I asked why it had a capacitor and he said he did it because it would make ESC run cooler and produce more punch (acceleration).

So basically 4 cables, yellow, red, black, blue. yellow and red are linked and have 1 leg of the capacitor soldered to them. the other leg is soldered to black.
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Old 05-28-2009 | 01:00 AM
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The red and black wires go to the battery so your capacitor is soldered to the battery (not on the battery, but the same effect) That's OK.

The speedo in the picture you posted above has reverse, that's why it has four power wires.

As for the link between yellow and red you need to jump on the LRP website and see what they say. I have never seen a speedo where those two wires are linked. That speedo is meant to have reverse, so in effect I think it has been transformed into a forward/brake speedo (perhaps the reverse function can be disabled). Not sure if this is possible with other speedos or if it's a in-house modification, but in my experience it isn't. Maybe yours allows it. Either way, you can't have both forward and reverse with that link there simply because the polarity to the motor can not be reversed once the yellow wire is always on positive. If the reverse has been disabled to allow for this modification, then if you enable reverse by accident or otherwise, you really need to take that link out or else. Normally this would fry the reverse fets in a speedo, but as I said, who knows what has been done to yours.

Perhaps a picture of your speedo would simplify things.

Good luck!
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Old 05-28-2009 | 08:24 AM
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Here the picture of my ESC. Please enlighten me! Thanks.
Attached Thumbnails ESC with Capacitor-28052009068.jpg  
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Old 05-28-2009 | 09:03 AM
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It is not clear from your picture if there is a definite bridge of solder between red and yellow or it just appears to be. Anyway. I think that soldering work is quite crappy (even crappier than my own, so it's pretty crappy).

My suggestion is that you redo the soldering on the red and yellow and take care to separate them carefully and neatly. The capacitor seems to be attached at the yellow wire, you need to move it to the red wire (as you can see the capacitor has a black and a red wire, those colours are not random, they are a key to suggest where they need to go).

All this should be done after you clear out with the seller why they soldered the bridge between red and yellow, and they batter had a good explanation. I wouldn't dare do that on my speedo (the same model as yours) and then plug it to the battery. I am not sure how he tested it for you (you said he did), because as it is I think it would fry straight away. Perhaps as I said before, he shorted out the reverse, but then you need to be aware you have bought a speedy with no reverse.

After you have a good explanation with the seller you will know a lot more. Just in case you don't, separate yellow and red as I explained above, and try the speedy. If you don't have reverse, you know why.

Good luck!

Last edited by niznai; 05-28-2009 at 09:15 AM.
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Old 05-28-2009 | 07:26 PM
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Originally Posted by niznai
It is not clear from your picture if there is a definite bridge of solder between red and yellow or it just appears to be. Anyway. I think that soldering work is quite crappy (even crappier than my own, so it's pretty crappy).

My suggestion is that you redo the soldering on the red and yellow and take care to separate them carefully and neatly. The capacitor seems to be attached at the yellow wire, you need to move it to the red wire (as you can see the capacitor has a black and a red wire, those colours are not random, they are a key to suggest where they need to go).

All this should be done after you clear out with the seller why they soldered the bridge between red and yellow, and they batter had a good explanation. I wouldn't dare do that on my speedo (the same model as yours) and then plug it to the battery. I am not sure how he tested it for you (you said he did), because as it is I think it would fry straight away. Perhaps as I said before, he shorted out the reverse, but then you need to be aware you have bought a speedy with no reverse.

After you have a good explanation with the seller you will know a lot more. Just in case you don't, separate yellow and red as I explained above, and try the speedy. If you don't have reverse, you know why.

Good luck!
The seller appears to be not the one who did it, so he must have bought it from another person.

Anyway, http://aedownloads.com/downloads/man..._userguide.pdf is the manual for the ESC. Yellow appears to be positive-motor and red is positive-ESC. Interestingly, the 4 cable tips are held by plastic material on the ESC. Blue and Black are on their own, but Yellow and Red share the same plastic material. Not sure if they are meant to be linked. Anyway, in the manual it only explains about soldering to motor, not ESC. Besides I am new to this. So hopefully you or anyone could shed some light. Thanks.
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Old 05-28-2009 | 08:00 PM
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Originally Posted by xniperliams
The seller appears to be not the one who did it, so he must have bought it from another person.
So did it test it for you? How? Did you actually see it work?
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