Kinetic/Ballistic Systems
 

Here is the press release for our upcoming Kinetic/Ballistic racing systems:

Energy in Motion

Nice to finally see Novak with new technology. Now, enough with the 540A rating. You guys should be the leader and start educating people. Do this, people like datasheet spec and there's a rating there which you can follow. Lets say you have 6 FETs per phase in a H bridge configuration that means 3 FETs should be calculated to get a AMP rating. Now if the FETs you're using has a Continuous Drain Current (TA) (ST Micro don't seem to use it), but lets use the 38A rating of the stk38n3llh5, that would give you a 114A rating and we all know the ESC can't dissipate that much heat. Use that as the maximum continuous burst, meaning it'll give that AMP rating everything one slams on the throttle. If it's marketing for the uneducated cool, but I really like honest looking specs and that's why Tekin and Castle gets my money. There are worst out there so you're not alone. To be honest, I would basically like something that can do 40A+ average throughout a race than anything and incase the sensor plug comes off, I would like to keep on going in sensorless mode instead of doing nothing.

540A is pretty silly when the lowest turn motor is only rated at 85A. Hard to take things serious w/ specs like that.

G/L anyways. Whats the price?

Interesting, race tech I guess. This stuff always makes me laugh, 2s max, motors rated by turns (not really the best way to rate a motor, unless they all use the identical construction, and then there is no benefit one brand from another), and other "spec" racing features.

The 540amp rating is funny too.

Yeah, this is kinda the wrong forum to get any excitement out of these - unless its a precursor to what might be coming to replace the HV system.

Hey Linc, now you have another ESC option for that dual 1527 GST you're building... :wink: :wink:

In all seriousness I like Novak's stuff. I had a HV4400 in my Rustler years ago and it was sweet. Really the only thing I could do without is that ridicuous current rating. Please? :yes:

Tough crowd here.......

Good to see PC programmability. Is this ESC marketed towards the 1s-2s limit only? And does it support sensorless yet?

Not being tough at all NovakTwo. Just like to be realistic and since Novak wants to be considered the leader in the Hobby, Novak should start setting some examples. This ratings game is over. This ESC probably has 18 FETs total correct? If so my calculation should be correct if you guys use the best ST Micro MOSFET or maybe you guys use some other PolarPAK style MOSFET from Vishay? The Vishay SiE874DF which is a 20V MOSFET has a TA rating of 52A at 25C degrees and if I use my calculation that should be a 156A rating, but we all know this little devices will never be able to dissipate so much heat if one actually sees 100A+ average. I would like to see some real world specs you know.

How do you guys come up with your ratings? Do you multiply 18 MOSFETs with 30A? If that's the way, I'm sorry to say it, but it's wrong. If you like to go with a 30A MOSFET then the max cont. burst should only be limited to 90A, but for a very short instant one can actually see a higher number depending on the voltage, motor, gearing, vehicle weight, rolling resistance, traction, tire size, aerodynamics and .....(Did I miss anything).

C & P from the press release:

Novak, I don't people are trying to kick you in the jewels, it's just that some here are quite technical and know that 540A is a pretty tall order. Sure, it looks nice on the adverts, but many people "in the know" might see that as deliberately misleading the customer. And, in business, if people think you are trying to mislead them, it could reduce credibility. Perception might as well be fact.

Like Lutach said, these controllers are H bridge config which means that the current rating should be 1/6 of the current of all FETs lumped together. I am glad that you do specify the temperature, but for future reference, it may be better to rate them according to their normal operating temps. I don't know about you, but I highly doubt the FETs in any system are operating at 77*F unless being run on a cold winter day lol.

Anyway, thanks for the heads up on the new product line.

Feedback.
 

Great feedback guys. I am sure he never expected that when he posted up in here. Like stated Novaktwo there are a lot of guys on this forum who know their stuff when it comes to electronics/ESC's from R/C experiences and also techinical training. This is why we are all in here, to learn from the guys who konw what the real deal is. So considering what has been said so far what kind of feedback do you have for us to learn from about this new gear that you are so proudly marketing??? What can it really do??

NovakTwo,

This is just absurd information my friend. I posted the continuous AMP rating of the FET at 25°C temp. and I posted the correct way of rating the ESC. The way Novak seems to be rating the ESC is multiplying the amount of FETs by the AMP rating (18 x 30 = 540), but that's wrong. Give me your thoughts on current lipo rating? It's great that you can finally use something other than the one touch set up to fine tune the ESC, but drop the over rating please, a lot of people will respect the brand even more.

If Novak still wants to use such rating, please offer some proof to back it up.

We have never claimed that this current rating applied to the speed control, itself.

This transistor info, (that we have been posting for decades in our BL esc spec chart,) is the transistor rating taken from the technical info sheets provided by the MOSFET manufacturers.

We have never claimed it to be anything other than that. But, I will forward these comments to Bob and Adnan.

If you have specific questions about the Kinetic, post them here and I will have Bob prepare responses.

I am not part of the Engineering/Technical group so I forward all tech questions to folks who have the answers.

Bob is flying home from iHobby, as I type

Ok, I have attached 2 datasheets that shows the 2 most powerful PolarPAK MOSFETs that I know of and the Vishay shows a 52A rating at 25°C. So lets try going with 6 FETs per phase, that's only 312A (But divide that by 2 since it's a H bridge config). Now here is the thing, if you go by the datasheet it clearly says the package is only limited to 60A, so lets go with that and multiply it by 6 and still only 360A. Now the silicon is limited to 258A, but that really doesn't mean anything if the package is only limited to 60A. Novak still uses the PolarPAK style MOSFET correct? Please have Mr. Novak and Adnan provide some input on why use such a rating if it doesn't apply to the ESC itself. At the moment, I think the Futaba brushless ESC has the most ridiculous rating of all brushless ESCs.

The historical, ridiculous current ratings were why Adnan decided to only publish the objective transistor ratings and not make any claims about the controller itself.

Putting it like that is somewhat more ridiculous if it has nothing to do with the ESC. If you want to put a transistor rating, add the datasheet of it to the website and how the 540A rating came to be. It really doesn't make any sense by putting a number out and not explain it to a simple guy like myself.

Novak, I totally understand your predicament. Many companies are, shall we say, "optimistic" in the their ratings. So, Joe Sixpack looks at two ESCs and brand A looks better on paper because it is rated 1000A. Of course, he doesn't realize that the claim is ridiculous, nor the fact that no motor will pull that kind of current on a regular basis (aside from instantaneous bursts) in a normal setup, not to mention 1000A is beyond the capabilities of just about any normal battery. As I'm sure you are aware, there are many other factors that affect current rating aside from pure FET specs: circuit design, amount of copper, wiring, heatsink area, etc.

Honestly, and no offense here, I think a certain company has the right idea when they rate their controllers as "more than you can handle". As long as the ESC can handle any motor in its class and is used properly (no s-size 6000kv motors running 2s in an 8th scale truggy), it will run fine.

Also, I'm surprised no idiot has tried pulling that 540A on a test bench to see what it would do. I'm pretty sure that would result in a melted controller and an attempted suit for false advertising. Again, I am not dogging on you, just trying to watch out for one of the few US companies.

In the arena of car racing for which we have designed controllers, both brush and sensored brushless, I have never seen, (or read about on forums), any interest in current rating specs.

If anything, about the only spec racers have ever been particularly interested in is on resistance. I'm just speculating here, but maybe these current rating specs have been valued and emphasized more in controllers for air models or non sensored controllers. Especially a few years ago, when European/Asian esc mfgs started re-purposing their airplane controllers for surface vehicles.

Personally, I would be just as content if we deleted all these numbers in our esc spec chart. If the rated/braking current numbers were once meaningful, they no longer are. Years ago, when we began listing only the MOSFET stats, it was because our engineers could never figure out how other companies' garbage ratings were measured; so we selected this alternative method.

Well, the majority of people probably don't care about the current spec as long as it works without overheating when geared reasonably in the vehicle it was meant. And trying to rate them to match other companies' overzealous methods is just bring you down to their level.

I can agree here. I just got into the world of Sensored 1/10th scale systems. The first question I was asked was about the resistance on the controller...

I have an idea. I'll make some phone calls and send some e-mails. It will be good if everything I have in mind works out.

Edit: Two e-mails sent and I'll wait for a reply, but will also make 2 phone calls tomorrow.

Do Li-Fe cells really need a voltage cut off?

Not from my experience. You will notice the drop in power - its significant. When you do, its time to shut down. If you keep running them after that, then yes, you can possibly damage a cell.

According to
 

According to all of the info provided by manufacturers a low voltage cut off is not required for LiFe cells. Like Thiessen stated when the LiFe cells are done there is a sharp drop in power and you will know it is time to stop and recharge. From what I have seen there is no real danger with the LiFe cells, and the power provided seems to be very similar or close to the same level as the LIpo cells without worry of catostrophic failure or fire due to over heating the cells.

Seems like a good laternative choice in my opinion over the Lipo technology, but how well they actually stand up against LIpo in performance is yet to be discovered or reported. Some feedback from those who have used them would be nice so we can weigh in on comparison.

I used 2S2P A123's in my Revo prior to going Lipo. In the same truck, the performance of the A123's was good - not as good as Lipo, but still a signifcant improvment over Nimh. Just off the top of my head, I would get 15-20 minutes of run time, compared to 20-30 on my lipos. And they charge so fast - 20 minutes or so.....I'd be just rotating packs off my charger and running them. Disadvantage is size - I tried setting them up as 3S2P but they were absolutely huge.

From what I've seen, LiFe cells drop off worse than a NiMH pack. When it's done, you know it.

Yup when the A123 dump, it's basically empty. As of late I've vented a couple of my A123's from pulling an overdose of amps in my crt.5. It has a funny smell, but there are no fires and whatnot. When they are overheated at around 160F, they lose some capacity. I'm sure lifecycle goes down quite a bit.

I have one 3s1p pack now in the crt.5 that overheated quite a few time. Once cell voltage is lower than the rest. But I still get 1800mah out before the pack loses its marbles. And under max throttle it still puts out 7.3V(nomadio telemetry).

I asked that question because on the novak web site it said something to that effect

540A current spec came from the FET's spec @25°C trans.temp. 180Ax3=540A.

The 180A is listed in IR's IRF6691 datasheet, which was employed in earlier batches of Novak's GTB ESC, but later GTB switched to STK850 which did not mention this spec in its datasheet but Novak continued using it.

It's good Novak didn't quote this spec in red circle, they can improve the ESC performance to 260*3= 780A ESC simply by this.
http://www.rc-monster.com/forum/atta...1&d=1258102494

I have to agree with lutach, a 90A rating for this small ESC would make Novak look more realistic and of a down-to-earth flavor, at least to those who know what the ratings are talking about.

We took a vote at Novak and are dropping all of those "current" specs.

They are meaningless, confusing and unnecessary.

The trick
 

I would believe that the trick is not to just drop all of your spec info, but to give us something that we can all rely on for accurate comparison. One of the main reasons we all come to forums like RCM is so that we can get the straight skinny from people who really do know what all of this info means. We are sure that alot of the companies use info that is not only somewhat untrue, but also very confusing. If you guys cannot really tell us what the truth is then how can anyone expect us to know what the truth is?

It would be nice if the major players in this could put your heads together and come up with one standard for everyone to go by, which would make things much simpler for the rest of us. Kind of like when all of the auto manufacturers came together and came up with OBD11 for computer analysis in trouble shooting codes, which is now a world wide system. I know that nothing like this is ever simple, but nothing changes if no one steps up and tries to make things better. With all of this goofy ESC info out there how can anyone figure things out?

I don't want to repeat myself, but we adopted the soon-to-be-deleted transistor current info years ago when other makers of (probably) brush controllers were making ridiculous claims for their escs current handling.

Expecting all mfgs to adopt esc current rating standards would probably be expecting too much...:lol: Maybe where speed control current ratings are concerned there is no "truth", only "it depends".

We will continue to rate our controllers by the motor wind limit and number of cells; anything exceeding that range could damage the electronics.

Didn't Novak just follow the same claims? We need data to back up such claims or at least the correct rating. Look at Castle and Tekin, they don't rate like you do. For example, the Tekin R1/RS ESC is rated for 104A when using the Ta 25C 26A rating and 76A when using the Ta 85C 19A rating of the On Semi NTMFS4833N. Now if I use he Tc 25C 191A rating the ESC would be a 764A and the Tc 85C 138A rating it would a 552A, but here is where things get interesting. The NTMFS4833N has a Pulse current of 288A which would give you a 1152A rating. How did I get those numbers you ask? Simple, the R1/RS uses 8 MOSFETs per phase, but I only multiplied the AMP number by 4 due to the H bridge design of a brushless ESC. Now the R1/RS has a total of 24 MOSFETs. If it's possible to get the part number for the MOSFET you use in your Kinetic ESC, we could come up with a better rating for it. Will it be less then the 540A rating yes, but I would respect the true rating more then the 540A out of the blue rating.

BTW, we are still waiting for an explanation on how Novak came up with the 540A rating.

For more info, email Bob.

I think a few people here would like to see some answer in the forum.

So true.
 

And instead of telling us to email BOB who's email we do not have, why not get him to chime in here himself and answer some questions for us. Why turn this into some secret rocket science when all we want is some raw data on how these ESC's are being rated. Don't get upset just because we are searching for some truth here. Help us understand your specs and get this straight.

+1. We're not asking for much and we don't want to upset anybody.

Guys - Novak Two's being reasonable and based on feedback they've decided to drop the current ratings and stick to motor / setup limits...

This seems like a step forward - You could say thank you and leave it at that!