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lokeycmos

Sat Oct 15 2011, 03:43AM

Registered Member #2553 Joined: Fri Dec 18 2009, 01:36PM
Location: St Cloud Minnesota
Posts: 97

this will be my 1st SGTC, more of a learning experience than anything else. i dont have the money to buy the caps i need, so im goona give the bucket cap a try. had a few Qs for others that have used these.

whats the average uF? how reliable? what is shelf life? How bad is the ESR? do they eventually go bad due to either overusage or age?

Goodchild

Sat Oct 15 2011, 05:00AM

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

You know an option you may want to look into that would be way better than a bucket cap would be a laminated cap made from like HDPE and aluminum or copper sheet.

I can't imagine it costing much more than $50 to make and would look supper pro and probably last a long time.

Basically you just sandwich the sheet metal in between the HDPE, using the HDPE as your dialectic. Now the capacitance would be very easy to calculate because you will know the surface area and the thickness of your dialectic. The thicker your dialectic the high the voltage rating (and lower C), and the more layers you stack makes for more capacitance. Very easy modular design that would be easy to assemble.

Just a thought, I don't know much about bucket caps

Jamie Cansdale

Sun Oct 16 2011, 03:25PM

Registered Member #3904 Joined: Sat May 21 2011, 10:32AM
Location:
Posts: 28

My 8 bottle bucket capacitor is 5.9nF. I'm not sure how to measure the ESR for such a low capacitance.

They're very easy to make and it's simple to add extra bottles while tuning the coil.

The main problem I've found is that it's bulky compared to the rest of the coil. I'll probably put together a more portable MMC next.

lokeycmos

Mon Oct 17 2011, 02:52PM

Registered Member #2553 Joined: Fri Dec 18 2009, 01:36PM
Location: St Cloud Minnesota
Posts: 97

Jamie Cansdale wrote ...

My 8 bottle bucket capacitor is 5.9nF. I'm not sure how to measure the ESR for such a low capacitance.

They're very easy to make and it's simple to add extra bottles while tuning the coil.

The main problem I've found is that it's bulky compared to the rest of the coil. I'll probably put together a more portable MMC next.

how reliable is it? does it have a shelf life? does it degrade over time? does its bulkiness and ineficencies adversly affect the output of the coil? doesnt the salt eventually precicpitate to the bottom?

Jamie Cansdale

Mon Oct 17 2011, 04:05PM

Registered Member #3904 Joined: Sat May 21 2011, 10:32AM
Location:
Posts: 28

If you zoom in on the photo, you can see how it looked after less than a week. The bucket and copper started off nice and clean. There's now a film over the water and the copper is starting to tarnish.

This is my first coil and it has only been up and running for a little over a week. With my variac turned half way up, I'm getting strikes to the window (which is 5 inches away). Its bulkiness limits where I can put it more than anything. I haven't tested it at full power yet.

I'd definitely recommend giving a bucket cap a try. :)

lokeycmos

Mon Oct 17 2011, 10:21PM

Registered Member #2553 Joined: Fri Dec 18 2009, 01:36PM
Location: St Cloud Minnesota
Posts: 97

i made one today! 12nF heres a link

here is it arcing:

Jamie Cansdale

Tue Oct 18 2011, 12:06AM

Registered Member #3904 Joined: Sat May 21 2011, 10:32AM
Location:
Posts: 28

Nice capacitor. It has to be bottles of corona doesn't it? :)

Tue Oct 18 2011, 02:15AM

Registered Member #4146 Joined: Tue Oct 18 2011, 02:01AM
Location: Wisconsin, U.S.A
Posts: 56

Nice cap, was that used motor oil? i actaully made a 5 gallon cap out of 7 1 liter big mouth bottles and a 2 liter bottle used sidewalk salt instead of table salt. Its working pretty well and measures at around 48nf odly i figured it would degrade but to my suprise its gaining capacitance. here is a pic if you would like a looksy.

lokeycmos

Tue Oct 18 2011, 06:48PM

Registered Member #2553 Joined: Fri Dec 18 2009, 01:36PM
Location: St Cloud Minnesota
Posts: 97

Lord Raiden wrote ...

Nice cap, was that used motor oil? i actaully made a 5 gallon cap out of 7 1 liter big mouth bottles and a 2 liter bottle used sidewalk salt instead of table salt. Its working pretty well and measures at around 48nf odly i figured it would degrade but to my suprise its gaining capacitance. here is a pic if you would like a looksy.

no i used new motor oil. i just got the cheapest i could find.

Tue Oct 18 2011, 10:22PM

Registered Member #4146 Joined: Tue Oct 18 2011, 02:01AM
Location: Wisconsin, U.S.A
Posts: 56

ahh ok it just looked really dark in the picture my bad

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