Author Topic: Strange PCB feature (PSU line filter)  (Read 2194 times)

0 Members and 1 Guest are viewing this topic.

Offline PhaedrusTopic starter

  • Frequent Contributor
  • **
  • Posts: 714
  • Country: us
Strange PCB feature (PSU line filter)
« on: September 05, 2013, 11:02:14 pm »
So I was dissecting a 700W ATX PSU, a very high end one, and found an unusual design feature. As you can see in the attachment, there are these unusual needle shaped solder points. These are across the windings of a common mode choke in the line filter, right before the bridge rectifier. I cannot fathom the purpose of this feature. I asked our consulting engineer with 25 years experience, and he has no idea either.

What's up with this?
"More quotes have been misattributed to Albert Einstein than to any other famous person."
- Albert Einstein
 

Online AlfBaz

  • Super Contributor
  • ***
  • Posts: 2184
  • Country: au
Re: Strange PCB feature (PSU line filter)
« Reply #1 on: September 05, 2013, 11:22:52 pm »
Doesn't look like the picture uploaded properly
 

Offline Fsck

  • Super Contributor
  • ***
  • Posts: 1157
  • Country: ca
  • sleep deprived
Re: Strange PCB feature (PSU line filter)
« Reply #2 on: September 05, 2013, 11:31:17 pm »
0kB photo.
"This is a one line proof...if we start sufficiently far to the left."
 

Offline PhaedrusTopic starter

  • Frequent Contributor
  • **
  • Posts: 714
  • Country: us
Re: Strange PCB feature (PSU line filter)
« Reply #3 on: September 05, 2013, 11:34:20 pm »
Crap. I'll reupload when I get home.
"More quotes have been misattributed to Albert Einstein than to any other famous person."
- Albert Einstein
 

Offline David_AVD

  • Super Contributor
  • ***
  • Posts: 2806
  • Country: au
Re: Strange PCB feature (PSU line filter)
« Reply #4 on: September 06, 2013, 12:18:03 am »
Spark gap?
 

Offline free_electron

  • Super Contributor
  • ***
  • Posts: 8517
  • Country: us
    • SiliconValleyGarage
Re: Strange PCB feature (PSU line filter)
« Reply #5 on: September 06, 2013, 12:39:53 pm »
Flashover structure. This is a trick used to be able to pass Hipot testing.
During hipot testing they apply a few kilovolt and see if nothing explodes violently or sets on fire.

This structure sparks over and protects the rest. One side of the structure should have a path to the chassis or neutral, possibly via a second of those spark gaps.

This is common on off-line smps's.
Professional Electron Wrangler.
Any comments, or points of view expressed, are my own and not endorsed , induced or compensated by my employer(s).
 


Share me

Digg  Facebook  SlashDot  Delicious  Technorati  Twitter  Google  Yahoo
Smf