Castle Creations Mamba Monster maxx ready for release

[lutach]

Originally Posted by Pdelcast

Lutach,

Haven't started working on an HV version yet. We could go as high as 8S with some part changes on the current Monster (using a 40V FET instead of a 30V FET and some other minor parts changes.) But don't see much demand for an 8S or 12S system right now.

Also, a 12S BEC would be an issue -- high voltage BECs that can handle a significant amount of current are huge. So, I would prefer to do it as an opto system.

So, an opto system, 60V design isn't too difficult. I just need to find time for the design. Got so many other things going on...

Patrick

I can work with opto as most of my ESC are opto. I think demand is there, but once folks understand the benefits of HV, there should be more demand and I'm sure the boat guys will use it as well. The Monster will be using the SUPERSO8 (TDSON-8) package MOSFET and Infineon has a BSC079N10NS that seems real good. I wanted to try something with my HV110 that I still have to send to Castle for repair. The MOSFET that I wanted to use has a 14 week lead time and the only one available is a 100V that has a cont. 34A at 25C and 21A at 100C. It has the same SO-8 foot print. All I would need is a simple forward/brake car program if it's possible. I called you, but I think it was on the day you were out sick. I know you are very busy and I would rather have you do it to my controller than waste a good one.

[Pdelcast]

Originally Posted by lutach

I can work with opto as most of my ESC are opto. I think demand is there, but once folks understand the benefits of HV, there should be more demand and I'm sure the boat guys will use it as well. The Monster will be using the SUPERSO8 (TDSON-8) package MOSFET and Infineon has a BSC079N10NS that seems real good. I wanted to try something with my HV110 that I still have to send to Castle for repair. The MOSFET that I wanted to use has a 14 week lead time and the only one available is a 100V that has a cont. 34A at 25C and 21A at 100C. It has the same SO-8 foot print. All I would need is a simple forward/brake car program if it's possible. I called you, but I think it was on the day you were out sick. I know you are very busy and I would rather have you do it to my controller than waste a good one.

Actually, the BSC079N10 doesn't work well at all in motor controller applications. We've been working with samples of that MOSFET for about six months and have had very serious issues getting that FET to work well in a bridge application.

However, the BSC118N10 works great, and is the FET we are using in the SHV controller. It is a little higher on resistance, but works in bridge applications. The BSC079 won't stay off on the low side due to gate capacitance ratio issues.

Now that said, the manufacturer's continuous amp ratings on ANY FET are total BS. It's mostly specmanship between manufacturers. There is no way the BSC079N10 can take 34 amps unless it was by itself with a near infinite heat sink... That's 10 watts of waste heat at 34 amps -- would burn up almost instantly.

Just look at how many FETs we use per amp on the phases of the HV controller.

You can assume that a dissipation of about 300-400 milliwatts (.3-.4 watts) per FET (of I^2R losses - -assumes very fast turnon / turnoff) is going to be a safe maximum. So for the BSC118 (11.8 milliohms) that gives a maximum of about 10-12 amps per FET on each half-bridge leg, when WELL heat sinked. Given that the MMM has 36 FETs (6 FETs per half-bridge leg) that would only yield a 60-70 amp controller. (I leave it as an exercise to the reader to try the math on the MMM NTMFS4833 FETs, to get a valid maximum continuous current for the MMM)

The HV-110 would be a better platform with 108 output FETs (18 per phase), but it cannot dissipate as much heat per FET as the MMM.

So, I think a 72 FET controller would probably be best -- using two power boards like the MMM, with good heat transfer. That would yield a pretty bulletproof controller in a smallish form factor.

We won't even talk about the SHV-250, because it is a little big (5" x 2.5" footprint.)

Patrick del Castillo
President (And still principle engineer!)
Castle Creations


I like the silly smilies -- even though my wife thinks they are annoying...

[lutach]

The 34A I mentioned is from NXP and I know Renessas have some as well with the same package. NXP said the MOSFET has an SO-8 foot print, but it acts as a DPAK. There is only one controller that I know of that is using these type of MOSFET (Not the 100V one though) and pictures can be found here:http://www.rc-monster.com/forum/show...&postcount=126. I was looking through the BSC079N10 datasheet and they say Tc 25C 100A and Tc 100C 64A, but the Ta at 25C is only 13.4A.

[Pdelcast]

Originally Posted by lutach

The 34A I mentioned is from NXP and I know Renessas have some as well with the same package. NXP said the MOSFET has an SO-8 foot print, but it acts as a DPAK. There is only one controller that I know of that is using these type of MOSFET (Not the 100V one though) and pictures can be found here:http://www.rc-monster.com/forum/show...&postcount=126. I was looking through the BSC079N10 datasheet and they say Tc 25C 100A and Tc 100C 64A, but the Ta at 25C is only 13.4A.

That's an LFPAK mosfet. Not as good as a SO-8 leadless (like the BSC079/BSC118/NTMFS4833) for dissipation. DPAK, SO-8, SO-8FL, LFPAK, it doesn't really matter. It's all about how much you can dissipate, and how much the FET can take internally. You see, the FET people have been "juicing" their ratings for years, so always take the ratings with a grain of salt. The NTMFS4833 we are using on the MMM is rated at 191A per FET -- can it really take that kind of current? No way, not even close!

About .3-.4 watts per FET is all you can hope to dissipate in a high density ESC type application (a little more with a good heat sink and fan, but not much more.) Anyone who tells you different is either wrong or lying.

The math really counts -- you can't fool physics.

Now, there are companies (like certain of our competitors) who like to just add up the FET ratings and call that the rating of their controllers. However, it is again total BS, as no FET can take that kind of power for more than a second or so. If we did that for the MMM, the rating of the MMM would be 1150 amps. Can the MMM take 1150A? No, it can't. Can our competitor's speed controls handle 700A? No, they can't, even if they are rated to do so.

And then some other competitors take a 20 second rating, and call that "continuous" --- Better, but still misleading in my opinion.

So we don't really want to get involved in creating total BS ratings for our controllers. And if we publish truly honest ratings, we will look anemic next to our competitors who are publishing BS ratings.

So what do we do? We create controllers that will handle pretty much anything you want to throw at them -- they are so over-built that there isn't any problems with power handling.

But I won't BS you and tell you the MMM will handle 1150A continuous like some of our competitors might... because the MMM won't handle 1150A continuous. Our Emaxx draws about 100A average, and about 800A during acceleration (for about a second or so), and the MMM handles it fine. (better than the motor in fact.) And it will take full throttle/ full brake / full throttle/ full brake continuously for as long as you want to do it on a system that will go 70mph on either an Emaxx or an 1/8 scale buggy, outputting about 2250 watts average and almost 10,000 watts peak.

So this is my dilemma.


So should I:

1. Give a real-world continuous and burst current rating that will make the MMM look anemic against competitors controllers when in fact the MMM will handle much more current than the competition?

or

2. Give a BS rating on the same scale as the competition which will allow customers to comparison shop on a level field, but are really totally BS numbers?

or

3. Just don't rate a continuous and peak rating because option 1 misleads some consumers and option 2 misleads other consumers?


Thanks for listening to me rant!!!


Patrick del Castillo
President
Castle Creations

[TexasSP]

Originally Posted by Pdelcast

So should I:

1. Give a real-world continuous and burst current rating that will make the MMM look anemic against competitors controllers when in fact the MMM will handle much more current than the competition?

or

2. Give a BS rating on the same scale as the competition which will allow customers to comparison shop on a level field, but are really totally BS numbers?

or

3. Just don't rate a continuous and peak rating because option 1 misleads some consumers and option 2 misleads other consumers?


Thanks for listening to me rant!!!


Patrick del Castillo
President
Castle Creations

I think number 1 is best, but I still understand your dilemma.

I think giving several setup examples with motor/voltage/performance information for several of the most popular vehicles would be good.

You had something similar for the MM and for most novices, that was helpful. As far as performance over the competitor, that will all be proven once these things hit the streets.

[lincpimp]

Originally Posted by Pdelcast

Our Emaxx draws about 100A average, and about 800A during acceleration (for about a second or so), and the MMM handles it fine. (better than the motor in fact.) And it will take full throttle/ full brake / full throttle/ full brake continuously for as long as you want to do it on a system that will go 70mph on either an Emaxx or an 1/8 scale buggy, outputting about 2250 watts average and almost 10,000 watts peak.

Patrick del Castillo
President
Castle Creations

Jesus, 100amps cont! Am I correct in thinking this is at 6s voltage (22.2?)?

What batteries do you have that can keep up with this load? Do they hold voltage well under these kinds of loads?

Seeing an emaxx do 70 must be cool. You guys need to add that vid to the MMM listing (or whatever it is now called)!

[lutach]

Patrick,

Have you tried the BSC082N10? Would it be possible to make a 12S Monster Max. I just need an HV from a company in the USA. Please don't make me start begging or sign my soul for one . I know this isn't much, but a few people want a 12S or maybe more for car use: http://www.rc-monster.com/forum/showthread.php?t=10609.

[Pdelcast]

Originally Posted by lutach

Patrick,

Have you tried the BSC082N10? Would it be possible to make a 12S Monster Max. I just need an HV from a company in the USA. Please don't make me start begging or sign my soul for one . I know this isn't much, but a few people want a 12S or maybe more for car use: http://www.rc-monster.com/forum/showthread.php?t=10609.

Yeah, we started with the BSC082N10 about a year ago on the SHV design. Found it had the same issues (even worse actually) as the BSC079

But that's OK, the BSC118N10 works fine, and handles almost as much current as the other two.

Now, a 12S controller only needs a 60V FET, not 100V.

One possibility is that I'm working on the 60V (12s) Phoenix-ICE controller line right now, and it will have the hardware support for Mamba type software (the current Phoenix-HV does not have similar hardware to the Mamba line.)

Patrick