Search found 2727 matches

by weber
Mon, 18 May 2009, 05:04
Forum: Technical and conversion discussion
Topic: Getting Started
Replies: 36
Views: 4873

Getting Started

Wow, that is some very fast replies! I hope you guys have lives outside this forum http://forums.aeva.asn.au/smileys/smiley2.gif . Sure. I work on the EV too, not just talk about it. http://forums.aeva.asn.au/smileys/smiley2.gif But if you mean a life outside coulomb's and my EV project, I'd have t...
by weber
Mon, 18 May 2009, 03:48
Forum: Technical and conversion discussion
Topic: Getting Started
Replies: 36
Views: 4873

Getting Started

Hi Mr Mik, I think if you told most people that you were working on an EV that would only have a 25 km range, they would assume you were joking. Holding 80 km/h on a 10% incline is a far more difficult ask than maintaining 110 km/h on the flat. About 45 kW versus 22 kW, assuming a Gross Vehicle Mass...
by weber
Mon, 18 May 2009, 01:44
Forum: Members Machines
Topic: Hemonster's ACIM conversion
Replies: 189
Views: 33805

Hemonster's ACIM conversion

I'm an embedded software engineer myself and this sounds complicated Weber, ... perhaps you have enough experience down the power side of things to do this, but I'm more comfortable just buying something that will work. Yes. It is complicated and despite the fact that coulomb and I have both spent ...
by weber
Sun, 17 May 2009, 18:03
Forum: The Lounge
Topic: Perpetual motion found
Replies: 0
Views: 775

Perpetual motion found

An animation of an old favourite. The cat/toast motor.
http://www.youtube.com/watch?v=wvRzWYCZ2e0
by weber
Sun, 17 May 2009, 17:26
Forum: Members Machines
Topic: Hemonster's ACIM conversion
Replies: 189
Views: 33805

Hemonster's ACIM conversion

Talking about charger isolation ... When using an industrial VF drive -- capable of regenerative charging -- it makes no sense to me to use a separate charger at all. Particularly when you pay so much for the VF drive compared to DC drives (controllers). This means non-isolated charging and so prote...
by weber
Fri, 15 May 2009, 19:44
Forum: Batteries, charging, management and monitoring
Topic: Home grown BMS ideas !
Replies: 781
Views: 129535

Home grown BMS ideas !

Firstly, http://forums.aeva.asn.au/smileys/smiley1.gif if my 125A fuse (Rodeo) does not blow in 1 second with the TS40 peak current flowing through it then I'll buy a lottery ticket ! I expect it will. Who said it wouldn't? By "peak current" I assume you mean short circuit current, not the 10C puls...
by weber
Fri, 15 May 2009, 17:24
Forum: Batteries, charging, management and monitoring
Topic: Home grown BMS ideas !
Replies: 781
Views: 129535

Home grown BMS ideas !

Sorry acmotor, but I was with Johny in wondering if you meant 16 mm^2 or perhaps 6 B&S(AWG) which is 13.3 mm^2. I agree that voltage drop isn't an issue with even the longest runs in an EV when you're dealing with 600 V. But I can't agree with your continuous current carrying capacities (CCC). In AS...
by weber
Thu, 14 May 2009, 15:01
Forum: Technical and conversion discussion
Topic: reverse cycle air conditioning
Replies: 44
Views: 11564

reverse cycle air conditioning

I doubt water would work for the purpose. It is not compressible. The hydrohalocarbons used in conventional systems are no more compressible. It's not the liquid that gets compressed. Another issue is that reverse cycle air conditioners seem to need a safety break when switching from one direction ...
by weber
Tue, 12 May 2009, 17:38
Forum: Members Machines
Topic: Hemonster's ACIM conversion
Replies: 189
Views: 33805

Hemonster's ACIM conversion

So my dilemma is still, should I go with PbA or pay the HUGE premium for LiFePO4 ... thinking, thinking ... thinking. Thoughts anyone? IMHO, you should not pay the huge premium for LiFePO4. This has more to do with your personal experience than any technical aspect of the conversion. You are clearl...
by weber
Sun, 10 May 2009, 04:10
Forum: Members Machines
Topic: Weber and Coulomb's MX-5
Replies: 1698
Views: 399518

Weber and Coulomb's MX-5

But perhaps the temp coeff of float voltage is not related to the temp coeff of internal or "rested no-load" voltage. This Google Book shows an extremely low coefficient of internal voltage for lead acid too.
by weber
Sun, 10 May 2009, 03:57
Forum: Members Machines
Topic: Weber and Coulomb's MX-5
Replies: 1698
Views: 399518

Weber and Coulomb's MX-5

Why do you think the internal voltage is affected by temperature? I haven't witnessed this on any battery (though to tell the truth, i havent looked for it either). Lead acid battery chargers sometimes have temperature sensors and they reduce the float voltage by about 30 mV per cell per degree Cel...
by weber
Fri, 08 May 2009, 07:30
Forum: Batteries, charging, management and monitoring
Topic: Sky Energy LiFePO4 Bulk Buy this Week
Replies: 48
Views: 11764

Sky Energy LiFePO4 Bulk Buy this Week

Apparently some Sky Energy factory photos here http://www.evdl.org/archive/index.html#nabble-td23251023 Also some discharge curves that look mighty strange when they go below about 2.3 V. I don't think I'd be taking them down there, and if this is how they get their higher capacity figures I think i...
by weber
Fri, 08 May 2009, 06:49
Forum: Batteries, charging, management and monitoring
Topic: Sky Energy LiFePO4 Bulk Buy this Week
Replies: 48
Views: 11764

Sky Energy LiFePO4 Bulk Buy this Week

Sky Energy has discontinued the "TK" cells that they were making for Thundersky. As of this month they are now making the SE cells that have a slightly better discharge rating of 4C vs the TS cells at 3C and 12C pulse vs the TS cells at 10C Dave, I note that the SE cells say charge 3.6 V and discha...
by weber
Fri, 08 May 2009, 05:26
Forum: Electric motors and controllers
Topic: Model Aircraft Motor idea
Replies: 17
Views: 4093

Model Aircraft Motor idea

OK. Didn't get it quite right. Individual prop blades mount to the back of the can, while the centre fairing mounts to the front. But I got it right that the shaft is stationary and mounted by the disk at the back that the wires come out one side of, while the can rotates. Here's a photo. http://www...
by weber
Fri, 08 May 2009, 04:40
Forum: Electric motors and controllers
Topic: Model Aircraft Motor idea
Replies: 17
Views: 4093

Model Aircraft Motor idea

... makes me wonder how they get so much power into such a little package OR what corners they had to cut and how long it might last... How are you supposed to bolt it down? 50Nm is a fair amount of torque and I'm not seeing any really solid mountings on the motor? The mounting is a disk at the bac...
by weber
Thu, 07 May 2009, 14:25
Forum: Batteries, charging, management and monitoring
Topic: Battery paralleling circuit
Replies: 24
Views: 4251

Battery paralleling circuit

However the problem as I see it is that when you get the warning, you don't know if it was one short or two shorts - ie. do you stay in the car and drive home and put "check electrics" on your todo list, or get to the kerb ASAP NOW! stop the car and break the contactors and call the tow truck? Neit...
by weber
Wed, 06 May 2009, 20:16
Forum: Technical and conversion discussion
Topic: Coupler Fabricators in Brisbane
Replies: 11
Views: 2795

Coupler Fabricators in Brisbane

Do you have details for a engineering signatory in Brisbane ... and should we be contacting them during construction or after we have something to show ? Definitely need to talk to them before construction about what they require. No use welding up a bunch of battery boxes or racks and then being t...
by weber
Wed, 06 May 2009, 01:17
Forum: Members Machines
Topic: Weber and Coulomb's MX-5
Replies: 1698
Views: 399518

Weber and Coulomb's MX-5

Yeah, thanks Johny. You (and James Carlon of ABB) made my day. Everyone should feel free to interrupt this thread with praise. http://forums.aeva.asn.au/smileys/smiley4.gif Or criticism. I can imagine that a lower internal resistance pack would average say 10°C lower in operation, and hence last abo...
by weber
Wed, 06 May 2009, 00:51
Forum: Technical and conversion discussion
Topic: Coupler Fabricators in Brisbane
Replies: 11
Views: 2795

Coupler Fabricators in Brisbane

For adapter and coupler machining, our engineering signatory, David Blyth, suggested:

Engine Engineering
45 Dunn Street
Rocklea QLD 4106
(07) 3277 8944

No website or email.

We haven't contacted them yet. Good luck. Let us know how you go.
by weber
Tue, 05 May 2009, 18:38
Forum: Electric motors and controllers
Topic: AC motors, multipoles, torque
Replies: 549
Views: 80348

AC motors, multipoles, torque

These Reliance RPM motors look interesting. http://www.baldor.com.au/product_view.php?PROD_ID=140 A NEMA (USA) 210 frame seems to be equivalent to an IEC 132 frame and in that frame they appear to have 45 kW @ 50 Hz, 200% torque overload for 1 minute, 8000 rpm max, US$5000. Don't see any weights but...
by weber
Mon, 04 May 2009, 02:47
Forum: The Lounge
Topic: Global Warming / Cooling / Lunacy is / isn't bunk
Replies: 21
Views: 4923

Global Warming / Cooling / Lunacy is / isn't bunk

Gary the Global Warming Goat knows just what to do with those dinosaur burners. Warning: Very little of the language in this video will not offend. Image
http://www.youtube.com/watch?v=x1ugtJEQ ... re=channel
by weber
Sun, 03 May 2009, 17:47
Forum: Batteries, charging, management and monitoring
Topic: Silly charging idea no1!
Replies: 11
Views: 1997

Silly charging idea no1!

Could I have some comments on the idiocy of the above idea please? Hi Paul9, You only get 4 out of 10 for idiocy on that one I'm afraid. http://forums.aeva.asn.au/smileys/smiley1.gif It probably falls in to the "It could be made to work but it's more trouble than its worth" category. But yeah. No p...
by weber
Sun, 03 May 2009, 17:38
Forum: Batteries, charging, management and monitoring
Topic: Silly charging idea no1!
Replies: 11
Views: 1997

Silly charging idea no1!

Induction can't be overdriven enough, and there haven't been any permanent magnet AC motors or controllers good enough yet. Series wound DC motors give the widest usable power band, which helps a lot when you're using a single speed drive to the wheels over a very wide speed range! Hmm. The Tesla R...
by weber
Sun, 03 May 2009, 17:19
Forum: Batteries, charging, management and monitoring
Topic: Silly charging idea no1!
Replies: 11
Views: 1997

Silly charging idea no1!

People modify 12v alternators to get 110+ volts, usually only needing higher current diodes and upping the field coil drive voltage. That doesn't sound right to me. You won't get much more current than standard out of it, or into its field coil (rotor) without frying the windings, so no need for hi...
by weber
Sun, 03 May 2009, 16:21
Forum: Batteries, charging, management and monitoring
Topic: Silly charging idea no1!
Replies: 11
Views: 1997

Silly charging idea no1!

Wayne obviously has far too much time on his hands. All that effort for something the motor could do by itself. If it wasn't a series-excited DC motor. Are there any induction or other brushless-motor dragsters yet. I watched a few electric dragsters on youtube the other day, e.g. White Zombie and O...