Re: Buzz box output voltage?

Think of the circuit.

The welders secondary circuit is a coil. A large one. It feeds two long lines that
are called for by a welder to move about - these are inductive by nature. The stick
or stinger - simply completes a circuit and you have an inductive loop.

The current flowing in the transformer when there isn't a current (or large one) flowing
in the secondary indicates loss in the transformer. This is a designed in loss - one that
makes excuses for you when you stick a stick to the work then the transformer takes the
hit - by making some noise some times - as the current increases in the secondary. The
loose coupling allows this short to not blow up the transformer or not to break the
breaker. The demand surges are lighter as well.

You don't want a tight coupled transformer as the work short could then melt the secondary.

Martin

Martin H. Eastburn
@ home at Lions' Lair with our computer lionslair at consolidated dot net
NRA LOH & Endowment Member
NRA Second Amendment Task Force Charter Founder
IHMSA and NRA Metallic Silhouette maker & member
http://lufkinced.com/


dcaster@xxxxxxx wrote:
Bruce wrote:


Well, my results have me a little puzzled. Open circuit we measured a 4
amp draw which I thought was odd. Then using 1/8 6011 we measured about
40 amps with the welder set on 90 and about 54 amps gouging at 225. I
dropped it down to 60 amps and ran some 3/32 6011 and we were getting
around 28 amps. I'm really very surprised at these readings. I suspect
this old amp hook meter is reading a little high but even if it's
reading 10 amps over I wouldn't try to run this on my little generator.
As a test we checked the welding lead and with the welder on 90 we were
reading around 100 amps. So the meter can't be totally bonkers.



The 4 amp draw open circuit does not seem odd to me. As I said I
measured 6.2 amps on my welder. The transformer draws current that is
out of phase with the voltage and then there is the fan ( at least on
my welder ). I added some power factor capacitors and dropped the
open circuit current down to 3 amps. I could have added more
capacitors and dropped it down to about 2.3 amps but it would have
required fifty percent more capacitors for very little gain.

I don't have anyone to read a meter while I weld, so can't check on the
current drawn while welding. But it looks like the arc is a lot more
of an inductive load than I thought.


Dan


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