Electric Vehicle Discussion List
Sat, 21 Jul 2007 01:21:23 -0700
EV Digest 7045
Topics covered in this issue include:
1) RE: batteries: another increasing range question
by "Roger Stockton" <[EMAIL PROTECTED]>
2) Re: 6v or 12v
by Jim Husted <[EMAIL PROTECTED]>
3) Tesla Roadster Drifting!
by "Joseph T. " <[EMAIL PROTECTED]>
4) Re: "Tree House" Controller
by "storm connors" <[EMAIL PROTECTED]>
5) Re: [EV] Re: "Tree House" Controller
by Eduardo Kaftanski <[EMAIL PROTECTED]>
6) MetricMind in the news
by JS <[EMAIL PROTECTED]>
7) Re: Drawbacks re Zap Xebra motor?...
by Bruce Weisenberger <[EMAIL PROTECTED]>
8) RE: Drawbacks re Zap Xebra motor?...
by <[EMAIL PROTECTED]>
9) individual chargers
by Tim Gamber <[EMAIL PROTECTED]>
10) RE: Drawbacks re Zap Xebra motor?...
by <[EMAIL PROTECTED]>
11) new motor concept, brushless
by "Fizzy Electricity" <[EMAIL PROTECTED]>
12) Re: individual chargers
by "Roland Wiench" <[EMAIL PROTECTED]>
13) Re: Simple Controller
by "Peter VanDerWal" <[EMAIL PROTECTED]>
14) Re: "Tree House" Controller
by "John G. Lussmyer" <[EMAIL PROTECTED]>
15) Zilla inside picture (Hot, Cold and Broken)
by Cor van de Water <[EMAIL PROTECTED]>
16) Re: Zilla inside picture (Hot, Cold and Broken)
by Rod Hower <[EMAIL PROTECTED]>
17) Unrealistic expectations (was Re: 'Tree House' Controller
by "Peter VanDerWal" <[EMAIL PROTECTED]>
18) Re: Zilla inside picture (Hot, Cold and Broken)
by Dan Frederiksen <[EMAIL PROTECTED]>
19) Re: "Tree House" Controller
by Dan Frederiksen <[EMAIL PROTECTED]>
20) Re: Number of E-mails
by Jeff Shanab <[EMAIL PROTECTED]>
21) ICS-200 (not 2000) Charger
by "Steve Gibbs" <[EMAIL PROTECTED]>
22) ICS-2000 Charger
by "Steve Gibbs" <[EMAIL PROTECTED]>
23) RE: "Tree House" Controller
by "Dale Ulan" <[EMAIL PROTECTED]>
24) Re: "Tree House" Controller
by [EMAIL PROTECTED]
25) Re: 6v or 12v
by "Dmitri" <[EMAIL PROTECTED]>
26) RE: individual chargers
by "David Sherritze" <[EMAIL PROTECTED]>
27) Re: new motor concept, brushless
by "Peter VanDerWal" <[EMAIL PROTECTED]>
28) Motor volts, was Re: 6v or 12v
by James Massey <[EMAIL PROTECTED]>
29) RE: "Tree House" Controller
by "Dale Ulan" <[EMAIL PROTECTED]>
--- Begin Message ---John G. Lussmyer wrote: > Aren't those different part numbers? Yep, but the case colour is a nice sanity check no matter what model/part number you are told you are getting. I think the deep cycle models suitable for EV use all start with a "D" (e.g. "D34" = deep cycle group 34, "D31"=deep cycle group 31), and the "M" suffix identifies the battery as a "marine", or Blue Top (BT) version rather than a Yellow Top. Cheers, Roger.
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--- Begin Message ---Hey Guys These motors will get into the danger "flashover" zone at around 160 volts to the motor, give or a take a few volts depending on individual motors. Make sure the motor brushes are advanced for your direction. Hope this helps Jim Husted Hi-Torque Electric --- "Joseph T. " <[EMAIL PROTECTED]> wrote: > "Is 240v too much?" > > I don't really know, but from looking at different > EV conversions, I > think that 240 volts might be too much for an 8'' > motor. > > On 7/20/07, Jack Murray <[EMAIL PROTECTED]> > wrote: > > I'll be moving my Optima batteries to my sailboat, > so I'm going to get > > some new batteries for the Fiero. > > I'm leaning towards getting the Trojan 24TM 12v > batteries, and go with > > 10-20 of them. It seems to me the higher voltage > is going to reduce > > current draw and be better for range via pukert. > How many volts can > > an ADC 8" motor be OK with? Is 240v too much? > > Jack > > > > > > ____________________________________________________________________________________ Looking for a deal? Find great prices on flights and hotels with Yahoo! FareChase. http://farechase.yahoo.com/
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--- Begin Message ---I found some videos on youtube of the Tesla Roadster racing a Ferrari, McLaren Mercedes, Corvette, and some motorcycle on youtube. http://youtube.com/watch?v=h-AWy2nBT-s (there's five of them) There was no info. however about why or where the Tesla roadster was racing on the Tesla Motors Website or by the person who posted the video on youtube. So I informed AutoBlogGreen.com of these videos and asked them to ask if anyone knows about this video. Sam Abuelsamid, who apparently is the Moderator of AutoBlogGreen.com or something, contacted Darryl Siry, who works for Tesla Motors. Well, this is what the article says: "According to Darryl, The upcoming Project Gotham Racing 4 from Microsoft will be featuring the Roadster. The video was shot during filming for a commercial from Microsoft that should begin airing in Mid-August. Apparently they closed off some streets and used professional drivers and the Tesla proved to be quite an accomplished drifter thanks to its Lotus-developed chassis. PGR4 is coming out in September if you've got an XBox 360." I know in the videos it looks like the Tesla Roadster is losing or having some troubles handling, but this person who is presumably Darryl, from Tesla Motors, posted this comment on AutoBlogGreen's website: "I wasn't there but the drivers are actually following a script and intentionally oversteering. The Corvette always loses control because that is what they want it to do. As an owner of a 73 Corvette, I can tell you it ain't hard to do so you don't need a professional driver for that. As a relatively frequent driver of the Tesla, I can tell you it handles incredibly well, and is not compromised in any way by the battery placement." Because of me squandering my time on youtube, watching videos of the Tesla Roadster, news has been revealed about the Tesla Roadster making an appearance in a video game and there's a video to go along with it !!! It's a small world. :)
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--- Begin Message ---Dan, Is there something in your makeup that causes you to disparage those who are trying to be helpful? You have continually acted in a childish manner, taking every opportunity to display (and taking pride in) your ignorance. There are lots of us here trying to learn and many who spend a lot of their time providing that education. You don't seem to fall in either group. Why are you here wasting your vauable time? If it is to prove you can be annoying, mission accomplished. Perhaps you could go somewhere else to see if you can meet similar success there? Storm On 7/20/07, Dan Frederiksen <[EMAIL PROTECTED]> wrote:wow, that had all the objectivity of a 'support the troops sign' is daddy in his sweatty wife beater getting afraid that his kids might succeed? Lee Hart wrote: > If you lower your expectations enough, then a simple PWM controller is > possible. The main tradeoffs are: >
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--- Begin Message ---On Fri, Jul 20, 2007 at 07:18:09PM -0400, storm connors wrote: > Dan, > Is there something in your makeup that causes you to disparage those > who are trying to be helpful? You have continually acted in a childish > manner, taking every opportunity to display (and taking pride in) your > ignorance. There are lots of us here trying to learn and many who > spend a lot of their time providing that education. You don't seem to > fall in either group. Why are you here wasting your vauable time? If > it is to prove you can be annoying, mission accomplished. Perhaps you > could go somewhere else to see if you can meet similar success there? If this was my list to administer, I would have kicked him out long ago. -- Eduardo K. | Darwin pone las reglas. http://www.carfun.cl | Murphy, la oportunidad. http://ev.nn.cl | | Yo.
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--- Begin Message --- PHOTO CAPTION: Plotting an automotive revolution. Victor Tikhonov (left), the owner of MetricMind looks on as Victor Juarez (center) and Xavier Niebla (right) discuss the placement of batteries in their next electric car project, this one destined for lease in the United States starting in early 2008.- - - - - - - - - See the article and pic at http://www.evworld.com/article.cfm?storyid=1294
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--- Begin Message ---Yes it is DC with an Altrax 7250 controller in it in the one I saw. However Zap dealer in my town has discontinued distributing the Zebra's --- [EMAIL PROTECTED] wrote: > I understand from one source that DC drive motors in > electric vehicles > are less fuel efficient than AC motors, but I > haven't been able to > confirm that. And I believe that the Zap Xebra drive > motor is DC, but I > haven't been able to confirm that either. > Can anybody out there help fill in some details for > me? > Thanks! > Bruce > > ____________________________________________________________________________________ Be a better Heartthrob. Get better relationship answers from someone who knows. Yahoo! Answers - Check it out. http://answers.yahoo.com/dir/?link=list&sid=396545433
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--- Begin Message ---Thanks. So do you know if that's inherently a bad thing? At least when compared to AC motors? -- Bruce England ES S&MC Information Development Desk: 650/625-2895 or Nokia internal: (864)2895 Cell: 650/580-3954 -----Original Message----- From: [EMAIL PROTECTED] [EMAIL PROTECTED] On Behalf Of ext Bruce Weisenberger Sent: Friday, July 20, 2007 4:47 PM To: ev@listproc.sjsu.edu Subject: Re: Drawbacks re Zap Xebra motor?... Yes it is DC with an Altrax 7250 controller in it in the one I saw. However Zap dealer in my town has discontinued distributing the Zebra's --- [EMAIL PROTECTED] wrote: > I understand from one source that DC drive motors in electric vehicles > are less fuel efficient than AC motors, but I haven't been able to > confirm that. And I believe that the Zap Xebra drive motor is DC, but > I haven't been able to confirm that either. > Can anybody out there help fill in some details for me? > Thanks! > Bruce > > ________________________________________________________________________ ____________ Be a better Heartthrob. Get better relationship answers from someone who knows. Yahoo! Answers - Check it out. http://answers.yahoo.com/dir/?link=list&sid=396545433
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--- Begin Message ---* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * ---REMAINDER OF MESSAGE TRUNCATED--- * * This post contains a forbidden message format * * (such as an attached file, a v-card, HTML formatting) * * Lists at sjsu.edu only accept PLAIN TEXT * * If your postings display this message your mail program * * is not set to send PLAIN TEXT ONLY and needs adjusting * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
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--- Begin Message ----- Bruce England ES S&MC Information Development Desk: 650/625-2895 or Nokia internal: (864)2895 Cell: 650/580-3954 -----Original Message----- From: [EMAIL PROTECTED] [EMAIL PROTECTED] On Behalf Of ext Bruce Weisenberger Sent: Friday, July 20, 2007 4:47 PM To: ev@listproc.sjsu.edu Subject: Re: Drawbacks re Zap Xebra motor?... Yes it is DC with an Altrax 7250 controller in it in the one I saw. However Zap dealer in my town has discontinued distributing the Zebra's --- [EMAIL PROTECTED] wrote: > I understand from one source that DC drive motors in electric vehicles > are less fuel efficient than AC motors, but I haven't been able to > confirm that. And I believe that the Zap Xebra drive motor is DC, but > I haven't been able to confirm that either. > Can anybody out there help fill in some details for me? > Thanks! > Bruce > > ________________________________________________________________________ ____________ Be a better Heartthrob. Get better relationship answers from someone who knows. Yahoo! Answers - Check it out. http://answers.yahoo.com/dir/?link=list&sid=396545433
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--- Begin Message ---Greetings from a new member.A question to anyone who can offer me help with the following concept for a hub mounted motor.Firstly, the motor is going to be mounted in a 37 inch diameter wheel. The rotor will be static, and mounted to the chassis via the suspension, and the rim will revolve around it and contain the permanent magnets. It is desired that the inner part be hollow for aesthetic reasons, and to help increase mechanical torque on the 37 inch drive wheel. The vehicle is a single seater, with the 37 inch wheel at the rear being driven from the internal hub motor. There will be two wheels at the front to complete the trike design.It will need to do about 538 rpm to do 100 Km/h and will have no transmission.Question: what sort of gauge wire will i need, and how many turns ? can the windings be rhombic ? I'm told i may need 40 lots of windings and something like 9 magnets. The power will be supplied by lead acids at 55Ah each, and there will be enough room for 10 to 12 12V batteries, plus one auxiliary.Thanks Grant Clinch _________________________________________________________________ Watch all 9 Live Earth concerts live on MSN. http://liveearth.uk.msn.com
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--- Begin Message ---Yes, you can charge each battery while they are all connected in series. With some battery chargers you can connect the output DC leads in series for increase voltage. If these are smart chargers, that this work good to keep the batteries in balance. It is best to disconnect the battery pack positive an negative leads from any load that is connected to. Lets say you want to charge a 72 volt pack, then you can also connect the output leads of the charger all in series and only connect the two end DC leads to the most positive and most negative of the battery. I had done this with a IOTA DC-DC converters or can be connected as a AC-DC converter as a battery charger. Roland ----- Original Message ----- From: "Tim Gamber" <[EMAIL PROTECTED]> To: "post post" <ev@listproc.sjsu.edu> Sent: Friday, July 20, 2007 6:36 PM Subject: individual chargers i was just wondering that lets say you had a string of 6 batteries and you had an individual charger attached to each battery like a soneil or something, do you have to disconect each battery from the string in order to charge them corectly (or keep the sparks from flying) ? _________________________________________________________________ Invite your mail contacts to join your friends list with Windows Live Spaces. It's easy! http://spaces.live.com/spacesapi.aspx?wx_action=create&wx_url=/friends.aspx&mkt=en-us
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--- Begin Message ---Yes, and 120V pack (I forgot to mention that) Max power is about 30kw, not a lot. > Your motor is series? > > I think this may be because at about 7mph the voltage in the armature of > this sepex motor is already about 90volts 90V x 200A is a > 15KW. > By about 15mph the voltage is about 140-180V depending on SOC. > The voltage in a series motor at 7-15mph is going to be about 10-20V ? > so it needs higher amps. > > I guess acceleration is relative but 0-60 in the van seems OK to me > probably about 30 seconds, its fairly aerodynamic, petrol version does > about 45mpg. > > Peter VanDerWal wrote: >> Something doesn't add up. My truck weighs 1.5 tons. My controller does >> 550 amps, motor loop, and 350 amps battery loop. Acceleration is >> lethargic, 0-60mph in about 1.5 minutes. >> >>> I have always been curious about the need for high amps. >>> >>> The documentation for Citroen Berlingos states that peak current is 200 >>> amps, and I think this is probably correct because the IGBT is only >>> rated 300 amps. There is more than enough acceleration. Vehicle weighs >>> 2 tonnes. >>> >>> The motor is a sepex, is that why Citroen can get away with this low >>> amperage and still have acceleration at low speed? >>> >>> Perhaps this a way forward for budget controllers, 100 amp continuous + >>> sepex motor? >>> >>> >>> Rich Rudman wrote: >>> >>>> 300 amps and 300 volts... Not even Curtis amps.... Hoo ho ho... Good >>>> one >>>> there... >>>> >>> >> >> > > -- If you send email to me, or the EVDL, that has > 4 lines of legalistic junk at the end; then you are specifically authorizing me to do whatever I wish with the message. By posting the message you agree that your long legalistic signature is void.
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--- Begin Message ---At 04:18 PM 7/20/2007, storm connors wrote:Dan, Is there something in your makeup that causes you to disparage those who are trying to be helpful? You have continually acted in a childishYou need to add Dan to your killfile. That way you never see his posts. Makes the list much more pleasant. In Eudora, you just add a filter to check for his Email in the From: address and have the msgs discarded.-- John G. Lussmyer [EMAIL PROTECTED] Dragons soar and Tigers prowl while I dream.... http://www.CasaDelGato.com
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--- Begin Message ---I do not know if it was posted already, but I was leafing through an EDN and suddenly my eye caught the captioning under the first picture of the article about thermal design "Hot Cold and Broken". It read: "This electric-car-motor controller experienced a catastrophic failure (courtesy Otmar Ebenhoech)." The picture show the Zilla that Otmar described in his blog that was one of 20 he was making around the beginning of the year and pushing it to its limits, he discovered that it was not working as he expected - causing a big, smoldering mess. The first picture in the article shows the Zilla after the events, I am also posting this just in case there is any interest in seeing the insides of a Zilla without actually purchasing one ;-) The article is online here: http://www.edn.com/article/CA6426879.html?ref=nbsa Cor van de Water Systems Architect Proxim Wireless Corporation http://www.proxim.com Email: [EMAIL PROTECTED] Private: http://www.cvandewater.com Skype: cor_van_de_water IM: [EMAIL PROTECTED] Tel: +1 408 542 5225 VoIP: +31 20 3987567 FWD# 25925 Fax: +1 408 731 3675 eFAX: +31-87-784-1130 Second Life: www.secondlife.com/?u=3b42cb3f4ae249319edb487991c30acb
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--- Begin Message ---Wow! that doesn't look anything like the 1k Zilla I took apart before installing it in a Sparrow!. Maybe Otmar should be brought up on charges for hamster genocide!! Oh well, throw them in the coffee can and learn from your mistakes. I'm guessing this is a Wayland control? If not I wonder who else blows thing up so you don't have too? Maybe we should be handing out a new Darwin award for the smoker of this control :-) No offense intended in these comments! Rod --- Cor van de Water <[EMAIL PROTECTED]> wrote: > I do not know if it was posted already, > but I was leafing through an EDN and suddenly > my eye caught the captioning under the first picture > of the article about thermal design "Hot Cold and > Broken". > It read: > "This electric-car-motor controller > experienced a catastrophic > failure (courtesy Otmar Ebenhoech)." > > The picture show the Zilla that Otmar described > in his blog that was one of 20 he was making around > the beginning of the year and pushing it to its > limits, he discovered that it was not working as > he expected - causing a big, smoldering mess. > > The first picture in the article shows the Zilla > after the events, I am also posting this just in > case > there is any interest in seeing the insides of a > Zilla > without actually purchasing one ;-) > > The article is online here: > http://www.edn.com/article/CA6426879.html?ref=nbsa > > Cor van de Water > Systems Architect > Proxim Wireless Corporation http://www.proxim.com > Email: [EMAIL PROTECTED] Private: > http://www.cvandewater.com > Skype: cor_van_de_water IM: > [EMAIL PROTECTED] > Tel: +1 408 542 5225 VoIP: +31 20 3987567 FWD# > 25925 > Fax: +1 408 731 3675 eFAX: +31-87-784-1130 > Second Life: > www.secondlife.com/?u=3b42cb3f4ae249319edb487991c30acb > >
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--- Begin Message ---"Tree house controller", I like that Lee. I think the main problem here is unrealistic expectations. There are about 1,000 people on this list and we all want a cheap and effective controller. The problem is that "cheap" controllers are already available, they just don't meet our misguided definition of "cheap" I don't think many of the newbies realize how much power it takes to move a car. The 450 Amp curtis controllers are generally accepted as being "whimpy" and under powered. Yet this lowly controller is capable of handling more power than a modern house with ALL of the appliances running at the same time (including the hot tub). The lowly Curtis is capable of handling more power than a 200 Amp service panel, which is nothing but circuit breakers and wire, and yet people want to buy a controller like this (or more powerfull) that said service panel costs. People, go down to the hardware store and price out a complete 200 amp service panel and compare that to what you think you can build a controller for. Keep in mind that the service panel has no silicon, no PWM control, nothing but circuit breakers, and also keep in mind that these parts are mass produced in the 100s of thousands, possibly millions. Once you do that, you'll realize what a bargin DC motor controllers are. > If you lower your expectations enough, then a simple PWM controller is > possible. The main tradeoffs are: > > - It will be acoustically noisy (you can hear it operating), > - It will be slightly less efficient (a few percent). > - Power will be modest, like a Curtis controller. > - It won't be "idiot proof", i.e. it will have little or no > protection from overtemperature, undervoltage, overcurrent, etc. > - It will have somewhat "lumpy" operation; things like a small > lurch when starting out, or a throttle response that doesn't > match a normal ICE's, etc. > - There will be "surprise" failure modes, due to design or > assembly errors (stuff you don't know when you build it). > > SCRs are cheap, rugged, and easy to turn on (even easier than MOSFETs or > IGBTs). The tradeoff is that they are hard to turn off. The classic > method is to have a big inductor, a big capacitor, and 1 or 2 extra big > SCRs or diodes. The circuits are very basic and well documented; it's > just that these are big parts! > >> could not the IGBTt just be in line with the motor and batteries >> switched on and off by a gate current? I'm well aware of the problems >> involved with real controllers, it just seems like a solid state >> on/off switch could be rigged up without any bells or whistles. > > If you're using the IGBT as a solid-state contactor, then there are no > switching loss concerns. You just have to deal with the heat produced by > its 3v drop at full current. > > You will always need a freewheel diode. It is easiest to get an IGBT > module that has one built-in, as it will naturally have short leads and > be matched to the IGBT's capabilities. > > If you want to duty-cycle modulate that IGBT to make a PWM controller, > then it gets interesting. Now you have to deal with switching losses, > which can exceed conduction losses (twice the heat, which means twice > the cooling and/or having to use the parts at half their ratings). And, > you have to make fast, accurate measurements in noisy high-power > switching circuits, for current limit and voltage protection to work. > > I think the trouble with simple cheap controllers is the "tree house" > problem. It goes like this: > > 1. Kids want a tree house. They know they can scrounge up some scrap > lumber, find a can of rusty nails in the garage, steal dad's hammer > and saw, and build it in a day or two! > > 2. But dad knows it will be a ramshackle structure, badly built, > probably unsafe, and certainly ugly. > > What's likely to happen? > > A. Kids don't tell dad. They build it themselves. It takes a week > instead of a month, due to all the "surprises" along the way. > They smash thumbs, get splinters, bend nails, need to scrounge > more materials, but manage to cobble something together. It looks > and works terrible; but they learned a lot and love it anyway. > > B. Dad gets involved. He says, "We have to do this right". He makes > plans, buys materials, tries to supervise but winds up doing it > himself because the kid's workmanship is so poor. It takes him > all summer to build it. It looks great and is safe; but the kids > rarely use it; they're off on some other hot new interest. > > It's hard for experts to remember that beginners have far lower > standards of quality and performance. The expert knows how to do it > "right" -- build something that even he would be proud to use. But it's > very hard for him to build a "tree house controller" that is > disgustingly cheap crude and primitive. > > But the beginner, having no experience with real controllers, may be > perfectly happy with a "tree house controller", thrown together out of > cheap surplus parts, that works but has all sorts of problems. > > The middle ground is difficult to achieve. It would be like: > > C. Dad supervises, but forces himself to keep his hands in his pockets > and his mouth shut most of the time. He shows them how to use a > hammer and saw, but doesn't do the work for them (so they learn how > to do it themselves). He shows them how to make strong joints so it > won't fall apart, but lets them do it their way (so they learn the > consequences of not doing it right). Dad knows that learning is the > real goal; not the end product itself. > > The end result is a tree house that still looks pretty crude; but it is > a heck of a lot stronger and safer that it would have been without adult > supervision. And the kids still love it, because they made it themselves! > -- > Ring the bells that still can ring > Forget the perfect offering > There is a crack in everything > That's how the light gets in -- Leonard Cohen > -- > Lee A. Hart, 814 8th Ave N, Sartell MN 56377, leeahart_at_earthlink.net > > -- If you send email to me, or the EVDL, that has > 4 lines of legalistic junk at the end; then you are specifically authorizing me to do whatever I wish with the message. By posting the message you agree that your long legalistic signature is void.
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--- Begin Message ---That's not a zilla. looks like a curtis Cor van de Water wrote:I do not know if it was posted already, but I was leafing through an EDN and suddenly my eye caught the captioning under the first picture of the article about thermal design "Hot Cold and Broken". It read: "This electric-car-motor controller experienced a catastrophic failure (courtesy Otmar Ebenhoech)." The picture show the Zilla that Otmar described in his blog that was one of 20 he was making around the beginning of the year and pushing it to its limits, he discovered that it was not working as he expected - causing a big, smoldering mess. The first picture in the article shows the Zillaafter the events, I am also posting this just in case there is any interest in seeing the insides of a Zilla without actually purchasing one ;-)The article is online here: http://www.edn.com/article/CA6426879.html?ref=nbsa Cor van de Water Systems Architect Proxim Wireless Corporation http://www.proxim.com Email: [EMAIL PROTECTED] Private: http://www.cvandewater.com Skype: cor_van_de_water IM: [EMAIL PROTECTED] Tel: +1 408 542 5225 VoIP: +31 20 3987567 FWD# 25925 Fax: +1 408 731 3675 eFAX: +31-87-784-1130 Second Life: www.secondlife.com/?u=3b42cb3f4ae249319edb487991c30acb
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--- Begin Message --- I didn't really want to dignigy the two attacks on me because they were not worth it but it seems there is several people that have a hard time recognizing the truth when they hear it. perhaps you all might notice how Lee Hart called everyone trying to develop a controller on a budget a misguided incompetent child trying to build a crappy tree house certain to fail. while Lee might have helped someone in the past he was certainly not trying to help here.Dan John G. Lussmyer wrote:At 04:18 PM 7/20/2007, storm connors wrote:Dan, Is there something in your makeup that causes you to disparage those who are trying to be helpful? You have continually acted in a childishYou need to add Dan to your killfile. That way you never see his posts. Makes the list much more pleasant. In Eudora, you just add a filter to check for his Email in the From: address and have the msgs discarded.-- John G. Lussmyer [EMAIL PROTECTED]Dragons soar and Tigers prowl while I dream.... http://www.CasaDelGato.com
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--- Begin Message ---Actually, something is up. I now only get every other digest. Somewhere in the loop someone has cranked up the spam filter or something. Without any feedback I just have to suffer I guess.
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--- Begin Message ---From: "Dale Ulan" <[EMAIL PROTECTED]> To: <ev@listproc.sjsu.edu> Subject: RE: "Tree House" Controller Date: Fri, 20 Jul 2007 16:43:36 -0600 Message-ID: <[EMAIL PROTECTED]> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit >wow, that had all the objectivity of a 'support the troops sign' >is daddy in his sweatty wife beater getting afraid that his kids might >succeed? It really is impressive watching (and listening) to a 300 amp IGBT blow up. It's impressive when your row of TO-247 MOSFET's, all in parallel, blow, leaving only the legs standing. And you don't even know what happened, but you have a smoking carcass of a controller in front of you. When I was designing an EV battery charger, I asked someone with more engineering experience how many spare IGBT's and other bits I should buy. He told me, seriously, get a couple of rails of them (50 or 60 parts), and buy that many driver chips, too. He was right. After three smoked PC boards, and probably 46 blown IGBT's, I had a charger that actually worked. This was a 25 amp, 250 volt PWM charger, operating at around 10 kHz. That was only at 25 amps. Of course, I wasn't as smart back then, so I'd probably be able to do it with maybe 3 or 4 blow-ups now. And that's 25 amps!!! The detail that goes into a controller is impressive. Shaping the turn-on or turn-off of the MOSFET or IGBT is critical. Too slow, they get too hot or the oscillate then blow up. Too fast, the high voltage spikes cause explosions, or the diode recovery time causes a rapid explosion. In an SCR control, if you apply insufficient gate drive, it blows up. If you apply too much gate drive, you blow things up too. Then you have to make sure your circuit will always fire the commutation SCR's in the right order and at the right times. If you don't then you get full battery to motor, no current limiting, and then something blows up. In some circuits, you only get one shot to commutate. If you fire the turn-off SCR, and for some reason the main SCR stays on (maybe noise, whatever), then you don't get another shot. Open a contactor and hope it doesn't weld itself shut. It's a case of people who have made the smoke already trying to help others not waste a lot of time and money blowing things up. Every time this topic comes up in EVDL, it's the same thing. It gets confrontational, and in the end, the people who have blown up stuff are almost always right. I'm looking at a new glider tonight, light car in ok shape but with a blown engine. Perfect! Which drive system? Brushless DC or AC induction? Which batteries? I dunno. Looking forward to a new project!!! -Dale
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