Paul & Sabrina's cheap DIY 144v motor controller

[squiggles]

Has anyone noticed that the IRFP4668PBF MOSFET has a reverse diode built in that has the full current rating of the transistor?

[adamj12b]

Yes the mosfets have a diode built into them, but they are much slower reacting then the STTH6002C diodes. The reverse recovery time of the mosfets diode is 130 ns while the reverse recovery time on the STTH6002C diodes is only 27 ns Max.

-Adam

[squiggles]

Adam,
What is the significance of the faster reverse recovery time?

[squiggles]

I did some reading about reverse recovery time today. It is quite a complex issue. Faster is not necessarily better, in as much there seems to be a theoretical point where the gains in efficiency by increasing speed start to be negated by losses increasing in other components.

I need to study it more closely when I have some time.

[MPaulHolmes]

I bought the remaining bolts and nuts I think for their complete assembly. Finally, I'll have a little time tomorrow to get Joe's maybe done! Then there is a bit more for Ben's, but not too much. Then I'll ship those buggers out, then they will blow up! I'm so excited!

I'm subbing in a math class that goes from 6pm to 9:15pm! yuck! That will get us a little extra money, so that we might be able to convert the mill to CNC a little sooner. That would be nice.

[charlie_fd]

So ... the European kit arrived a few days back in Copenhagen and it has travelled since (2300km south). Can't wait to start the assembly and testing!

[MPaulHolmes]

Well thank goodness! Ben's assembly has helped me to work out some of the kinks in the process.

[bennelson]

Originally Posted by MPaulHolmes

Ben's assembly has helped me to work out some of the kinks....

Good to know that I REMAIN the lone guinea-pig on this project.

Seriously though, I have felt that there is little I can add to this project because I know nearly nothing about electronics. I am however HAPPY to be an official test pilot, and you know there will be some YouTube videos coming out once I get another controller in!

Also, have we ever discussed LOGO design for the project? I loved the "name the controller" contest. I have some ideas for a logo that I sketched out, and passed off to my sister, who is a graphic designer. I'd like to have something a little nicer looking before showing you guys.

-Ben

[SVOboy]

Propose a contest in the forum news section and we can try to think of something to give away for it, if Paul is willing

[MPaulHolmes]

Heck ya, SVOBoy! Ben, your sister is a graphic designer!? Not fair!