blowing power supplies ;(

[ltj]

I have two Phihong 9V 1.67A open frame supplies that I've managed to blow...
they now have no output except some mVs pulsing every few seconds.
(Mouser# 552-PSA-15LN3-090).

I tested them on the bench and they were initially fine. They seemed to die
when I was attaching AC to them. I say this because it was all working
fine, I unplugged it to work on other things then plugged it back in and got
nothing at that point. There was no load attached at the time. The other
one I never got to work (except on the bench).

The factory power was running 127VAC and is probably noisy but everying else
we hooked up runs fine including a similar 5V Mean Well open frame supply.

Any thoughts or suggestions on what could have caused this and how to avoid
it in the future?
newbie,
ltj

 

[William P.N. Smith]

"ltj" <ltj@yahoo.com> wrote:

There was no load attached at the time.

Many switchers will fail to run (or trip a crowbar or other shutdown
circuit) with no load...

--
William Smith
ComputerSmiths Consulting, Inc. www.compusmiths.com

 

[ltj]

Would what you described cause permanent damage?

It is rated at 0-1.67A. Does this means it is "ok" with no load?

I just realized that the enclosure might not have been grounded properly. I
had no ground when bench testing and it ran fine. Perhaps it matters out on
the floor?

thx


<William P.N. Smith> wrote in message
news:4lbb805kljjroabk5l7tqk4ebqnnrttjls@4ax.com...

"ltj" <ltj@yahoo.com> wrote:
There was no load attached at the time.

Many switchers will fail to run (or trip a crowbar or other shutdown
circuit) with no load...

--
William Smith
ComputerSmiths Consulting, Inc. www.compusmiths.com

 

[William P.N. Smith]

"ltj" <ltj@yahoo.com> top-posted:

Would what you described cause permanent damage?

It is rated at 0-1.67A. Does this means it is "ok" with no load?

I just realized that the enclosure might not have been grounded properly. I
had no ground when bench testing and it ran fine. Perhaps it matters out on
the floor?

thx


William P.N. Smith> wrote in message
news:4lbb805kljjroabk5l7tqk4ebqnnrttjls@4ax.com...
"ltj" <ltj@yahoo.com> wrote:
There was no load attached at the time.

Many switchers will fail to run (or trip a crowbar or other shutdown
circuit) with no load...

--
William Smith
ComputerSmiths Consulting, Inc. www.compusmiths.com

No, and it should mean that, and grounding shouldn't make much
difference. I'd try it with a 10-ohm resistor and see if it makes any
difference...


--
William Smith
ComputerSmiths Consulting, Inc. www.compusmiths.com

 

[none]

On Tue, 20 Apr 2004 15:36:10 -0400 "ltj" <ltj@yahoo.com> wrote in
Message id: <40857bdb$0$73096$a0465688@nnrp.fuse.net>:

I have two Phihong 9V 1.67A open frame supplies that I've managed to blow...

Wow! Did your lips get burnt?