Search found 3147 matches

by Lebowski
Jan 11 2019 1:18pm
Forum: General Discussion
Topic: List of small hatchback cars
Replies: 116
Views: 4199

Re: List of small hatchback cars

Ordered the Citroen C3 I was talking about, this is what it looks like (for people not familiar with Citroen) No radio, but will install a 7" tablet and a bluetooth speaker. No airco but will go redneck on that when necessary (frozen bottles in a cooler, with forced airflow over it, or build a dual ...
by Lebowski
Jan 09 2019 3:35am
Forum: Motor Technology
Topic: Sensorless at standstill, development updates and status
Replies: 78
Views: 4294

Re: Sensorless at standstill, development updates and status

If I understand correctly (difficult to concentrate properly) this is about a company making their own product open source and selling more in the process. Not about someone having IP but no company. If I make my IP public I'm not going to sell more as there is nothing to sell except the IP.
by Lebowski
Jan 08 2019 2:48am
Forum: Motor Technology
Topic: Sensorless at standstill, development updates and status
Replies: 78
Views: 4294

Re: Sensorless at standstill, development updates and status

My code is all written in assembly :D , I use lots of macros which are faster to execute than call / return combos. Those take around 10 cycles, while most floating point functions are also roughly 10 cycles (meaning that its better to waste 10 memory locations here and there, instead of doubling th...
by Lebowski
Jan 07 2019 2:54pm
Forum: Motor Technology
Topic: Sensorless at standstill, development updates and status
Replies: 78
Views: 4294

Re: Sensorless at standstill, development updates and status

Been using home brew FP in my controller IC (and also this one) for some time now...

I use two words, one is between -32767 and -16384, and 16384 and 32767, the other words is the exponent. 1.0 for instance is 16384 2^-14
by Lebowski
Jan 07 2019 8:37am
Forum: General Discussion
Topic: List of small hatchback cars
Replies: 116
Views: 4199

Re: List of small hatchback cars

I've crossed mountains with my 8 hp scooter, going up 15% inclines in second gear going really slow. This gives a sense of accomplishment you'll never have on a 'proper' motorcycle. Granted, with 68 hp you'll be in front of the traffic jam, but the next engine up is a 82 hp which is not much faster....
by Lebowski
Jan 06 2019 8:48am
Forum: Motor Technology
Topic: Sensorless at standstill, development updates and status
Replies: 78
Views: 4294

Re: Sensorless at standstill, development updates and status

I don't think it would impact other engineers having jobs, Ti and many others offer sensorless software based off rotor saliency and induction, they just aren't on the public sections of their websites and are only offered to larger companies under NDA. It's unlikely many are writing their own impl...
by Lebowski
Jan 05 2019 2:46pm
Forum: General Discussion
Topic: List of small hatchback cars
Replies: 116
Views: 4199

Re: List of small hatchback cars

I'm about to order the most basic Citroen C3. Extremely comfy car also when you're 1m92 tall. Very economical but only 68 hp from a three cilinder non turbo 1.2L . 0 to 60mph take 16.4 seconds. Has the only option I really care for, cruise control (who cares about hp when you're doing 60mph on cruis...
by Lebowski
Jan 05 2019 2:35pm
Forum: Motor Technology
Topic: Sensorless at standstill, development updates and status
Replies: 78
Views: 4294

Re: Sensorless at standstill, development updates and status

Well, I am considering writing down how the 'standard' Lebowski controller works, but not releasing the code. All I think about when I hear open source is lots of companies getting rich of my work without any kickback to me (even though I spent a few 100k$ worth of time and thousands of my own money...
by Lebowski
Jan 05 2019 6:32am
Forum: Motor Technology
Topic: SPM VS IPM Motor - And Field weaken, is it worth it
Replies: 82
Views: 1795

Re: SPM VS IPM Motor - And Field weaken, is it worth it

Dont know about the James Mevey thesis, but I remember that in the early 90ies at the technical university of Eindhoven I had a 'electronic machines' class where the professor told us that making power with a motor comes down to stuffing current into the bemf...
by Lebowski
Jan 05 2019 3:19am
Forum: Motor Technology
Topic: Sensorless at standstill, development updates and status
Replies: 78
Views: 4294

Re: Sensorless at standstill, development updates and status

Hmmm, sounds interesting. Are there examples on the net ? Which crowdfunding website would be a good one ?
by Lebowski
Jan 04 2019 3:06pm
Forum: Motor Technology
Topic: SPM VS IPM Motor - And Field weaken, is it worth it
Replies: 82
Views: 1795

Re: SPM VS IPM Motor - And Field weaken, is it worth it

I've experienced hundreds of controller faults from various types of field weakening controllers while deep into field weakening and never had that damage anything. This seems odd because the BEMF if you spun the motor up with a drill to that same RPM you faulted at would be above Vdsmax for the mo...
by Lebowski
Jan 04 2019 11:39am
Forum: Motor Technology
Topic: SPM VS IPM Motor - And Field weaken, is it worth it
Replies: 82
Views: 1795

Re: SPM VS IPM Motor - And Field weaken, is it worth it

Inductance measured on the revolution (with ebay meter, don't know how hard it is to measure inductance accurately) for QS3000W motor: Max: 78 mH Min: 58 mH Can any estimations of the reluctance torque potential be done based on this? Check my equations (and I mean check for mistakes :wink: ) a few...
by Lebowski
Jan 03 2019 2:13pm
Forum: General Discussion
Topic: MUSIC thread
Replies: 159
Views: 17470

Re: MUSIC thread

Needs to be played very loud
by Lebowski
Jan 03 2019 1:43pm
Forum: Motor Technology
Topic: Sensorless at standstill, development updates and status
Replies: 78
Views: 4294

Re: Sensorless at standstill, development updates and status

With transition between saliency and bemf running. The transition is around 6 k-erpm, drill can now reach top speed (44k-erpm), limited by battery voltage:


by Lebowski
Jan 03 2019 11:58am
Forum: Motor Technology
Topic: SPM VS IPM Motor - And Field weaken, is it worth it
Replies: 82
Views: 1795

Re: SPM VS IPM Motor - And Field weaken, is it worth it

If it lost control under field weakening, not such a big deal as long as the battery fuse does not blow. If you look at my field weakening explanation, the extra voltage c9mes from the field weakening current combined with (motor) inductance. Should the controller lose control, the max current the m...
by Lebowski
Jan 01 2019 6:21am
Forum: Motor Technology
Topic: SPM VS IPM Motor - And Field weaken, is it worth it
Replies: 82
Views: 1795

Re: SPM VS IPM Motor - And Field weaken, is it worth it

My take on switched reluctance and how it produces a voltage:
(bear with me if there are any mistakes, it was new year eve after all :? )
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by Lebowski
Dec 31 2018 3:56pm
Forum: Motor Technology
Topic: SPM VS IPM Motor - And Field weaken, is it worth it
Replies: 82
Views: 1795

Re: SPM VS IPM Motor - And Field weaken, is it worth it

Lebowski, not sure if i get u right, but if u mean that u align ur current with the "bemf" formed out of the magnetic inducted voltage and the inducted voltage by the current flowing then u would handle IPMs and SPMs not in the optimal operation point. I know ur implementation is not like industry ...
by Lebowski
Dec 31 2018 11:44am
Forum: General Discussion
Topic: List of small hatchback cars
Replies: 116
Views: 4199

Re: List of small hatchback cars

Testdrive tomorrow in a Honda Jazz CVT :D 2017, 22000km, costs 65% of new. I like the whole seat folding system, and the cars reliability. Lets see what the cvt is like... No jazz cvt for me, the car drives like the engine is filled with molasses. Also on cruise control, with the Swiss up and down ...
by Lebowski
Dec 31 2018 11:39am
Forum: Motor Technology
Topic: SPM VS IPM Motor - And Field weaken, is it worth it
Replies: 82
Views: 1795

Re: SPM VS IPM Motor - And Field weaken, is it worth it

It depends on how the Leaf motor is build. Getting power out of a motor is all about aligning the bemf voltage vector with the current vector (assuming no field weakening). You can show mathematically that the reluctance also follows this, i.e. the reluctance of the motor also results in a backemf l...
by Lebowski
Dec 30 2018 2:02pm
Forum: Motor Technology
Topic: SPM VS IPM Motor - And Field weaken, is it worth it
Replies: 82
Views: 1795

Re: SPM VS IPM Motor - And Field weaken, is it worth it

In my particular controller algo it will always try to make the torque producing current (Id ?) equal to what is asked for by the throttle. It will raise controller output voltage to achieve this. When raising motor voltage is not enough to produce the wanted Id (?) it will start adding (ramping up)...
by Lebowski
Dec 30 2018 12:10pm
Forum: Motor Technology
Topic: SPM VS IPM Motor - And Field weaken, is it worth it
Replies: 82
Views: 1795

Re: SPM VS IPM Motor - And Field weaken, is it worth it

Have you guys seen my thread on fieldweakening ? That it has nothing to do with weakening fields ? That you can do 'field weakening' with inductors EXTERNAL to the motor, so where they dont impact the field in the motor ? (typing on a tablet, copying link is difficult). And what do you need a table ...
by Lebowski
Dec 30 2018 12:02pm
Forum: General Discussion
Topic: List of small hatchback cars
Replies: 116
Views: 4199

Re: List of small hatchback cars

Testdrive tomorrow in a Honda Jazz CVT :D 2017, 22000km, costs 65% of new. I like the whole seat folding system, and the cars reliability. Lets see what the cvt is like...
by Lebowski
Dec 14 2018 6:22am
Forum: Motor Technology
Topic: Sensorless at standstill, development updates and status
Replies: 78
Views: 4294

Re: Sensorless at standstill, development updates and status

I am not a company starter. I cannot really do anything with this tech except build a one-of-a-kind ebike :? . Want to get rid of it (sell it), maybe get a consultancy job with the buyer... I'd recommend doing a reference design - a PWB that you can build 20 of, that will also drive a motor. (Pick ...
by Lebowski
Dec 14 2018 6:21am
Forum: Motor Technology
Topic: Sensorless at standstill, development updates and status
Replies: 78
Views: 4294

Re: Sensorless at standstill, development updates and status

Another early drill video (sorry this one is sideways to get the laptop screen in the picture): -bS9-QNsUpE BLDC drill running at (close to) full torque, sensorless running on saliency... meaning the phase information for the FOC control loop comes from additional code that measures the differences ...
by Lebowski
Dec 13 2018 1:10pm
Forum: Motor Technology
Topic: Sensorless at standstill, development updates and status
Replies: 78
Views: 4294

Re: Sensorless at standstill, development updates and status

So this is all done sensorless on saliency (did not have the transition to standard sensorless FOC in yet, so it did not go to full speed). It basically runs a sensored FOC but without sensors, the (I believe at this point still 8 bit) phase information comes from the stator inductors having rotor p...