On 02/09/2017 09:56, alan_m wrote:
On 01/09/2017 22:28, newshound wrote:


Yes. It's not much bigger than a toaster, weighs I suppose about 3 kg.
I think it goes up to 90 amps, claims to do 3 mm rod. Runs off 13A
socket.

I inherited a traditional transformer one some years ago, still ran
off 13A but weighed at least 20 kg. I think it came with 4 mm rods but
I could never sustain an arc, and I gave it away.


Could it be that being an inverter that the output frequency is a lot
higher than 50Hz?Â* I remember seeing a TV program some time back where
to weld certain materials more reliably they required 'specialised'
equipment and then went on to state that the equipment welded at a
higher frequency.


Inverter welders, whether stick or TIG, provide DC to the arc. I guess
that inside them they have a meaty switched mode power supply, i.e. with
an oscillator running at higher than mains frequency which means that
you need less iron and copper in the transformer, and hence less weight.

Professional TIG welders have an additional high frequency supply which
helps to initiate the arc, without this you have to "scratch" to start.

Plenty on the web about AC and DC welding.