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klugesmith

Tue Dec 07 2010, 05:56PM

Registered Member #2099 Joined: Wed Apr 29 2009, 12:22AM
Location: Los Altos, California
Posts: 1716

The capitalization of the unit symbol (cal,Cal) has nothing to do with the capitalization of the unit name.
s, S, ns, nS, nSv stand for second, siemens, nanosecond, nanosiemens, nanosievert.

From Wikipedia:
In an attempt to avoid confusion the large calorie is sometimes written as Calorie (with a capital C). This convention, however, is not always followed (and is sometimes impossible). Whether the large or small calorie is intended often must be inferred from context. When used in scientific contexts, the term calorie refers to the gram calorie. In nutritional contexts, however, a larger unit is more useful. In such contexts the term calorie can be taken to refer to the kilogram calorie. The term kilocalorie (symbol: kcal) can also generally be taken to refer to 1000 gram calories since metric prefixes tend to be used only with the gram calorie.[citation needed]

Examples where following the convention is impossible in proper written English:
1) When the word for small calorie is the first word of a sentence.
2) When the word for large calorie is attached to a prefix such as kilo or milli.

pauleddy

Tue Dec 07 2010, 08:11PM

Registered Member #2909 Joined: Wed Jun 09 2010, 12:31AM
Location: fort belvoir, Va USA ( south of DC)
Posts: 145

for a science fair i studied the the force applied to a metal disk by a varied energy pulsed magnetic field, i basicly had 10 identical flas caps that i ran trials with. seing how high, inturn how much force, the disk went. i add one cap at a time (with my costume varieble capcitor bank) and did the math. i evently had the disk fly nearly 3 meters. thats pritty good for 1000uf at 300v.
but i now have a .0376F bank at 800v which is about 12Kj ithink i had the same type of scorch marks on my drive way, but i never found my penny, just had a ringing noise in my ears and a after image of where it was, from charing test for my future railgun project.

wylie

Wed Dec 08 2010, 09:28PM

Registered Member #882 Joined: Sat Jul 07 2007, 04:32AM
Location:
Posts: 103

Now if only you could harvest that all into a capacitor right

In a way, that soda IS a charged capacitor, just takes some oxidizer (and possibly a source of ignition) to discharge.

Electroholic

Thu Dec 09 2010, 01:26PM

Registered Member #191 Joined: Fri Feb 17 2006, 02:01AM
Location: Esbjerg Denmark
Posts: 720

This IRFP264 got a little bit too hot, the silver stuff you see between the copper/plastic junction was the die attach solder.

This was C-clamped to a heatpipe based heatsink out of a laptop.
I was logging a 9A discharge curve for a 4S lipo pack that i got, using this and a 1ohm resistor as the dump.

Arcstarter

Fri Dec 10 2010, 09:17PM

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

I got some small 700v 20w dissipation horizontal amplifier tubes from eBay. It was a lot of 8 for 6 dollars plus 11 shipping, and this is what i received...

Ten tubes

. When i first opened the box and picked up a tube in it's original box to check the condition, it dropped 4.5 feet onto the tile floor due to a ripped box! The little sucker did not break!

Now, i still have some GU-50's coming

Turkey9

Sat Dec 11 2010, 08:52AM

Registered Member #1451 Joined: Wed Apr 23 2008, 03:48AM
Location: Boulder, Co
Posts: 661

Haha nice. Gotta love people that have a hard time counting.... Good thing you didn't receive 6 instead!

Arcstarter

Sat Dec 11 2010, 09:10PM

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

Turkey9 wrote ...

Haha nice. Gotta love people that have a hard time counting.... Good thing you didn't receive 6 instead!

Indeed! Some damn quality tubes, too. I ran it with a fairly cool plate (just a tiny bit of color change on the edges of the plate where the two halves meet) but a molten screen grid and it still works! I accidentally ended up with CW DC on the screen and AC on the plate due to a dead diode... Anyone well versed with tubes knows that is bad!

Adam Munich

Thu Dec 16 2010, 12:41AM

Registered Member #2893 Joined: Tue Jun 01 2010, 09:25PM
Location: Cali-forn. i. a.
Posts: 2242

Internal current limiting my ass, this 7805 died with a bang.

Ken M.

Thu Dec 16 2010, 01:09AM

Registered Member #618 Joined: Sat Mar 31 2007, 04:15AM
Location: Us-Great Lakes
Posts: 628

It was current limiting, and current reserving, reserving all the current in its silicone die, it just decided it couldn't handle it any more.

Dalus

Wed Dec 22 2010, 08:58AM

Registered Member #639 Joined: Wed Apr 11 2007, 09:09PM
Location: The Netherlands, Herkenbosch
Posts: 512

Another sneak peak of my ongoing project.

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