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View Full Version : Capacitor, power caps and Shottky diods?


Spihc
16-10-2008, 03:07 PM
Hi folks,

I'm using a GM v12xc esc, and has a couple of questions.

1. The Shottky diod, should it be placed on the +/- poles on the ESC, or directly on the motor? Why is one way better then the other?

2. Using a rather old motor, wich i'm 99% shure that dont have any capasitors, are they placed on the motor? If shottky is placed on motor, they wont fit!?

3. Power Caps, what are they, where do they go, what do they do and why!?

Any help is appreciated, have only been using mild motors (19-27t) and reversable esc's before, so Im 100% green on this.

Regards

Tobias

sosidge
16-10-2008, 03:20 PM
Hi folks,

I'm using a GM v12xc esc, and has a couple of questions.

1. The Shottky diod, should it be placed on the +/- poles on the ESC, or directly on the motor? Why is one way better then the other?

Doesn't really matter. Supposedly on the motor is ever so slightly more effective.

2. Using a rather old motor, wich i'm 99% shure that dont have any capasitors, are they placed on the motor? If shottky is placed on motor, they wont fit!?

Should do. Just solder them on the same contacts.

3. Power Caps, what are they, where do they go, what do they do and why!?

They smooth the supply from the battery. Go across the battery +/- connections. The V12 should have one fitted.

Spihc
16-10-2008, 04:32 PM
Sosidge,

On my ESC I have a Schottky diod (that's at least what it looks like to me), not a power capacitor from the looks by it (remember, new to this), going from motor + to -.

When you say "The V12 should have one fitted", do you meen, "It does have one built in", "you should ivest in one ASAP" or "you can if you want to".

sosidge
16-10-2008, 04:41 PM
Sosidge,

On my ESC I have a Schottky diod (that's at least what it looks like to me), not a power capacitor from the looks by it (remember, new to this), going from motor + to -.

When you say "The V12 should have one fitted", do you meen, "It does have one built in", "you should ivest in one ASAP" or "you can if you want to".

I mean "it should have one supplied in the box for you to fit". It should always be run with one.

Spihc
16-10-2008, 05:28 PM
It was sold to me as used, so no box, no manual etc.

I did now check that the schottky was connected to + (wich is used by booth battery and motor), and - battery.

Should it be this way? I thought it should be +/- for motor, not battery.

Feeling confused here.

JCJC
16-10-2008, 05:48 PM
http://www.teamnovak.com/Tech_info/how_to/schottky/index.html


from... http://www.teamnovak.com/tech_info/how_to/index.html


and found this: http://www.gm-racing.de/rwdownload/index.php?url=&dlid=22

some pages in english

Spihc
16-10-2008, 06:48 PM
Thanks for the answers, Did solder the schottky directly to the motor instead as the way it was soldered, it had no actuall function at all.

Will check the "how to connect a power cap" next.

Rich D
16-10-2008, 07:24 PM
If schottky diodes are fitted with reverse polarity then they are buggered. If its cracked or has a hairline crack then you need a new diode.

The small motor capacitors are to reduce radio interferrence from the arc of the brushes on the commutator. Some motor end bells ( not bell ends :woot: ), have small capacitors built into them removing the requirement for extras.

Spihc
16-10-2008, 07:41 PM
Dont think the schottky is damaged as I tested it with a multimeter tool and it had a resistance one way, and did not let anything through the other way. No cracks or anything like that.

gapesterr
18-02-2011, 04:22 PM
that diode just gives you better brakes and it has to be put on in the right way