HV caps

[Enzo]

Saw mention of these caps.

Film caps 8 to 55uf at 700 to 1100 volts DC. There you go, large enough for B+ filters and up to 1100v AND not electrolytic. Mouser has them in stock, and prices are from $10 to $20 depending on values.

https://disti-assets.s3.amazonaws.co...eets/16505.pdf

A sample value from Mouser:

BLC400J901B4F Cornell Dubilier | Mouser

[Chuck H]

I didn't check the specs. I wouldn't be sure of all that I was looking at anyhow. I did post a similar thread regarding some film caps available through Mopuser and took a beating from R.G. because, though they had the UF's and voltages in spec, they couldn't handle the current to operate in a power supply. I don't know exactly how to determine this from the given specs. Nomenclature and industry speak, along with the logarithmic math can put me off any certainty.

[Enzo]

I freely admit this is not my area of expertise. I found it interesting and threw it up here. If they are not suited to our applications, I am sure RG or someone will point it out.

The data sheet does state that they are intended for power inverter and similar applications, and that they have "very high" ripple current ratings.

I am open to analysis.

[Steve Conner]

Nice, I was looking for something like this for an upcoming power electronics project. I think they would fit RG's Immortal Amplifier concept nicely too. The RMS current ratings are huge, 15 to 30 amps, far in excess of anything a tube amp power supply could throw at them.

[tedmich]

nice 4 lead black box caps! More subtle than these Italian Ducati motor run caps
New Ducati Capacitor 10uF 16 17 13EB En 60252 | eBay

or any of the similar CBB60 series motor run caps found on the ebay.

If we could just get them in black with a Red Ducati label...

[R.G.]

Sorry about the beating, Chuck. It was almost certainly a result of some of my early days in the power supplies lab where I kinda life tested a lot of parts. I did in fact cause some ceramic disk caps to sweat out impregnant, then toast, and some film caps to rupture their cases. We won't even talk about the stains on the ceiling from some electrolytics.

These things look GREAT! Polypropylene in oil is a very, very sturdy cap if it can be set up to get out whatever heat is generated in the ripple current losses. As Steve notes, the ripple current ratings are far, far above what would be minimally needed. I love it that they put in estimated life charts, with temperature lines. Keep these things cool and don't apply voltages over the rated ones, and they should last semi-forever.

[Enzo]

PLus at those prices, you can justify your boo-teek amp pricetags.

[pdf64]

Has anyone tried these caps yet?
It occurred to me that with them having such a high ripple current rating, might they draw a high current surge at power up? eg higher than the electrolytics normally used for this application.
Which might stress the rectifier, fuse etc, unless some mitigation was made, eg PTC surge suppressor.
But worth it for long life, high performance, not-esoterically priced B+ caps.
Pete

[Enzo]

I wouldn't think their ability to handle high currents would mean they NEEDED high currents. Just as using a heavier power cord would not make an amplifier use more power. I am out of my depth, but I had thought ripple current rating was more about how robust the connections were inside the part. For example, in a large filter e-cap, the capacitor part is a couple foils rolled up, then from them, small wires go to the terminals to go outside the container. If you charge up some hefty cap, and them short it out with a screwdriver, you might burn up those inner connecting wires as if they were fuses - voila, dead cap.