HFT ac/dc welder

Soundguy · Jan 31, 2006

Is that price an only in store price? I see it online and it is 179$. I see what you mean.. duty cycle on the dc is 15% at 100a.. so i guess something like 7.5% on 200a.

Funny to see a unit with more dc amps than ac amps. Most of the big name units are 225a ac and 160 dc.. etc..

Soundguy

jimgerken · Feb 1, 2006

Soundguy, good catch on that AC/DC rating. It may be printed backwards. The same transformer output is either fed directly to the welding leads for AC, or rectified and then fed out for DC. The rectification drops the voltage, hence the lower current. I bet its posted incorrectly.
In fact Kossetx, if you simply rectified your old Lincoln output with a large stud-mount diode, you'd have a DC output. Four diodes would be smoother yet, allowing a bridge configuration.

kossetx · Feb 2, 2006

Jim, You're above my head on that. Can you explain farther? MP

Soundguy · Feb 2, 2006

Most common way to get dc from ac source is to rectify it... diodes are the components that do this. A single diode providing rectification is termed 'half wave'.. and looks like half an ac sine waveform. full wave rectification is much smoother.. near steady state dc... requires 4 diodes if using a non centertapped secondary ont he transformer, or 2 diodes if using a secondary that is center tapped.

Soundguy

Hydraman · Feb 9, 2006

Another point is that once you start welding with a dc rig, ya probably will not spend much time with the ac unit again. Don

Soundguy · Feb 9, 2006

I'd say that is a subjective response there.

I've weldedon a big mig, and on ac/dc stick machines.. and also just ac machines. .. I only have an ac machine myself.. but have access to the big mig and ac/dc stick any time I want at work.... I find the ac stick I have at home fine.

More options do not always obsolete 'older' options... that's more of a personal preference kind of thing, IMHO.

Soundguy