Electronics > Projects, Designs, and Technical Stuff
Homemade IGBT MIG welder with ATX PSU parts. [blown yet again][blown count: 5]
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Refrigerator:

--- Quote from: strawberry on July 06, 2019, 02:22:46 pm ---RC snubbers for IGBT and rectifier

--- End quote ---
I already had those but i assume they were insufficient, now i have a new board with a RC snubber and a 470V MOV right on the MOSFETs.
Also i soldered on much bigger screw terminals because the smaller ones had a problem with stripping the threads or being a pain to fit the wire in.
profdc9:
I have made boards for building half and full bridges.  They are intended to be used with dual resonant solid state Tesla coils, but they can work for other IGBT based bridges as well.  For example:

https://github.com/profdc9/DRSSTC-PCB-Pack/tree/master/full-bridge-transistor

The whole project is at

https://github.com/profdc9/DRSSTC-PCB-Pack/

There are spots for the IGBTs, DC link capacitors, snubbers, TVS diodes, gate drive transformer inputs, etc. to help minimize the inductance of the layout.

Dan
Refrigerator:
I tried running the inverter on 12V with my new MOSFETs and was getting completely nothing.
Turns out at least one secondary diode is shorted, could this be why the IGBTs blew?
Well as they say when it rains it pours and i happen to be absolutely drowning right now (in crap diodes and IGBTs that is).
T3sl4co1l:
Current mode control won't save you from counterfeit transistors*, but it will save you from failed diodes and shorted loads.  I don't recall a control scheme being posted in this thread so I'm reiterating this.

*If you have to ask, they're counterfeit.  If they're too cheap to believe, they're counterfeit.  If they're from eBay or Ali or Amazon, they're probably counterfeit.  It's very little labor to grind down the face and laser a new label.  Anything from 2N3904s to 2N3055s to power modules and ICs.

Tim
Refrigerator:

--- Quote from: T3sl4co1l on July 06, 2019, 10:33:57 pm ---Current mode control won't save you from counterfeit transistors*, but it will save you from failed diodes and shorted loads.  I don't recall a control scheme being posted in this thread so I'm reiterating this.

*If you have to ask, they're counterfeit.  If they're too cheap to believe, they're counterfeit.  If they're from eBay or Ali or Amazon, they're probably counterfeit.  It's very little labor to grind down the face and laser a new label.  Anything from 2N3904s to 2N3055s to power modules and ICs.

Tim

--- End quote ---

Actually the one diode that was the closest looking to the original did give different measurements, but i suspect the TO-247 ones are probably some 40V 20A shottky diodes or something along those lines.

I'll pull them apart to see how the die looks.
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