Re: Gaps in laminations of high-current C-core transformer

Paul E. Schoen a écrit :
"Phil Allison" <philallison@xxxxxxxxxx> wrote in message news:5fgrbmF3d3gefU1@xxxxxxxxxxxxxxxxxxxxx
"Paul E. Schoen"
The company I work for makes high current circuit breaker test sets, using a transformer which can produce pulses of 60,000 amperes with an open circuit output of about 12 VAC. Today, our production assembler brought it to our attention that one of the C-core laminations had very visible gaps. It appears that the tension on the steel strap that holds the assembly together is insufficient to provide proper pressure, or perhaps the laminations retained too much springiness. There is a jagged opening along one edge of the core, showing where it had been cut in a staggered pattern.


** That is not a conventional C-core.

The lams are not properly glued together and the gap is not flush but staggered.

It is a poor man's excuse for one.

I'll inform my client of your observation. I concur completely. The earlier versions of this tranny looked pretty good. Somebody's getting sloppy, and we pay over $6000 each for these beauties!



$6000!
The fact is that the mag inductance might still be OK like this, but it wont take much of additional opening for it to vanish and you're screwed.

If they insist on these trasnformers to be OK, then make them write and sign that they claim it to be OK, now and for the future, and in case the transformers later fail, then then fully pay for *all* the incuring costs (xfrmer, xfrmer replacing costs, customer damage, loss of production, loss of image,...)
That should make them rethink their statement.


--
Thanks,
Fred.
.

Relevant Pages

  • Re: Gaps in laminations of high-current C-core transformer
    ... using a transformer which can produce pulses of 60,000 amperes with an ... Today, our production assembler ... production, loss of image,...) ...
    (sci.electronics.design)
  • Re: Help: how to design air-core transformer?
    ... >> What is your loss like WITH a core? ... Insertion loss is higher than 10dB. ... >I googled air core transformer before i posted my question. ... The old Motorola App Note AN1304 discusses the use of coaxial baluns ...
    (sci.electronics.design)
  • Re: Help: how to design air-core transformer?
    ... >> What is your loss like WITH a core? ... Insertion loss is higher than 10dB. ... >I googled air core transformer before i posted my question. ... The old Motorola App Note AN1304 discusses the use of coaxial baluns ...
    (sci.electronics.components)
  • Re: Efficiency of a transformer with increasing frequency
    ... >>> Why does the effciency of my low voltage transformer very much ... > (The inductance won't decrease much if at all) .but the total exciting ... > current increases due to hysteresis and eddy current loss increases. ...
    (sci.electronics.basics)