I'm in Brisbane and got the torch from "State of the arc" they are at Capallaba. I did ring the Binzel supplier in Aus. and he gave me contacts for a supplier in Brisbane but i went with the one i have(Parweld) as it was a bit cheaper.
After much stuffing about i think i have got the wiring diagram. Now i know nothing about electronics so this is just a guess at what i thought might work
Its a long time since this this was posted, but I thought I'd update it with my findings
I tried making this mod, with the exact same components..but couldn't make it work with just the bits listed
.... but with the addition of a 1k resistor and a change to the connections on the MOSFET it sprang into life !
The capacitor increases the effective torque of the motor and also smooths any hesitation when the arc is struck.
The Mosfet disconnects the capacitor from the motor when the trigger is released (if this didn't happen, the capacitor makes the motor run-on for almost a second !)
The resistor is needed to pull the gate of the mosfet down., otherwise it can float and will not switch off ...
Modified circuit layout below.
Realise this is a little late but for the Ozzies on here I find the online trader "Bobthewelder" to be quite good and competatively priced
http://www.bobthewelder.com.au/home.php?xid=fd3f6cae3d9f7aed09a553b4eff3c0e9
I bought a SIP replacemnet torch from him and I see he has the Euro torch conversion kit as well
Bluekoop
Sorry to sound stupid, but I understand why the capacitor is there, I don't understand what the mosfet and diode do in your circuit.
The Mosfet source leg, hooks to the source of electrons, the negative side of the power source.heya spiyda, i dunno why mine works and yours didnt but i will try your mod anyway to see if there is a difference. Is it just the run on that was the problem? or was there other problems?
I tried to use mine a little while ago(i now have a new welder) and it didnt seem to be running right, i just figured it was me after using a good welder for a while!
edit: I've just noticed your legs on the mosfet have the motor as the source? how come?
The Mosfet source leg, hooks to the source of electrons, the negative side of the power source.
The drain leg drains the negative electrons into the positive side of the power source.
Robert
"Drain" hooks to positive,"Source" hooks to negative,"Gate" switches "on" with positive voltage.
Like this.:http://brunningsoftware.co.uk/FET.htm
Robert
heya spiyda, i dunno why mine works and yours didnt but i will try your mod anyway to see if there is a difference. Is it just the run on that was the problem? or was there other problems?
I tried to use mine a little while ago(i now have a new welder) and it didnt seem to be running right, i just figured it was me after using a good welder for a while!
edit: I've just noticed your legs on the mosfet have the motor as the source? how come?
Well i welded the curcuit together but the old man inlaw told me what to do so no doubt i have just stuffed up the drawing, especailly since they seem to be flow directional. Might have to change the drawing!
if you run it with a separate power supply for the feed then you take away the problem that is the massive and fluctuating wire speed voltage to the motor.My other question relates to the maximum safe gate voltage for the MOSFET. As the motor voltage ranges from 13-40v on my machine, and the maximum Vgs is 20v for this MOSFET - not sure why these do not fry at high wire feed speeds? Would an 18v zener diode from gate to ground provide protection?