Search found 2714 matches

by weber
Thu, 09 Apr 2009, 15:15
Forum: Batteries, charging, management and monitoring
Topic: High voltage cabling
Replies: 26
Views: 3990

High voltage cabling

I'll second that. Zeva, those diagrams really are very beautiful as well as very logical and easy to follow. And most important of all, they are correct and safe (particularly when taken with the comments in the text). I'd also like to take this opportunity to thank you for your excellent MX-5 conve...
by weber
Tue, 07 Apr 2009, 19:52
Forum: Members Machines
Topic: Weber and Coulomb's MX-5
Replies: 1698
Views: 379253

Weber and Coulomb's MX-5

A clever suggestion for weighing a car, from my friend Mike Stasse: Paint the tyre with something so it leaves an imprint of its contact-area on something. Estimate that area, measure the tyre pressure, and use the following formula. mass(kg) = pressure(Pa) * area(m^2) / gravity(9.8 N/kg) Not sure h...
by weber
Tue, 07 Apr 2009, 19:37
Forum: Members Machines
Topic: Weber and Coulomb's MX-5
Replies: 1698
Views: 379253

Weber and Coulomb's MX-5

Are you suggesting that a newspaper hides the real story ! http://forums.aeva.asn.au/smileys/smiley36.gif Good one. Re tools.. No no, I thought I was saying that it is the user that makes it safe. That includes the user chosing the right tool or at least having the skill / judgement to manage the t...
by weber
Tue, 07 Apr 2009, 18:12
Forum: Members Machines
Topic: Weber and Coulomb's MX-5
Replies: 1698
Views: 379253

Weber and Coulomb's MX-5

ACmotor, there is a very substantial subframe bolted under those rails, hidden by the newspaper. You can see it in this picture. http://home.comcast.net/~aschwarz7/images/t_hole8.jpg      (Click to enlarge) So it may not be as bad as you thought in regard to suspension dynamics. But I still tend to ...
by weber
Tue, 07 Apr 2009, 17:01
Forum: Members Machines
Topic: Weber and Coulomb's MX-5
Replies: 1698
Views: 379253

Weber and Coulomb's MX-5

acmotor wrote:Nice red weber ! Image

If you mean the painted battery racks in the above images, those are not ours. We're not that far along yet. They belong to Andrew Schwarz's MX-5 in the US.
by weber
Tue, 07 Apr 2009, 16:25
Forum: Members Machines
Topic: Weber and Coulomb's MX-5
Replies: 1698
Views: 379253

Weber and Coulomb's MX-5

It turns out that "Dave" wasn't such a bad guy after all. He didn't cut off the spot-welded flages as I had thought, but bent them upward. And he at least partly replaced the cut-out cross-member with a piece of angle welded in further back. You can see these things in this photo. http://home.comcas...
by weber
Mon, 06 Apr 2009, 23:44
Forum: Members Machines
Topic: Weber and Coulomb's MX-5
Replies: 1698
Views: 379253

Weber and Coulomb's MX-5

I'm lost... you wouldn't ever use a drop saw to cut a piece out of the boot it is designed to be used on solid surface like the floor or a bench. Quite right. Coulomb read the safety brochure I posted on angle-grinders and saw that the overriding consideration is not to use them with cutting disks ...
by weber
Mon, 06 Apr 2009, 23:29
Forum: Members Machines
Topic: Weber and Coulomb's MX-5
Replies: 1698
Views: 379253

Weber and Coulomb's MX-5

Here we were, thinking the owner of that white MX-5 above was a bit naughty, cutting into a cross-member. Andrew Schwarz was doing the right thing, even leaving the spot-welding flanges beside the rails and cross members. Then he invited his mate "Dave" over to help, and Dave just cut them all away ...
by weber
Mon, 06 Apr 2009, 17:32
Forum: Members Machines
Topic: Weber and Coulomb's MX-5
Replies: 1698
Views: 379253

Weber and Coulomb's MX-5

Thanks Johny. It wasn't file space. But when I went to the control panel I found the upload there worked so I went back and edited the post and it worked there too. So you can see the ladder detail there now. Here's a good angle-grinder safety checklist from the WA government: http://www.safetyline....
by weber
Mon, 06 Apr 2009, 15:58
Forum: Members Machines
Topic: Weber and Coulomb's MX-5
Replies: 1698
Views: 379253

Weber and Coulomb's MX-5

The 4300 kg strap was only $60 from SuperCheap Auto. It's probably way overkill but it sure "feels" safer. I know logically that if you have a nylon webbing strap and a steel rope with the same strength, the nylon will elongate about 6 times more than the steel under the same strain, and that that's...
by weber
Sun, 05 Apr 2009, 17:33
Forum: Technical and conversion discussion
Topic: Energy Transfer Capacity Balancing
Replies: 9
Views: 1584

Energy Transfer Capacity Balancing

It at least means that when one cell fills up before the others they do not merely burn off the excess energy as heat but transfer it to the remaining cells. There are various ways to do this, e.g. flying capacitors, transformers, switching bypass circuits.
by weber
Sun, 05 Apr 2009, 16:56
Forum: Batteries, charging, management and monitoring
Topic: Battery Chargers
Replies: 9
Views: 3387

Battery Chargers

Stanbury Scarf & Lord is an Aussie/Kiwi company that make very reliable battery chargers. Originally for forklifts. http://www.stanburysl.com.au/?showPage=Product+Information I install solar power systems and I use only SS&L chargers in my off-grid systems, for backup charging from an ICE genset whe...
by weber
Sun, 05 Apr 2009, 04:15
Forum: Members Machines
Topic: Weber and Coulomb's MX-5
Replies: 1698
Views: 379253

Weber and Coulomb's MX-5

Rotisserie style is good :-) Using a ladder as a safety under a car is probably not up to your usual standards though. 1/2 a car : 500kg whereas a ladder normally says 120kg is too heavy. Ignoring that the car will be moving already when it crushes the ladder like a coke can... It would not be movi...
by weber
Sat, 04 Apr 2009, 14:29
Forum: Members Machines
Topic: Weber and Coulomb's MX-5
Replies: 1698
Views: 379253

Weber and Coulomb's MX-5

By the way guys, the 150% overload I was referring to was for the VF drive, i.e. the motor controller, not the motor. However the VF drive power ratings are given as mechanical power out of the motor, because induction motor efficiencies are well defined (and high). So you can see that with a 500% o...
by weber
Fri, 03 Apr 2009, 19:38
Forum: Batteries, charging, management and monitoring
Topic: Home grown BMS ideas !
Replies: 781
Views: 123867

Home grown BMS ideas !

An LMC555 works down to 1.5 V, so that's a likely contender. Yes! That's what's been missing from this thing. Everyone knows every DIY circuit must have at least one 555 timer in it, and preferably a 556 dual. And it must use those timers in the most obscure manner possible. http://forums.aeva.asn....
by weber
Fri, 03 Apr 2009, 16:30
Forum: Members Machines
Topic: Weber and Coulomb's MX-5
Replies: 1698
Views: 379253

Weber and Coulomb's MX-5

... are you still after the following spec. for your desired VFD (EValbum): "Control Techniques, Likely 75/90 kW SK5402" ? I've found some dealer's pricing on them, and it looks quite *attractive < £2,500 for a new drive in the area of 30-45kW nominal rating (RedSuzi&Mal comparison) Well found, Mes...
by weber
Fri, 03 Apr 2009, 04:38
Forum: Members Machines
Topic: Weber and Coulomb's MX-5
Replies: 1698
Views: 379253

Weber and Coulomb's MX-5

That's our friend Eddie with the camera and the bare feet. You'll note he was well back. http://forums.aeva.asn.au/smileys/smiley1.gif Although he had crawled under the vehicle earlier, to free the gearbox from something it was catching on. It really helped to have 4 competent people there when remo...
by weber
Wed, 01 Apr 2009, 22:30
Forum: Batteries, charging, management and monitoring
Topic: Home grown BMS ideas !
Replies: 781
Views: 123867

Home grown BMS ideas !

Here's another idea, in the spirit of brainstorming. Instead of analog current we use PWM current. We'd need optos going in the opposite direction (two optos per cell) to synchronise. But we'd still use only the single-wire loop. The LEDs of the input optos could be in parallel with the collector-em...
by weber
Wed, 01 Apr 2009, 20:43
Forum: Batteries, charging, management and monitoring
Topic: Home grown BMS ideas !
Replies: 781
Views: 123867

Home grown BMS ideas !

If you can collect more data and still keep it simple, low cost and reliable then got for it. http://forums.aeva.asn.au/smileys/smiley1.gif Your circuit is a masterpiece of minimalism. The best I can do to reduce it further is save maybe 2 resistors. One by taking the bypass and overvoltage sensing...
by weber
Wed, 01 Apr 2009, 20:16
Forum: Batteries, charging, management and monitoring
Topic: Home grown BMS ideas !
Replies: 781
Views: 123867

Home grown BMS ideas !

Ah'm back and ah'm bad(-er). http://forums.aeva.asn.au/smileys/smiley2.gif As a point of interest, are the FET output opto isolators any more linear? They would presumably also have less voltage drop (when conducting fully), important when a large number of optos will be in series. FET output is res...
by weber
Wed, 01 Apr 2009, 17:53
Forum: Batteries, charging, management and monitoring
Topic: More Li batteries
Replies: 84
Views: 11919

More Li batteries

Here's some data from Foxx Power. http://www.coloradoautoconnection.com/pdf/Foxx_intro.pdf On page 4 we see a photo and table of elements straight out of the ThunderSky manual, but the charts are out of the China HiPower blurb. A real hotch potch. I wouldn't trust Foxx Power as far as I could kick '...
by weber
Wed, 01 Apr 2009, 16:47
Forum: Batteries, charging, management and monitoring
Topic: More Li batteries
Replies: 84
Views: 11919

More Li batteries

The cells shown in this Porsche look exactly like China HiPower. They even have the same (bad rigid) connecting links. http://www.youtube.com/watch?v=msScGHvIuyM&feature=related But the blurb says they are from Foxx Power. http://www.foxxpower.com/Foxx%20Power%20Specs.pdf Foxx Power claim to have de...
by weber
Wed, 01 Apr 2009, 14:53
Forum: Batteries, charging, management and monitoring
Topic: More Li batteries
Replies: 84
Views: 11919

More Li batteries

When I use the EVAlbum search, on battery brand, I find one for China HiPower.
http://www.evalbum.com/2430

Summary:
11 A123
1 China HiPower
3 DeWalt
0 Headway
4 Kokam
3 Ping
0 PSI/LiFeBatt/BMI
60 Thundersky
9 Valence.
by weber
Wed, 01 Apr 2009, 07:14
Forum: Batteries, charging, management and monitoring
Topic: More Li batteries
Replies: 84
Views: 11919

More Li batteries

coulomb wrote: Also assuming that this is from the same "HiPower" company.

It is. I got to that page by clicking a picture on this page.
http://hipower.en.ecplaza.net/
by weber
Wed, 01 Apr 2009, 06:56
Forum: Batteries, charging, management and monitoring
Topic: Home grown BMS ideas !
Replies: 781
Views: 123867

Home grown BMS ideas !

Here is my circuit again just to start the topic here. http://forums.aeva.asn.au/uploads/24/BMS_jpeg_final.JPG I can't help thinking that instead of only a single bit of information, we could have an analog quantity represented on that single optocoupled daisy chain, so the motor controller or char...