Page 1 of 2 12 LastLast
Results 1 to 10 of 17

Thread: How do medical power supplies achieve such low leakage current??

  1. #1
    Join Date
    Oct 2006
    Location
    jonnyGURU forums, of course!
    Posts
    15,929
    Thanks Thanks Given 
    528
    Thanks Thanks Received 
    208
    Thanked in
    152 Posts

    Default How do medical power supplies achieve such low leakage current??

    Honestly, I've never had a chance to tear one apart, but in your typical desktop PSU, I've not seen lower than 3.5mV. Medical PSUs can be as low as .2mV.

    To reduce EMI, we tend to put a Y capacitor to ground, and that's where you get most of your leakage. But it's not like medical PSUs don't use a Y cap and say "EMI be damned!"

    What's the secret sauce?

  2. #2
    Join Date
    Oct 2017
    Location
    Grand Junction, CO
    Posts
    1,899
    Thanks Thanks Given 
    108
    Thanks Thanks Received 
    44
    Thanked in
    38 Posts

    Default

    https://378m1o49xyfcl4may47q66uc-wpe...%20Current.pdf

    " ...important to substantially reduce the capacitances that cause leakage currents. This poses a special design problem for the power supply and especially EMI filters."

  3. #3
    Join Date
    Oct 2006
    Location
    jonnyGURU forums, of course!
    Posts
    15,929
    Thanks Thanks Given 
    528
    Thanks Thanks Received 
    208
    Thanked in
    152 Posts

    Default

    That document does not answer my questions at all.

    I know what leakage current is and how we reduce it today.

    I want to know how they reduce it as much as they do in medical PSUs and still pass EMI.

  4. #4
    Join Date
    Oct 2017
    Location
    Grand Junction, CO
    Posts
    1,899
    Thanks Thanks Given 
    108
    Thanks Thanks Received 
    44
    Thanked in
    38 Posts

    Default

    Same document

    "Condor's medical designs and patented EMI filtering techniques have overcome these problems."

  5. #5
    Join Date
    Oct 2006
    Location
    jonnyGURU forums, of course!
    Posts
    15,929
    Thanks Thanks Given 
    528
    Thanks Thanks Received 
    208
    Thanked in
    152 Posts

    Default

    Quote Originally Posted by ashiekh View Post
    Same document

    "Condor's medical designs and patented EMI filtering techniques have overcome these problems."
    No offense, but I don't know what your deal is. LOL!

    Let's forget this document and move on because clearly it's not going to answer my question.

    I mean, if they had a diagram and component list of what "Condor's medical designs and patented EMI filtering techniques" comprise of... Otherwise, you're answering my questions with ambiguous statements that merely taunt my original question.

    Seriously. It's like if I asked how the Prius regenerative braking system works and you replied with "when you slow down the car, it generates electricity."

    It's not what I'm asking for.

  6. #6
    Join Date
    Oct 2017
    Location
    Grand Junction, CO
    Posts
    1,899
    Thanks Thanks Given 
    108
    Thanks Thanks Received 
    44
    Thanked in
    38 Posts

    Default

    I just don't have the time to track down their patent but thought you might if you knew of its existence, given your question. It didn't give you the answer but rather a clue as to where to find it; thought that might be of interest.

    Now do you know what my deal is?
    Last edited by ashiekh; 07-01-2018 at 06:48 PM.

  7. #7
    Join Date
    Jul 2009
    Location
    Germany
    Posts
    3,574
    Thanks Thanks Given 
    6
    Thanks Thanks Received 
    46
    Thanked in
    43 Posts

    Default

    Buy a Medical PSU, tear it down and post pics of it here?

    Maybe they don't use Y Caps.
    Maybe they do use Y-Caps but "special ones"...

  8. #8
    Join Date
    Oct 2006
    Location
    jonnyGURU forums, of course!
    Posts
    15,929
    Thanks Thanks Given 
    528
    Thanks Thanks Received 
    208
    Thanked in
    152 Posts

    Default

    Quote Originally Posted by Stefan Payne View Post
    Buy a Medical PSU, tear it down and post pics of it here?

    Maybe they don't use Y Caps.
    Maybe they do use Y-Caps but "special ones"...
    I plan to eventually, but they're so expensive.

  9. #9
    Join Date
    Oct 2017
    Location
    Grand Junction, CO
    Posts
    1,899
    Thanks Thanks Given 
    108
    Thanks Thanks Received 
    44
    Thanked in
    38 Posts

    Default

    An isolation transformer is one solution, although probably not the one being used.

  10. #10
    Join Date
    Oct 2006
    Location
    jonnyGURU forums, of course!
    Posts
    15,929
    Thanks Thanks Given 
    528
    Thanks Thanks Received 
    208
    Thanked in
    152 Posts

    Default

    Quote Originally Posted by ashiekh View Post
    An isolation transformer is one solution, although probably not the one being used.
    Yeah. That's a solution, but you wouldn't have 80 PLUS Titanium medical PSUs with an isolation transformer on the primary side.

Similar Threads

  1. 8 to Dual 8 Pin EPS for high power current generation Boards
    By Dirtymacho in forum PC Power Supply Discussion
    Replies: 10
    Last Post: 03-04-2017, 12:53 PM
  2. Help Current Sharing 12v Server PSUs for Desktop Mod Power
    By U25a0 in forum PC Power Supply Discussion
    Replies: 18
    Last Post: 08-20-2015, 06:04 AM
  3. Is my current power supply sufficient
    By Sgt Bashir in forum General PC Hardware
    Replies: 2
    Last Post: 09-22-2014, 06:23 AM
  4. Medical ATX power supplies?
    By cheese007 in forum PC Power Supply Discussion
    Replies: 1
    Last Post: 06-08-2011, 01:34 AM
  5. Power supplies degrade in power output over time?
    By dangman4ever in forum PC Power Supply Discussion
    Replies: 20
    Last Post: 11-19-2010, 10:26 AM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •