SD Gen head (welding use)

[Crofter]

Bob mentioned the SD 5 generator that can be used for 120/240 or welding with a 70 open circuit voltage. I wonder if that is basically the leads from the 4 stator coils brough out similar to what BSwartz accomplished with his ST 5 and contemplated using for battery charging. How would current regulation be accomplished? Selecting 1, 2, 3 or 4 coils for coarse adjustment then a rheostat control of the exciting voltage? Has anyone played around with this setup. I see they are advertised in China up to much larger size than 5KW and the pictures look similar to ST's

[mobile_bob]

i would have to go dig out a schematic for one of the sd heads,

from memory, and bear in mind it is not as good as it once was.

the schematic illustrated some sort of transformer like winding that was attached to the welding output leads.

iirc the 4poles were all connected in series for 240 volt operation, but were not used for the welder output
that was illustrated as a second winding.

the reostat controlled the welding output from low all the way up to high, iirc the unit would go to 160 or 180amps
for the sd5 and up to 240-260amps for the sd10

i was mistaken on the sd5 we have, they only are setup for 240volt ac output and no 120 tap, i suppose one could use
a transformer to step down to 120 if he needed to.  it might be that the unit must be connect as a 240vac only unit in order
to get the welder section to work properly at the needed voltage, i just don't remember.

my biz partner has the sd10 setup on a small aircooled 2cylinder air cooled engine, from what i am told it is a good welder
however the diodes need replaced because of an errant wrench that fell into the works while testing with the cover off or something.

we have 3 more of the sd5's, two of which are on my side of the ledger i believe. i just haven't looked into them because i have
so many welders now that there has been no pressing need to get one out and hook it up.

i think it might well be that the sd head would make one hell of a 48volt battery charger, a purpose built regulator would have to be fitted unless one were to use a smaller automotive alternator controlled by a balmar or other 3step controller as an exciter to power the sd field.  the sd would also have to have a nice heavy set of diodes to make up a full wave rectifier because the head is an AC welder.

bob g

[Tom Reed]

Hey Bob, do you know where I can find some specs on that head I might be interested in one.