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Old 05-24-2003, 02:05 AM   #1
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What is the significance of the capacitor that comes with electric motors? I've never used them before, should I? Do they give a noticeable difference in motor performance? Thanks for your help.
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Old 05-24-2003, 08:29 AM   #2
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They help supress electrical noise generated by the motor which can cause interference, i allways use 3 on my motors, from + to can, - to can and + to -. I have to admit tho i have had surface mounts capacitors fall out and havnt noticed untill i checked them.
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Old 05-24-2003, 09:01 AM   #3
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I have another question in regards with capacitors.. I hope you don't mind TripleD with me buggin' in your thread, anyways, it also concerns capacitors, only this time about power cap.. I've seen one guy at our local track putting such a huge power cap in his esc, when I checked it out myself, I found out the values are as follows:

10,000 uF
16v

what are the advantages/disadvantages of using this one?
thanks in advance!
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Old 05-25-2003, 01:22 PM   #4
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Ok,that is what it call power cap.It help to smooth out the ripple of the power supply to the esc.Cause the battery power is raw so
the supply is not smooth.For me i install one on my esc too.

Advantage
1.Smooth the supply power.
2.Extra punch for the car on acc.
3.Extend the life of you esc ,servo,reciever.Cause raw power shorten the life of electronic.

Disadvantage
1.the size of the power cap.Cause the bigger the value the bigger the size.So you need space to install the power cap.

You can use use 4700uf-22000uf.The bigger the value the smoother the supply is and of cause more punch on your car.Remember get those polarise(theres a - marking on 1 side) cap rated 10v or higher.
You can get it at Sim Lim tower,around $3 for a 10000uf 16v.Don't get those from NOVAK,LRP etc.Is the same but the price is crazy.I can get 10 with 1 novak type.

Check the pic on how to install.

Good luck
Attached Images
File Type: gif power cap.gif (11.3 KB, 178 views)
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Old 05-25-2003, 09:49 PM   #5
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Thanks guys. Nice post Adamn.
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Old 05-26-2003, 02:43 AM   #6
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Addicted2rc,which reach track you go to.Me go to Tamam jurong track.But now got no car.Still waiting for my car 2 arrive.TRF414MII.
Don't have much track in Singapore.
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Old 05-26-2003, 06:08 AM   #7
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thanks Adamn! that was really enlighthening.. got one power cap from sim lim tower, cost me $2.50. it's 25mm long, 25mm dia.., brand is ELGEN, 10,000micro Farads, 16v.. haven't fix it up though! anyways, i'm thinking of trying it this weekend at Marina South.. Thanks again man!
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Old 05-26-2003, 08:03 AM   #8
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Remember when u first use it,connect the battery and let the power cap charge for 2mins.Cause is new and it need to be charge.But don't turn on you receiver.1 min for the following play.
After 2 mins turn on the receiver and try it u notices the different with your car acceleration.

After u finish every run of a pack,turn off your reciever and unplug your battery,turn the reciever on again and let it draw a the power off from the power cap.Around a min.Cause you don't want to have a accident shock cicuit with you plug(etc DEAN plug)
It's not very healthy with your electronic,especially you esc.Cause it hasa microcontroller in it,the shock might damage it or erase the memory in it.
Remember
So for every play u will need to let it charge and discharge.

No bullshit,i have been using this power cap six years ago,since the day one of my TEKIN esc is dead cause i never use the POWER cap.Got this idea from my friend who is in electronic repair.

Sorry guys every time have a reply i talk too much.Hope you guys don't mind.
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Old 05-27-2003, 01:56 AM   #9
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Adamn: I'll keep that in mind! I've just completed building my power cap last night, got one more question though, will this thing reduce my run time or will it be the other way? so eager to try it out, can't wait till saturday.. ei Adamn, want to go have a run at Marina South? I'm using Sanyo HV 3300s and Novak CycloneTC on my Xray T1..
Cheers!
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Old 05-27-2003, 04:11 AM   #10
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To learn correct information about "power" capacitors, please read the older threads on this topic. There is much misinformation around about these capacitors. And certainly they don't affect the acceleration nor the maximum power available of the motor/battery/ESC. Also the time a 10 mF cap charges is some microseconds.
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Old 05-27-2003, 10:21 AM   #11
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Jesst.if there is a different or not we always have to test it on the track.And i don't know you into electronic or not.
If you open you a radio,TV computer,etc you find this power cap in it.Why it you cause it help to smooth out th ripple from the power supply to the equipment.This ripple does kill electronic component.
Why i said 1-2 mins,cause the cap is new,we don't know the any defect to it.And we too need the power to be smooth through out all the electronic first.Don't just plug on the power and ramp on the trigger.Most misfortune is always cause by misuse and Misunderstanding.
Test the equipment by field test not by just listening others.

See this link if you like to read more on these power cap.
http://www.schumacher.clara.net/powercap.htm

Jesst hope that you don't mind what i said.This is not a challange of who right or wrong.Is exchange of idea ,knowledge and point of one anothers.If not this world won't be a better world.
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Old 05-28-2003, 05:09 AM   #12
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I like your approach. Test it on the field. I have tested the caps on dyno as well because I couldn't fell much of a difference on the track. One thing I would like to clear, is about the smoothing of the power. Because the ESC works with pulse width modulation, there is no smooth power. Power is the product of voltage and current, and the current is constantly switched on and off by the ESC to the motor. However what the capacitor does, is that it smooths the current flow from the battery to the ESC. So even in the off-period there is current flowing from the battery to the cap. Then on the on-period the ESC sees a lower impedance level because of the cap and the battery voltage drops less. This is the key! While pulsing the current to the motor, the battery voltage during the on-period is kept higher. Whenever the trigger is pulled all the way in for maximum power, the pulse width reaches 100% and there is no more pulsing of current, because the current is constant. Therefore the effect of the capacitor is eliminated in a few microseconds. For the capacitor to actually aid in the acceleration at full throttle, the capacitance would have to be several tens or hundreds of Farads.
The effect of the motor drawing more or less current depending of the position of the armature of negligible in this case.
So what does the cap do then? It improves the efficiency of the battery at partial throttle resulting in more power, but only at partial throttle. If you find anything else on the track that works for you stick with it.
BR/ JesseT
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