Inverter welder

Thread Starter

M braley

Joined Feb 19, 2020
4
Hi need help have Chinese inverter mig stick 180 welder that blows the four mosfets on gate drive board soon as strike a arc, can’t find replacement mosfets they are marked K50t60 and HAU209 under part number what ever that means, when looking for replacement all that comes up is IGBT. The pinouts on circuit board are marked GDS and on main circuit chart show a depletion N channel mosfet any help or advice on where to find these and why they are blown replaced the board with new one once along with mother board blew again soon after arc struck. Will try and post pictures. Q1 through Q4 are blowing.Thanks for any help.
 

Papabravo

Joined Feb 24, 2006
16,836
The "K" prefix appears on several families of "Russian" Transistors. The datasheets, if you can get them, are a hoot to read. I've never tried to buy any, but you're welcome to try.
Specifically:
KT872A​
KT819G​
KT315G​
KT6113G​
 
Last edited:

Irving

Joined Jan 30, 2016
2,112
Strange the on-device marking of K50t60 translates back to an Infineon IGBT IKW50N60T which is a good device for that purpose. It won't be the first time I've seen Chinese schematics show a MOSFET instead of an IGBT. The package and logo on your device is right for that part.
 

Papabravo

Joined Feb 24, 2006
16,836
Strange the on-device marking of K50t60 translates back to an Infineon IGBT IKW50N60T which is a good device for that purpose. It won't be the first time I've seen Chinese schematics show a MOSFET instead of an IGBT. The package and logo on your device is right for that part.
They don't make accurate maps of their cities either.
 

Irving

Joined Jan 30, 2016
2,112
Never been, except to HK which was great (worked on a contract there for 6 months back in 1992!)

@M braley if it keeps blowing then there's some other significant fault which needs proper investigation.

Did this work OK previously? Was there some change that occurred before it stopped working? Have you done obvious checks, like does it have a 110/220 voltage selector and is it set right?
 

Thread Starter

M braley

Joined Feb 19, 2020
4
Never been, except to HK which was great (worked on a contract there for 6 months back in 1992!)

@M braley if it keeps blowing then there's some other significant fault which needs proper investigation.

Did this work OK previously? Was there some change that occurred before it stopped working? Have you done obvious checks, like does it have a 110/220 voltage selector and is it set right?
Yes it worked alright never used it much,bought it for the stick feature had maybe 2 hours on it from new but was a year off its 3 year warranty, only thing I found strange about it was it wouldn’t arc weld unless the wire feed potentiometer had to turned up above 6or7 ,was welding fine then made a rattling sound and bang and that was it.
 

Irving

Joined Jan 30, 2016
2,112
That's always a problem with kit like that - you don't use for ages then when you need it, bang... And always just out of warranty!

Not sure how to advise you to proceed - diagnosing this needs some suitable test gear and some luck... And you could be spending multiple lots of $25 for 4 replacement igbts!
 

Thread Starter

M braley

Joined Feb 19, 2020
4
They don't make accurate maps of their cities either.
That's always a problem with kit like that - you don't use for ages then when you need it, bang... And always just out of warranty!

Not sure how to advise you to proceed - diagnosing this needs some suitable test gear and some luck... And you could be spending multiple lots of $25 for 4 replacement igbts!
yes and it is a discontinued model, did get in touch with factory HuGong in China and have to say they were helpful,engineer said to change the main control board along with heat sink driver board switch they sent no charge checked voltages out of step down transformer all okay,changed the bridge rectifier also tried it with cheap igbt and mosfets but wouldn’t put any current out to the stinger 10 volts between stinger and ground ,guess will try with name brand transistors see what happens
 
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