Good enough for brick IGBT gate drive ~160khz? / Tesla Coils / Forums

Forums

4hv.org :: Forums :: Tesla Coils

« Previous topic | Next topic »

Good enough for brick IGBT gate drive ~160khz?

previous 1 2

Move Thread

LAN_403

brtaman

Fri Mar 26 2010, 02:35PM

Registered Member #2161 Joined: Fri Jun 05 2009, 03:36PM
Location:
Posts: 247

Kizmo based on my experience and looking over your datasheet it shouldn't be a problem for those bricks to function at 100kHz.

Check out this thread I started some time ago:

I am running about equally "fast" (based on datasheet, taking into account differing factors, such as stated operating temperature and Rg) bricks with a 220kHz secondary, mind you the primary is at 170-180ish kHz (been tuning, haven't checked). Is the secondary going to be 100kHz? If so the primary will be somewhat lower again. Shouldn't be a problem just make sure to test thoroughly at low voltage, before applying off-line power.

Best Regards,
brtaman

Kizmo

Fri Mar 26 2010, 02:45PM

Registered Member #599 Joined: Thu Mar 22 2007, 07:40PM
Location: Northern Finland, Rovaniemi
Posts: 624

Yep, i have old SGTC secondary-toroid assembly which runs at 100kHz (calculated value without streamer load)

uzzors2k

Fri Mar 26 2010, 06:49PM

Registered Member #95 Joined: Thu Feb 09 2006, 04:57PM
Location: Norway
Posts: 1308

Arcstarter wrote ...

For the power source i would probably make a seperate smps with around 30 volts output driven straight from the mains and a uc3842 to drive it. Or i could just use iron cored transformers, but that would be a bit bigger, and less of a challenge.

Don't do it, man! I've fallen into that trap on many occasions, and always end up wishing I went with an iron-core from the start. Between noise from the Tesla coil and my inability to properly design a flyback transformer, every SMPS project of mine has been a mess. Not to mention the extra time it takes, which is always more than the original project itself.

Arcstarter

Fri Mar 26 2010, 08:05PM

Registered Member #1225 Joined: Sat Jan 12 2008, 01:24AM
Location: Beaumont, Texas, USA
Posts: 2253

Uzzors wrote ...

Last time i made a drsstc lashup i used a smps. It worked ok with shielding, but the sparks where only like 8 inches and 200 primary amps. I am going with iron core. My problem was that i did not have a linear regulator at the time, and on this little project i am not spending a single cent

. If i could not find a linear regulator, i would probably try smps. And some ridiculous amount of shielding and output RFI filtering

. Beside, the smps i would use is completely isolated from the primary side. Basically, no matter what happens to the output side the primary is unaffected, other than capacitively coupled interference. Which again, could be bypassed.

Dr. Mario

Tue Aug 03 2010, 04:35AM

Registered Member #3059 Joined: Tue Aug 03 2010, 04:09AM
Location: My turf
Posts: 18

Yea. I agree with Uzzors. Beware the cheaply-made SMPS... -___-
If you got some nice BIG energy-storage capacitor, use one with voltage rating
bit over what you're pumping in and want to use SMPS, USE it, your transistors will thank you.

And, I also would use higher-resistance resistor, like 100 kilo-ohms or higher,
that way those suckers will shut down quickly after the gate driver shuts down.
26 V? You may want to try and browser through Maxim's MOSFET driver portfolio:

- just helping you out a bit.
(Microchip may have some too...)

Also, I may want to put the driver QUITE CLOSE to the gate, that way you don't get some
weird alse-tiggering behavior that would send your monies you spent on that pretty bricks down the toilet.

Goodchild

Tue Aug 03 2010, 05:07AM

Registered Member #2292 Joined: Fri Aug 14 2009, 05:33PM
Location: The Wild West AKA Arizona
Posts: 795

I agree with some of the other people on this page a simple GDT is definitely the way to go in my opinion. Ive done it before with large bricks including CM300s with grate success. Also I don't see any need to drive the gate with 30V I see that as over kill, 24V works just fine and is a bit easier to get.

Just out of curiosity which Semikron brick are you using? Ive seen them run fast, but not at 160Khz.

teravolt

Tue Aug 03 2010, 07:34PM

Registered Member #195 Joined: Fri Feb 17 2006, 08:27PM
Location: Berkeley, ca.
Posts: 1111

I made a fiber optic driver with at least 24A worth of drive for my cm600's and never got them over 100khz you should build a coil that is big about 60khz that is well top loaded and make it easy on your self.

Arcstarter

Tue Aug 03 2010, 07:51PM

Registered Member #1225 Joined: Sat Jan 12 2008, 01:24AM
Location: Beaumont, Texas, USA
Posts: 2253

That was awhile back. I have a new coil that is 68KHz loaded, but i have not messed with drsstcs in awhile. It is near 1800 turns of 36 gauge, and more than 25 coats of varnish.

previous 1 2

Moderator(s): Chris Russell, Noelle, Alex, Tesladownunder, Dave Marshall, Dave Billington, Bjørn, Steve Conner, Wolfram, Kizmo, Mads Barnkob