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 11-16-2012, 12:15 PM   #5911 (permalink)
EcoModding Lurker
 
Join Date: Aug 2012
Location: Germany, Saarland
Posts: 8
Thanks: 1
Thanked 0 Times in 0 Posts
So my controller works now. Great and thank you paul for all your help. But now i have another issue. So i want to use my Original Gas-pedal its already an electronic one. But now i have the problem it starts at 2.42 Ohm and goes down to 1.9 ohm. Is it possible to use it with that controller? because i tryed it but i cant configure it. When i enter for throttle max 166 and for throttle min 296 it just does nothing. And if i have it on the basic settings and i move the pedal i can see the red trottle bar going up and down for a little in the rtd explorer...

  Reply With Quote
Alt Today
Popular topics

Other popular topics in this forum...

   
Old 11-16-2012, 02:21 PM   #5912 (permalink)
PaulH
 
MPaulHolmes's Avatar
 
Join Date: Feb 2008
Location: Maricopa, AZ (sort of. Actually outside of town)
Posts: 3,831

Michael's Electric Beetle - '71 Volkswagen Superbeetle 500000
Thanks: 1,367
Thanked 1,119 Times in 734 Posts
Quote:
Originally Posted by blacksun1989 View Post
So my controller works now. Great and thank you paul for all your help. But now i have another issue. So i want to use my Original Gas-pedal its already an electronic one. But now i have the problem it starts at 2.42 Ohm and goes down to 1.9 ohm. Is it possible to use it with that controller? because i tryed it but i cant configure it. When i enter for throttle max 166 and for throttle min 296 it just does nothing. And if i have it on the basic settings and i move the pedal i can see the red trottle bar going up and down for a little in the rtd explorer...
Do you mean that it goes from 2.42v down to 1.9v? In that case, you would set "throttle-max-rc" (or whatever the heck it's called) to anything LOWER than 495. I'd try 485 to allow for some dead zone for zero throttle. Then set "throttle-min-rc" to 389.

By the way, 495 = 2.42volts/5volts * 1024, and 389 = 1.9volts/5volts*1024.

The 1024 is because the A/D converter is 10 bits (2^10 = 1024), and it's on a scale of 0 to 5 volts. 0 volts corresponds to an A/D reading of 0, and 5v is 1023. oops, I used 1024 above. haha.

-Paul
__________________
kits and boards

Last edited by MPaulHolmes; 11-17-2012 at 01:36 PM..
  Reply With Quote
Old 11-17-2012, 01:42 PM   #5913 (permalink)
PaulH
 
MPaulHolmes's Avatar
 
Join Date: Feb 2008
Location: Maricopa, AZ (sort of. Actually outside of town)
Posts: 3,831

Michael's Electric Beetle - '71 Volkswagen Superbeetle 500000
Thanks: 1,367
Thanked 1,119 Times in 734 Posts
I had an interesting failure of the DC test controller. I bumped up the voltage to 144v, precharged the capacitor bank, verified that the bank was full, and then removed the precharge resistor. I figured it would be safer to do a test just with the energy stored in the capacitor bank, not directly hooked up to the batteries. I had changed the code so that twisting the throttle to 100% corresponded to only like 6% duty, just to be safe. I gave it a tiny bit of throttle, and the gate to source signal on the oscilloscope looked perfectly clean. I turned it back to 0, and found that the capacitors were discharged. I tried to recharge the capacitor bank, but the mosfets had failed shorted!
__________________
kits and boards
  Reply With Quote
Old 11-19-2012, 12:12 PM   #5914 (permalink)
EcoModding Apprentice
 
apowers's Avatar
 
Join Date: Aug 2009
Location: Tn
Posts: 126
Thanks: 14
Thanked 18 Times in 15 Posts
Hi Paul

I see you pre-charged the caps checked the voltage then removed the resistor. Was there still voltage on the caps then? If not then one of the MOSFET's may have already been bad. It could have been damaged from soldering. Or bad right out of the box.

Mine is still working. It has been in use for over 3 years.

Thank You Very Much

Alvin
  Reply With Quote
Old 11-20-2012, 07:00 PM   #5915 (permalink)
PaulH
 
MPaulHolmes's Avatar
 
Join Date: Feb 2008
Location: Maricopa, AZ (sort of. Actually outside of town)
Posts: 3,831

Michael's Electric Beetle - '71 Volkswagen Superbeetle 500000
Thanks: 1,367
Thanked 1,119 Times in 734 Posts
I verified that the caps were at around 145v, and falling slowly due to some leaking. Then as soon as I gave it some throttle, the mosfets were failed shorted. Maybe I should do an experiment with some exotic solder that melts 140 degC or something. Maybe they don't like the thermal shock of going from 20degC to "really hot" to 20degC in like 5 or 6 seconds.
__________________
kits and boards
  Reply With Quote
Old 11-21-2012, 08:09 AM   #5916 (permalink)
EcoModding Apprentice
 
apowers's Avatar
 
Join Date: Aug 2009
Location: Tn
Posts: 126
Thanks: 14
Thanked 18 Times in 15 Posts
Maybe pre-heat them in the oven. Is this the controller with the mosfet's attached to the bus?
  Reply With Quote
Old 11-22-2012, 11:51 AM   #5917 (permalink)
PaulH
 
MPaulHolmes's Avatar
 
Join Date: Feb 2008
Location: Maricopa, AZ (sort of. Actually outside of town)
Posts: 3,831

Michael's Electric Beetle - '71 Volkswagen Superbeetle 500000
Thanks: 1,367
Thanked 1,119 Times in 734 Posts
Yep, I heated the bus bar, and stick the mosfets on, and as soon as the middle leg (connected to the back of the mosfets) gets to solder temp, I submerse the bus bar in water. The whole process only takes maybe 6 seconds, and the bar is less than 500 degF. The datasheet says the mosfets' legs can be at 500degF for 10 seconds, but it says nothing about the back metal heatsink. The diodes have never failed. I think you are right about preheating the mosfets too.
__________________
kits and boards
  Reply With Quote
Old 11-26-2012, 10:40 AM   #5918 (permalink)
PaulH
 
MPaulHolmes's Avatar
 
Join Date: Feb 2008
Location: Maricopa, AZ (sort of. Actually outside of town)
Posts: 3,831

Michael's Electric Beetle - '71 Volkswagen Superbeetle 500000
Thanks: 1,367
Thanked 1,119 Times in 734 Posts
I remember when Joe (yanof) was telling me that he tried the cincon as a high side power supply for a charger, and it worked for low voltage, but not high voltage. Maybe I screwed up the isolated supplies. I did pick the cheapest possible line filter. I know for a fact that if I use a powerex isolated 15v-15v dc-dc converter, that an isotop mosfet switches just fine at high voltage. That's how I did the charger... So, I could try the powerex dc-dc instead of my isolated dc-dc. It may not be a problem with the soldering at all.
__________________
kits and boards
  Reply With Quote
Old 11-27-2012, 05:38 PM   #5919 (permalink)
Joe
 
Join Date: Feb 2009
Location: phx
Posts: 260
Thanks: 0
Thanked 41 Times in 34 Posts
Quote:
Originally Posted by MPaulHolmes View Post
I remember when Joe (yanof) was telling me that he tried the cincon as a high side power supply for a charger, and it worked for low voltage, but not high voltage.
yeah, in my application, the high barrier capacitance in the DCDC caused the micro to lock up, but the fets were still fine. it was really weird, but using the powerex dcdc solved it.

would you be able to rig up some way to clamp the mosfets to the bus bar for a quick test instead of using solder? That might be a quick way to see if the soldering was the problem. Just add a little thermal grease and maybe just weigh them down with something heavy. You probably won't be able to go to as high of currents, but if it still has problems, then that rules out the soldering...
__________________
ReVolt AZ testing thread:

http://ecomodder.com/forum/showthrea...ting-9325.html
  Reply With Quote
The Following User Says Thank You to jyanof For This Useful Post:
MPaulHolmes (11-29-2012)
Old 11-28-2012, 12:13 PM   #5920 (permalink)
EcoModding Lurker
 
Join Date: Feb 2010
Location: Frilsham
Posts: 7
Thanks: 0
Thanked 7 Times in 6 Posts
fwiw

It may be worth baking the mosfets for 24 hours prior to soldering at about 30-50C - that helps get rid of any moisture the package may have absorbed - it's a reasonably common procedure. The cooling probably shouldn't be more violent than a cool air blower; too bigger dT/dt can be quite damaging, due to differential coefficients of expansion. (or contraction)

Regards,

Roche

  Reply With Quote
The Following 2 Users Say Thank You to Roche For This Useful Post:
MPaulHolmes (11-29-2012), Ryland (12-02-2012)
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 3472 01-12-2021 05:47 PM
Paul & Sabrina's Cheap EV Conversion MPaulHolmes Fossil Fuel Free 542 11-12-2016 10:09 PM
Three Dirt Cheap DIY Electric Cars - Part 5 SVOboy EcoModder Blog Discussion 0 12-12-2008 05:10 PM



Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2021, vBulletin Solutions Inc.
Content Relevant URLs by vBSEO 3.5.2
All content copyright EcoModder.com