Search found 937 matches

by mxlemming
Oct 01 2022 1:30pm
Forum: Motor Technology
Topic: Axiom: a 100kW+ motor controller
Replies: 611
Views: 152626

Re: Axiom: a 100kW+ motor controller

analog based PID is just super fast and zero software so has that appeal. of course it takes an extra day to tune the PID and better hope you never have to tune it to another motor... but in fixed motor application, its the simple cheapest and highest bandwidth solution there is. i think i did dq/a...
by mxlemming
Sep 18 2022 7:12am
Forum: Motor Technology
Topic: Axiom: a 100kW+ motor controller
Replies: 611
Views: 152626

Re: Axiom: a 100kW+ motor controller

Quick comment on what mxlemming wrote about the ADC in the 30F... yes it has only one ADC but it has 4 samplers. So it samples the 3 voltages from the current sensors all at the exact same moment, and then does the ADC conversion on the sampled voltages one after the other. So the ADC readings the ...
by mxlemming
Sep 14 2022 2:39am
Forum: Motor Technology
Topic: Multistage axial flux motor design and prototyping
Replies: 25
Views: 1617

Re: Multistage axial flux motor design and prototyping

Hi, beautiful work on that motor. Best guess to why it won't spin in sensorless is the lambda is wrong. You can calculate lambda from the kV using lambda = 60 / (sqrt(3) * 2 * pi * kv * Npp) = 0.046. lambda is the most important parameter for sensorless. At the moment there are a lot of people strug...
by mxlemming
Sep 10 2022 10:18am
Forum: Motor Technology
Topic: Modular, Multi-Platform, 300A ESC
Replies: 15
Views: 1455

Re: Modular, Multi-Platform, 300A ESC

I have been playing with my one for a few hours this afternoon, I can only dream of neat tidy wires like Netzpfuscher... instead I have settled for a mess of 17AWG cables that have turned slightly brown from heat. Anyway, I have been gradually ramping up the power, by running an open loop protocol p...
by mxlemming
Sep 06 2022 2:43am
Forum: Motor Technology
Topic: Axiom: a 100kW+ motor controller
Replies: 611
Views: 152626

Re: Axiom: a 100kW+ motor controller

Ok, I searched and read through per unit https://en.m.wikipedia.org/wiki/Per-unit_system , it's a system for rating large motors and transformers on the 3 phase grid. I don't think it's really applicable to field oriented control, the solutions from ST, Infineon, TI... Don't use per unit either. To ...
by mxlemming
Sep 05 2022 7:51pm
Forum: Motor Technology
Topic: Axiom: a 100kW+ motor controller
Replies: 611
Views: 152626

Re: Axiom: a 100kW+ motor controller

@mxlemming ok, credit for actually doing the experiment. its possible that you do not see any difference because you are using low side shunts as these are referenced to DC negative and that's not going to help for high performance application because your motor is not such referenced (its floating...
by mxlemming
Aug 22 2022 4:38pm
Forum: Motor Technology
Topic: Axiom: a 100kW+ motor controller
Replies: 611
Views: 152626

Re: Axiom: a 100kW+ motor controller

Bob White told me once never make a presentation on a subject that's not in the book. he was right, but i do it anyway ;) i would encourage you to try it. make the experiment on the same machine under the same conditions and take measure using a torque cell with two sensors and with three and try t...
by mxlemming
Aug 19 2022 5:31pm
Forum: Motor Technology
Topic: Axiom: a 100kW+ motor controller
Replies: 611
Views: 152626

Re: Axiom: a 100kW+ motor controller

I have only seen one design feature in any of the OEM inverters I have had in my lab that could not be explained by sound electrical engineering principals and that would be cost accountants cutting current sensor counts from three to two ya this is pretty common. the text book says you can sum 2 o...
by mxlemming
Aug 10 2022 2:42pm
Forum: Motor Technology
Topic: Magnet coverage and hall sensors
Replies: 8
Views: 477

Re: Magnet coverage and hall sensors

+1 for sensorless. I experienced the same thing with a smaller motor, and actually found the distortion of the magnetic flux caused hall sensor phase shift. Since I programmed sensorless I've never wanted to go back. Another option is an encoder, which is a bit more off the shelf and makes accurate ...
by mxlemming
Aug 08 2022 6:24pm
Forum: Motor Technology
Topic: Motor comparisons [CA120 et al.]
Replies: 429
Views: 48740

Re: Motor comparisons [CA120 et al.]

sauerpower wrote:
Aug 08 2022 1:35am
Hi community,
i recently bougt a ca-120 Motor.
I want to create a powerful E-Bike.
Does anyone have a compete CAD model of this motor?
Many thanks.
Page 10 miles posted some cad files. Perhaps that's it?
Depending what version of this thing and how much detail you want, I might have something...
by mxlemming
Aug 08 2022 2:23am
Forum: EBike Technical
Topic: Any reason to buy a Classic Trap controller versus an FOC controller anymore?
Replies: 10
Views: 520

Re: Any reason to buy a Classic Trap controller versus an FOC controller anymore?

How do these 3 speed switches work? I see 3 wires... I guess Plus gnd an signal of some sort? All the ones I've seen use two inputs (with 5v pullups internal to the controller) and a ground. No grounded signal means setting 2, grounding either of the others means that setting. What the settings the...
by mxlemming
Aug 07 2022 8:00pm
Forum: EBike Technical
Topic: Any reason to buy a Classic Trap controller versus an FOC controller anymore?
Replies: 10
Views: 520

Re: Any reason to buy a Classic Trap controller versus an FOC controller anymore?

The 3 speed switch, i like very much.. i set my controller speeds to ~66% ( easy cruising at 30mph ), 100% ( usually around 40mph ), and 120% ( usually 45-50mph ). I love having that 3 speed switch because i can alternate between motorcycle like speeds ( when i need to - IE i am on a street with a ...
by mxlemming
Aug 07 2022 6:58pm
Forum: EBike General Discussion
Topic: Science of cycling still largely mysterious. No one knows why bikes stay upright
Replies: 20
Views: 1100

Re: Science of cycling still largely mysterious. No one knows why bikes stay upright

What bit about this exactly do "we" not understand? It seems pretty obvious to me. When the bike is rolling, a deviation from upright means the weight of the bike causes the steering to twist which in turn creates a corrective centrifugal acceleration to stand the bike back up. There's als...
by mxlemming
Aug 06 2022 6:46pm
Forum: EBike General Discussion
Topic: Precharge resistors
Replies: 29
Views: 935

Re: Precharge resistors

Screenshot_20220807-003831.png This randomly selected 100 ohm to220 resistor for example. It has a graph of energy vs time. Your controller probably has about 2500uF of capacitors. Probably. Time constant RC is 0.0025x100 is 250ms. Therefore you can safely dissipate at least 17J based on that chart...
by mxlemming
Aug 06 2022 6:21pm
Forum: EBike General Discussion
Topic: Science of cycling still largely mysterious. No one knows why bikes stay upright
Replies: 20
Views: 1100

Re: Science of cycling still largely mysterious. No one knows why bikes stay upright

But we don't know how bicycles stay upright? Of course we do. The articles themselves say that we know. The thread title is just clickbait. :lol: and we're meant to trust CBC and nature... No my contention and dismay is that there are genuinely still people getting paid to research this at universi...
by mxlemming
Aug 06 2022 6:17pm
Forum: EBike General Discussion
Topic: Precharge resistors
Replies: 29
Views: 935

Re: Precharge resistors

You can use pretty much anything for the précharge connector. I'm using xt30. The current requirement is Vbat/R so 117V/100 ohm=1.17A. tiny. You need lower resistance. Like fechter said. Below 100 ohm. The xt90 anti spark connectors use 2.2 ohm. They rapidly die with bigger higher voltage controller...
by mxlemming
Aug 06 2022 5:50pm
Forum: EBike General Discussion
Topic: Science of cycling still largely mysterious. No one knows why bikes stay upright
Replies: 20
Views: 1100

Re: Science of cycling still largely mysterious. No one knows why bikes stay upright

So we can stabilise fighter jets, fly quadcopters up down left right... down a chimney and out the door, we can land rockets on the moon, stabilise orbits around our planet, slingshot probes off other planets, stabilise flows of subatomic particles close to the speed of light in 27km tunnels we've d...
by mxlemming
Aug 06 2022 2:11am
Forum: Motor Technology
Topic: Iron Nitride magnets, maybe better than neo's
Replies: 24
Views: 1203

Re: Iron Nitride magnets, maybe better than neo's

Think I'm with LFP on the chance of this being real. I really sincerely hope it's real, but the properties of FexN were known about in the 70s... They had even more motivation to use it then and heavily research it because of the lack of neodydliums... On a crate of beer scale bet, I'm going with it...
by mxlemming
Aug 05 2022 8:46pm
Forum: Motor Technology
Topic: Modular, Multi-Platform, 300A ESC
Replies: 15
Views: 1455

Re: Modular, Multi-Platform, 300A ESC

Well I'll be brief because it's kinda 2am... But... The board works. I've only built it up with 6/18 MOSFETs but it's been spinning the motor. No little wires :lol: With not enough MOSFETs the switching is brutal. 20ns rise time and ringing at 70mhz, though that's all damped out within 250ns. The ex...
by mxlemming
Jul 30 2022 11:38am
Forum: Motor Technology
Topic: New ground-up ESC - MESC_FOC_ESC
Replies: 214
Views: 17737

Re: New ground-up ESC - MESC_FOC_ESC

Vbruun wrote:
Jul 28 2022 3:49pm
so nice! At the current rate, this project will some day become beginner friendly, which makes me happy :)
https://youtu.be/Tf3uwAzrEbk


Made a video on how to go about programming/running MESC.
by mxlemming
Jul 28 2022 6:30pm
Forum: Motor Technology
Topic: New ground-up ESC - MESC_FOC_ESC
Replies: 214
Views: 17737

Re: New ground-up ESC - MESC_FOC_ESC

so nice! At the current rate, this project will some day become beginner friendly, which makes me happy :) It might be more beginner friendly than you think. Just download/install stm32cube ide, clone/download this project from github, double click the project file for your choice of chip... And yo...
by mxlemming
Jul 28 2022 5:46pm
Forum: Motor Technology
Topic: Modular, Multi-Platform, 300A ESC
Replies: 15
Views: 1455

Re: Modular, Multi-Platform, 300A ESC

The first thing I thought of when I saw it was that you could mount the fets straight up and put a block of aluminum between them to get the heat out. This could then screw to a heatsink case top or bottom. If the fet legs make contact at the thick section I'd imagine they could supply a bit more p...
by mxlemming
Jul 25 2022 3:20am
Forum: Motor Technology
Topic: Modular, Multi-Platform, 300A ESC
Replies: 15
Views: 1455

Re: Modular, Multi-Platform, 300A ESC

I'm pretty happy with this as a first iteration. Hopefully should have one in hand within a few weeks to test. I think the main thing we've all learnt over the last year is that part availability is crucial. I think that's the best thing about this board... There will always be to220 MOSFETs, always...
by mxlemming
Jul 24 2022 8:34pm
Forum: Motor Technology
Topic: New ground-up ESC - MESC_FOC_ESC
Replies: 214
Views: 17737

Re: New ground-up ESC - MESC_FOC_ESC

Excellent, any hardware changes as well? No. The original hardware with the TOLL FETs just keeps on giving. The project is also ported to other hardware (compatible with most VESC boards and the boards badgineer has been making). If I did update the hardware it would probably just be to improve the...
by mxlemming
Jul 24 2022 6:13pm
Forum: Motor Technology
Topic: New ground-up ESC - MESC_FOC_ESC
Replies: 214
Views: 17737

Re: New ground-up ESC - MESC_FOC_ESC

Quick update, since there have been a lot of changes over the last month or two. MTPA added Different circle limitation added Optional features and cleanup of settings Various options for observer, including non linear, flux linkage tracking, and the MESC observer is now the default option in VESC f...