Power Cap

Reply

Old 10-21-2001, 08:17 AM
  #1  
jcr
Tech Regular
Thread Starter
 
Join Date: Aug 2001
Location: Toronto
Posts: 457
Post Power Cap

Is there any difference between the Power Caps in R/C compare to regualr capacitors in the electronic store?? Also on Novak's message board, they're suggested Low ESR capacitor any difference in use that or not?
jcr is offline  
Reply With Quote
Old 10-21-2001, 09:17 AM
  #2  
Tech Elite
iTrader: (1)
 
Nipple's Avatar
 
Join Date: Sep 2001
Location: Kallang Airport
Posts: 2,031
Trader Rating: 1 (100%+)
Default

Yes, there is a difference in capacitors.
Those used in R/C has a lower resistance then those normal one find in electric stores.
The ones novak sells have lower resistance.......
But the ones other R/C brand selling may not be......
Nipple is offline  
Reply With Quote
Old 10-21-2001, 01:56 PM
  #3  
Tech Master
 
Join Date: Aug 2001
Location: England
Posts: 1,483
Default

Not strictly true. The ones we use are simply the lowest impedance that are available. Generally i think that the Panasonic FA series is very popular. I think this is what Novak use. I have been using FA and FC (slightly higher imp) for some time now.
MattW is offline  
Reply With Quote
Old 10-21-2001, 05:09 PM
  #4  
Tech Champion
 
Manticore's Avatar
 
Join Date: Aug 2001
Location: Heaven
Posts: 9,999
Default

Originally posted by MattW
Not strictly true. The ones we use are simply the lowest impedance that are available. Generally i think that the Panasonic FA series is very popular. I think this is what Novak use. I have been using FA and FC (slightly higher imp) for some time now.
agree, the ESC manufactorer cannot order an non-existing spec of cap as the minimum quantity is going to kill them.

as a matter of fact, rubycon makes the most variety of specs on cap.
Manticore is offline  
Reply With Quote
Old 10-21-2001, 09:50 PM
  #5  
Tech Elite
iTrader: (1)
 
Nipple's Avatar
 
Join Date: Sep 2001
Location: Kallang Airport
Posts: 2,031
Trader Rating: 1 (100%+)
Default

So how many caps or total 'farah' you all use?
Nipple is offline  
Reply With Quote
Old 10-21-2001, 09:54 PM
  #6  
Rog
Tech Apprentice
 
Join Date: Aug 2001
Location: SGV - So Cal
Posts: 55
Default

Does anyone know the difference in ratings between the big LRP cap and the Novak cap. My friend and I both run Quantum Competitions. He has the Novak cap and I run the LRP cap. Is there an advantage to running one or the other. Also, the LRP World Option kit comes with 2 caps. A large one and a small one. Is there any benefit to putting them both on?
Rog is offline  
Reply With Quote
Old 10-22-2001, 10:15 AM
  #7  
Tech Master
 
Join Date: Aug 2001
Location: England
Posts: 1,483
Default

I wouldn't bother with the small one. It will have larger impedance than the big one. I think the novak one is slightly smaller rated, but i'm not sure.
MattW is offline  
Reply With Quote
Old 10-22-2001, 10:29 AM
  #8  
Tech Apprentice
 
Join Date: Oct 2001
Location: Buffalo, NY
Posts: 81
Default

Can someone please explain what those big caps actually do? In simple terms please...LOL
WHITESTER is offline  
Reply With Quote
Old 10-22-2001, 10:52 AM
  #9  
Tech Master
iTrader: (15)
 
David Galdo's Avatar
 
Join Date: Aug 2001
Location: Euless, TX
Posts: 1,652
Trader Rating: 15 (100%+)
Default

The higher frequency ESC's require a cap to clean up the signal to the motor and receiver. The ESC in turn does less work and should run cooler since the cap also fills the void between frequency changes (open and close of the transistors). I use a 16v 6800uF radio shack cap and also bought a couple extras from Stormer Hobbies.
David Galdo is offline  
Reply With Quote
Old 10-22-2001, 02:14 PM
  #10  
jcr
Tech Regular
Thread Starter
 
Join Date: Aug 2001
Location: Toronto
Posts: 457
Default

so is the Radio Shack capacitor is a normal one?
jcr is offline  
Reply With Quote
Old 10-22-2001, 03:52 PM
  #11  
Tech Master
 
Charlie's Avatar
 
Join Date: Aug 2001
Location: I'm All Over The Place
Posts: 1,160
Default

Power capacitors affect different brands of ESCs differently. The Cyclone line is very reliant on them due to the extremely high rate the mosfets turn on and off. The power capacitor actually catches the ripple current that is created by how hard the Mosfets switch. If not used the ripple current turns into heat and will damage the ESC. Mosfets are the fins that stick out. They are transistors and what carry the power in your ESC.

That's why it is very important to use Low ESR (electro-static-resistance) capacitors. If you use the wrong value the cap will only do part of the work or none at all. And yes it will work for a while. It will slowly deteriorate the performance of the ESC. Most people won’t notice until the ESC is so damaged it slows down. Then they go out and buy a new ESC and think their Cyclone was slow all along. Not the case at all. This is very common. Almost all Cyclones that come back with a different external power cap installed have a shorted internal Polar Drive Cap.

Now I can't speak for the LRP units so lets focus my Info on the Cyclones as power caps affect the LRP units differently.

Once again, we have all of this information post in the tech info section of www.teamnovak.com.

Hope this helps, if you need anything else please don't hesitate to email me.
Charlie is offline  
Reply With Quote
Old 10-22-2001, 03:54 PM
  #12  
Tech Master
 
Charlie's Avatar
 
Join Date: Aug 2001
Location: I'm All Over The Place
Posts: 1,160
Default

I almost forgot. The radio shack capacitors will damage Cyclones and Atoms.

Low ESR caps usually have values of 40 to 50 milliohms.
Charlie is offline  
Reply With Quote
Old 10-22-2001, 04:00 PM
  #13  
Tech Master
 
Charlie's Avatar
 
Join Date: Aug 2001
Location: I'm All Over The Place
Posts: 1,160
Default

Power capacitors affect different brands of ESCs differently. The Cyclone line is very reliant on them due to the extremely high rate the mosfets turn on and off. The power capacitor actually catches the ripple current that is created by how hard the Mosfets switch. If not used the ripple current turns into heat and will damage the ESC. Mosfets are the fins that stick out. They are transistors and what carry the power in your ESC.

That's why it is very important to use Low ESR (electro-static-resistance) capacitors. If you use the wrong value the cap will only do part of the work or none at all. And yes it will work for a while. It will slowly deteriorate the performance of the ESC. Most people won’t notice until the ESC is so damaged it slows down. Then they go out and buy a new ESC and think their Cyclone was slow all along. Not the case at all. This is very common. Almost all Cyclones that come back with a different external power cap installed have a shorted internal Polar Drive Cap.

Now I can't speak for the LRP units so lets focus my Info on the Cyclones as power caps affect the LRP units differently.

Once again, we have all of this information post in the tech info section of www.teamnovak.com.

Hope this helps, if you need anything else please don't hesitate to email me.
Charlie is offline  
Reply With Quote
Old 10-22-2001, 08:08 PM
  #14  
Tech Master
iTrader: (15)
 
David Galdo's Avatar
 
Join Date: Aug 2001
Location: Euless, TX
Posts: 1,652
Trader Rating: 15 (100%+)
Default

Originally posted by jcr
so is the Radio Shack capacitor is a normal one?
I had to special order the cap, so pay close attention to what you see in the catalog.
David Galdo is offline  
Reply With Quote

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
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
Trackbacks are On
Pingbacks are On
Refbacks are Off


Thread Tools
Search this Thread

Contact Us Archive Advertising Cookie Policy Terms of Service