Go Back   EcoModder Forum > EcoModding > Fossil Fuel Free
Register Now
 Register Now
 

Reply  Post New Thread
 
Submit Tools LinkBack Thread Tools
Old 10-02-2010, 12:29 PM   #411 (permalink)
EcoModding Lurker
 
Join Date: Jul 2010
Location: Cleveland, OH
Posts: 89
Thanks: 5
Thanked 7 Times in 5 Posts
there is a trick I've used on FET's before, honestly I haven't worked with IGBT's nearly as much so I'm not sure how similar the results would be. We put a diode across the gate resistor because we wanted the turn-off to be faster than the turn-on, I think for EMI tuning or something at the time. Cool trick though, it worked.

  Reply With Quote
Alt Today
Popular topics

Other popular topics in this forum...

   
Old 10-02-2010, 01:08 PM   #412 (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: 1,362
Thanked 1,202 Times in 765 Posts
Hey! That's the exact trick that Fran suggested to me. I ordered some schottky diodes, 1.8Ohm, and 3.0 Ohm resistors, so that the turn on will be 3 Ohm, and the turn off will be 1.1 Ohm. Those resistances work out so that the turn on current will be about 5 amps, and the turn off will be about 5 amps too, since the miller knee or whatever it's called happens around 6v for big igbts.
__________________
kits and boards
  Reply With Quote
Old 10-04-2010, 04:44 AM   #413 (permalink)
EcoModding Lurker
 
Join Date: Mar 2010
Location: South Africa
Posts: 16

Tazzy - '02 Toyota Tazz Sport
90 day: 43 mpg (US)
Thanks: 5
Thanked 3 Times in 3 Posts
Paul, are you using a negative voltage rail on your drivers to turn the IGBT's off? Not using it could also lead to slow turn-off times, making it run hot.
  Reply With Quote
Old 10-05-2010, 10:06 PM   #414 (permalink)
dcb
needs more cowbell
 
dcb's Avatar
 
Join Date: Feb 2008
Location: ÿ
Posts: 5,038

pimp mobile - '81 suzuki gs 250 t
90 day: 96.29 mpg (US)

schnitzel - '01 Volkswagen Golf TDI
90 day: 53.56 mpg (US)
Thanks: 158
Thanked 269 Times in 212 Posts
well I'm finally at a point where I can appreciate microchip more glad they have such a pdip selection. The examples compile "out of the box", no-charge. And they have some nifty features (i.e. quadrature encoders, can bus), plus 16 bit architecture (yess!) and 30mhz clock. Had some build goodness on sine-drive pmac without much fuss. got my pickitclonekit and a couple dsPIC30F4012 en route

Release build of project `AN1017.mcp' succeeded.
Language tool versions: pic30-as.exe v3.24, pic30-gcc.exe v3.24, pic30-ld.exe v3.24, pic30-ar.exe v3.24
Tue Oct 05 19:32:10 2010
----------------------------------------------------------------------
BUILD SUCCEEDED
__________________
WINDMILLS DO NOT WORK THAT WAY!!!
  Reply With Quote
Old 10-05-2010, 10:18 PM   #415 (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: 1,362
Thanked 1,202 Times in 765 Posts
Heck ya! Getting everything initialized properly with the dsPICs is a little like giving birth to a very very large talk show host, but once it's done it's done. They really are very versatile chips, that are designed around every type of motor control. It really shows.

Oh! The gate resistors and diode came today, so now I get to see how that bugger behaves with on gate resistor value of 3 Ohms, and off resistor value of 1.1 Ohms. I can't wait! It's so much fun having a job so that there's no time to work on this! hurray! hahahaha. Just kidding. That's not actually fun.
__________________
kits and boards
  Reply With Quote
Old 10-05-2010, 10:28 PM   #416 (permalink)
EcoModding Lurker
 
Join Date: Jul 2010
Location: Cleveland, OH
Posts: 89
Thanks: 5
Thanked 7 Times in 5 Posts
more fun than not being able to afford parts
  Reply With Quote
The Following User Says Thank You to Automcdonough For This Useful Post:
Electroddy (10-23-2012)
Old 10-05-2010, 11:25 PM   #417 (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: 1,362
Thanked 1,202 Times in 765 Posts
From experience I can say its the same amount of fun. haha
__________________
kits and boards
  Reply With Quote
Old 10-09-2010, 03:39 PM   #418 (permalink)
EcoModding Lurker
 
Join Date: Apr 2010
Location: Cali
Posts: 35
Thanks: 3
Thanked 4 Times in 3 Posts
:3 So any improvement with them new parts? XD Or just too busy?
  Reply With Quote
Old 10-09-2010, 03:43 PM   #419 (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: 1,362
Thanked 1,202 Times in 765 Posts
I just added the new gate resistors and diodes this morning. And am waiting until more time available for testing. I re-did the board to fix a couple tiny things, and I need to test an overvoltage/undervoltage circuit on a breadboard. I'm thinking of just doing a mindless top voltage hardware pwm cutout circuit so that regen doesn't get to wild with the batteries.
__________________
kits and boards
  Reply With Quote
Old 10-09-2010, 07:34 PM   #420 (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: 1,362
Thanked 1,202 Times in 765 Posts
Oh ya, and I am waiting a couple days for the oscilloscope for testing the new gate resistors. What? Didn't it arrive already?! Yes...

Here's the story. The oscilloscope was bought by a dear dear friend that I owe a kidney to, and then the guy on ebay didn't have it in stock (he had it posted on accident), so he asked if it was ok to send me a lower end version for a few days until the other one arrives. I said sure! It arrived a couple days later, and worked great, and just 2 days ago the new and improved one arrived at his store, so that I mailed the other one back to him, and I'm waiting PATIENTLY for the other one to get here. It'll be here in a couple days! hurray!

__________________
kits and boards
  Reply With Quote
Reply  Post New Thread




Similar Threads
Thread Thread Starter Forum Replies Last Post
Paul & Sabrina's cheap DIY 144v motor controller MPaulHolmes Open ReVolt: open source DC motor controller 7381 08-02-2023 11:55 PM
Paul & Sabrina's Cheap EV Conversion MPaulHolmes Fossil Fuel Free 542 11-12-2016 10:09 PM
Contest! Name Paul & Sabrina's controller MetroMPG Forum News & Feedback 120 10-22-2011 02:59 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