low inductance output stage contruction

[Futterama]

closer together is better so thin twisted magnet wire is better than the thick isolated stuff i used in the first post.

And thin parallel is even better due to shorter wire length than twisted.

 

[speedmd]

If your looking for thin close and parallel and also need a boat load of current. Dont over look ribbon style bus.

 

[h0tr0d]

Speedmd, thin layer of katpon and you are set to go.

And mixing art and science, we could twist various parallel wires, positive and negative, in a patern like so:

 

[speedmd]

thin layer of katpon and you are set to go.

exactly!

 

[Lebowski]

v2 as it were, to be used in my recumbent:

 

[Futterama]

Looking very good!

I found that even with my 80W soldering iron and the big tip, it took me a long time to heat those copper plates for soldering but I see you did a very good soldering job with your plates.

 

[parabellum]

I usually shortly connect my cheap 100W 110v iron to 220v outlet while soldering massive bars and wires. They go puff from time to time but I have few in reserve. :lol:

 

[Lebowski]

strangely, I only have a 50W soldering iron. I pre-tinned the locations where the FETs connect to the busbars. Expecially the first
one, you have to hold the iron to the metal for about 15 seconds before the solder starts to flow properly. But once the copper
is nice and toasty soldering is quite easy. I have an old 1960's Weller with exchangable tips, I use a big tip since this seems to make
the iron hotter.

 

[Futterama]

I soldered the plates when holding both plates in a small vise. Lebowski, how did you hold the plates?

 

[Lebowski]

I soldered the plates when holding both plates in a small vise. Lebowski, how did you hold the plates?

I didn't want to hold it with anything metal or heat conducting, so I used a miniature wooden clothespin

 

[Futterama]

That was probably my problem, the heat conducting vise. Did you hold both copper plates at the same time when soldering or did you solder one at a time?

 

[Lebowski]

That was probably my problem, the heat conducting vise. Did you hold both copper plates at the same time when soldering or did you solder one at a time?

one at a time... and when soldering the second one the first one was still warm, so not too much heat loss there.

 

[speedmd]

You need more thermal mass at the tip of the iron to do plate. Torch, or large iron is a must if you want to be productive.
Forget about the little circuit board stuff for this job.
http://www.ebay.com/itm/lot-of-vintage-solder-irons-as-shown-/191094805452?pt=LH_DefaultDomain_0&hash=item2c7e2353cc

 

[Lebowski]

well I know they look big in the picture but the copper plates are 6 x 2 x 0.6 cm .... no need for a blowtorch

 

[speedmd]

Yes, understood, but you are getting into stained glass type materials, and the last thing you want is cold solder joints/ trapped flux and the like. Heating should be as fast as possible, 10 - 20 seconds max.

 

[zombiess]

I have a 500w american beauty iron I have yet to need. Tip is 7/8" and the thing weighs almost 5lbs > 2kg. It will straight up own some copper buss bar. Almost all my heavy duty work is done with just a 125w iron, but its a high quality american beauty and I regulate the tip temp with a router speed controller. Not much it can't do so far. Lebowskis plates can probably be done with a quality hakko 70w station and patience.

Unlike aluminum, copper holds in heat better, but copper transfer the heat into itself faster.

 

[CNCAddict]

I find it's much easier to preheat the entire assembly on a hot plate, oven, or hot air station to just below a temperature that will start damaging components. Soldering anything massive is far easier that way.

 

[speedmd]

Thermal mass is more important than wattage. Even 70 watts can be enough if the tip/ body sink is enough. Agree, if warm and no breezes it is much more easy to get a good flow and bond.
Looks like a good econo iron for the job.

 

[BigOutrunner]

Yup this is what I was talking about with the big stator I have. Maybe splitting it into 12 or 15 different 3 phase motors wound on one stator. Have each one on a fuse... If its one solid stator it would be ok to have dummy sections with a master section where only one section does the current measurement and coil position detection while the rest are a perfect copy of that.

Assuming that I have a very large stator that has 16 poles by 18 teeth, which would have ordinarily be wound with copper in this sequence - AaABbBCcCAaABbBCcC , how would I wire my stator instead ( as suggested in the above quote) to take advantage of Lebowski's low inductance output stage?

Thanks in advance!

BigOutrunner

 

[BigOutrunner]

You could match top fuel power densities with 27 of this module properly cooled (LN2? Dry ice?) forming a 9 lebowski stand alone units and a motor with some multiple of 9 teeth and each set kept separate so the motor ends up with 27 phase leads in 9 sets of electrically separated motors to power with the 9 stand alone, phase current controling and BEMF sensorless 6fets. Maybe throttle and enable signal to each unit is done over fiber. Intrensicly balanced current sharing possible with out the need for symetry in layout/packaging that makes the alternative approach too impractical to manufacturer. That type of array seems likely to become a high power EVs drive geometry to enable intrinsically safer lower voltage and higher current EV drives. It's going to be more efficient, cheaper, higher reliability with comparatively safe fails while-running situations (can limp on remaining non-failed functioning stages).

This thread seems to have died despite its revolutionary potential as Luke pointed out above. Is Hotrod's / Njays suggestion about the caps significantly better or more correct leading to less interest in this? No responses to my previous query too.

 

[h0tr0d]

This thread seems to have died despite its revolutionary potential as Luke pointed out above. Is Hotrod's / Njays suggestion about the caps significantly better or more correct leading to less interest in this? No responses to my previous query too.

Good question.
Perhaps Lebo can answer that with an oscilloscope... :wink:

 

[Lebowski]

Well, as far as I am concerned this is not a discussion thread, more something that belongs in a wiki or reference section on how an output stage should be build.

Regarding Luke's suggestions, I wish I had the funds and time to try them out, but I don't so no reason for me to follow up there. A few thread above
it shows the output stage in my recumbent, which holds up very nicely at 100V and 32A phase (amplitude). I don't have a motor/vehicle combo that asks
for more power...

Adding all the caps on top as Hotrod suggested, I don't have the room for that in the controller box.

Last, for the output stage it doesn't matter how the motor is wound...

 

[BigOutrunner]

Well, as far as I am concerned this is not a discussion thread, more something that belongs in a wiki or reference section on how an output stage should be build.

Regarding Luke's suggestions, I wish I had the funds and time to try them out, but I don't so no reason for me to follow up there. A few thread above
it shows the output stage in my recumbent, which holds up very nicely at 100V and 32A phase (amplitude). I don't have a motor/vehicle combo that asks
for more power...

Adding all the caps on top as Hotrod suggested, I don't have the room for that in the controller box.

Last, for the output stage it doesn't matter how the motor is wound...

No offense intended All, because I sincerely do believe as Luke does that Lebowski's low inductance powerstage is a huge breakthrough and would like to find out from any capable ES experts with time on their hands how much they would charge to build it according to Lebowski's specs. PM me please if interested.

My stator is nearly 17 inches in diameter and about 3 inches thick. It is modular. Also experimental.

Luke has written very eloquently why large brushed AC motors and controllers rule today. Perhaps Lebowski's controller and output stage can change all that - powerful non lethal voltage brushless DC for any sized vehicle or device.

Now isn't that worth pursuing earnestly? And I'm not joking - 'for all mankind'?

 

[Arlo1]

I have had plans for something along these lines for years and in have posts explain how I will do it but I need to get finished my power stage first then I will parallel them up. Most likely it will be 4 FETs in parallel and then multiple power stages parallel to either 3 6 9 or any multiple of 3 phase wires. I will do this to get the desired inductance and rpm per volt.!

 

[BigOutrunner]

I have had plans for something along these lines for years and in have posts explain how I will do it but I need to get finished my power stage first then I will parallel them up. Most likely it will be 4 FETs in parallel and then multiple power stages parallel to either 3 6 9 or any multiple of 3 phase wires. I will do this to get the desired inductance and rpm per volt.!

Arlo, let me PM you my stator images. Thanks!