EUC - PWM Explained

[@roghaj]

I raced in China without any info. I felt blind. Love my pwm display.

[@TheAnimeist]

There are several ways to control motor speed. One method is varying the voltage to the coils-the more voltage, the more speed. Another approach is adjusting how long the voltage is applied to the coils; longer application means more speed. This second method is called PWM (Pulse Width Modulation). With PWM, the voltage alternates between 0 and full voltage (e.g., 84V) in periodic cycles, typically around 20 MHz. For example, at 50% PWM, the motor is on half the time, resulting in half speed. The controller adjusts the PWM percentage. While PWM maximizes torque and efficiency, it can't exceed the system's power limits

[@Area51Enduro-Tony]

Good point on the app updating and someone might not even be thinking about it because they previously had pwm set.

[@SergioFlorente]

I’m new to this (not EUC, but riding with the APP) and really, you opened my eyes to the real advantage of monitoring our wheel with an app. Thanks to you Dawn, my old bones are safer from now on. 😎

[@DawnSChampion]

@@SergioFlorente I’m so glad to hear!! Be safe!! ❤️

[@ThaBlackCobra]

Great job explaining this Dawn. I never ever use PWM because I’m usually not really pushing my wheels to the limit after my shoulder break years ago, but after your description I think I’ll start setting mine whether I’m pushing hard or not. Great vibes as always… 😊 👍🏾

[@DawnSChampion]

Thank you!! Yes, it’s a good idea because of things like you’re in a group ride, your battery is low, wind picked up, you start going a little faster…. The pwm beep will remind you that the wheel can’t go as fast right now. I would love to help keep you safe, my friend!! ❤️❤️

[@ThaBlackCobra]

@ You just convinced me to actually start using it, especially since I have the Cardo now as well… 👍🏾

[@RadiantFreeEnergyResearch]

Thank you so much Dawn, I have been trying to understand pwm for the longest time. your video made the pwm easy to understand. thank you!

[@DawnSChampion]

Oh good!! I have two other videos about pwm but still found people confused about it, so I’ve been trying to figure out the best way to break it down for everyone! I’m glad it helped!! Thank you for letting me know!! ❤️❤️

[@haroldsmith45302]

Thank you, Dawn.

[@DawnSChampion]

You’re welcome!! ❤️

[@haroldsmith45302]

@ I hope you and your home are safe from the wildfires.

[@DawnSChampion]

@ thank you!! ❤️

[@stevesmith3033]

Thanks Dawn! You explained that very well and succinctly. I expected a lot of rambling, especially😁 when getting technical but you didn't

[@DawnSChampion]

@@stevesmith3033 oh pheww!!! Thank you!! 😄

[@DonovanWert]

Thanks Dawn!! ✨🙏✨

[@DawnSChampion]

@DonovanWert you’re welcome!!

[@PacificNorthwest360]

Great explanation, I’ve been commuting to work occasionally on my CP 50s and never messed with this setting because I didn’t fully understand it, sometimes I find myself cruising in the 40’s MPH and I’m going to set this starting tomorrow since my speeds are slowly increasing. Cheers and thank you. Olympia WA

[@DawnSChampion]

You’re welcome!! Thank you!!

[@PacificNorthwest360]

@@DawnSChampion My PWM on my CP 50s was 138% so I did -38 and set my 80% alarms :-) she cut out at 90 mph. Cheers

[@renatoalcantara5961]

Hi Dawn! One question … when you calibrate the PWM, is better do that with full battery charge?

[@DawnSChampion]

Yes, absolutely!!

[@WillofNewZealand]

Yip good subject. Hi from Will in NZ, I'm 80% pwm...beep. side angle 65° tiltback usually on, incase I'm not listening to any beeping. Wishing you nice success and to be well.

[@zweemz2255]

thank you for a racers perspective on PWM, helpful.

[@DawnSChampion]

You’re welcome!!

[@Rockin_EUC]

I'm so thankful you're making this video, I've learned about pwm but you explain it in detail, thanks again so thoughtful of you to make this video! I've been wondering what's the recommended settings for setting up speed alarms, so now I'm going to try this out on euc world. Do you ever use euc world? I use it because I can stream it through to my galaxy watch.

[@DawnSChampion]

You’re welcome! No, I don’t use EUC World. Look for it as “Safety Margin” on there!

[@divingfalconfpv4602]

On our drones we go as 80% max pwm for safety reason. That what we like to not pass

[@russellzauner]

PWM can't physically be more than 100% because PWM is literally a method using a pulse width duty cycle (yes, a varying square wave); the duty cycle of anything can't be more than 100%. In a three phase system you're looking at some sort of averaging between the phases being controlled to give you a universal single readout value for PWM when in fact PWM is three synchronous pulse trains (in a three phase motor). The futzing around is due to sloppy margins of error in the firmware and averaging deltas at any given instant between the three phases, so it's literally never going to be the same actual value with any averaged measurement (unless rounded to whole units) and the telemetry is the system's best effort to report as close as it can to a constantly changing value, but those are also calculated values so more error can be injected there as well. It's good to have an eye on it but never trust it and it's not a great idea to keep trying to slice it thinner, because, the error stackup will only let you slice it so thin until you're operating in a region of uncertainty of unknown breadth and scope. What we should be focusing on is 6 and 12 phase axial flux reluctance based motors but since they're not commercialized yet it's a huge financial hit to try to qualify and introduce models with radically different motor topology and footprint, regardless of the advantages over simply brute forcing it and scaling up voltage and hardware and weight. New battery cell releases can only drop your weight so much in the same battery chemistry category. Single swingarm designs are also coming up, which could counteract some of the gyro effect when flexing/cornering hard; that could reduce weight by maybe another 20% outright. Above that, new motor designs with new materials are what's needed as well as upgrades to modern, well tested in industrial applications, 6 and 12 phase true sinewave controllers - for better efficiency, smoother load transitions, tighter accuracy/tolerances, and more constant power/cleaner regulation.

[@DawnSChampion]

Thank you!! ❤️

[@grb1969]

Agreed. Axial Flux motors are inevitable for EUCs. 😊. I’m also a fan of ‘mass gyro stabilization’, which has been prototyped already and should be available for EUCs in about 8 years from now. MGS will make EUCs mainstream because even someone with moderate Parkinson’s symptoms would be able to ride and balance without any experience… no wobbles, traction control, power-sliding and power-jumping (Mario-style) all become possible with mass control gyros… also possible to effectively raise instantaneous PWM to eliminate PWM concerns for all over-power situations except sustained top speed (although top speed can be significantly increased without changes to motor/battery output limitations. The best part of MGS is the ability to absorb/release regenerative energy much more efficiently than the battery pack can handle alone so range will be much higher as well. Good times if we can survive Empire collapse and WW3.

[@lepp_]

Thanks for the video!

[@DawnSChampion]

@@lepp_ you’re welcome!!

[@RalphBucci]

Any videos on HOW to correctly set PWM? I use EUC world.

[@DawnSChampion]

@@RalphBucci in EUC World, just set your Safety Margin to 20%. Then set your alarms to that

[@Ronin_Ryder]

Very nice. I would have added that its not clear if the PWM works with field weakening activated (i tend to think it doesn't but im hearing mixed feedback). My speed runs i don't activate it because of that...

[@DawnSChampion]

@@Ronin_Ryder I think it does. It’s working for me

[@Ronin_Ryder]

@@DawnSChampion so with magnetic at 9 PWM is accurate on Begode wheels? This is great, thanks.

[@DawnSChampion]

@Ronin_Ryder I believe so! I haven’t had any issues yet!!

[@jkeyohm9524]

Maybe a vid on field weakening🤔(very good pwm explanation😁👍)

[@thanh-nguyen1976]

Great instrumental video.

[@DawnSChampion]

Thank you!! ❤️

[@jeffspooner1246]

Thanks, very informative...

[@JrVill-xf1qn]

Thanks Dawn, nice EUC tips Maybe a short video on TILT Assist

[@DawnSChampion]

@@JrVill-xf1qn tilt assist? What’s that? Is that the Acceleration/ Brake Assist stuff?

[@JrVill-xf1qn]

@DawnSChampion yes

[@DawnSChampion]

Ok

[@ChrisH0Y]

I have a question for you Dawn. Is PWM relevant to battery charge state? Say you are at 90% battery, riding at 30% PWM on a flat road at 30mph. Later, you are at 50% battery, riding at 30mph on the same flat road. Would your PWM go up?

[@DawnSChampion]

@@ChrisH0Y yes. It’s dynamic. It takes into account wind, going uphill, all of that

[@ChrisH0Y]

@@DawnSChampion Thanks! - Good to know.

[@DawnSChampion]

@ you’re welcome!

[@mikearnold5554]

i just realized my ex30 was reading pwms wayyy inaccurately like yesterday, by doing a free spin test, this video helped confirm my suspicions on how to resolve. thanks dawn, great explaination. any advice on field weakening on ex30? ive read that max field weakening is ok to ride on, as long as you are aware that theres less torque. do yo use FW on your ex30? if so what level do you use, and have you experienced less torque at high speed? I think the ex30 motor is high torque to begin with, so maybe it has enough torque despite the trade off at higher speeds.

[@DawnSChampion]

@@mikearnold5554 my v1 ex30 has the 50E batteries and I ride it on FW4. It dips too much any higher. I talk about it in the videos when I was riding my EX30 and testing the FW in depth. It’s not that you lose torque. It’s that it will dip if it hits a bump and it’s much easier to overtorque it.

[@mikearnold5554]

@DawnSChampion wow okay thanks Dawn! Any idea how I can tell what version my ex30 is? Maybe I'll have to do the same.

[@DawnSChampion]

@@mikearnold5554 did you get the ones with the 50S batteries? I’m not sure if it matters. I just know the 50S are the better batteries, but I would say still proceed with caution.

[@krishnascully4357]

What set up do you have in your helmet?

[@DawnSChampion]

@@krishnascully4357 I have a Cardo PackTalk Edge

[@Reawer]

The fires in LA are scary AF I hope you are safe

[@DawnSChampion]

I know, right? Year of the Dragon is not going to end without fire breathing!!

[@pacochawa2746]

Ya the dragon was a wild ride money vilolence fires now floods for us north

[@DawnSChampion]

Ugh. Stay safe!!

[@Roskellan]

Pulse Width Modulation (PWM) from a electrical perspective. PWM is how the current is delivered to the motor from the battery, instead of a continuous flow. The current is instead delivered to the motor in pulses, The pulses have a "MARK" which is the pulse itself and a "SPACE" which is the period where the motor is receiving nothing from the battery. PWM is the percentage of one in relation to the other, 0% would be no mark and all space, 50% would be a mark and space of equal duration and 100% would be all mark and no space. Clearly at 100% you have effectively just applied the battery directly across the motor and the motor would have no more to give (more complicated than that because a conversion from DC [the battery] and 3 phase AC [for what is an induction motor] is also performed but you get the idea. Knowing the PWM is a good thing in respect to riding safely you clearly need a margin before 100% PWM, however the PWM can change dramatically on hitting bumps bad surfaces, or by suddenly accelerating for example. Not to mention hills or head winds. To throw a spanner in the works so-to-speak, the power/torque an induction motor can produce changes radically with speed regardless of how much power you have in a battery to turn it. At zero mph you have lots of torque but no power (no work being done here), and at full speed you have lots of power but torque is declining fast. Torque is that which is resisting you going flat on your face, so accelerating hard at speed is a really bad idea.

[@DawnSChampion]

Thank you!! ❤️

[@pacochawa2746]

Ya nobody rold me about pwm nor explained it at all. Thanks

[@DawnSChampion]

@@pacochawa2746 you’re welcome!!

[@Funcentric]

Do you think off-road mode and racing mode in begode wheels affects PWM? My guess is that if it makes a difference at all, PWM would stress less on high torque or off road mode. In the flip side, I can see how off road mode would allow the rider to gin it harder without much effort and actually reach the PWM more easily. Both scenarios make sense to me but are opposite. Hmmmm. Thoughts? Okay, if you don’t know. I know this is a bit more technical.

[@DawnSChampion]

I think more torque is more effort by the wheel. It also eats up battery faster. Race mode allows the wheel to spin faster with less torque.

[@Blox117]

to be more specific, pwm is duty cycle % of the mosfets - the thing that directly provides and controls power to the motor. the thing is, I have read that begode wheels do not report their actual PWM and that EUC world uses safety margin which is an estimate. i also did not think begode wheels use dynamic tiltback or beeping based on voltage/pwm because older wheels certainly did not. in fact on the forums, there was custom firmware for dynamic tiltback on begode wheels. to note: i only have older begode wheels so i dont have experience with how this works for leaperkim, etc or any newer wheels released since 2021

[@DawnSChampion]

@@Blox117 the Begode wheels are supposed to have true pwm now. That’s why we don’t have to calibrate it anymore

[@Blox117]

@@DawnSChampion thats why i was confused. thank you for clarifying

[@mikearnold5554]

@@DawnSChampion my ex30 was reading 120something or maybe 130 pwm during spin test, this should be corrected down to 100% right? i might correct it to 105, for that extra 5% safety.

[@Blox117]

i feel like you made this video specifically cause of a comment i made a few weeks ago xD

[@DawnSChampion]

What happened?? I’m sorry, I don’t remember what happened a couple hours ago, much less a few weeks ago! 🤣

[@skan8]

EUC world app doesn't have PWM measurements.

[@DawnSChampion]

@@skan8 that’s correct. Their equivalent is Safety Margin

[@skan8]

@@DawnSChampion Oh then I am already set.

[@grb1969]

@skan8, PWM=100-Safety Margin. So 80% PWM correlates to a 20% safety margin. {i.e. don’t set safety margin to 80% because then you’ll only have 20% of PWM available before alarms.

[@phoenixvolunteeradatitleiiS.C.]

Hey GTSY always

[@DawnSChampion]

Hi!! ❤️

[@christopherhart1640]

if your lynx cuts out at 77mph freespin, regardless of pwm, then how do you find your 100% pwm?

[@DawnSChampion]

I don’t understand. 77mph is your speed. Now you need to see at what pwm does it cut out at? Then you can proceed.

[@ANoobis715]

Depends on many factors.... your weight, height, wind, incline all contribute to load rating. Someone weighing 160lbs will cause different load demand to the wheel than a bigger rider. If you want to find your 100% pwm you're going to have to ride out the beeps on a full charge and wait until you faceplant. This is why there's multiple alarms

[@Ronin_Ryder]

PWM is completely wrong on LK wheels, forget about it. An issue i have escalated to LK since NOV 2023 and properly ignored by them since then.

[@DawnSChampion]

@Ronin_Ryder for LK wheels, in DarknessBot, select “Calculated PWM”.