Design Con 2015
Breaking News
News & Analysis

The Ampere, Redefined

4/11/2014 00:01 AM EDT
24 comments
NO RATINGS
1 saves
More Related Links
View Comments: Newest First | Oldest First | Threaded View
<<   <   Page 3 / 3
MeasurementBlues
User Rank
Blogger
Re: Ampere's long arm
MeasurementBlues   4/11/2014 2:29:19 PM
NO RATINGS
@Sheepdol,

Franklin flew his kite on a Philadelphia night;
He saw that lightning was electricity.
Coulomb could tell that like charges repel
By the inverse square of their distance.
Orsted saw magnetic fields make a compass needle yield
When current passed through a nearby wire.


From my song, Electrical Heroes


Sheepdoll
User Rank
Blogger
Re: Ampere's long arm
Sheepdoll   4/11/2014 1:58:37 PM
NO RATINGS
I have a number of old science text books. Some dating as far back as the 18th century. Most of this relates to static electricity.  What I found interesting was how the quantities were measured.  Franklin's spark gap was used.  The length of the spark was what we call voltge.  The diameter of the spark was the current.  To measure the current a card was placed into the gap.  The spark would then burn a hole through the card.

 

MeasurementBlues
User Rank
Blogger
Re: Ampere's long arm
MeasurementBlues   4/11/2014 10:07:07 AM
NO RATINGS
Here's a link to NIST about the SI units.

http://physics.nist.gov/cuu/Units/units.html

 

MeasurementBlues
User Rank
Blogger
Ampere's long arm
MeasurementBlues   4/11/2014 10:05:47 AM
NO RATINGS
The Ampere is one of just seven basic units of measurement. Others are the kilogram, meter, Kelvin, second, Mole, Candela. But, the ampere is used to derive many other units of measurement such as the Farad, Ohm, Henry and yes, even the volt.

 

<<   <   Page 3 / 3
Flash Poll
Like Us on Facebook

Datasheets.com Parts Search

185 million searchable parts
(please enter a part number or hit search to begin)
EE Times on Twitter
EE Times Twitter Feed
Top Comments of the Week