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Help with capacitor please

Help with capacitor please

Old 11-16-2006, 04:30 PM
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Default Help with capacitor please

Hi,

I'm a hardcore offroad buggy racer grease monkey that just decided to spend winter racing instead of going nuts. I just bought a spankin new T2'007 with a LRP Quantum Competition 2 + a C027 and another 19 turn motor on it's way. I just need plain frank unbiased answers on the need for a capacitor on this specific ESC cause I'm a total noob to electric rc.

Is it required, is it just optional ? If optional, what would I gain from it, if required what do I stand to lose by not adding it.

I get different answers all over the place and I am definitly going nuts about this.

LRP QC2 owners' answers prefered.

thanks in advance.
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Old 11-16-2006, 05:38 PM
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Punch. The cap will dump it's stored power when you get back on the throttle getting out of corners. This will make racing easier on your batteries as well.. IMO, a cap is very necessary in racing on-road, regardless of which ESC you choose. BTW, I use LRPs...
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Old 11-16-2006, 06:34 PM
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a capacitor also helps to keep the esc cool by charging itself w/ the voltage spikes. the cap. absorbs the extra volts and uses it to give extra punch out of the corners.

-Zac
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Old 11-16-2006, 06:56 PM
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I couldn't wait, read one of the threads about caps and I just installed a 16v 4700uF capacitor and a schottky diode on my motor and notice the motor runs MUCH faster.

Another question then. Can a capacitor harm the motor or ESC if I choose the wrong one. I think I got the right thing on as per what I read but just in case...
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Old 11-16-2006, 07:21 PM
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Yeah sorry montrealer just saw your post. The QC2 worlds kit should come with 2 Power Capacitors. They greatly increase the punch of the speedie which is a must in any spec motor class, such as stock or 19T.

Basically the capacitor helps to maintain the voltage supplied by the battery when you are accelerating hard (thus the extra punch).

The difference in the two Power Capacitors is also very noticable, i think you have installed the big one which is the best choice.

I dont understand schoktty's so much but my understanding is that it will protect the fet's on the speedy while also increasing the breaking effect of the motor.

I dont know if choosing the wrong capacitor will harm the motor or esc. Manufacturers reckon they select the capictors based on testing which i guess means you dont want one too big that its going to drain your power **SHRUG**.

No idea if it can damage your equipment or not.
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Old 11-16-2006, 08:12 PM
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Originally Posted by mangoman
Yeah sorry montrealer just saw your post. The QC2 worlds kit should come with 2 Power Capacitors. They greatly increase the punch of the speedie which is a must in any spec motor class, such as stock or 19T.

Basically the capacitor helps to maintain the voltage supplied by the battery when you are accelerating hard (thus the extra punch).

The difference in the two Power Capacitors is also very noticable, i think you have installed the big one which is the best choice.

I dont understand schoktty's so much but my understanding is that it will protect the fet's on the speedy while also increasing the breaking effect of the motor.

I dont know if choosing the wrong capacitor will harm the motor or esc. Manufacturers reckon they select the capictors based on testing which i guess means you dont want one too big that its going to drain your power **SHRUG**.

No idea if it can damage your equipment or not.
It's not actualy the worlds upgrade kit I installed but rather a 2$ capacitor I got from an electronics store. The schottky came with my ESC. Anywho, the results are spectacular.
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Old 11-16-2006, 09:20 PM
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It depends where you are installing the capacitor. If its on the power leads or plugged into the receiver, you can use whatever size you want. If its on the output from the ESC, which is high frequency DC pcm, you should not install a large capacitor. It will absorb the power that was meant to go into the motor. Only extremely low value caps (0.1uf) are installed at the motor, and that is to absorb unwanted rfi. Capacitors block DC and pass AC. That's why you don't put a large on on the output of the esc or across the motor leads.
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Old 11-17-2006, 11:21 AM
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Damn !

Now I'm getting even more confused. I installed the Cap on my QC2, it does run faster. Called my LHS, they say they are not required as one of these capacitors is integrated in the ESC. Will this additionnal capacitor, assuming there is one equal inside the ESC, harm my motor put throwing too much power to it ?

Summer...nitro... please come back
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Old 11-17-2006, 11:39 AM
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Originally Posted by Montrealer
Will this additionnal capacitor, assuming there is one equal inside the ESC, harm my motor put throwing too much power to it ?
No - it will not harm the motor. Some racers even elect to install larger caps on their speed controls. With the size of QC2 I doubt the cap inside the shell is 4700 Uf.
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Old 11-17-2006, 12:25 PM
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Originally Posted by Montrealer
Called my LHS, they say they are not required as one of these capacitors is integrated in the ESC.
Your LHS is run by an uneducated d**t. Ok, that may have been a little harsh, so he's just uneducated in the fine ways of on-road. Put a nice fat cap on the battery leads going into your esc for more punch. Plug one into your receiver to help keep the voltage up going to the electronics, and put .01uF caps on the motor (most have them now) to keep stray rf away. Caps are your friend. I know someone that runs 2 caps in parallel on the battery in for the ESC... I don't like to spin my foam tires on carpet.
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Old 11-17-2006, 12:38 PM
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Originally Posted by timmay70
Your LHS is run by an uneducated d**t. Ok, that may have been a little harsh, so he's just uneducated in the fine ways of on-road. Put a nice fat cap on the battery leads going into your esc for more punch. Plug one into your receiver to help keep the voltage up going to the electronics, and put .01uF caps on the motor (most have them now) to keep stray rf away. Caps are your friend. I know someone that runs 2 caps in parallel on the battery in for the ESC... I don't like to spin my foam tires on carpet.
: Capacitors are my friends... capacitors are your friends... everybody should have a capacitor friend... dum dudum dudum...

LOL !!! thanks, I feel better already.

E.
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Old 12-19-2006, 04:59 PM
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i saw this post and maybe i can ask questions here.. i have a TC2 esc and bought it 2nd hand, and there's no power cap installed on i but it do have the wires for the power cap.. if i will be buying at a local electronic shop what it should buy.. wat farad and voltage??
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Old 12-19-2006, 06:15 PM
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Originally Posted by nikkiesteban
i saw this post and maybe i can ask questions here.. i have a TC2 esc and bought it 2nd hand, and there's no power cap installed on i but it do have the wires for the power cap.. if i will be buying at a local electronic shop what it should buy.. wat farad and voltage??
4700uf 10 volts

Should be about the size of a thimble. You can go larger on either number, but the physical size will increase. Increased voltage rating is not necessary and would be unnecessary added size.
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Old 01-17-2007, 06:55 PM
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Sorry to bring back an old thread, but Im curious.. Does anyone know where there is.. or HAVE.. a diagram showing the installation of a power capacitor?

And can you use one on ANY ESC? Im was just looking at an LRP Quantum 2 Super Reverse.. http://www2.towerhobbies.com/cgi-bin...?&I=LXLTY2&P=7

and wondering if it would ham this?

This is the only thread with real good answers I found, just looking for more of an installation step-by-step...
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Old 01-17-2007, 07:02 PM
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Oooh, also... is there any charging required for these caps? With a car stereo cap, I know you have to hook it up to power through a resistor, and let the power gradually build before installation...

Anything similar with these?
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