Pulse Frequency

[rbengines]

Someone enlighten me on pulse frequency hz's. Is there any advantage to go pass 25hz? I notice some of the machine go up to 500hz's. If so what is the advantage of this feature?

[SICFabrications]

pulse frquency determines how fast the machine switches between on and off pulse. the major differences are gonna lie in whether youre talkin bout tig or mig process tho. the faster the pulse freq on mig, the longer the arc is going to be, basically saying that it will spray transfer the wire a little more "unfocused" the higher the freq is.

tig, the difference is going to be between the machine being transformer or inverter based and ac or dc... i am too tired to go in depth on this one tonight, but will try to explain it better tomorrow

[rbengines]

Thanks, It's tig inverter AC/DC. Miller DX goes to 500hz and Longevity 25hz. In the market for a inverter unit and don't know what I need. I do a lot of thin aluminum corner and butt welds.

[SICFabrications]

ok, i have a better idea now. you are comparing apples to oranges. on the miller dynasty dx, you are looking at the ac frequency ranges and on the longevity, you are looking at pulse frequency. the longevity tig machines have 250 hz for ac freq and the new weld alls will soon be equipped with the same.

changing the ac frequency accomplishes this: on inverter based machines, you should be running tri-mix aka rare earth aka gray band tungsten for aluminum. sharpen the tungsten as though you were going to weld steel. now that this has been done, you can actually "sharpen" the arc cone with frequency changes. the higher the ac freq, the more sharp and focused the arc is, also creating less heat input and less penetration into the parent metals. you will also drastically reduce the HAZ (heat affected zone) however, the higher the frequency, the harder it is to establish and maintain the puddle and it also makes it harder to push the puddle along.

exactly how thin of aluminum are you trying to weld? i say this because, even with an old transformer based machine that is not capable of creating the high frequency ranges of the ac current, i can still butt weld two beer cans together, although having the frequency range capabilities sure makes it a whole lot easier...

hope that i have explained this enough, if i havent, then ask more questions =))

[rbengines]

.050 Aluminum is pretty regular. My Miller Syncrowave HF welds it ok and the Lincoln is terrific but sometime the pistol gun is not real comfortable to use. Sometimes the welds are not prefectly straight leaving a gap here and there. I just thought I try a Inverter machine. Probably don't need it but the pulse intrigued me.