Bridge from ebay
bomber315, Mon Jun 30 2014, 12:14PMhello everyone,
I am keeping my eyes open for parts and pieces to build a 4 foot coil during my slow time this winter. I have seen a couple of these kind of setup on ebay over the past few months.
not sure if they are a good starting point or not. I understand that the igbt's might not be best for a drsstc. I am wondering if i were to swap them out with some better, stronger, faster pieces if everything else would be good for this sort of thing.
Admittedly i do not fully understand the importance of inductance and capacitance in the connections (cables) between the igbts and such. It seems real tempting when most of not all of the hardware is there already.
Second question: What are these big heat sinks/ bridges out of?!? The listings never seem to say "removed from a ...." but i feel like if i knew where they were from i would be able to come across more/ better used setups
Thanks
Re: Bridge from ebay
Steve Conner, Mon Jun 30 2014, 12:26PM
The MG200Q2YS40 is a somewhat slow device with turn-off times up to 1.5us. You might be able to make it work, but the Powerex CM300DY-24H is the classic tried and tested device for a DRSSTC and you can pick surplus ones up quite cheaply. CTR Surplus should have them.
These assemblies are usually out of large motor drives (VFDs, inverter drives) or large UPSs. They tend to run at low switching frequencies like 5kHz, so the stray inductances and capacitances are less of an issue than in DRSSTC work.
Steve Conner, Mon Jun 30 2014, 12:26PM
The MG200Q2YS40 is a somewhat slow device with turn-off times up to 1.5us. You might be able to make it work, but the Powerex CM300DY-24H is the classic tried and tested device for a DRSSTC and you can pick surplus ones up quite cheaply. CTR Surplus should have them.
These assemblies are usually out of large motor drives (VFDs, inverter drives) or large UPSs. They tend to run at low switching frequencies like 5kHz, so the stray inductances and capacitances are less of an issue than in DRSSTC work.
Re: Bridge from ebay
bomber315, Mon Jun 30 2014, 12:45PM
but do you think buying that and swapping out the igbt's with some 300's would be a good idea? or would all of the cables and connections be worthless in a coil?
bomber315, Mon Jun 30 2014, 12:45PM
but do you think buying that and swapping out the igbt's with some 300's would be a good idea? or would all of the cables and connections be worthless in a coil?
Re: Bridge from ebay
teravolt, Mon Jun 30 2014, 04:20PM
if you want it the heat sync is ok and the igbt are probably ok for induction heater or a ferrite core set up. they probably are for a power inverter. i bouhgt some and have used the syncs for other things but steve is right they are slow junk for teslas.
teravolt, Mon Jun 30 2014, 04:20PM
if you want it the heat sync is ok and the igbt are probably ok for induction heater or a ferrite core set up. they probably are for a power inverter. i bouhgt some and have used the syncs for other things but steve is right they are slow junk for teslas.
Re: Bridge from ebay
bomber315, Mon Jun 30 2014, 06:03PM
well wouldn't all of the igbt's be connected the same as in a tesla coil? couldnt i use all of the big heavy wires to connect better igbt's on the same heatsink?
or would i have to run the heavy copper bus bars like i see other people doing?
its not like i am in love with this particular item, im just curious if it would be a good idea or not
bomber315, Mon Jun 30 2014, 06:03PM
well wouldn't all of the igbt's be connected the same as in a tesla coil? couldnt i use all of the big heavy wires to connect better igbt's on the same heatsink?
or would i have to run the heavy copper bus bars like i see other people doing?
its not like i am in love with this particular item, im just curious if it would be a good idea or not
Re: Bridge from ebay
Mads Barnkob, Mon Jun 30 2014, 06:08PM
It is in my opinion a bad deal to pay 60$ for a heat sink, some wire with shoes, brass fittings and snubber capacitors.
If you want to build a DRSSTC at the power level CM300s can deliver, better invest the money to make it good and sturdy, like the ones you see with copper bus bars, going cheap usually leads to disappointment or short life time.
Mads Barnkob, Mon Jun 30 2014, 06:08PM
It is in my opinion a bad deal to pay 60$ for a heat sink, some wire with shoes, brass fittings and snubber capacitors.
If you want to build a DRSSTC at the power level CM300s can deliver, better invest the money to make it good and sturdy, like the ones you see with copper bus bars, going cheap usually leads to disappointment or short life time.
Re: Bridge from ebay
teravolt, Mon Jun 30 2014, 07:12PM
how big a tesla you want to build
teravolt, Mon Jun 30 2014, 07:12PM
how big a tesla you want to build
Re: Bridge from ebay
bomber315, Mon Jun 30 2014, 08:59PM
oh thats fine, i figured that was probably the case. I have no problem spending the money or fabricating the bus bars and such. I did actually see one with bus bars on there once but it didnt last long, it went for $70 i believe.
i am still in the very early stages of gathering parts, technically all i really have is a secondary coil form. It is 8" OD and as long as need be (36"-48" im guessing)... still trying to get a grasp on everything so i can plug some better numbers into javaTC
I suppose with enough looking i can find a heatsink and build bus bars cheaper than that stuff on ebay any ways. as stated before the igbts on it are basically worthless to me
bomber315, Mon Jun 30 2014, 08:59PM
Mads Barnkob wrote ...
It is in my opinion a bad deal to pay 60$ for a heat sink, some wire with shoes, brass fittings and snubber capacitors.
If you want to build a DRSSTC at the power level CM300s can deliver, better invest the money to make it good and sturdy, like the ones you see with copper bus bars, going cheap usually leads to disappointment or short life time.
It is in my opinion a bad deal to pay 60$ for a heat sink, some wire with shoes, brass fittings and snubber capacitors.
If you want to build a DRSSTC at the power level CM300s can deliver, better invest the money to make it good and sturdy, like the ones you see with copper bus bars, going cheap usually leads to disappointment or short life time.
oh thats fine, i figured that was probably the case. I have no problem spending the money or fabricating the bus bars and such. I did actually see one with bus bars on there once but it didnt last long, it went for $70 i believe.
i am still in the very early stages of gathering parts, technically all i really have is a secondary coil form. It is 8" OD and as long as need be (36"-48" im guessing)... still trying to get a grasp on everything so i can plug some better numbers into javaTC
I suppose with enough looking i can find a heatsink and build bus bars cheaper than that stuff on ebay any ways. as stated before the igbts on it are basically worthless to me
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