Brad93
Member
- Messages
- 17,568
- Location
- Essex, United Kingdom
View attachment 143415
Sounds like youre using something expensive.
In its simplelest form the mig weder is not a complicated device.
My Cebora 130 has none of the bells & whistles you seem to be refering to but welds perfectly well & has done since I purchased it from new many moons ago. The attached wiring diagram is of such a simple mig welder.
The main item is the multi tapped transformer, the contactor is on the input side whereas the contactor on my machine switches DC on the output side. The transformer has a switched multi turn input to give the various power settings. The output current is rectified to give the DC for welding.
The transformer on my machine is in essence no different to the transformer of a buzz box or the Oxford oil cooled which I also own. The Oxford has two outputs 50 & 80 V which is quoted as O.C. or open circuit voltage because as soon as you commence welding the voltage drops. There is no device in the wiring diagram to keep the voltage constant other than natural short lived “reluctance” of a coil to changes of voltage determined by its inductance.
Apart from the transormer, rectifier & contactor the only remaing components are the cooling fan & motor for controlling the wire feed. There is no voltage or current control.
You mention wire “stick out” which I take to mean the amount of wire between the contact tip & free end of the wire. You are correct in stating this will affect the process but only in so far as this is must be melted before the pool has formed.
In the simple mig weder it is the energy available at the given power setting which must melt both the parent metal & the wire being fed in. If the wire feed is too slow the excess energy will cause burn through, if too high the weld will be cold & prevent adequate penetration.
RonA
I know I’m correct Ron with the contact tip to work distance, I test welding machines day in day out.
If the wire feed speed is too low there isn’t excess energy, you get a cold weld not the opposite.
Like I said I’m not an electrical engineer but I’ve got a book at home that may shed some light on the situation.