Search found 683 matches

by Tritium_James
Thu, 07 Apr 2011, 22:19
Forum: EV Motoring
Topic: Nissan Leaf Range
Replies: 14
Views: 3481

Nissan Leaf Range

The UDDS is designed to test tailpipe emissions, so a dyno is perfectly OK. When using it for range estimates in an EV, if they are doing it properly the UDDS velocity profile will be fed into their vehicle modelling software (which will have been calibrated against the real-world vehicle), and give...
by Tritium_James
Thu, 07 Apr 2011, 15:29
Forum: Members Machines
Topic: Weber and Coulomb's MX-5
Replies: 1698
Views: 402611

Weber and Coulomb's MX-5

Although using the motor controller waste heat for cooling is a pretty elegant concept (and we've been considering it in the past!) it's not really something we're interested in doing. Basically the hotter that waterblock is, the shorter period of time you can put out high currents for before it has...
by Tritium_James
Mon, 04 Apr 2011, 15:33
Forum: Technical and conversion discussion
Topic: Mini or Moke conversion
Replies: 25
Views: 8311

Mini or Moke conversion

There's a Mini conversion in Melbourne that's been around for 5-6 years. Custom BLDC motor & controller through a chain drive, and I think it was PbA batteries.
by Tritium_James
Sat, 02 Apr 2011, 17:42
Forum: Technical and conversion discussion
Topic: synthetic transmission oil-educate me!
Replies: 22
Views: 6059

synthetic transmission oil-educate me!

Peter, you probably should be using a *much* thinner oil than what is recommended in the manual. This is because when it was petrol powered, the engine heated up the gearbox significantly, making the oil less viscous. So the recommended viscosity would be assuming that the gearbox was operating at s...
by Tritium_James
Wed, 30 Mar 2011, 14:41
Forum: Batteries, charging, management and monitoring
Topic: how would you do this
Replies: 16
Views: 2661

how would you do this

Why not just put in a 24V alternator?
by Tritium_James
Sun, 27 Mar 2011, 21:42
Forum: Technical and conversion discussion
Topic: Neutral wobble theory
Replies: 6
Views: 2939

Neutral wobble theory

Coulomb, I think you'll find the previous poster was a spammer (antiscab nicely removed the spam links) who made up a plausible-sounding post to keep his links visible for longer. The keyword you need to search for for more info on your neutral wobble topic is "space-vector modulation". The wikipedi...
by Tritium_James
Tue, 15 Mar 2011, 15:32
Forum: Electric motors and controllers
Topic: In wheel Motor by Protean
Replies: 17
Views: 7262

In wheel Motor by Protean

Probably because in-wheel motors, while seemingly cool, and actually pretty lousy for driving cars. Motor size, weight, and cost are basically proportional to torque. Since it's in a the hub, speed is slow, only up to around 1000rpm or so. The much better option is to gear it down say 4:1 (can do th...
by Tritium_James
Wed, 09 Mar 2011, 21:31
Forum: General EV Discussion
Topic: Fuji variable speed drive any good?
Replies: 26
Views: 4995

Fuji variable speed drive any good?

Richo, that motor looks exactly the same as what AC Propulsion sell with their system - it looks identical to what we had in the Porsche. Might give you another avenue of enquiry...
by Tritium_James
Tue, 08 Mar 2011, 20:23
Forum: EV Racing
Topic: Burnouts in an electric drag car
Replies: 25
Views: 5756

Burnouts in an electric drag car

You run either an AC motor, or a DC motor with a speed sensor of some sort and a controller that's smart enough to use it.
by Tritium_James
Tue, 01 Mar 2011, 14:40
Forum: Members Machines
Topic: Weber and Coulomb's MX-5
Replies: 1698
Views: 402611

Weber and Coulomb's MX-5

Nice, guys! Don't forget when you reassemble the pack with the BMUs in there that you should wire-brush the cell terminals and busbars and apply a smear of anti-oxidation compound in there before it goes back together. Matt, what drills do the electric torque limit? I'd really like one, but all the ...
by Tritium_James
Thu, 17 Feb 2011, 17:36
Forum: EV Motoring
Topic: VW Hybrid Concept Car - Not a drag!
Replies: 12
Views: 3071

VW Hybrid Concept Car - Not a drag!

And the small gas turbine isn't very efficient, so you have loads of waste heat to boil the plastic with! It's all good :)
by Tritium_James
Thu, 10 Feb 2011, 22:44
Forum: Technical and conversion discussion
Topic: Clueless take 2
Replies: 70
Views: 13529

Clueless take 2

Those power limits for regen are only when the motor is at max speed. So if you're only at (say) 20% of full speed, and your pack can accept a 100A charge rate, then your motor and controller could be doing up to 100A/0.2 = 500A regen current without stressing the batteries. As you go faster, the ba...
by Tritium_James
Thu, 10 Feb 2011, 18:00
Forum: Members Machines
Topic: Weber and Coulomb's MX-5
Replies: 1698
Views: 402611

Weber and Coulomb's MX-5

Re: badness, cell volts, charge algorithms, etc, why not just run a PID control loop that controls charger current based on highest cell voltage. Then current then backs off automatically, there's no real concept of charging vs balancing, etc. It all just happens nicely by itself. If you change the ...
by Tritium_James
Fri, 04 Feb 2011, 19:25
Forum: Batteries, charging, management and monitoring
Topic: Battery charging and BMS function
Replies: 17
Views: 2719

Battery charging and BMS function

evric, nice explanation. Just one small nitpick, you said "When current drops to below 2 amps say 1.5amps (due to the charger throt'ling back as is reaches the CV point.) then 1.5 amps will flow thru the BMS shunt and nothing into the cell." What will actually happen in this situation is 2A will sti...
by Tritium_James
Sat, 29 Jan 2011, 00:01
Forum: Batteries, charging, management and monitoring
Topic: LiFeP04 batteries, series only or parallel series?
Replies: 10
Views: 1671

LiFeP04 batteries, series only or parallel series?

Yes, but don't get too complacent just because it's 48V. Low voltage DC with big potential short circuit amps behind it can also do untold damage if it all went wrong...
by Tritium_James
Tue, 18 Jan 2011, 00:07
Forum: Technical and conversion discussion
Topic: TIM600 Explosion
Replies: 80
Views: 19404

TIM600 Explosion

Short the motor phases together, then try and turn it by hand. PM motor = basically impossible to turn; induction motor = same as with phases not shorted.
by Tritium_James
Sun, 16 Jan 2011, 15:56
Forum: The Lounge
Topic: Tritium factory and the floods of 1974 and 2011
Replies: 11
Views: 2993

Tritium factory and the floods of 1974 and 2011

Here's us:
http://www.nearmap.com/?ll=-27.527901,1 ... d=20110113

This looks to have been taken after the water was back down by about 1m, judging by where the mud is on a few features, eg the road past the golf course is open, but it was definitely under at the peak.
by Tritium_James
Fri, 14 Jan 2011, 19:58
Forum: Technical and conversion discussion
Topic: How controllers work
Replies: 10
Views: 1788

How controllers work

Coulomb, fig8 is actually correct, from the phase winding's point of view. Each end can be tied to either V+ or V-, so you can have the full pack voltage across it, nothing, or the inverted pack voltage across it.
by Tritium_James
Fri, 14 Jan 2011, 19:53
Forum: The Lounge
Topic: Tritium factory and the floods of 1974 and 2011
Replies: 11
Views: 2993

Tritium factory and the floods of 1974 and 2011

Thanks guys. We're OK, the water didn't come up this far, it was around the corner on Tennyson Memorial Ave though. Still in the yellow section and almost at the green, on Coulombs first map image - probably another 1 - 1.5m before it was into our carpark and lower floor. We moved everything upstair...
by Tritium_James
Sat, 08 Jan 2011, 21:21
Forum: Technical and conversion discussion
Topic: Poor Man's Regen. air con.
Replies: 20
Views: 3351

Poor Man's Regen. air con.

You'd be much better off water cooling the motor, and using that for cabin heat. Motors are much less efficient than controllers...
by Tritium_James
Mon, 03 Jan 2011, 19:29
Forum: EV Motoring
Topic: UltraCommuter
Replies: 13
Views: 4317

UltraCommuter

Pics:

Image

Image

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by Tritium_James
Mon, 03 Jan 2011, 19:23
Forum: EV Motoring
Topic: UltraCommuter
Replies: 13
Views: 4317

UltraCommuter

I'm not entirely sure on the IP, I think Ultramotive might have some kind of stake but I'm not certain. The reason it's stalled is that going from a hand-built one-off car with a fairly bodgy fiberglass shell (no stiffening in doors, etc) to an actual production vehicle, produceable in the 1000's, w...
by Tritium_James
Mon, 03 Jan 2011, 18:57
Forum: General EV Discussion
Topic: to coast or not to coast
Replies: 4
Views: 947

to coast or not to coast

Constant speed is best. Surge driving is more efficient with an ICE motor, because they run at max efficiency with a wide-open throttle. So a short pulse of 100%, followed by as long as possible at idle (or switched off, ideally) is best for an ICE. Since this is completely meaningless for an EV, yo...
by Tritium_James
Sun, 02 Jan 2011, 20:00
Forum: EV Motoring
Topic: UltraCommuter
Replies: 13
Views: 4317

UltraCommuter

They built just one. There's also a Lamborghini green foam/fiberglass dummy that the RACQ used for their "100 years of motoring" exhibit, sitting in our front carpark. Ultramotive used to have it up on the wall of their shed once RACQ finished with it. It's free to a good home if anyone wants to com...
by Tritium_James
Sun, 02 Jan 2011, 19:35
Forum: Electric motors and controllers
Topic: AC drive programming and pedal mapping
Replies: 67
Views: 14542

AC drive programming and pedal mapping

'B' is used in plenty of mainstream EVs (Leaf, iMiev, etc) to indicate the drive mode that has increased regen (compared to 'D' mode). Weber, the Wavesculptor uses the absolute value of the incoming command torque, so no need to reflect your torque commands in the Y axis. You're still only going to ...