Cool thread, and it strikes home, as I just plonked down some 600 bucks on a KEB72801. I just couldn't find anything else affordable that was buy-it-now-able with close to my target performance. I'm hoping it survives in _intermittent_ use at it's 150A continuous rating!
Interesting to see the Curtis cracked open, it reminds us that the limitations of Curtis's designs are sort of what spawned the Zilla so many years ago. I think Otmar originally started out modding 1231s or something similar. Though better than the Kelly, if you look at a Curtis apart on the bench and compare it to a Zilla, you begin to see how much work is really involved in building something capable of dealing with big amps/volts. Liquid cooling, massive billet copper cooling plate with machined in coolant channels, igbts, high grade bus caps, hairball interface, etc. Not to mention the thousands of hours spent training people to assemble the things properly. And of course testing. If you ever run into him, ask Otmar to tell a few of his plasma explosion stories. All this probably explains why there are no affordable, reliable, high power controllers out there for big brushless motors.
I do not know the man well, but I know enough not to ask him if he will help with a controller design (ok, I'm a liar, I did - but I won't again!). I think he is devoting his time to other loftier goals now ;+}
So who will the next Otmar be? While it's true he is an incredibly smart guy, he didn't start out as a degreed EE with 20 years experience designing high power stuff. He was a guy like one of us that was frustrated with the status quo. Through force of will and persistence, he taught himself the necessary skills to build, test, market and sell those magic green boxes.
You'd think the least they could do is use TO-247 FETs. I'm sure they could make up the cost difference if they added "Now with less explosions!" to their marketing materials.
