IXYS 72N60 or CM300s?

Aragorn, Sun May 17 2015, 07:48PM

Was ready to order the IGBT's for my coil but i've had second thaughts...

I've based the coil around various designs including Erics DRSSTC1/2/"2400w twins" coils. 4" secondary coil form, ~18" winding and a calculated Fres of around 120khz.

My plan was a full bridge of IXGN72N60C3H1's, which are IXYS's recommended replacement for the common but now discontinued IXGN60N60C2D1. They're cheap (~£17 each) and readily available from the big electrical suppliers like digikey and mouser etc. However, they're pretty much untested in the tesla world from what i can find, and i'm aware that newer chips can have less "headroom" due to smaller dies and thus despite their higher datasheet power rating they could potentially perform worse than the tried and tested 60n60's in the DRSSTC application.

However today i've noticed some "new" CM300DY-12H's on ebay for an appealing price. A pair will end up costing slightly more than the 72n60's (~£70 vs £100), but they are robust, tried, tested etc etc...

On the one hand i feel i should just get the CM300's, as once its up and running, i think i'd feel happier with the CM300's higher thresholds and current limits, on the other i'm thinking frying silicon might be inevitable and blowing up the IXYS parts ends up costing me less...

Thoughts? What would you do?
Re: IXYS 72N60 or CM300s?
loneoceans, Sun May 17 2015, 08:15PM

Aragorn wrote ...

Was ready to order the IGBT's for my coil but i've had second thaughts...

I've based the coil around various designs including Erics DRSSTC1/2/"2400w twins" coils. 4" secondary coil form, ~18" winding and a calculated Fres of around 120khz.

My plan was a full bridge of IXGN72N60C3H1's, which are IXYS's recommended replacement for the common but now discontinued IXGN60N60C2D1. They're cheap (~£17 each) and readily available from the big electrical suppliers like digikey and mouser etc. However, they're pretty much untested in the tesla world from what i can find, and i'm aware that newer chips can have less "headroom" due to smaller dies and thus despite their higher datasheet power rating they could potentially perform worse than the tried and tested 60n60's in the DRSSTC application.

However today i've noticed some "new" CM300DY-12H's on ebay for an appealing price. A pair will end up costing slightly more than the 72n60's (~£70 vs £100), but they are robust, tried, tested etc etc...

On the one hand i feel i should just get the CM300's, as once its up and running, i think i'd feel happier with the CM300's higher thresholds and current limits, on the other i'm thinking frying silicon might be inevitable and blowing up the IXYS parts ends up costing me less...

Thoughts? What would you do?

The new minBloc igbts look pretty good but they do have about 3/4 the die size of the older 60N60 IGBTs if I recall correctly. What sort of driver do you plan to use? If you're keeping the frequency <100kHz you will do fine with the CM300 bricks. With phase lead you can go even higher. In fact if you search around ebay a bit harder you should be able to find them for even cheaper. In fact you can get the same performance with a single half bridge module but at twice the bus voltage with a simple voltage doubler and a 1200V module.

For example, my DRSSTC 2 ( Link2 ) uses a CM200 half bridge module running at 400-500A with a foot tall secondary making almost 5 foot sparks. You could probably also use a full bridge of CM150 600V modules which are slightly faster as well. In short - if I were you I'd go for the 150, 200 or 300A bricks. The Semikron ones are great as well. On the other hand, if I were building a small coil running at higher frequency, I'd go for the faster IXYS igbts instead.
Re: IXYS 72N60 or CM300s?
Aragorn, Sun May 17 2015, 08:37PM

The power handling is certainly lower on the newer ones, 450w vs 360w.

The driver is a UD2.1.

Frequency is definitely going to end up over 100, calcs on JavaTC suggest somewhere between 115 and 130. I'll measure it soon, waiting on the toroid centre welded up so i can assemble it. I dont know exactly how many turns of wire i managed to get onto the secondary, just squeezed on as many as i could.

Eriks blog suggests his "DRSSTC2" ran 120khz on a CM300 and his later twins ran 108khz on a CM300 bridge so it seemed like an acceptable range of operation when you factor in the ~10% detuning of the primary...

Cheers
Kev
Re: IXYS 72N60 or CM300s?
Alex Yuan, Sun May 17 2015, 08:53PM

I would definitely go for the bricks. As long as you double check yourself you will not blow any silicon, but if you do make a mistake, the bricks can take more abuse.
Re: IXYS 72N60 or CM300s?
Aragorn, Wed May 20 2015, 02:16PM

Ordered some "new" CM300DY-12NF's from Aliexpress for less than the 72n60's in the end! Just need to wait and see if they turn up and are actually what they claim to be!
Re: IXYS 72N60 or CM300s?
Justin, Wed May 20 2015, 03:17PM

Aragorn wrote ...

Ordered some "new" CM300-12NF's from Aliexpress for less than the 72n60's in the end! Just need to wait and see if they turn up and are actually what they claim to be!


If you don't mind me asking, how much did the CM300-12NF's cost per brick?
Re: IXYS 72N60 or CM300s?
Aragorn, Thu May 21 2015, 10:39AM

They were $35 per brick plus shipping (~15$)

A couple of sellers were cheaper, but had never sold any, this guy seemed to have sold some last month and got good feedback so went with him.