Vedder's VESC 6.0

Alright, the delta voltage is a function of the resistance thru the FET, which once again brings up the P=UI, U=RI → P=R*I^2. Showing the square relation from the current. Anyone familiar with a exponential function knows that the current is the heaviest factor. Are people still debating this? :sleeping: :rofl:

@linsus Can I ask you a more technical question? Since rpm depends upon voltage, and since higher switching frequency leads to higher impedance in the traces+mosfets, is it correct to assume that driving a motor with higher voltage at the input could produce more heat in the esc(because of the higher impedance)?

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Its a complicated question, switching frequency depends on sevral different factors other then the voltage level. But yes the RPM or ERPM is directly correlated to the switching and while i dont meddle with power electronics that much as a proffession, I know quite abit about semiconductors. I’m afraid its not as easy as a yes or no answer. Both current and voltage play a part towards the actual losses while current being the desiding culprit. One cant exist without the other.

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I agree, fairly certain at this point that current dominates the losses overall for the eskate operating regime. Started looking into modeling the FETs in the system analytically and it was way more complicated than I anticipated and got lazy a few hours in.

As far as real world testing, ran some tests on the unity comparing our bench testing of 60 amps through motor at like 5-10% duty cycle vs. real-world hill climbing of 60 amps at around 80% duty cycle. In terms of thermals there wasn’t much noticeable difference in the rate the boards heated up suggesting that motor current and not power is the best indicator of heat losses in the FETs.

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@Blasto But this is kind-of irrelevant because the average current in the ESC is probably limited by pulsewidths and impedances, and not by voltage drops across resistive loads.

We just need a side-by-side thermal test with same load on identical esk8 ESCs (using mechanical resistance on the motor axle) but different battery voltages.

Amp rating is for copper wire while voltage rating is telling you about arcing protection that cable insulation provides.

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Thanks @Deodand … this thread of amps / volts / heat is running in several places. Seems like motor amps (which seems to be a 'balancing number) Vs battery amps (less efficiency loss). It would help if the real world was bench simulated so that there’s consistency in how this is talked about. There is a long rant here from 2016 which goes into a lot of detail http://buildelectricboards.com/showthread.php?tid=164&page=2 … about how the battery and motor amps balance out.

When we tested our worst case of max motor torque based on full input of 48v/30a constant, we get a reading of someone doing their worst until the battery runs out. We are trying to make sure nothing can be broken. It was explained to me that there is less going to the motor due to efficiency, but this nonetheless represents our system running at full torque @ max speed the torque is available.

I’m not sure that the ‘80 amps all day’ statement is a good description of what the controller does. Even the Maytech 100a … with no airflow, it won’t sustain our test for longer than 10 minutes before it gets to 100 degrees. So, this is not 100a … we are using 30a. Obviously, the 100a is the wrong measure and is maybe a peak inbound measure … or something.

Not sure of the solution, but we are doing our own testing as we can’t work out from the marketing material what the actual maximum thresholds are. It’s not the same with commercial controllers. What they will do is very clear.

The VESC community ‘big brains’ could devise a series of measures / tests that all vendors need to supply data for so that comparisons can be made … now that would be interesting :slight_smile:

Cheers

Maytech is responsive and more honest

Flipsky is just bullshit, no R&D, but just sell cheap price by changing low quality components.

@esk81 Not my experience.

@esk81 again, not my experience. We’ve had flipsky develop a custom remote control for us. It wasn’t easy and they have done a good job so far.

They’ve taken the reference V6 design and done what appears to be a good implementation with anti-spark and other features added as well as a smart layout for heat. Clearly, they’ve done R&D. We’ve tested their FSesc 6.6. Can bus works great, heat dissipation is the best we’ve tested by a long way.

Have you got any evidence, or just insults?

Your posts look like sabotage posts …

Cheers

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We tested Maytech 100A vesc, much better than 50A

The answer is that it depends on use. Amps and Volts together are the relevant measure and are what creates heat. See my previous posts. If you are using standard components for an e-board, chances are it’ll be fine unless you are doing something off the map. I’d buy a V6 if you can as they are a substantial step up. Cheers

Obviously the ESC with the higher amperage is going to be able to get more performance. Unfair comparison

That remote is a copy from Firefly remote project… you can even see from views on OLED… So not much R&D was done just new case

@Kug3lis … no, this is not public. It’s a new remote. We haven’t released it yet. So far, so good. Cheers

Before you said you were independent from flipsky, and now “we” so you work for flipsky so all the stuff mentioned was just biased reviews? :smiley:

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I think the “we” he’s using in this instance is the same “we” that had Flipsky developed the remote such as when he says:

So we would me him and who ever he’s associated with to make Flipsky make the remote , not we as in him and Flipsky

Maybe, but I can’t find right now video, I saw in some flipsky thread where you can clearly see oled screen :smiley:

Oh yea i agree with you on that, More than likley they took Solidgeeks Firefly and ran away with it, just wanted to clarify his use of we in context.