MMC Caps any good for my DRSSTC?

[AiYumeNekoAliena]

Hi,
i have this old caps that im looking forward to use as an MMC for my mediumish DRSSTC..

Specs of my coils:
Frequency: 50kHz
Primary inductance: 22.30 uH
Primary peak current: 500 A
On time/BPS: unknown for now.. (i need help understanding more how should i set them and how sould i choose wich one to put..)

single caps is rated for 1200VDC 500VAC and has 0.47uF
my currend mmc is 4x4 series/parallel.. so 4800VDC ans 0.47uF

i will attach the only things i know so far as specs... and my javatc 13.6 load file.


SavedCoil - Blossium.txt

[Mads Barnkob]

I ran the numbers through MMC calculator: https://kaizerpowerelectronics.dk/calculators/mmc-calculator/

I used thermal resistance from a 940C, similar capacitor and the Kemet C4C datasheet values.

You will run a bit low on RMS current capability, so keep runs short and watch the MMC temperature. You are in the high end of temperature rise on the single capacitor, 8-9 degrees Celsius.

See attached for all numbers.

[AiYumeNekoAliena]

I ran the numbers through MMC calculator: https://kaizerpowerelectronics.dk/calculators/mmc-calculator/

I used thermal resistance from a 940C, similar capacitor and the Kemet C4C datasheet values.

You will run a bit low on RMS current capability, so keep runs short and watch the MMC temperature. You are in the high end of temperature rise on the single capacitor, 8-9 degrees Celsius.

See attached for all numbers.

thx a lotty Mads!
I tryed running them into your calculator too with similar resoults before wtiting this comment but i didnt know henaf of this caps to be sure my self...
Do you have any idea of a cheaper option that is super good and that could give me 470nF with 4000 ish Volts (or more)?
im looking for something super stable so im gonna change the caps since i want to be able to make this coil fully stretch her wings...

i looked into some ECWH8223HA from Panasonic... but they would have to be around 3 in series and 64 in parallel... so a lot of caps.. (there is a good deal for 500 of them so not a big deal price wise.. but yeah... a bit of pain to solder etc...) could them be any good?

[flyingperson23]

2s2p of these would probably work pretty well. It would give you 12000Vdc 120Arms 0.44uF.

https://www.aliexpress.us/item/3256805358622144.html?spm=a2g0o.productlist.main.1.508f60282TnWrg&algo_pvid=6d50b251-49ee-46dd-94a0-4dffa2988549&algo_exp_id=6d50b251-49ee-46dd-94a0-4dffa2988549-0&pdp_npi=4%40dis%21USD%2110.42%2110.42%21%21%2174.16%2174.16%21%402103243417312629326315228ebd93%2112000033482385018%21sea%21US%210%21ABX&curPageLogUid=5Rm1cqxIM3PH&utparam-url=scene%3Asearch%7Cquery_from%3A

[davekni]

im looking for something super stable so im gonna change the caps since i want to be able to make this coil fully stretch her wings...

If you have more of your existing 0.47uF caps, you could use 5s5p or 6s6p to increase RMS current capability along with other specs.

[AiYumeNekoAliena]

2s2p of these would probably work pretty well. It would give you 12000Vdc 120Arms 0.44uF.

https://www.aliexpress.us/item/3256805358622144.html?spm=a2g0o.productlist.main.1.508f60282TnWrg&algo_pvid=6d50b251-49ee-46dd-94a0-4dffa2988549&algo_exp_id=6d50b251-49ee-46dd-94a0-4dffa2988549-0&pdp_npi=4%40dis%21USD%2110.42%2110.42%21%21%2174.16%2174.16%21%402103243417312629326315228ebd93%2112000033482385018%21sea%21US%210%21ABX&curPageLogUid=5Rm1cqxIM3PH&utparam-url=scene%3Asearch%7Cquery_from%3A

this seems a great option, can anyone confirm i will be fine with this ones?

[Mads Barnkob]

Dawncap has been successfully used in DRSSTC, by multiply people. Search on forum shows dawncap mentioned in 26 posts, there is properly what you need there.

[AiYumeNekoAliena]

Dawncap has been successfully used in DRSSTC, by multiply people. Search on forum shows dawncap mentioned in 26 posts, there is properly what you need there.

Hi again Mads,
so.. i checked all the datasheets etc but there is no real esr rating curve for my 50kHz coil, since i dont know how to do math (dyscalculia) stuff and im dyslexic could you help me out there? i know there are some calculations at the bottom of your page at
"https://kaizerpowerelectronics.dk/tesla-coils/drsstc-design-guide/good-mmc-capacitors/" and i asked chat gpt to help me out ith that but i recived the unreal "16,970 mΩ (or 16.97 Ω)" response from it.. and i dont really know if thats right but seems a super lot to me..

if any of you guys can help me out.. i will attach the specs and all the sheets i could find of the cap..

Caps:
"DAWNCAP DTR 0.47UF 3000V DC 60A High-voltage Resonant Capacitor"

Here is the pdf, my model is "DTR3000K0.47-*-# 0" on the sheet.

20220423110139.pdf

[flyingperson23]

Those caps will work fine wrt esr/heating, you probably don't need to calculate anything if using 2s2p. The datasheet rating for each one lists 70A rms and 1500A peak, and from personal experience I haven't noticed any heating running them at 500A peak.

[AiYumeNekoAliena]

Those caps will work fine wrt esr/heating, you probably don't need to calculate anything if using 2s2p. The datasheet rating for each one lists 70A rms and 1500A peak, and from personal experience I haven't noticed any heating running them at 500A peak.

they are rated for 705A peak and 50A.. the one im looking forward to use.. is it still oky if i go with a 2s2p?

[flyingperson23]

Yes, they'll work fine

[AiYumeNekoAliena]

Yes, they'll work fine

thx a lotty girly!
and if you are from America... well.. stay strong! you are not alone! and i'm with you like we all are! bye from Italy :* :3