Go Back   EcoModder Forum > EcoModding > Fossil Fuel Free > Open ReVolt: open source DC motor controller
Register Now
 Register Now
 

Reply  Post New Thread
 
Submit Tools LinkBack Thread Tools
Old 02-02-2010, 12:49 PM   #2921 (permalink)
Master EcoModder
 
Join Date: Apr 2009
Location: Charlton MA, USA
Posts: 463

EVVette - '71 Chevy Corvette Coupe
Thanks: 31
Thanked 183 Times in 94 Posts
Quote:
Originally Posted by MPaulHolmes View Post
Hey, I soldered my first surface mount components (in my whole life! for the bms):
This is a 1.25v reference (+/- 0.2%). It costs like $2.80 just for that microscopic little sucker! I thought it was a piece of dirt when it was on my desk.
Looks like a SOT-23-3....Am I right?? Dont you like how those little parts stick to the iron more then the board your soldering them to??

Its not too bad once you get the hang of it!!

-Adam

__________________
www.EVVette.com - 1971 Corvette Coupe Conversion to all Electric!
www.AdamBrunette.com - Machining, CNC, Robotics and Electronics.

You can download RTD Explorer for the Cougar controllers at www.EVVette.com
  Reply With Quote
Alt Today
Popular topics

Other popular topics in this forum...

   
Old 02-03-2010, 09:05 AM   #2922 (permalink)
EcoModding Lurker
 
Join Date: Apr 2009
Location: North Carolina, US
Posts: 17
Thanks: 1
Thanked 8 Times in 5 Posts
Bms

Has anyone looked at MiniBMS?

It has some decent functions and more reasonable than a lot I have looked at. It would be great to get something we could customize for any Lithium battery pack at a resonable cost.
Thanks Paul
  Reply With Quote
Old 02-03-2010, 09:16 AM   #2923 (permalink)
Master EcoModder
 
jackbauer's Avatar
 
Join Date: Sep 2009
Location: Ireland
Posts: 734
Thanks: 26
Thanked 304 Times in 171 Posts
Just a quick question. How does the contactor connect to the drive circuit on the main pcb? Is it open collector or grounded?

Yesterday we took the bmw out for a short drive. Managed to pump 250 battery amps through the controller during acceleration. Heatsink never went above 30 degrees C. thats with an additional diode and gate resistor on the igbt for faster turn off.
__________________
Now, Cole, when you shift the gear and that little needle on the ammeter goes into the red and reads 2000 Amps, that's bad.
www.evbmw.com
  Reply With Quote
Old 02-03-2010, 12:52 PM   #2924 (permalink)
PaulH
 
MPaulHolmes's Avatar
 
Join Date: Feb 2008
Location: Maricopa, AZ (sort of. Actually outside of town)
Posts: 3,832

Michael's Electric Beetle - '71 Volkswagen Superbeetle 500000
Thanks: 1,368
Thanked 1,202 Times in 765 Posts
Hi Jack, do you mean the contactor for the controller? or the bms above? For the controller, the contactor is disabled while pin 13 is high. If the software sets it low, then that turns on the LED in U9, which causes the gate of Q1, (which is normally pulled high to battery 12v), to suddenly be shorted to about 0.3v, which turns on the p channel fet (Q1), which connects 12v to the coil.

I haven't heard much about the mini-bms. A couple concerns I have is that it continuously draws "less than" 10mA, which could mean 9mA. hehe. people that leave their car parked for too long or sent in for repair could destroy their batteries. It would take a pretty long time though. It also can only shunt 0.75amp for a little while, rather than continuously. I think it shuts off the charger if one of the shunts gets too hot, so the rest of the cells may not have a chance to balance. I'm also not sure how it will work in a noisy environment. Some people have had problems with this sort of thing under heavy acceleration I think.

Mine (from Fran's ideas haha) will use like 1uA (1 millionth of an Amp) when not in use, shunt any amount of current you want (continuous) from 0amp up to 2 amps away from each cell for as long as you want, causing anywhere from 2amp down to 0amp go through the battery until the rest are completely balanced (the programmer can have that 2 to 0amp be whatever he wants based on the "topping off" profile). This shortens the time necessary during the balancing phase. Each 25w power resistor is off board, on aluminum. Also, the charger and controller will know the exact voltage of every single cell, so you can output it to a laptop or something and watch the state of each and every battery while charging or discharging. Also, because CANbus is used, the communication will be very noise tolerant. ya!
__________________
kits and boards
  Reply With Quote
Old 02-03-2010, 05:07 PM   #2925 (permalink)
Master EcoModder
 
jackbauer's Avatar
 
Join Date: Sep 2009
Location: Ireland
Posts: 734
Thanks: 26
Thanked 304 Times in 171 Posts
so .........the output on the control board goes to +12v at the end of precharge? So i'd just connect the contactor positive to the control board o/p and the ground to 0v? Sorry for the silly questions.
__________________
Now, Cole, when you shift the gear and that little needle on the ammeter goes into the red and reads 2000 Amps, that's bad.
www.evbmw.com
  Reply With Quote
Old 02-03-2010, 06:00 PM   #2926 (permalink)
PaulH
 
MPaulHolmes's Avatar
 
Join Date: Feb 2008
Location: Maricopa, AZ (sort of. Actually outside of town)
Posts: 3,832

Michael's Electric Beetle - '71 Volkswagen Superbeetle 500000
Thanks: 1,368
Thanked 1,202 Times in 765 Posts
Ya! Exactly. That's not a silly question. Connect ground of the contactor coil to the 12v battery negative, and the Positive end of the contactor coil to the Contactor Pin on the control board (middle pin of J1).
__________________
kits and boards

Last edited by MPaulHolmes; 02-03-2010 at 06:12 PM..
  Reply With Quote
Old 02-06-2010, 12:27 PM   #2927 (permalink)
EcoModding Lurker
 
Join Date: Aug 2009
Location: Netherlands
Posts: 13
Thanks: 1
Thanked 5 Times in 2 Posts
And another relay parallel with he contactor with the resistor to charge the caps directly from 12V initiated by the normal contact key switch.

* digs his memory on how to calculate the charging time again in an RC-circuit to set the proper rc-time value with the rtd-explorer *
  Reply With Quote
Old 02-06-2010, 01:28 PM   #2928 (permalink)
EcoModding Lurker
 
Join Date: Sep 2009
Location: EDMONTON
Posts: 26
Thanks: 1
Thanked 3 Times in 2 Posts
Hi Paul,

How's your SR design coming along? I'm interested mostly in the power stage. Have you cnc'd any boards yet?

I figure it will be awhile before the surface mount control boards are all the rage, so I figure I can patiently wait for all that goodness.

Cheers, Richard
  Reply With Quote
Old 02-06-2010, 03:11 PM   #2929 (permalink)
PaulH
 
MPaulHolmes's Avatar
 
Join Date: Feb 2008
Location: Maricopa, AZ (sort of. Actually outside of town)
Posts: 3,832

Michael's Electric Beetle - '71 Volkswagen Superbeetle 500000
Thanks: 1,368
Thanked 1,202 Times in 765 Posts
RC time constant:

You need about 5 RC time constants for the capacitors to be 0.99 full. Well, to be (1 - exp(-5)) full.. hehe.

So, capacitance*Resistance is 1 time constant. The capacitance is around 820uF each:

5*820uF*16*ResistorSize = time in seconds.

////////////////////////////////////////////////////////////////////////////

I designed the power pcb section for the SR controller, and did most of it in GCode, but there's a tiny bit left. I'm going to redo the control board for SR to use 2 drivers for mosfets, and 2 for freewheel mosfets. There's not much to add. I'm waiting on my tax returns to get the pcb done.

It's also going to have CAN, and interface with the bms if there is a bms to interface with.
__________________
kits and boards
  Reply With Quote
Old 02-06-2010, 04:25 PM   #2930 (permalink)
EcoModding Apprentice
 
dave koller's Avatar
 
Join Date: Feb 2010
Location: Northern Wisconsin
Posts: 137
Thanks: 32
Thanked 39 Times in 23 Posts
Good to see lots of EVer's from DIY in here

Jack, adamj12b, etc.......:

This might be good for me as I am a ROBOT builder, a lurker of this site, an EV builder and a hardware software old guy... Like the controller and that is that

Dave

  Reply With Quote
Reply  Post New Thread


Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
Paul and Sabrina's Cheap 3 Phase Inverter (AC Controller) with Field Oriented Control MPaulHolmes Fossil Fuel Free 3480 05-04-2022 05:43 PM
Paul & Sabrina's Cheap EV Conversion MPaulHolmes Fossil Fuel Free 542 11-12-2016 09:09 PM
Three Dirt Cheap DIY Electric Cars - Part 5 SVOboy EcoModder Blog Discussion 0 12-12-2008 04:10 PM



Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Content Relevant URLs by vBSEO 3.5.2
All content copyright EcoModder.com