Pics of the Hacker Sport ESC

[lutach]

Originally Posted by GriffinRU

Same thing as with MambaMax.

I re-worked old, thermalled BK-Electronics ESC with copper plates in-between pcb's and now it works much cooler, plus caps and zener (I am thinking about an option to change zener on-the-fly based on battery voltage).

I can tune your ESC, but that would be after May,24.

Cool. What about a FET change? I've seen a few controllers out there that have some king of extra copper wire instead of just the PCB traces. Can that improve how the ESC eliver it's power?

[GriffinRU]

Originally Posted by lutach

Cool. What about a FET change? I've seen a few controllers out there that have some king of extra copper wire instead of just the PCB traces. Can that improve how the ESC eliver it's power?

I do not think we can gain allot by replacing fets.

Always, but new layouts have power leads right at fet's. Although there is always room for improvement...

[lutach]

Originally Posted by GriffinRU

I do not think we can gain allot by replacing fets.

Always, but new layouts have power leads right at fet's. Although there is always room for improvement...

What I meant to say about the FETs is if they are old with high resistance, would it be better to go with a lower resistance one? Also, a bit off topic, but I keep forgeting to ask you. What is the advantage of adding more FETs to a controller? What needs to be changed? I'm having a hard time trying to figure this out. I've seen many 3-4 board ESC use the same FET driver as a single and double board one. I know there are drivers out there that can put out 3-8A, but what is actually needed to open a lot of FETs? I use a MOSFET Driver Calculator made by Microchip, but it only uses a few simple numbers that can be found on a FET datasheet. It doesn't give an option for multiple FETs though.

[BrianG]

FETs are "voltage driven" (very high input impedance) as opposed to current-driven transistors, so paralleling them is easy without "loading down" the driver circuit. FETs also have a negative temperature coefficient which means they conduct less the more they heat up, so they are kinda self-regulating in a way.

And parallelling more FETs splits the current load between each as well as reducing the overall Rdson for reduced voltage drop and heat for a given current.

But the more FETs you have, the longer the signal paths become, which may be a problem with noise and/or transient response since we're dealing with capacitive FET gates.

I'm sure Griffin can elaborate much more on this, but I saw he was offline so I thought I'd throw in my $0.02.

[GriffinRU]

Originally Posted by lutach

What I meant to say about the FETs is if they are old with high resistance, would it be better to go with a lower resistance one? Also, a bit off topic, but I keep forgeting to ask you. What is the advantage of adding more FETs to a controller? What needs to be changed? I'm having a hard time trying to figure this out. I've seen many 3-4 board ESC use the same FET driver as a single and double board one. I know there are drivers out there that can put out 3-8A, but what is actually needed to open a lot of FETs? I use a MOSFET Driver Calculator made by Microchip, but it only uses a few simple numbers that can be found on a FET datasheet. It doesn't give an option for multiple FETs though.

BrianG

Microchip calc good tool, but you need to use it multiple times to cover full duty cycle. More fets -> add total gate charge and capacitance, but be aware that fet's parameters are dependent on load. This tool helps to calculate driver for fixed circuits like DC-DC convertors. In addition to verify high side, in H-Bridge, you need to calculate bootstraps diode and caps parameters. As well as rated gate voltage and drives power supply requirements. Then to minimize ringing in mutifets applications you need to add series gate resistor and do the calc again.
In general it is not that bad once you get the entire picture, but can be complex to estimate working parameters across all temps, loads and fets.

P.S. More fets -> it’s like more micro switches which can split the task, but the most important task would be to keep them synchronized!!! And that can be lost quite easy, you've seen plenty of smoke...
It is like single strand in multi-strand wire...

[lutach]

All this information is really good as my design keeps geting better . Right now I know I can design a controller that will be smaller then the Tekin's R1 series. Now, I'm not an engineer and my design might not be possible. To me it makes complete sense and I've seen a couple of controller done the same way, but different layout.

heres an action shot of one...


the cool thing is, they put it red smoke for a little while...

[lutach]

Originally Posted by Bomb-Proof

heres an action shot of one...


the cool thing is, they put it red smoke for a little while...

Wow.

[snellemin]

WOW! was that with the limiter disabled?

ya, it ran cooler that way. It was a dually, the other suffered the same fate. 2 ESCs, and 1 motor...in one weekend. Hacker made it right for me though, so no biggie.

[lutach]

I have my limiter off and my Master Car race gets hot quick. My HW controller doesn't get hot at all. Do you guys think it's because of the Trinity N80's slotted design? I might try my Hacker B50-6S or the Trinity N60 to see if it works better.

[snellemin]

Running a 6L 380c feigao heated up the esc really quick. 130f on the stock caps, 139F on the heatsink and 134F on the battery. Mind you that this is with the limiter enabled. Gearing was at 54/18. Dropped a basic lehner 5300 and it ran cooler on 54/14 and had about the same power as the feigao . On 54/18 the Lehner was just a sissy. Cried like a bia***. Power came from 3s1p A123. With the 54/14 gearing it peaked at 798W, 106.25A@7.39V.

[JERRY2KONE]

I guess it all depends on the circumstances. When I was pushing boots in Orlando we picked up approx 130 women on day one and it was easy to shut them up when you put them in the pushup position for 20 minutes. It was great cycling them till they were soaken wet. They actually whined less then the male companies did. Of course they were not as strong as the male squads, but they worked harder trying to prove that they could do what men could do.

Originally Posted by TexasSP

The toughest of them all, especially if you have a majority of women. I have always said that I would rather manage 100 men than 3 women. I have had women managers agree with that statement as well.

I could just sense the QA in their somewhere, as I have that in my background as well.

[snellemin]

Small update on the Hacker ESC.

pushed 5s A123 through it for about 10 minutes running up and down the street. ESC temp was 127F and motor was 164F. Gearing was 60/14 in the rustler on a hacker 8L c40 motor. It peaked at around 1200 watts and the limiter was still enabled.