I bought a Hobbywing ESC - Is this our Holy Grail?
- Thread starter AlexLTDLX
- Start date
WB projects
Active member
BTW Alex, I can't go on the forum on my cellphone anymore. I had an android and now I just change for an Iphone and both can't access to the forum. Personally I can go on my computer, but the new persons who want to go to the forum may be can't?
I e-mailed EPC about your question above and got this reply:
GaN FETs work very well for 3-phase brushless DC motors, including the speed control.
There are many designs for motor control using GaN FETs, most of them are embedded in products (not sold as separate controllers).
EPC does have evaluation boards, but again, they need to be configured for your particular motor.
There are many advantages of GaN FETs for motor control, including less audible noise, torque efficiency, smaller size.
Reverse conduction loss in GaN FETs is higher, but if a controller is designed so that the FETs are turned on when in reverse conduction, that isn’t an issue.
Here is a link to an EPC page on Motors, and it has several other resources you may be interested in: videos, notes, boards, FETs, etc.
https://epc-co.com/epc/markets-and-applications/consumer-electronics/motor-drive
regards,
Brian Miller
Field Applications Engineer
Efficient Power Conversion – EPC www.epc-co.com
919-680-2902
brian.miller@epc-co.com
Hope this helps!
Wow - that's really cool that he got back to you. That link is interesting, but it look to be more for developers. I'm sure we'll see products coming down the pike soon enough that use GaN FETs. I've said it like a thousand times, but things like this keep popping up - we're at the nascence of this technology, and I think it's really exciting!
EUREKA! I just shot the high power, LTO-powered tests with the HobbywingCastle setup. It was consistantly pulling around 315 amps at about 45 volts at the ESC (internal datalog). That, dear friends, outperforms the APD/TP Power combination - it's holding a consistant 14kW! I can't even begin to tell you how excited I am...
WB projects
Active member
Thats impressive! Omg!
At 300+ amps the ESC temp never reached steady state. Any data on how long it took the ESC to cool back down? Since my project is for a sports car, I need to be able to get on and off the throttle while driving winding roads. I'll have plenty of battery capacity just wondering if there is an ESC duty cycle limit.
Hytek - I think you hit the nail on the head - once the thing is spinning, it starts to cool itself off. Not what I expected.
88fiero - I don't think it would have any problems. The fan is pretty hyperactive, and it wasn't even on (or plugged in) in that datalog. The OTA module plugs into the fan port; and I didn't bother powering the fan separately or using a Y cable. Especially if you put it somewhere where there's airflow. Keep in mind, that's enough power for at least 600hp on the right engine, if not more. I don't think you'd be staying in it under any circumstances for longer than 15 seconds, except for one (which I intend to do) - running the Texas mile. Even then it would only be running for less than 30 seconds. Though I understand what you're saying - on the throttle/off the throttle - but I think it would be fine.
88fiero - I don't think it would have any problems. The fan is pretty hyperactive, and it wasn't even on (or plugged in) in that datalog. The OTA module plugs into the fan port; and I didn't bother powering the fan separately or using a Y cable. Especially if you put it somewhere where there's airflow. Keep in mind, that's enough power for at least 600hp on the right engine, if not more. I don't think you'd be staying in it under any circumstances for longer than 15 seconds, except for one (which I intend to do) - running the Texas mile. Even then it would only be running for less than 30 seconds. Though I understand what you're saying - on the throttle/off the throttle - but I think it would be fine.
Homemade WRX
New member
While I don't have exact belt temps, We ran ~10mm wide cog belts to drive 5 stage dry sump pumps on endurance engines with no actual cooling (see 24 Hours of LeMans and Daytona 24). Shoot, in the Ford GT is was slammed up against the bulkhead and had a full undertray. We also used them on every cup engine that runs an even larger pump albeit with a wider belt for 600 miles of WOT.
At most, you might want to 3D print a small duct to scoop air and dump it on the belt (like a brake duct).
Also off to go look up this ESC and see if it has specs on regenerative braking.
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I am looking at putting a Chevy Vortec 4200 (has all the latest tech that the original Jag 4.2L doesn't, plus is very durable and loves boost) in my '67 Jag XKE with a ZF8HP style trans behind it. There is a hybrid version of the trans set up for regenerative braking, so thanks for mentioning that the WRX and APD ESC can do that! Could certainly reduce battery KWH needs. I will definitely check that out. Would be great to set up an electric P2 with some kind of flexible, proportional throttle control for carving mountain roads!
I have owned the XKE since 1976 and had it stored since early 1980's. I have retired recently and am almost finished building out the apartment in my shop, so about ready to start restoring it. It is in need of a complete restore, although it is almost all original. I plan to keep the engine, trans, etc. so someone can put it back to original with matching #'s, etc., but in the meantime, I want to swap to an engine and trans I can have fun with. The Vortec 4200 (some call it the AmeriBarra) is plentiful and inexpensive - I can buy all I want here in Houston for less than $500.00 each. If you are interested, check out Calvin Nivlac at Nivlac57 on YouTube - recent example is
. He is doing some neat things with the Vortec 4200. The ZF8HP is 8 speed and can shift way faster than I can, so should be a good match. Attached is recent picture (dust and all, LOL) with bonnet removed - had to save it as reduced size pdf and original jpg was too large.
At some point it would be interesting to measure air temp rise coming out of your elec. turbo at what you consider normal boost conditions.
Hytek, if you can provide a compressor map that has efficiency on it, I can tell you the temperature rise at various pressure ratios. For example at 10 psi (about 1.69 pressure ratio), the temperature rise from ambient is as follows vs supercharger efficiency:
55% - 150 'F
60% - 137 'F
65% - 127 'FD
70% - 118 'F
75% - 110 'F
A rough number is that every 10 'F manifold inlet temperatures will reduce the mass flow of air to the engine by about 1% at constant boost.
Another interesting intermittent power adder idea is to use a slip stream of freon from the A/C system to chill a reservior of coolant and then route that through a liquid to air intercooler (really an aftercooler) when the supercharger comes on. There are a couple of companies selling expensive kits to do this but probably could be done for under $1000 DIY.
Homemade WRX
New member
Hello again.
So I've been digging a bit more and it actually seems that this EZ Run has braking which you can program. From what I see from all of these larger car and scooter oriented ESCs is that they all seem to use regenerative braking as their brakes. Alex, want to add some regenerative braking to your blower for some chu-chu-chu-chu noises?
So seeing the entry price point on this and a cheap SSS motor (but 6-poles, 50k RPM and fears of eRPM control), I might just start there. I'll have more than enough tied up in the housing, high speed bearings, gears, gearbox, driveshaft, etc...
After all this is really just a project to demonstrate a DIY MGU-H.
And Alex, big thanks on doing your homework with the LTO cells. They look like they'll save me a lot of them temperature sensitivities of LiPo or Li-ion.
So I've been digging a bit more and it actually seems that this EZ Run has braking which you can program. From what I see from all of these larger car and scooter oriented ESCs is that they all seem to use regenerative braking as their brakes. Alex, want to add some regenerative braking to your blower for some chu-chu-chu-chu noises?
So seeing the entry price point on this and a cheap SSS motor (but 6-poles, 50k RPM and fears of eRPM control), I might just start there. I'll have more than enough tied up in the housing, high speed bearings, gears, gearbox, driveshaft, etc...
After all this is really just a project to demonstrate a DIY MGU-H.
And Alex, big thanks on doing your homework with the LTO cells. They look like they'll save me a lot of them temperature sensitivities of LiPo or Li-ion.