DIY Electric Car Forums - Technical Discussion http://www.diyelectriccar.com/forums Designs, Wiring, Adapters, Converters, Contactors, Switches, etc en Sat, 21 Nov 2009 01:35:04 GMT vBulletin 60 http://www.diyelectriccar.com/forums/images/misc/rss.jpg DIY Electric Car Forums - Technical Discussion http://www.diyelectriccar.com/forums Ceramic Heater and 160VDC? http://www.diyelectriccar.com/forums/showthread.php?t=38696&goto=newpost Fri, 20 Nov 2009 01:42:52 GMT Ceramic heaters are meant for 120V RMS (or 240V RMS), but what about in-between voltages? I hope to use 160VDC for my pack voltage - how will a 120V... Ceramic heaters are meant for 120V RMS (or 240V RMS), but what about in-between voltages? I hope to use 160VDC for my pack voltage - how will a 120V ceramic heater work?

I know they have an "inverse resistance" characteristic, which hopefully will increase the resistance as it gets hotter... It is the RMS value of an AC waveform which dominates its energy rating (ie thermal heating capacity) not the peak voltage (which would be 169.7V).

Anyone used 160V (or higher) and a 120V ceramic heater? ]]> Technical Discussion gdirwin http://www.diyelectriccar.com/forums/showthread.php?t=38696 Why do I have pulsing starts? http://www.diyelectriccar.com/forums/showthread.php?t=38694&goto=newpost Fri, 20 Nov 2009 01:11:09 GMT My Del Sol has a Kelly Controller and Warp 9.

When I'm starting off in second gear going up hill, if I accelerate too quickly I get a pulsing sensation from the motor. It pulses at about 5 cycles per second while its accelerating.

Has anyone else experienced this? Is it caused by the Kelly limiting the current? Does it have to do with the motor rotating slowly?

Thanks for the help.

- Brad ]]> Technical Discussion BradQuick http://www.diyelectriccar.com/forums/showthread.php?t=38694 U.S. source for 250 amp disconnect? http://www.diyelectriccar.com/forums/showthread.php?t=38651&goto=newpost Thu, 19 Nov 2009 01:22:44 GMT I like this Nanfeng emergency disconnect button but I'd rather not pay shipping from Aus http://www.evworks.com.au/index.php?product=SWI-ZJK250


I've seen similar here but for almost 3 times the price.
http://www.tecknowledgey.com/catalog...55e220102cf404 ]]> Technical Discussion JRP3 http://www.diyelectriccar.com/forums/showthread.php?t=38651 Solid state relays for switching ceramic heaters? http://www.diyelectriccar.com/forums/showthread.php?t=38646&goto=newpost Wed, 18 Nov 2009 21:37:55 GMT Does anyone think that using a couple of these Solid State Relays would be a bad idea to switch ceramic heater elements? It's hard to find electromechanical relays that handle 200vdc, other than expensive contactors.

Magnecraft 6312AXXMDS-DC3

Looks like a 10A contact rating, 3-200v load voltage. 1.6v voltage drop. At 10A that would only be 16W which is manageable. They're about $20 each.

Or if anyone has a more conventional suggestion, I'm all ears.

My battery pack voltage will be 205v nominal, and I'd like to use two ceramic elements for two heat settings, so two relays. Each 110v 1500w ceramic core has two sets of elements that are usually switched in parallel to control heat output. I'll be using both elements of one core in series for the 200v pack... Two cores, for two levels of heat. ]]> Technical Discussion Overlander23 http://www.diyelectriccar.com/forums/showthread.php?t=38646 DC/DC converter installation confusion http://www.diyelectriccar.com/forums/showthread.php?t=38643&goto=newpost Wed, 18 Nov 2009 20:06:14 GMT Hi all. Well after my last post I was definitely convinced that the dc/dc converter along with small 12v aux battery was the right way to go. One... Hi all. Well after my last post I was definitely convinced that the dc/dc converter along with small 12v aux battery was the right way to go. One question though: I don't know how an alternator is wired, so I'm wondering how the dc/dc wiring works? Should it just be wired right to the posts of the aux battery? Also, looking at some wiring diagrams in my books, I don't see how the power is actually reaching the dc/dc converter to begin with. It looks like an isolated system. ]]> Technical Discussion Frankencar http://www.diyelectriccar.com/forums/showthread.php?t=38643 Converting to a hybrid ? http://www.diyelectriccar.com/forums/showthread.php?t=38637&goto=newpost Wed, 18 Nov 2009 16:22:07 GMT Hi,
This is my first post here. Not sure I'm posting in the right section or even on the right forum :) .
I wonder if somebody here is converting a petrol car into a hybrid one. I'm especially interested in this topic to convert old cars like my classic manual Mini.
My idea is to replace the alternator with a few KW DC (brushless) motor. It would help the engine to make accelerate the car and during low speed cruise phases (in town). During this periods the IC would run in the stratified mode just to maintain itself in rotation to avoid wasting electric power on the compression work (no variable valve lift in old engines). The motor would also act as an alternator. An electric throttle (like) device is of course mandatory.
Any input would help.
Thanks ]]> Technical Discussion alpa http://www.diyelectriccar.com/forums/showthread.php?t=38637 A fun and dangerous idea... http://www.diyelectriccar.com/forums/showthread.php?t=38574&goto=newpost Tue, 17 Nov 2009 14:53:50 GMT In real life I recently worked with a wireless product that is "strand mounted", meaning that they simply clamp it around power lines and steal their power inductively.

Has anyone thought about an inductive charger for EV opportunity charging? Perhaps carry a small crossbow to loft the initial hoist cord over the line?

I imagine that it would be inefficient and dangerous, but it's a fun idea to simply "borrow" power wherever you go...

:D ]]> Technical Discussion PhantomPholly http://www.diyelectriccar.com/forums/showthread.php?t=38574 A different idea of opurtunity charging.... and a little about re-charge systems. http://www.diyelectriccar.com/forums/showthread.php?t=38506&goto=newpost Sun, 15 Nov 2009 03:18:11 GMT Hello, I'm a little new to this idea but I am officially addicted to the whole concept of EV conversions. I am in the very early planning stages of my project and have a few questions that I haven't seen addressed as of yet.

My first question is; Why don't I see more EV conversions with solar panels on their roofs? I know it would ever be enough to do anything while you are driving. But what if you could get five 210 watt panels on the roof of your car. Wouldn't you get a few more miles every time you go to wal-mart on a sunny day? (it always takes me at least an hour to get in and out of there)

My second question is simply and extension of the first. Why not use a solar array (i know it would need to be in the 4KW range) to charge a battery bank and then use a direct charge controller to charge your cars batteries off of those? Would that not make your EV 100% clean?

Thank you for all of your comments and answers! ]]> Technical Discussion surgy http://www.diyelectriccar.com/forums/showthread.php?t=38506 24 v to 12 v http://www.diyelectriccar.com/forums/showthread.php?t=38457&goto=newpost Fri, 13 Nov 2009 03:15:15 GMT Hi , I'm not sure if this the right forum . If not I apologize in advance. I have a race car that I'm trying to start the engine on 24 volts but run the rest of the car on 12 v. any ideas how I can do this ? Thanks ]]> Technical Discussion TD 1229 http://www.diyelectriccar.com/forums/showthread.php?t=38457 Most efficient placement of Ceramic Heater http://www.diyelectriccar.com/forums/showthread.php?t=38436&goto=newpost Thu, 12 Nov 2009 17:01:42 GMT Looking at ceramic heater now, convincing myself to give up amps for sake of easier use and installation.

But here is dilema - my Fiero doesn't have air recirculation, so i'd have to heat up outside air pushed to inside car.
On the other side - I could simply install 1 heater per foot area for drive rand passenger, and use outside air only to clear the windshield when needed. Wouldn't this be more efficient?


And how much would I save on such recirculation? ]]> Technical Discussion Stunt Driver http://www.diyelectriccar.com/forums/showthread.php?t=38436 Automatic Gearboxes revisited http://www.diyelectriccar.com/forums/showthread.php?t=38410&goto=newpost Wed, 11 Nov 2009 18:33:22 GMT After reading "The Reasons why Automatic Gearboxes WILL Work with EV's & how to do it.." thread, my inclination to use a gear box was reafirmed. I am in the planning stages of a Triumph Spitfire conversion, I have the car and I want to use a transmission.
After considering the swing axles that are in the Triumph, I had the thought that I might be able to adapt a front wheel drive trans axle and replace both the transmission ( which is from a Ford Escort in this case) and the flakey differential in one effort.
I would like to solicit recommendations for what trans axle to use. Obviously it needs to be able to handle the power levels, but the most important considerations I gleaned from the thread would be lowest pressure leakage for easy start up, or a relatively strait forward way of connecting an external oil pump to pressurize the hydraulic circuits until the input shaft is turning and the ability to control the shifting using the internal solenoids with out to much difficulty. It may well be in a light vehicle that one may only have to select the proper gear without to much thought to the full auto functions of the transmission. In lieu of a torque converter to unload the trans for shifting maybe just freewheel the motor until after the shift.
Looking for input for this possible route.
Thanks
Paul ]]> Technical Discussion wb9hco http://www.diyelectriccar.com/forums/showthread.php?t=38410 Tachometer module for NetGain motors http://www.diyelectriccar.com/forums/showthread.php?t=38398&goto=newpost Wed, 11 Nov 2009 14:26:26 GMT I found a guy who has a bolt on module pickup assembly for the Netgain motors that will provide logic to any Tachometer 2,4,6,8cyl. I bought one from... I found a guy who has a bolt on module pickup assembly for the Netgain motors that will provide logic to any Tachometer 2,4,6,8cyl. I bought one from him at $100 and it works REAL good. It is possible to attach it to other motors as long as they have a tail shaft. I was able to contact him at allanbull@sbcglobal.net. Anybody want information on how I hooked it up you can email me at cruisin@live.com. ]]> Technical Discussion cruisin http://www.diyelectriccar.com/forums/showthread.php?t=38398 cheap (free) heater for low-cost conversions http://www.diyelectriccar.com/forums/showthread.php?t=38337&goto=newpost Tue, 10 Nov 2009 01:07:07 GMT Let me have a patent on this, if it's a new idea:)

Idea is - fill gas tank with water (antifreeze), and have it heated up to 90C with thermostat control while plugged in. Tank would have to be insulated, so heat doesn't escape.
When driving - pump water thru heater core. Possibly can use existing fuel pump, or better something less noisy.

8 galons of hot water while cooling down from 95 to 45C will give out 1.6KWh of energy - that is 3 T-105 batteries of energy, and with 1KW of heat - will last over an hour ( which is more than my car's range).

If properly insulated - should be hot even after 5-8 hours parking at work. Drain it at summer for less weight to carry around.

the only downside - have to carry 60-80 pounds of weight with you, which is same as batteries of such energy capacity, but doens't cost a bit :)
In Fiero - gas tank is located in tunnel, which is hardly usable for anything else anyway. ]]> Technical Discussion Stunt Driver http://www.diyelectriccar.com/forums/showthread.php?t=38337 Total N00b with Questions http://www.diyelectriccar.com/forums/showthread.php?t=38334&goto=newpost Mon, 09 Nov 2009 22:27:22 GMT Hello, I'm new here. First Post!

I have some background with Ebikes, and while planning out my latest bike, I realized that for just 10 times the cost, I could build something 10 times as usefull, potentialy.

I want to research this as much as I can, but I have a few questions before I start reading that might help guide my searching.

What makes the Ideal doner car?

What is the minimum sized motor (in wattage or horsepower) needed to power the average sized E Car? Whats the average sized motor used?

How many Watt hours does the average E Car use in a 20 mile one way trip?

Are Large format LiFePO4 prizmatic batteries a viable option for e Cars?
or is Lead Acid the best power source? ]]> Technical Discussion Drunkskunk http://www.diyelectriccar.com/forums/showthread.php?t=38334 Electrical Metal http://www.diyelectriccar.com/forums/showthread.php?t=38296&goto=newpost Sun, 08 Nov 2009 15:04:59 GMT Nothing new here.
Just some food for thought for some who haven't already seen some of these old ideas before.

I attached a basic picture.

While Copper is used as the dominate metal by far ... there are some interesting possibilities for alternatives... of course you can't have your cake and eat it to... there are trade offs and issues to deal with.

Silver is a slightly better conductor of heat and electricity per volume than Copper but is actually worse per unit weight due to silver's higher density... and is grossly more expensive... a Silver wire to yield the same resistance could be 8% smaller by volume but would end up being 8% heavier by weight ... To conduct the same amount of heat it could be 7% smaller by volume , but would end up weighing 10% heavier... all while the silver wire would cost as much as ~90 times more than the copper.

Copper is a better conductor by volume of heat and electricity than aluminum ... but Aluminum is actually much better by weight ... To result with the same resistance for electricity an Aluminum Wire would be 64% larger than a Copper power by volume... but would weigh 51% less by weight.... To conduct the same amount of heat the aluminum would have to be 69% larger by volume but would be 49% lighter by weight... all while the aluminum would only cost about 17% the cost of the copper wire.

There are other issues people have run into as well... Metal to metal corrosion is an issue with aluminum that caused many fires years ago... some application the additional size / volume needed for equal electrical and or thermal conduction was not followed which also lead to fires ... and Aluminum has different metal fatigue properties that must also be considered where there are stresses and loads.

In application that experience significant skin effect combinations have sometimes been used where the core is aluminum and is coated with a shell of copper.

In motor windings the difference in type of magnetic material needs to be considered as well as the metal fatigue , additional volume for current and cooling... and the needed increase in volume has penalties for magnetic fields which dissipate with distance ...etc...

In short ... there is no free lunch... the way we design many things today is based on the specific properties of the materials we use... nd have been using and learning about these same materials for a very long time... including copper... so while there are alternatives... they can not be effectively just blindly substituted ... to exchange one material for another without very careful consideration and then testing is only inviting undesirable issues and side effects.

Still ... Sometimes I do wonder.

And sometimes I wonder a bit further about some of the much newer discoveries in material science ... even if I might not see some of these possibilities on the market any time soon ... or ever... still sometimes I do find it entertaining to entertain a bit of out of the box thinking.
:cool:
Attached Images
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]]> Technical Discussion IamIan http://www.diyelectriccar.com/forums/showthread.php?t=38296