Nasa has used them to remove magnetic fields from objects (ie, a residual field on a piece of hardware going into space). You don't want to go to the red planet and worry about ferrite gunking up your mechanics or sensors. You can use the coil to cancel out the Earth's magnetic field, and then test CRT tubes inside it. You can test sensitive electronic equipment in a strong varying field before deploying it to a factory where it'll reside next to a monster motor winding. You can construct plasma balls inside it and know they aren't going to zip around due to external fields (or make them move according to your needs). You can place atmoic clocks in them to make sure external fields are compensated for and don't affect the accuracy of the clock. You can use it with a very sensistive field detector in a closed loop to enhance the sensitivity or range of the sensor. -Adam On Wed, Aug 6, 2008 at 8:10 PM, Forrest Christian wrot= e: > That's pretty much what I got from it... I was just wondering if there > was some non-obvious but useful application not in the realm of > scientific experiments as about the only thing I could figure out was > basically what you came up with - some esoteric science experiments and > perhaps testing certain sensors such as electronic compasses and the > like - although it would seem that most apps I can think of would not > require such a complicated device. > > That doesn't change the fact that I love the fact that that when you > read the advertising slicks for real versions of this, they sound like > something which some science fiction writer would have just made up. > > -forrest > > Sean Breheny wrote: >> I had to look it up but it looks like it is simply an arrangement of >> coils used to generate a very uniform magnetic field in a volume - >> probably for science experiments and possibly medical instrumentation. >> >> http://en.wikipedia.org/wiki/Helmholtz_Coils >> >> Sean >> >> >> On Wed, Aug 6, 2008 at 2:56 AM, Forrest W. Christian wrote: >> >>> Are you trying to build a time machine? >>> >>> Sorry, that was my first impression (meaning a "Helmholtz coil" sounds >>> like the type of weird concoction which would be part of a time machine >>> - you know right alongside the flux capacitor), and after looking at the >>> pictures of the gear and reading the datasheet at >>> http://www.meda.com/Data_Sheets/hcs01.pdf , I'm not 100% convinced that >>> a Helmholtz coil isn't the key component in either a time machine or >>> other similar devices. >>> >>> After all, anything which includes the following description: >>> ----------- >>> "In the open loop system, fixed currents are passed through the coils to >>> produce a coarse null in the control volume. The null is trimmed to its >>> final value under computer control. Precision control currents are added >>> to the fixed currents to generate accurate and stable uniform fields >>> within the control volume" >>> ----------- >>> *has* to be from some science-fiction story. Especially when the >>> features include "Three Square Concentric Orthogonal Helmholtz Coils" >>> and "=B1200,000 nT Control Field Range." >>> >>> So on a more serious note, what exactly do you use a Helmholtz coil >>> for? In the real world, that is...all of the purposes I could come up >>> with seem rather esoteric or more easily obtained in another way. >>> >>> -forrest >>> >>> >>> Jonathan Hallameyer wrote: >>> >>>> Hello All, >>>> I'm looking to buy a tri-axis helmholtz coil system and having a bit >>>> of difficulty finding manufacturers of such systems with google, The >>>> Ive found a couple, but the majority of the results are technical >>>> papers and links to patent sites. Anyone know of any manufacuturers, >>>> or a better search engine to use? Ive tried globalspec but that >>>> returns nothing at all for "helmholtz" >>>> >>>> Thanks, >>>> Jonathan Hallameyer >>>> >>>> >>> -- >>> http://www.piclist.com PIC/SX FAQ & list archive >>> View/change your membership options at >>> http://mailman.mit.edu/mailman/listinfo/piclist >>> >>> >> >> > > -- > http://www.piclist.com PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist > -- = EARTH DAY 2008 Tuesday April 22 Save Money * Save Oil * Save Lives * Save the Planet http://www.driveslowly.org -- = http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist