Search found 90 matches

by Hemonster
Thu, 25 Feb 2010, 00:05
Forum: Electric motors and controllers
Topic: Incrimental encoders for closed loop $$$
Replies: 47
Views: 5765

Incrimental encoders for closed loop $$$

800ppr, 2000rpm, 1 pulse every 37.5uSec or 533 pulses every 50Hz cycle....man that has got to be enough! Well I thought the high PPR was for low RPM (from starting up to xxx RPM), not much doing with the high RPM. I'm sure they can skip every few pulses at 2000rpm and still do a great job, but you ...
by Hemonster
Sun, 21 Feb 2010, 17:12
Forum: Electric motors and controllers
Topic: Changing an induction motor voltage
Replies: 433
Views: 113815

Changing an induction motor voltage

Hi Mal, Interested in your update, thanks for posting. I selected the encoder based on the Danfoss input max frequency with a push pull driver is 65khz. This equates to 886 pulses per revolution at 4400rpm. Is this really enough pulses per revolution? The recommended for the controller I have (a PDL...
by Hemonster
Wed, 04 Nov 2009, 11:44
Forum: Members Machines
Topic: Red Suzi
Replies: 217
Views: 53907

Red Suzi

Quite right, I do need a lighter motor anyway. Sounds like it might not be that easy - ie. the flux path may be different??

by Hemonster
Wed, 04 Nov 2009, 10:52
Forum: Members Machines
Topic: Red Suzi
Replies: 217
Views: 53907

Red Suzi

Why do a 2 pole ? the rev range will not suit direct drive and if you go to 1/4V then the 12,000RPM alone will be a challenge ! But yes, 2 pole can be done the same I'd guess. Only because I've got one http://forums.aeva.asn.au/smileys/smiley1.gif I meant really was it possible to change a 2 pole i...
by Hemonster
Wed, 04 Nov 2009, 01:00
Forum: Members Machines
Topic: Hemonster's ACIM conversion
Replies: 189
Views: 29625

Hemonster's ACIM conversion

Not much happenning in my land of AC, am expecting my 2nd baby at the end of this month ... serious time gobbler that one http://forums.aeva.asn.au/smileys/smiley1.gif I've also been rethinking how complexity and costs increase dramatically as the weight goes up. Also in particular the drop in the v...
by Hemonster
Wed, 04 Nov 2009, 00:24
Forum: Members Machines
Topic: Red Suzi
Replies: 217
Views: 53907

Red Suzi

Excellent work ACMotor, an inspiration to all of us. How much was the rewind mind you? and can a rewind be done in the same way for a 2 pole original motor as for a 4 pole?
by Hemonster
Sun, 23 Aug 2009, 17:43
Forum: Members Machines
Topic: Hemonster's ACIM conversion
Replies: 189
Views: 29625

Hemonster's ACIM conversion

If you go with the 15kW 2 pole, keep the gearbox and the clutch. It will make changing faster and less drama. I am guessing AC, with its flat torque, on a gearbox is not the same as series DC. You are more likely to use first gear at takeoff than stay in one gear all the time as many DCs do. IMHO W...
by Hemonster
Wed, 19 Aug 2009, 14:53
Forum: Batteries, charging, management and monitoring
Topic: Pack charging with an AC controller
Replies: 65
Views: 9870

Pack charging with an AC controller

Are you using the software in the inverter to drive the IGBT? Yes, that's the plan. If separate, will you be adding hardware to sense battery current? battery voltage? The controller has all that already. ... We paid a fair bit extra for our controller to have a secondary micro, so the main micro c...
by Hemonster
Wed, 19 Aug 2009, 12:51
Forum: Batteries, charging, management and monitoring
Topic: Pack charging with an AC controller
Replies: 65
Views: 9870

Pack charging with an AC controller

Are you using the software in the inverter to drive the IGBT? or separate boost controller? If separate, will you be adding hardware to sense battery current? battery voltage? How big is the inductor likely to be (what sort of power?) and at what switching freq. are you likely to run this at?
by Hemonster
Tue, 18 Aug 2009, 13:49
Forum: Members Machines
Topic: Hemonster's ACIM conversion
Replies: 189
Views: 29625

Hemonster's ACIM conversion

Say however that you wanted to implement a rotary converter, does that mean turning the 3P AC motor with another 1P motor and asking the inverter to effectively regen the energy back into the pack? I would think that means you need to be able to disengage the motor from the drive shaft which means r...
by Hemonster
Tue, 18 Aug 2009, 02:16
Forum: Members Machines
Topic: Hemonster's ACIM conversion
Replies: 189
Views: 29625

Hemonster's ACIM conversion

No problem Sparky Bro. I can't really speak for 3 phase rotary converters because I haven't really dug deep into how this could be implemented. Can you give me your ideas on how you will implement it, and what sort of issues are you likely to face ... some of the aspects I don't find too alluring is...
by Hemonster
Thu, 06 Aug 2009, 14:15
Forum: Members Machines
Topic: Hemonster's ACIM conversion
Replies: 189
Views: 29625

Hemonster's ACIM conversion

Hi Johnny, Yes, that's a bit high for me too (and I imagine for most) ... that's why I've asked them for a 3-4A charger instead (preferably 3). Also the 8A chargers are 3.5kg and 263*120*157mm ... a little large to have 14x of these around. I also like the idea of equalisation circuits on the BMS ra...
by Hemonster
Thu, 06 Aug 2009, 02:38
Forum: Members Machines
Topic: Hemonster's ACIM conversion
Replies: 189
Views: 29625

Hemonster's ACIM conversion

Hi all, Sorry for the long leave of absense - things have been pretty busy around here. Anyway I have managed to do another discharge test on the Headway cell. http://forums.aeva.asn.au/uploads/624/Discharge_2009-08-05.GIF It is interesting to note that even at the lower continuous discharge rate of...
by Hemonster
Tue, 21 Jul 2009, 14:49
Forum: Technical and conversion discussion
Topic: Soapbox on regenerative braking
Replies: 278
Views: 30645

Soapbox on regenerative braking

Turn on the heater before starting your trip .... that should get the batteries down a bit http://forums.aeva.asn.au/smileys/smiley1.gif I found with my headway cell testing that at 2C charge rate on a medium flat pack, the voltage on the cell very quickly rises to beyond 3.65V - is it then common t...
by Hemonster
Sun, 19 Jul 2009, 21:11
Forum: Members Machines
Topic: Hemonster's ACIM conversion
Replies: 189
Views: 29625

Hemonster's ACIM conversion

Hey Mesuge, Thanks for posting that article from Endless Sphere, the foam mounting looks quite interesting - I might have to try it out first for my ebike with these test headways I've got here. Interesting to know that the cases they sell normally might have issues with vibration, certainly hadn't ...
by Hemonster
Tue, 14 Jul 2009, 23:39
Forum: Electric motors and controllers
Topic: Changing an induction motor voltage
Replies: 433
Views: 113815

Changing an induction motor voltage

I was following this thread for technical interest, now its just plain entertaining ... Image

Thanks guys ... keep it up ...
by Hemonster
Mon, 13 Jul 2009, 01:15
Forum: Electric motors and controllers
Topic: Changing an induction motor voltage
Replies: 433
Views: 113815

Changing an induction motor voltage

(I did ask for a shaft torque meter in an earlier post. I checked the letter box and none arrived ! http://forums.aeva.asn.au/smileys/smiley36.gif ) Hi Acmotor, Can't you figure out the torque of the driving motor by working out the slip bettween the electrical and mechanical rotations of the drivi...
by Hemonster
Mon, 29 Jun 2009, 15:53
Forum: Members Machines
Topic: Hemonster's ACIM conversion
Replies: 189
Views: 29625

Hemonster's ACIM conversion

The standard Headway forwarder was $500USD !!! ... by sea! just be weary of that. Could this US$500 be the AU$700 that Matt spoke of? $700USD was quoted to me for air freight. That's probably what Matt is referring to. I had to ask for sea freight, and then I had to ask them specifically to investi...
by Hemonster
Mon, 29 Jun 2009, 14:17
Forum: Members Machines
Topic: Hemonster's ACIM conversion
Replies: 189
Views: 29625

Hemonster's ACIM conversion

I was going on Zeva's price here: http://www.zeva.com.au/tech/headway/ That might have been a theoretical or very old price, I don't know. Of course, the shipping, GST, import duty etc etc would apply equally to both. Though I didn't realise that there was a substantial fixed port charge that would...
by Hemonster
Mon, 29 Jun 2009, 02:54
Forum: Members Machines
Topic: Hemonster's ACIM conversion
Replies: 189
Views: 29625

Hemonster's ACIM conversion

Just another update. My friend did bring over his PSU and we tried to do a 20A 2C charge and the battery didn't seem to mind. There was only a marginal temperature rise no higher than 35 deg. It was quite difficult to maintain that charge current without hitting the 3.65V voltage limit however ... d...
by Hemonster
Sun, 28 Jun 2009, 17:34
Forum: Members Machines
Topic: Hemonster's ACIM conversion
Replies: 189
Views: 29625

Hemonster's ACIM conversion

Great work hemonster. From the raw data, do you have an initial idea of the internal resistance for the cell? Assuming 3.2V once the surface charge has gone, and 2.65V under 77A load - I make it 7.1 mOhm. That means 2 in parallel (for 20Ah pack) would be 3.5 mOhm per twin-cell. I guess I'm asking w...
by Hemonster
Sun, 28 Jun 2009, 17:30
Forum: Members Machines
Topic: Hemonster's ACIM conversion
Replies: 189
Views: 29625

Hemonster's ACIM conversion

There are more detailed pictures of my setup in the previous page:
viewtopic.php?start=4&t=1113

by Hemonster
Sun, 28 Jun 2009, 16:18
Forum: Members Machines
Topic: Hemonster's ACIM conversion
Replies: 189
Views: 29625

Hemonster's ACIM conversion

Thanks Coulomb, I had read your battery tests too and got some inspirations there http://forums.aeva.asn.au/smileys/smiley1.gif Might I suggest the simple idea of a bigger jar for the load? More water means it takes longer to heat up. I'm not too worried about the water, after all it can't exceed 10...
by Hemonster
Sun, 28 Jun 2009, 03:47
Forum: Members Machines
Topic: Hemonster's ACIM conversion
Replies: 189
Views: 29625

Hemonster's ACIM conversion

Here is the chart: http://forums.aeva.asn.au/uploads/624/2009-06-27_Battery_test_1_result_chart.jpg Battery voltage is on the right y-axis, both power and amps are on the left y-axis. Note that I've modified the data to take out all the periods where the load was not turned on. The spikes you see ar...
by Hemonster
Sun, 28 Jun 2009, 03:40
Forum: Members Machines
Topic: Hemonster's ACIM conversion
Replies: 189
Views: 29625

Hemonster's ACIM conversion

The recovery is a bit slow but at least it is steady http://forums.aeva.asn.au/smileys/smiley1.gif However I have since been able to do some testing. Here is a picture of my latest setup: http://forums.aeva.asn.au/uploads/624/2009-06-27_Battery_tester_setup.JPG I borrowed the clamp meter from a frie...