Quote:
Originally Posted by BrianG
lol, not nearly a professor, just a bit of simple common sense and elementary math. 
From what I've seen, many manufacturers tend to rate the current ratings on their ESCs according to the pure FET current rating. They don't take into account the temperature derating (our ESCs do NOT run at 25*C on a hot sunny day during track use!), the fact that there are a LOT of FETs packed into a TINY area with minimal cooling, and don't seem to figure in a little headroom for "overzealous" gearing.
Side note: Does anyone besides me appreciate the fact that companies are producing devices that control hundreds of amps in such a small space? I find it staggering personally. It's one thing to occasionally turn on/off devices that draw this current, but to do so thousands of times per second to precisely control a motor load? Man!
Anyway, the trouble with rating an ESC by the burst value is: what constitites a burst? Depending on how highly geared (effectively "stalled") a motor is, even 1/10 scale, a burst can get well into the high hundreds of amps during that initial microsecond. Eagletree does not catch that, or averages it out or something, since it seems to only catch sustained bursts. So, say you rate your ESC for 200A. People will inevitably push that ESC to 400A+ thinking it'll take it (think Trx noobs).
I would rather underrate an ESC to compensate for those people and have my product last longer - or at least design for huge bursts. But, it would be difficult to produce something at a decent price that matches other companies' overrated ESCs.
Personally, I think consumers should be required for IQ tests for any product like this. But that includes 1:1 vehicles, computers, TV's, etc. Basically, if your IQ is under that of my coffee cup, you shouldn't be using anything that you could hurt yourself with - which is why lawyers are so popular nowadays.
There I go again rambling on. I'll just blame this stupid head cold I have. Go figure. I take steroids to treat an insane poinon ivy outbreak and it weakens my defenses against everything else. Argg. Time for a smoke. |
You are 100% right and it amazes me to see so many people without common sense (I hate to say it, but it's true). I actually tried to figure out how some big names (Castle and Tekin are not one of those as they don't claim such crazy out of this world numbers) claim such a high number and I must say it's not adding up even if I go with the MOSFET's burst rating. Are they using alien technology?
Get well soon Brian, sorry for all the questions.