Jump to content


Freewheel diodes

  • Please log in to reply
1 reply to this topic

#1 glen65


    Junior Member

  • Members
  • PipPip
  • 2 posts

Posted 16 November 2005 - 05:43 AM

I am working with a motor controller that runs a 3 phase switched reluctance motor. I am in the process of replacing the freewheel diodes
for the power mosfets. The originals are ST microelectronics number BYW98 200 fast recovery diodes. These are rated at 200 volts. I would like to upgrade these with 400volt units but some I am running across are ultra fast recovery. Would using the ultra fast recovery units cause a problem if I were to use them?
The mosfets I will be using are Fairchild FQP17N40.


#2 marke


    Posting Freak

  • Moderator
  • PipPipPipPipPipPip
  • 2,651 posts
  • Gender:Male
  • Location:Christchurch, New Zealand

Posted 16 November 2005 - 10:06 AM

Hello glen65

The answer depends on the characterisitcs and the application.
In many cases, the use of the ultra fast diodes will not be a problem, but you need to look at the recovery energy, voltage drop etc.

Best regards,

0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users