needing some ideas for a radio controlled car re capacitors!!

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
Jump to Latest
T

ThyDntWntMusic

Member
Joined 2008
Jambi said:
Silly question but what are the actual ratings for the speed controller? These things are built for toys not industry, they're wimpy, without adequate cooling or are open to elements and can short out easily. Further there's very little margin as to where they'll work happily for more than five minutes. Your charged battery could easily trigger overvoltage proection for instance.
Click to expand...

if its a silly question, why are you asking it?

what do you actually want to know?

* Continuous current: 120A
* BEC: 3A/6V
* Suitable for car: 1/8 car
* Motor Type: Sensored / Sensor less brushless motor
* Momentary Peak Current: 760A
* Size: 66 x 53 x 42mm
* Cable type: 12AWG 200°C
* Length: 150mm (battery) , 140mm (motor) , 280mm (receiver)
* Weight: 350g
* Input: 6-12 cells NiMH/NiCd or 2-4 cells LiPo.
Click to expand...

it doesn't have overvoltage protection, and it isn't going to short out unless I drive it through water, which I did..
 
T

ThyDntWntMusic

Member
Joined 2008
Jambi said:
Yeah, when the parts are melting things will short sooner than you realize.

They probably rate these in a wind tunnel. You should consider dropping your battery voltage to something that falls in between the min/max spec and consider that your real world usable max. Stick to 12 volts.

Seperate your output from your input wires too, might help a bit, probably not. Consider solid polymer caps.
Click to expand...

you don't seem very smart.

but thanks for the input...
 
T

ThyDntWntMusic

Member
Joined 2008
Jambi said:
From a guy who brings his broken toy car to an audio forum.. and believes toy marketing specs :rolleyes:
Click to expand...

no, I asked about capacitors on a forum where most people are quite knowledgeable. Most.. but not all..

There's no point in asking about capacitors on a hobby forum, as I'm quite sure they'd have no idea!

I've pulled enough speed controllers apart to believe the continuous specs, what specs are you questioning?
 
T

ThyDntWntMusic

Member
Joined 2008
Jambi said:
To the ignorant, a smart person is someone that tells them whatever they want to hear.

Other people in this thread have already given you similar advice not to believe the specs. I know you want the fastest toy on the block. I know you went out and bought the hottest battery, the hottest ESC, the hottest motor and oops, doesn't work so well, does it?

How about timing options is that all set to flat out as well?

It might work better had you a motor that had 30 turns instead of 2 or 6 but lacking that you might want to derate the voltage so that you get closer to the 120 amps it is rated for instead of the 160 you are getting, clearly you're using it out of spec.
Click to expand...

hottest? how do you mean hottest? as in, the hottest running?

Its already obvious that you have some idea, but not a lot.

I simply bought the cheapest motor possible, as I'm already using 3 others the same, or similar without issue.

dropping the voltage isn't the answer to reducing the current, dropping the gearing down is, and I have some new pinion gears on the way, but I'm not sure that will help with the hot capacitors.

Its more like a 6 turn motor, and its perfect for the esc, and the battery, just need some gearing changes.

I know you've probably grown up with brushed motors, drawing 10amps or less, but why would I want that?
 
T

ThyDntWntMusic

Member
Joined 2008
Jambi said:
Yeah, like I live and die by "your" performance review.. You might like to stop projecting your insecurity.

If you brought this question to a relevant forum they'd be likely to tell you what I just did, so you probably went elsewhere.

That you're getting 160 while it is rated to 120 is indicative of your using it out of specification.

What will help with the heat reduction, which is likely the main problem, is to derate the voltage.

Your other choice is to improve on cooling and it is unlikely you'll be able to do much there.

Those 10 amp motors did 30k to 50k RPM on just 10 amps before melting down the speed controllers. You're using over 10 times that and obviously not getting any further.
Click to expand...

I'm really not sure what you're arguing anymore?

most likely arguing for the sake of it would be my guess, but whatever works for you.

I'll most likely replace the capacitors with the low esr 25volt from Jaycar, and reduce the pinion from 15t down to 13t.
 
G

godfrey

Member
Joined 2009
Huh?

From Jaycar:

Capacitor Electrolytic 220uF 25V 105C L/ESR - Jaycar Electronics
Impedance: 0.13
Ripple Current mA rms: 640

Capacitor Electrolytic 220uF 35V 105C L/ESR - Jaycar Electronics
Impedance: 0.09
Ripple Current mA rms: 840

Capacitor Electrolytic 220uF 63V 105C L/ESR - Jaycar Electronics
Impedance: 0.060
Ripple Current mA rms: 1220

I thought the specs you gave looked like that last one.
The 1000uF 35V one is about twice as good, but also twice the price.
It would be nice to know what size they all are...
 
Last edited:
T

ThyDntWntMusic

Member
Joined 2008
Magura

Magura

Member
Joined 2003
class-a-labs.com
Not necessarily, they can survive quite some time if they are not loaded real hard, and the voltage is much lower than the rating.

Instead of wild guessing, how about you actually measure if they are in the right way?
After that, take one out and measure if it's in reasonable condition.

You have had quite a few suggestions so far, but have failed to take any action.
None of the suggestions made, would take more than 15 minutes to test.
Either take some action, or quit wasting our time.

Magura :)
 
T

ThyDntWntMusic

Member
Joined 2008
godfrey said:
Ah, OK. There's no specs for that one online.:)

For 470uF, the 35V and 63V ones have better specs, but I suppose you have to consider what fits too.

Anyway, good luck with it!
Click to expand...

yes, the 25volt, 470uF are the same dimensions as the 35v 220uF.

plus, the 150amp esc I have only uses 25volt capacitors, and is rated for the same voltage.

I'm quite sure that 25volt caps is enough for 17volts :p
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
Top Bottom