to-220 mosfet to to-247 PCB

[steveo]

Hey Everyone,

I was wondering if i could get some help, I'm looking to build some pcbs adapter boards that will allow the user to use a Infinion 12 mosfet or 18 mosfet Board that regularly uses to-220 mosfets & adapt to-247 mosfets to it.

I remember a while back, there are some websites where you can send some sort of image where they can design a pcb, does anyone know what i'm referring too?

I've found a way to run the vr cirucit only off of 15v max** battery, ( i use a 3s lipo & try to keep it fully charged), I will post a pic on this easy mod soon!..

By doing so, it allows you to safely run a higher voltage to your caps & mosfets, the goal hear is to build a reliable 150v controller ( all ways use a precharge resistor for 100v+ ) i use a 1k 5w resistor with my ev200 contactor.

I will be going with the irfp4568 mosfets, discussed in another thread to be a good choice for the project.

some of you may remember an old thread with my first attempt of 133v which i was successful with my x5304 motor at 50amps...

Hear is a picture of that same controller but the pcb replaced with the new infinion programmable board.

thanks
-steveo

 

[bigmoose]

Steve I may have missed your intent, what I am going to propose may be what you are trying to do. If so I apologize.

I think you need to create a separate power board based on a good layout. That power board will contain the TO247's and you Source to Drain Caps (Rail Caps) The choice of, and layout of the caps is as important as the FETs. Consider the rest of the controller the "brain board" and bring the gate drive to your power board. I would also put the current shunts on your new power board.

Putting 2 or 4 inches of wire in the "legs" of the FETs is adding appreciable inductance, and will severely limit the design, perhaps making it worse than the original. Lead/wire impedance at switching frequencies is hard to get a handle on when the pure resistance is 0.001 ohm, we think "who cares", but Luke can attest to his experiments where he was inducing near 100 volts in a 6 inch bussbar, IIRC.

 

[steveo]

Steve I may have missed your intent, what I am going to propose may be what you are trying to do. If so I apologize.

I think you need to create a separate power board based on a good layout. That power board will contain the TO247's and you Source to Drain Caps (Rail Caps) The choice of, and layout of the caps is as important as the FETs. Consider the rest of the controller the "brain board" and bring the gate drive to your power board. I would also put the current shunts on your new power board.

Putting 2 or 4 inches of wire in the "legs" of the FETs is adding appreciable inductance, and will severely limit the design, perhaps making it worse than the original. Lead/wire impedance at switching frequencies is hard to get a handle on when the pure resistance is 0.001 ohm, we think "who cares", but Luke can attest to his experiments where he was inducing near 100 volts in a 6 inch bussbar, IIRC.

Hey,

I understand what you mean, this is simalar to the paul & sabrinas dc motor controller layout.

I guess i could go that route however id like to start with a very simple lost cost design, i dont think i would be able to Design something that advance with out some help

The copper wires are about 1" at the longest point

The controller traces have as much copper as i could fit on the 12 fet pcb traces

Thanks
Steveo

 

[amberwolf]

I strongly suspect that if you're basically just mounting the FETS on a PCB that is then just wired over to the TO-220 PCB holes, regardless of the gauge of wire used, it's going to end up blowing up FETs under even moderate loads, because you're running at such a high voltage already. The spikes that get generated across those wires may even be enough to induce a trigger pulse in the gate wire to FETs that should be turning off, and cause shoot-thru and BANG.


If you at least mount caps on the TO-247 FET board, for each FET or each bank of FETs, it'll probably work more reliably.

Moving the drivers over, too, would be even better.

FWIW, if all else fails, and you can't design it from scratch, you could simply take a bare 220 PCB, photographically scale up the power section until the mounting holes are right for the 247s, and then use that as a guide to drawing out the traces you'd need for the 247 board. You could also probably just copy over the whole driver section from the other board, too, and populate it just like it had been on the other board, and run signals from the other board's MCU and whatnot from the equivalent spots on the other board to the new one.

If you wanted to be really ambitious, you could scan in each side of a bare 220 PCB, enlarge the FET mounting area till 247s would fit, move the connections over as needed to mate up with the still-normal-sized driver area, and then have a PCB or two made and populated, then install your FETs and test it.


None of that deals with the possible different driving methods or amounts that may be needed for the larger FETs, but if it works with the existing drivers, you'd be ok.

 

[bigmoose]

For months I have been thinking of this dilemma we all have in controller development. Let me see if I can get the words to come out right for the image that is in my mind. What we need and want is the most compact, highest power rated controller in Kw/Kg on the face of the earth, and we want to buy it for $150 or be able to build it ourselves. Noble goals. Guys we are asking for a really hard thing!

From forum members we have been able to see the insides of some of the best commercial controllers made on the planet. We have seen good ones, and cheap ones, blown up and naked. Folks have said in the FET thread that we have to be GM or Toyota or the big UPS manufacturer to get the "good parts"... and they are likely right. GM, Toyota or the big UPS maker would put a team of engineers on this multi-million dollar development program. They will build off of the success of past designs, and use proprietary, validated models. They would order laminated 3 dimensional buss bars to keep interconnect inductance at bay... they have all the good design tools. They might take a year to design and validate a controller. We have also seen how one big chip manufacturer interacted with an OEM and proposed using off the shelf parts in a design that was worse than some of ours. They recanted and went with the same TO247 parts that we can buy.

Tomorrow I will post a pix of the kind of rail caps that I think we need to gravitate towards for these new designs. Leaded electrolytics will not cut the mustard at these power levels. The low ESR caps are big. They will dominate the design. We are all going to have to learn about lead inductance, and layout effects together.

That is what we are trying to do. It is hard stuff. I believe we are at the cutting edge of what can be done. It will take a lot of creativity to move forward. It is not simple or it would have been done before.

BTW I think we can have the driver's "a bit" away and be ok. Modules are sometimes fed with a bit of twisted pair to the gate and the source. But the power layout needs to be rock solid. The rail caps and the FETs are an integrated "family" that lives or dies together.

 

[steveo]

Hey everyone

I was having some issues getting the controller running, but i have managed to get things working

I've mounted the controller on my kmx with the x5303 @ 150v. 36s1p turnigy 5ah lipo

I havent pushed it to the limits, but wow the torque difference!!!!!

Acceleration from 25-50km/h has greatly improved

All my wires are 10gauge, most of my connectors are 75amp poles

Ive got a nice inverter (laptop power adapter) that will run my 2 led lights/contactor/and controller vr circuit at 12.4v!!



The strangest thing though, i"ve kept the factory 2 wire shunt in the infinion pcb board, however the cycle analyst displays im pulling about 75 -80amps


C/a is set at a shunt value of 1.500 mohms which should be about accurate

I have managed to blow out 3- 15amp fuses in parrallel on acceleration, i wanted to try 3- 20 amp fuses but i only have some 25amp fuses handy so ill step up to them

Wish me luck, i hope she wont blow, anyone have any idea why my amp drap is higher then 50amps???

Maybe my c/a is off but i doubt it

Steveo

 

[liveforphysics]

Tomorrow I will post a pix of the kind of rail caps that I think we need to gravitate towards for these new designs. Leaded electrolytics will not cut the mustard at these power levels. The low ESR caps are big. They will dominate the design. We are all going to have to learn about lead inductance, and layout effects together.


BTW I think we can have the driver's "a bit" away and be ok. Modules are sometimes fed with a bit of twisted pair to the gate and the source. But the power layout needs to be rock solid. The rail caps and the FETs are an integrated "family" that lives or dies together.

This is pure gold here.

 

[bigmoose]

Shouldn't you be on your way to a race, or am I off a week?

I shouldn't double post, but if someone missed it (because I posted it in another thread) here are the caps:

These are the kind of Rail Caps that I believe are necessary as we design 5Kw and above 3phBLDC controllers driving low R, Low I motors. Leaded electrolytics are to reduce ripple, these caps snub spikes and save the FETs.

 

[John in CR]

Shouldn't you be on your way to a race, or am I off a week?

I shouldn't double post, but if someone missed it (because I posted it in another thread) here are the caps:

These are the kind of Rail Caps that I believe are necessary as we design 5Kw and above 3phBLDC controllers driving low R, Low I motors. Leaded electrolytics are to reduce ripple, these caps snub spikes and save the FETs.

Those sound great. Can I just replace existing caps with this type, or will the required long leads to fit come back an bite me? I'm game for any controller safety equipment to avoid having to reduce current settings.

 

[drunkencat129]

WOOT me and steveo just did a run tonight with the 12 fet controller runing the bigger fets and it ran and jesus crist was it fast lol need a seat belt to keep his ass on the trike lol got vids are going up soon going to make a new vid soon got radar gun to get proper top speed so stay tuned to see the update on the progress

wonder if eney ones down to make a bigger batch pcb now lol

 

[steveo]

Those caps look great!!!

I have 3 low esr caps rated at 200v in that 150v controller im using, these caps could be useful when i build the 18 mosfet version

Steveo

 

[bigmoose]

John these types of caps have tabs for a reason, and that is to minimize lead inductance. The two ingredients in the controller FET survival recipe are lead and layout inductance and switching speed. They are related in that V= L dI/dt. We win with either low inductance or acceptably slow switching speed. Too low a switch speed and we stay in the active region of the FET too long and dissipate "resistive" heat. So it's a trade. When you go to the absolute minimum in layout inductance you can tune the switching speed.

If you are adding or using these caps to an existing controller, you want to put them from the Top FETe Drain to the Lower FET Source in each 1/2 bridge. Minimize lead length. These caps being there with a #12 wire to them is better than not being there. Like in a boat, every bit of buoyancy helps. These caps should be very helpful when pushing the supply voltage right up against the FET ratings. They will snub spikes 100x better than electrolytics.

 

[Kingfish]

Subscribed 8)

Appreciate the help as I figure out my next motor.

Many humble thanks, KF

 

[steveo]

Can anyone help with how i would go abouts designing a PCB that can adapt a 18 mosfet infinion board that fits to-220 mosfets pcb to a to-247 package mosfet??

can anyone please shed some light if you have any experience with doing something of this nature?

thanks
-steveo

 

[BatteryMooch]

Tomorrow I will post a pix of the kind of rail caps that I think we need to gravitate towards for these new designs. Leaded electrolytics will not cut the mustard at these power levels. The low ESR caps are big. They will dominate the design. We are all going to have to learn about lead inductance, and layout effects together.


BTW I think we can have the driver's "a bit" away and be ok. Modules are sometimes fed with a bit of twisted pair to the gate and the source. But the power layout needs to be rock solid. The rail caps and the FETs are an integrated "family" that lives or dies together.

This is pure gold here.

I agree!

 

[whatever]

has anyone contacted xie cheng to see if they make t0-247 boards? that would be the easy way

 

[Arlo1]

Subscribed!

 

[gwhy!1]

the power boards that I have made will interface with a standard 12fet controller ( I think ) , I havent tried it yet but I think I must give it ago just to see



These boards can also be easily stacked to parallel the fets up :wink:

 

[steveo]

the power boards that I have made will interface with a standard 12fet controller ( I think ) , I havent tried it yet but I think I must give it ago just to see



These boards can also be easily stacked to parallel the fets up :wink:

you have the idea i'm looking for ... now we need to make it mate up with a 12 mosfet infinion board!!!

FYI my testing of my diy irfp4568 controller handled 84 amps @ 150v loaded on x5303 with the 12 mosfet infinion board!!!!

and that is with the tiny copper wires i used .. similar to 14 or 18 gauge wires...

-steveo

 

[fechter]

I think your add-on board need to have the main power and phase wire connections on it. The gate drive wires can be extended.

 

[gwhy!1]

I think your add-on board need to have the main power and phase wire connections on it. The gate drive wires can be extended.

Yes the main power into and out of will go straight to this board. the gate drives will be taken straight from the donor board to this board and will be less than 10mm away from the gate of the fet also the current sense will have to go to this board as the shunt is on it. I will dig out a old 12 fet board and see how well they match up.

Edit: it may be ok to use with a 6fet board.

 

[Arlo1]

I quickly looked at the irfp4568 and it looks like you will get about 24% more heat at the same amprage. And they can't handle as manny amps as a 4110 (looking at the hot specs) But if you are upping the voltage from a 4110 33% you can reduce the amprage 25% and achive a little more power or top speed. Cool. But make sure you keep them cool! Im going to look at getting a few of theses to play with.

PS a more advanced member may look at my numbers and make corrections.

 

[steveo]

I quickly looked at the irfp4568 and it looks like you will get about 24% more heat at the same amprage. And they can't handle as manny amps as a 4110 (looking at the hot specs) But if you are upping the voltage from a 4110 33% you can reduce the amprage 25% and achive a little more power or top speed. Cool. But make sure you keep them cool! Im going to look at getting a few of theses to play with.

PS a more advanced member may look at my numbers and make corrections.

Hey Arlo

you are correct imo that they will generate a bit more heat, however consider the bigger package mosfet to take the heat!, and also it is a fast switching mosfet like the irfb4110's!

I've successfully run my controller at 84amps@150v with my x5303 on my kmx and i love it... best controller i've ever built... and its a 12 fet infinion board lol!!

i'm drawing out a pcb and will try to get some into production for some fourm member that are interested... if anyone has any interested .. just add your name in on the thread .. and we will build a list of people that are interested

so far

i will keep mosfets, capasitors, shunt on new pcb i will design, if project goes well i want to maybe try 6 mosfet & 18 mosfet

-steveo

 

[gwhy!1]

I quickly looked at the irfp4568 and it looks like you will get about 24% more heat at the same amprage. And they can't handle as manny amps as a 4110 (looking at the hot specs) But if you are upping the voltage from a 4110 33% you can reduce the amprage 25% and achive a little more power or top speed. Cool. But make sure you keep them cool! Im going to look at getting a few of theses to play with.

PS a more advanced member may look at my numbers and make corrections.

Im not using IRFP4568 Im using IRFP4368's but they are only rated for 75v

Edit: I just checked for size and my powerboard looks like if it could of been made for this purpose it matches up pretty well, the 6fet board may also work but will need a little more pushing and shoving . I think Im going to have to try this myself

 

[steveo]

here is a photo of what i was able to draw out here ... using a picture of the backside of the board i found...

anyone have a nice front image of the pcb so i can check the traces...

thanks