300A VESC in the works, feature suggestions wanted

[TechAUmNu]

A200S V2 Now available for pre-order here: http://teamtriforceuk.com/a200s-v2/
The A200S is a 200A 16S ESC, based upon the VESC®*-Project.
* VESC is a registered TM, owned by Benjamin Vedder

[typhoon_driver]

Features - cost less than a tenner. You'll be very popular

[overkill]

A potted case is a REALLY bad idea! I tried that on a number of IFI Victors a few years ago and they all eventually died. It was traced back to the potting resin expanding at a different rate to the PCB and causing solder joints to crack. A thin conformal coating is a better bet. Room to add our own shock mounts is a good idea.

[TechAUmNu]

A potted case is a REALLY bad idea! I tried that on a number of IFI Victors a few years ago and they all eventually died. It was traced back to the potting resin expanding at a different rate to the PCB and causing solder joints to crack. A thin conformal coating is a better bet. Room to add our own shock mounts is a good idea.

Good to know! Its probably best to not have any coating then to make it easier to replace parts.

As for pricing I don't want it to be over £300 current BOM is ~£120 + board.

[Pinski1]

There's a couple of us trying to build 300A ESCs now.

Personally I'm not a fan of directFETs, can't inspect joints, package is unique to Infineon and they seem to discontinue them quickly. HSOF packages seem much better to me, it's what they use in the Vex BB controllers.

[shakesc]

Not sure on the integrated shock mounts. Prefer some flexibility on mounting e.g. mount into a shock mounted electronics box

I'm looking to drive 8019 Neumotors - http://neumotors.com/80xx-series-electric-motors/

[TechAUmNu]

Not sure on the integrated shock mounts. Prefer some flexibility on mounting e.g. mount into a shock mounted electronics box

I'm looking to drive 8019 Neumotors - http://neumotors.com/80xx-series-electric-motors/

I will make the mounting points on the board with plenty of room around them instead, then it gives people mounting flexibility.

So about 350A peak on those motors, I might end up making another board with 6 or 8 fets per phase if there is demand. It really bumps the price up though.

[TechAUmNu]

There's a couple of us trying to build 300A ESCs now.

Personally I'm not a fan of directFETs, can't inspect joints, package is unique to Infineon and they seem to discontinue them quickly. HSOF packages seem much better to me, it's what they use in the Vex BB controllers.

I was thinking that too, only real reason I was going with them was for the ability to stick a heatsink directly onto them, but looking at the HSOF I am going to use this one instead.
http://www.mouser.com/ds/2/196/Infin...-en-767648.pdf
Has almost half the on resistance and bumps the current rating way up for a very small price increase.

Thanks!

[TechAUmNu]

Would people prefer it to be

A) Smaller with no 5v Dc-DC. i.e. OPTO
B) Larger with integrated 5v Dc-Dc about 2A (also makes it £10-20 more expensive)

I think its best to be OPTO since people will likely already have a 5v dc-dc and if they don't they can easily add one.

[shakesc]

My vote would be OPTO

[R9000]

OPTO sounds sensible to me.

[Pinski1]

OPTO, but integrated diode on the output works quite well too.

[TechAUmNu]

OPTO, but integrated diode on the output works quite well too.

What do you mean?

[Rapidrory]

If you're going opto, may as well go with a proper opto isolator to avoid joining ground planes through the RX; I've had signal issues when joining up non opto isolated high power ESCs.

Also, the HSOF packages ideally need thermal vias and to be heatsunk through the board. You can heatsink the case but it's not as efficient. Without a heatsink you'll likely get about 160A cont from 4 of those FETs, so to get to 300A you'll need to dump a lot of heat.

[TechAUmNu]

If you're going opto, may as well go with a proper opto isolator to avoid joining ground planes through the RX; I've had signal issues when joining up non opto isolated high power ESCs.

Also, the HSOF packages ideally need thermal vias and to be heatsunk through the board. You can heatsink the case but it's not as efficient. Without a heatsink you'll likely get about 160A cont from 4 of those FETs, so to get to 300A you'll need to dump a lot of heat.

I have added an opto isolator for the reciever input.

For the current design it works out about 110W of dissipation, which should be fine. It will run quite hot 120oC at 300A continuous load. The heatsink is in contact with all power components on both sides of the pcb and some of the board itself next to the fets. Board is probably going to be 2-4 layer with 4oz - 6oz copper and copper bus bars for each phase and power input.

The heatsink is going to be around 1oC/W or better and will form a custom two part machined aluminium case.