Electric conversion: Project ForkenSwiift - Page 35 - Fuelly Forums

Android Users - Coming Soon! - Migrating from aCar 4.8 to 5.0

Reply
 
Thread Tools Display Modes
 
Old 01-09-2007, 08:09 PM   #341
Tuggin at the surly bonds
 
Silveredwings's Avatar
 
Join Date: Apr 2006
Posts: 839
Country: United States
Also you should fuse the controller +36V small wire, and the clock wire (it's better than having burned wires - see I do have a serious side ). The Ammeter fuse may not be needed but if the shunt ever comes loose, it'll save the meter from being fried.

Maybe like this?
Attached Thumbnails
Click image for larger version

Name:	schematic-forkenswift-2.GIF
Views:	141
Size:	7.7 KB
ID:	133  
__________________

__________________
Reality is merely an illusion, albeit a very persistent one. - Albert Einstein
Silveredwings is offline   Reply With Quote
Old 01-09-2007, 08:35 PM   #342
Registered Member
 
MetroMPG's Avatar
 
Join Date: Dec 2005
Posts: 4,223
Country: United States
Awesome - thanks.

OK, so maybe I should have an interlock. I never thought it was a problem, but if there's a law...
__________________

MetroMPG is offline   Reply With Quote
Old 01-09-2007, 08:48 PM   #343
Registered Member
 
MetroMPG's Avatar
 
Join Date: Dec 2005
Posts: 4,223
Country: United States
PS - didn't realize I was mis-using the chassis ground symbol. Learned sumpin' new today! Just in time too - the day's almost over, here.
MetroMPG is offline   Reply With Quote
Old 01-09-2007, 09:29 PM   #344
Tuggin at the surly bonds
 
Silveredwings's Avatar
 
Join Date: Apr 2006
Posts: 839
Country: United States
Quote:
Originally Posted by MetroMPG
OK, so maybe I should have an interlock. I never thought it was a problem, but if there's a law...
I think it's more of a dummy-proofer. A boss of mine once told me "you can't make anything foolproof because fools are so ingenious."

I seriously think a kill switch would more worthy of your time and more likely to be appreciated by first responders. Another place for an interlock is on any opening compartment that exposes the traction wiring - but then again good insulating covers may be better overall. Those kind of interlocks too often get defeated while the thing is in "R&D."

Quote:
So essentially everything gets fused? Should I put a fuse inline with the potbox microswitch too?
Pretty much. Besides being a safety valve of sorts, it's also a way to disconnect parts of the circuit w/o putting switches everywhere. The potbox probably doesn't need a fuse because it's just a 'sense' circuit. The 5k pot varies from a dead short to 5,000 ohms and is just a voltage divider for the controller input. It shouldn't have much current flowing if all connections remain correct. Besides some controller internal malfunction, the only danger would come from some higher power wire coming in contact it. This is where the quality of your physical electrical connections will pay off in overall reliability.

Quote:
Here's another question: someone asked why I was using pack voltage to control the main contactors. Do you happen to know if they'll work on 12v? Or will they just pull more current and get hotter?
It would be easier to wire if everything except 'power' was 12V but it depends on the parts themselves.

A 36 volt contactor coil energized with 12V won't pull more current because of the lower voltage (prob less) and thereby heat up, but there could be another problem with the lower V. If as you said, they came out of the forklilft as 36V devices, then 12V may not be enough to get them to close firmly. If they engage weakly, or worse chatter, then the power contacts will probably arc, self destruct, and otherwise ruin your day.

Also, if the correct V is 36V, then 48V into the contactor coils would entail more power draw and more heat, but I don't know if that's destructive. If it is and you still want to go to 48V or more, there are ways you could handle that with varying amounts of scope creep:
1. Just use a wire coming from the third battery (36V worth) for the contactor circuit. This one falls into the "if it's stupid and it works then it ain't stupid" category. It means assymetrical loading of the batteries but maybe only slightly.
2. Use an electronic regulator circuit to drop the 48V down to 36V for those coils (it's not as complicated as it sounds).
3. Change the contactors to 12V ones (prob the most expensive).

BTW, I'm pretty sure the small wire to the controller still has to be at full pack V.
__________________
Reality is merely an illusion, albeit a very persistent one. - Albert Einstein
Silveredwings is offline   Reply With Quote
Old 01-09-2007, 09:45 PM   #345
Tuggin at the surly bonds
 
Silveredwings's Avatar
 
Join Date: Apr 2006
Posts: 839
Country: United States
Quote:
Originally Posted by MetroMPG
PS - didn't realize I was mis-using the chassis ground symbol. Learned sumpin' new today! Just in time too - the day's almost over, here.
Sometimes a circuit will have 2 different 'grounds.' Sometimes there is a chassis ground, and an earth ground. Sometimes they're just used to simplify 2 different circuit common points to reduce clutter in the drawing. In any case they usually each use a different symbol for clarity:

In your case, the traction battery negative side isn't really a ground, especially since the negative side is the part that is regulated (chopped by the PWM). OTOH, the -12V is a true chassis ground since it's used throughout the car.

BTW, cars used to have positive ground - or in the Healey, "positive earth." The convention changed to negative ground to reduce the effects of electrolytic corrosion in the body.
Attached Images
 
__________________
Reality is merely an illusion, albeit a very persistent one. - Albert Einstein
Silveredwings is offline   Reply With Quote
Old 01-10-2007, 07:45 AM   #346
Registered Member
 
MetroMPG's Avatar
 
Join Date: Dec 2005
Posts: 4,223
Country: United States
Quote:
Originally Posted by Silveredwings
I seriously think a kill switch would more worthy of your time and more likely to be appreciated by first responders.
You mean like a big read panic button on the dashboard
MetroMPG is offline   Reply With Quote
Old 01-10-2007, 07:50 AM   #347
Registered Member
 
MetroMPG's Avatar
 
Join Date: Dec 2005
Posts: 4,223
Country: United States
Battery news: just got off the phone with the company that sold us the forklift.
MetroMPG is offline   Reply With Quote
Old 01-10-2007, 08:24 AM   #348
Moderator
 
GasSavers_DaX's Avatar
 
Join Date: Oct 2005
Posts: 1,209
Country: United States
Floodie = wet cell?
GasSavers_DaX is offline   Reply With Quote
Old 01-10-2007, 09:03 AM   #349
Registered Member
 
MetroMPG's Avatar
 
Join Date: Dec 2005
Posts: 4,223
Country: United States
Yup. Flooded lead acid batteries, that need periodic watering to replace electrolyte lost during charging.

Golf carts, industrial floor sweepers, and most EV conversions use 6v floodies.
MetroMPG is offline   Reply With Quote
Old 01-12-2007, 12:55 AM   #350
Registered Member
 
Join Date: Jan 2007
Posts: 5
Country: United States
That's my car...

Quote:
Originally Posted by brelandt
Nope he did but it looks just like this one but baby blue......

http://www.austinev.org/evalbum/991
I was just browsing along seeing how things were going with Project Forkenswift and I clicked on the link and... THAT'S MY CAR.

That's so funny.

I just purchased it in December and while it does run, there are problems with it--the Forward/Reverse contactor spits blue-green flame in reverse and when I try to go forward at low speed it jumps like a jerky start in a clutch--if I press down the pedal more it evens out but apparently I can't use low speed.

With the problems I haven't tried taking it further than the end of the block so far.
__________________

Len Case is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Fuelly Android App - eehokie Fuelly Web Support and Community News 2 07-14-2010 09:59 PM
Combined totals of all my vehicles? nizationpcs Fuelly Web Support and Community News 0 03-30-2009 07:41 AM
Vehicle Notes pb Fuelly Web Support and Community News 4 10-08-2008 12:38 PM
Converting numeric to current tire sizes. omgwtfbyobbq General Maintenance and Repair 5 06-01-2007 05:51 AM
Prius. First Impressions zpiloto General Fuel Topics 17 09-03-2006 11:49 PM

Powered by vBadvanced CMPS v3.2.3


All times are GMT -8. The time now is 02:13 PM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.