New 6 FET Water Cooled using 200v 230Amp FETS!! :D

[mystamo]

Okay okay so before you all jump on me .. No the controller wont do 230AMPS lol.. but it sure will do a lot for a 6 Fet. I plan to do it very similarly to my old 6FET but this time I have TO-264s so mounting should be easier and I will use two aluminum slabs that will have two channels for inlet and outlet. Still haven't ironed out all the cooling details but I've started to make the controller.

Mo

 

[NeilP]

Those are huge FETs!!

 

[mystamo]

Lol Tell me about it!



I made this Controller last year and it really worked great.. My only main issue was it was a bitch to mount the FETS. I made the mistake of not getting them with holes in them. This controller should behave the same but should allow a much smaller sink source and be a hell of a lot easier to mount. I was getting 140V 75amps. I never tried pushing it further but I think if i beefed up to 3 shunts I should be able to put that much current through the whole system.

I recently got a 5403 so I'm getting all crazy developing shit to make my ride as sweet as I can.. OUT WITH THE CAR!

Mo

 

[NeilP]

So with that 3 FET controller, have you just fitted those FETS to a standard 3 FET controller? or modd'ed the controller (apart from thicker traces) to drive those FET's differently

Oh, crop to 800 or less and then the image displays

 

[mystamo]

No it's actually a 6fet controller. 3 fets up 3 fets to the side.. You sort of can't see it in the picture. In the Picture your looking at the FETS out to the side. On the previous post I had made regarding that controller there is a pic from the top side of the Controller board which makes it easy to see.

I did have to drill out the holes in the board slightly to make the FETS fit but it works great. Steveo which I know on this forum tried something similar to this after I did mine on a 12 FET with great success.

Is there a point? Most likely not. I just like to be able to say my 6 FET can do more then your 12 FET. If you sink it properly it's not much smaller then a 12FET .

Thanks for the tip on the pics.

Mo

 

[mystamo]

This is a pic of my work table.. Things are a realllllllllll mess right now .. But you can see my old controller sitting on the table .. This picture shows the up standing FETS I took the sinks off the controller and used them for something else. So this controller is currently homeless.

 

[h0tr0d]

Don't forget new 250v low ESR and ESL caps. Lots! Pic just to show good position...

The gate charge of those fets is very high! At least put some 15ohm resistors parallel to existing gate resistors to minimize switching losses

 

[Arlo1]

Don't forget new 250v low ESR and ESL caps. Lots! Pic just to show good position...

The gate charge of those fets is very high! At least put some 15ohm resistors parallel to existing gate resistors to minimize switching losses

Giving advice already hu?
Mystamo did something I did not think possilbe. HMMM cool. The thing is h0tr0d the fets are so big you might find the fet driver won't last at all with <15 ohm gate resistors.
I think jeremy has shown the OEM gate resistors ~100 ohms with these controllers and this will limit the current the gate drivers have to push!
If you put a 100ohm resistor parallel to a 15 ohm resistor you get ~ 13ohms gate resistance.

Mystamo I have 70 of the ixfk230n20t TO264 fets they are pretty bad ass. I have pushed a honest (scoped on a phase current sensor) 130 amps though one at 100v! I am aiming for more but it takes time. Pops man the little 6 fet is more bad ass then a 12fet should be able to make the same HP(KW) with higher voltage and lower amp settings as a 18 if you can control it right.

 

[Jeremy Harris]

Don't forget new 250v low ESR and ESL caps. Lots! Pic just to show good position...

The gate charge of those fets is very high! At least put some 15ohm resistors parallel to existing gate resistors to minimize switching losses

First off, those capacitors aren't low ESR, for that you need the Rubycon ZL series. The YX series are obsolete, cheap, general purpose capacitors that have a much higher ESR, so high that Rubycon don't even bother to put it on the datasheet.

Secondly there is no way on earth that the tiny little gate drive transistors on a typical controller board are going to drive 15 ohm gate resistors.

Finally, if you did try to increase gate turn on time by reducing the value of the gate resistors, and if the gate drive transistors did survive, then in all probability the FETs would die from the lack of any decent transient or ringing control.

These cheap controllers use relatively slow gate drive for a reason, to avoid having problems with transients and ringing. It neatly sidesteps a whole host of issues at the expense of relatively high, but acceptable in a small controller, switching losses.

 

[mystamo]

Hummmmmmmm

You guys bring up a few pretty good points I hadn't even considered....

On the other controller that I had made successfully (6 Fet) I only replaced all the caps with 200-400v versions of everything and one transistor with a higher voltage unit.. Made tails for my two largest caps and everything seemed to work properly. I never did push more then 100amps at 140v into it but it didn't seem to have any short term survival issues.

The only reason I'm making this new one is due to the easier mounting of the FETS... They are the exact same model I have tried before with nice luxurious holes in them for mounting to my sink more peacefully.

If shit starts to blow up. I will consider the above noted issues as the source of my problems.

Mo

 

[h0tr0d]

Giving advice already hu?

Trying...
"You are never too old to learn, you are never too young to teach".

Gave one good advice, cap location and specs to look for. crappy one regarding gate resistors.

Jeremy, thank you for the explanation but like I wrote "pic just to show good position..."
It's better to emphasize the fact those are not good caps for the application, so thanks again.

Mo,
The controller you modded before, was with the same fets? Where are you located?
Would like to test that personally and possibly give to NJay so he could play with the oscilloscope...

What parts are you going to use for water cooling the fets? Custom made, ram coolers, hobbyking ESC coolers....?
Good luck and photographe everything and put it here.

 

[h0tr0d]

Mo,
What battery voltage are you going to use?

Arlo1,
I replied your PM, still stuck in my outbox. Do you have some restrictions regarding incoming PM's...?

 

[Arlo1]

When its still in your put box means people have not read it yet. Busy dude very busy today is drift trike day

 

[h0tr0d]

Mo,

Anything new?