Go Back   XmodSource.com > Xmods > XMOD Electronics
Register FAQ Members List Calendar Gallery iTrader Search Today's Posts Mark Forums Read

Reply
 
Thread Tools Display Modes
  #1  
Old 02-14-2007, 11:49 PM
BART's Avatar
BART BART is offline
XMS Administrator
 
Join Date: Dec 2006
Location: Ohio
Posts: 2,621
Trader Rating: (5)
Default The truth about Capacitors!

I'll try to make this as simple and as useful as i can.

I have read plenty of misconception on this site about the use of capacitors for performance gains. First of all, replacing or adding capacitors to your motor will not make your car faster, in fact it will make it slower. A capacitor is an electrical storage device which discharges it's stored energy very quickly when presented with a load in which to discharge. If placed on the motor leads or directly on the motor itself it would have to use the energy which was intended to power your motor to charge the capacitor (which would take away from the energy that was intended for your motor in the first place).

The capacitors that are already on your motor are intended to reduce "noise" produced by a brushed motor and to absorb peak transient voltages caused by counter emf which occurs at high speeds and when the power to the motor is suddenly cut off.

Now for the slightly good part, there is a way to use capacitors for a slight performance advantage.

If a capacitor is connected to the battery connection of the main board (and in this case bigger is better) the capacitor would be charged whenever the batteries are inserted and able to discharge on demand much quicker than the batteries themselves whenever the board demanded power (when you hit the gas). The gains would be small but from reading your posts most of you guys are looking for any advantage possible.

A capacitor could be connected anywhere along the wires from the battery tray to the board but the closer to the board the better.
Reply With Quote
  #2  
Old 02-14-2007, 11:59 PM
Numbchux's Avatar
Numbchux Numbchux is offline
The Daywalker
 
Join Date: Feb 2006
Location: Duluth, MN
Posts: 1,509
Trader Rating: (1)
Send a message via AIM to Numbchux Send a message via MSN to Numbchux Send a message via Yahoo to Numbchux
Default

nice...but I've got a better place for this
__________________
-Chux

"Where are we going, and why are we in a handbasket?"
Subaru --- All We'll Drive
Member: NSW, USC, MNS, C4C. Founder/Owner: NCC
Reply With Quote
  #3  
Old 02-15-2007, 09:46 AM
streetballerzz3's Avatar
streetballerzz3 streetballerzz3 is offline
Elite member
 
Join Date: Aug 2006
Location: NEW YORRK
Posts: 346
Trader Rating: (1)
Default

great job zx9rbart explains it in good detail
__________________
Helpful Warnings: "CAUTION: Knife is very sharp. Keep out of children"
^
i got that from a box of kitchen knifes at IKEA

aka DJ KraZe
Reply With Quote
  #4  
Old 02-21-2007, 06:17 PM
Red10152's Avatar
Red10152 Red10152 is offline
Stage 2 member
 
Join Date: Jul 2006
Posts: 90
Trader Rating: (0)
Default

so if i took the capacitor (the little Orange thing with a number on it) off my motor would it go faster or just be really noisy

also i can put a capacitor on the battery wires to th eboard and it would be a slight performance boost
Reply With Quote
  #5  
Old 02-21-2007, 08:41 PM
BART's Avatar
BART BART is offline
XMS Administrator
 
Join Date: Dec 2006
Location: Ohio
Posts: 2,621
Trader Rating: (5)
Default

Quote:
Originally Posted by Red10152 View Post
so if i took the capacitor (the little Orange thing with a number on it) off my motor would it go faster or just be really noisy

also i can put a capacitor on the battery wires to th eboard and it would be a slight performance boost
1...no dont do it, I'm not talking about noise you can hear. 2...yes,read my original post in its entirety.
Reply With Quote
  #6  
Old 04-16-2007, 09:02 PM
texan_idiot25's Avatar
texan_idiot25 texan_idiot25 is offline
Yes, 1945 Cadillac Tank
 
Join Date: Jun 2006
Location: Austin, TX
Posts: 3,366
Trader Rating: (5)
Send a message via AIM to texan_idiot25
Default

Truth about capacitor turbos on the motor? Indeed, read the thread

http://xmodworld.com/modules.php?nam...wtopic&t=20824
__________________
You know what I'm gonna do? I'm gonna get myself a 1967 Cadillac Eldorado convertible, hot pink, with whale
skin hubcaps and all leather cow interior and big brown baby seal eyes for headlights. Yeah! And I'm gonna drive
around in that baby at 115 miles an hour, getting 1 mile per gallon.

I may be king of the idiots, but my kingdom is vast and my subjects are everywhere
Reply With Quote
  #7  
Old 04-16-2007, 09:18 PM
BART's Avatar
BART BART is offline
XMS Administrator
 
Join Date: Dec 2006
Location: Ohio
Posts: 2,621
Trader Rating: (5)
Default

Quote:
Originally Posted by texan_idiot25 View Post
Truth about capacitor turbos on the motor? Indeed, read the thread

http://xmodworld.com/modules.php?nam...wtopic&t=20824
Thanks...I think that backs my claims up pretty well.
Reply With Quote
  #8  
Old 07-07-2007, 10:40 PM
RedSXmodder's Avatar
RedSXmodder RedSXmodder is offline
Rethink It All
 
Join Date: Nov 2006
Location: Earth...why?
Posts: 1,447
Trader Rating: (8)
Send a message via AIM to RedSXmodder Send a message via MSN to RedSXmodder
Default

I did some searches on your capacitor trick, and I learned alot. But I have a few questions.

1) If the capacitor is farther away from the board, what are the negative effects? I don't think it'd be too noticeable, unless you really know the powers of the capacitor your using, right?

2) The capacitor fills, and discharges, many times a second, is there a way that could cause jumpiness in response (lowering smoothness and control ever so slightly) or becuase its connected to the battery it would have nothing to do with it?

3) Say I wan't my xmod as smooth as a mini-Z, would putting capacitors on the battery, servo, and motor create excellent, smooth response?

4) Does the size of the capacitor create different filtering effects? I know that the bigger the one on the battery section would be better, but if you had a smaller one on the motor and servo would it still be able to filter as well or better then a bigger one, or is the bigger one better?

I know putting a capacitor on the servo wouldn't do much, since its only being used when that particular function has battery power going through it (along with the motor) but it still should filter electrical noise on the servo motor. Also, would you be able to put a capacitor near the board by the servo and use that as a torque effect, and then have a capacitor up on the motor acting as a filtering effect.

I guess I'm kinda asking the same question over and over again, but, I'm learing alot about this whole thing...

Later,
RedSXmodder
__________________

Team Redmade Motors- Building Motors that rise above the rest!

Rethink It All
Reply With Quote
  #9  
Old 07-07-2007, 10:51 PM
BART's Avatar
BART BART is offline
XMS Administrator
 
Join Date: Dec 2006
Location: Ohio
Posts: 2,621
Trader Rating: (5)
Default

Quote:
Originally Posted by RedSXmodder View Post
I did some searches on your capacitor trick, and I learned alot. But I have a few questions.

1) If the capacitor is farther away from the board, what are the negative effects? I don't think it'd be too noticeable, unless you really know the powers of the capacitor your using, right?

The closer to the source the better but you would likely never see a noticeable difference in this situation

2) The capacitor fills, and discharges, many times a second, is there a way that could cause jumpiness in response (lowering smoothness and control ever so slightly) or becuase its connected to the battery it would have nothing to do with it?

No...it does not fill and discharge many times a second. It fills when supplied with power and discharges when presented with a load (just like a rechargeable battery only much faster)
3) Say I wan't my xmod as smooth as a mini-Z, would putting capacitors on the battery, servo, and motor create excellent, smooth response?

4) Does the size of the capacitor create different filtering effects? I know that the bigger the one on the battery section would be better, but if you had a smaller one on the motor and servo would it still be able to filter as well or better then a bigger one, or is the bigger one better?

I think the problem you are getting to here is not the smoothness of the servo but glitches in the radio system


I know putting a capacitor on the servo wouldn't do much, since its only being used when that particular function has battery power going through it (along with the motor) but it still should filter electrical noise on the servo motor. Also, would you be able to put a capacitor near the board by the servo and use that as a torque effect, and then have a capacitor up on the motor acting as a filtering effect.

You couldnt use a cap for added torque on a servo as it would only charge when powered (you kinda answered this for yourself above)

I guess I'm kinda asking the same question over and over again, but, I'm learing alot about this whole thing...

Later,
RedSXmodder
I answered below each question...not quite sure how to do all the fancy quote in blocks stuff.
Reply With Quote
  #10  
Old 07-07-2007, 10:57 PM
RedSXmodder's Avatar
RedSXmodder RedSXmodder is offline
Rethink It All
 
Join Date: Nov 2006
Location: Earth...why?
Posts: 1,447
Trader Rating: (8)
Send a message via AIM to RedSXmodder Send a message via MSN to RedSXmodder
Default

Realisticly, the only real advantage of a "turbo cap" would be at the board connection to the batteries.

Also, having a bigger cap on the servo and motor would help smooth out electrical noise, and cause smoother throttle response, and servo response, right? (I still don't understand your answer to that one) Or would it just filter noise, and leave it at that?

Thanks for the other answers though!

Later,
RedSXmodder
__________________

Team Redmade Motors- Building Motors that rise above the rest!

Rethink It All
Reply With Quote
  #11  
Old 07-07-2007, 11:04 PM
BART's Avatar
BART BART is offline
XMS Administrator
 
Join Date: Dec 2006
Location: Ohio
Posts: 2,621
Trader Rating: (5)
Default

Quote:
Originally Posted by RedSXmodder View Post
Realisticly, the only real advantage of a "turbo cap" would be at the board connection to the batteries.

Also, having a bigger cap on the servo and motor would help smooth out electrical noise, and cause smoother throttle response, and servo response, right? (I still don't understand your answer to that one) Or would it just filter noise, and leave it at that?

Thanks for the other answers though!

Later,
RedSXmodder
A cap on the servo would be useless...it would slow steering response and i dont think the jitter in xmod servos is from noise. A bigger cap on the motor would smooth throttle response but i see it as useless. More could be done with smoother finger control and besides that when you nailed the throttle you would actually lose some acceleration as the cap would have to be charged from the same power source you are trying to feed the motor with. And yes...the only advantage would come from putting a cap on the board at the battery connections (I have done this and posted about it...look up experimenting)
Reply With Quote
  #12  
Old 07-07-2007, 11:07 PM
RedSXmodder's Avatar
RedSXmodder RedSXmodder is offline
Rethink It All
 
Join Date: Nov 2006
Location: Earth...why?
Posts: 1,447
Trader Rating: (8)
Send a message via AIM to RedSXmodder Send a message via MSN to RedSXmodder
Default

Yep, I gotcha now.

The only usefull place for a capacitor is the batter connection to the board. I'll have to expiriment with this like you did...

I want an xmod that can rival a Mini-Z's responce and smoothness...

Later,
RedSXmodder
__________________

Team Redmade Motors- Building Motors that rise above the rest!

Rethink It All
Reply With Quote
  #13  
Old 07-07-2007, 11:14 PM
Stampedekid's Avatar
Stampedekid Stampedekid is offline
is here
 
Join Date: Mar 2007
Location: Long Island, New York
Posts: 2,297
Trader Rating: (1)
Send a message via AIM to Stampedekid Send a message via MSN to Stampedekid
Default

what about capacitors on motors?
__________________
Brushless RC18T, Brushless Micro DT, Midwest AeroStar .20, SCX10 Honcho, Duratrax 1/5 Firehammer MT, Traxxas Nitro 4Tec 3.3
Reply With Quote
  #14  
Old 07-07-2007, 11:16 PM
RedSXmodder's Avatar
RedSXmodder RedSXmodder is offline
Rethink It All
 
Join Date: Nov 2006
Location: Earth...why?
Posts: 1,447
Trader Rating: (8)
Send a message via AIM to RedSXmodder Send a message via MSN to RedSXmodder
Default

Read the **** thread!
__________________

Team Redmade Motors- Building Motors that rise above the rest!

Rethink It All
Reply With Quote
  #15  
Old 07-07-2007, 11:17 PM
Stampedekid's Avatar
Stampedekid Stampedekid is offline
is here
 
Join Date: Mar 2007
Location: Long Island, New York
Posts: 2,297
Trader Rating: (1)
Send a message via AIM to Stampedekid Send a message via MSN to Stampedekid
Default

sorry, i have to sign off soon thats why, i wanted a quick explanation
__________________
Brushless RC18T, Brushless Micro DT, Midwest AeroStar .20, SCX10 Honcho, Duratrax 1/5 Firehammer MT, Traxxas Nitro 4Tec 3.3
Reply With Quote
  #16  
Old 07-07-2007, 11:22 PM
BART's Avatar
BART BART is offline
XMS Administrator
 
Join Date: Dec 2006
Location: Ohio
Posts: 2,621
Trader Rating: (5)
Default

Quote:
Originally Posted by xmodracer1 View Post
sorry, i have to sign off soon thats why, i wanted a quick explanation
One filters the electrical noise caused by the brushes opening and closing as they cross from the north to south poles on the armature. The other smooths out the square wave which is output by the fets. They are fine...leave them alone.
Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 05:16 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2024, vBulletin Solutions, Inc.