Recent content by opster

Hello, I'm designing a magnetic device very similar to a speaker circuit (i.e. a bottom and top plate, a central pole, and a ring magnet). The only exception is that I'm adding an adjustable leakage path on the outside diameter, and inserting a coil in the empty space between the ring magnet...

I don't think so. I have two 1in diameter by .5inch length NdFeB magnets and they would give around .4T over that gap, but the field is not uniform at all, a lot stronger in the middle and weaker as you head towards the edge (by about 50%). I probably could have designed the circuit to eliminate...

I'm in need of a integrating flux meter. Does anyone know of one that is below $1000.00. I've been sampling the voltage at 5000Hz and digitally integrating, but I still I have some drift (1%of reading per second) that has been giving me a headache.

I'm currently working on two projects that deal with magnetism, and one of them invlolves pulling a piece of iron .75x.6x.1in from a distance around .3-.5inches. I have been able to generate a force of 2 to 4lbs, with a 1inch cube permanent magnet (NdFeB). The pulling force is varied (1 to 4lb)...

I'm done! Everything went well. I ended up with 14.5gauge wire rated at 200C. The vendor wasn't going to have 14gauge in for a few weeks, so I settled. For a recap: Structure (frame): "As I mentioned before I have a space restriction that limits the pole center to be 4.5" off the ground. What...

Mike, Sorry, my fault. I checked my spreadsheet and realized I used 10% oover the gauge diameter (for insulation) and then an additional 15% for random wound so that's how I got 18lbs per coil. Oh well, if the magnet doesn't end up being strong enough I'll get some more wire.

Mike, I think you meant 18 pounds per coil and roughly 14000 turns per coil, right? Else I'll need to get some more wire. Saul

For an update, I have nearly finished constructing the electromagnet. The frame is done. As I mentioned before I have a space restriction that limits the pole center to be 4.5" off the ground. What I ended up with was 1.5"x4" cross section steel for the base and two yokes (I think that's the...

Oh, Actually the trial version I have been using is the 2D version of Magnet. I like it a lot better than the other trial version by Maxwell, but it's still a trial version so I haven't been able to simulate a exact design, only an approximation. Thanks for all the help, I'm going to talk...

Thank you MJR2, Are you working with something similar to MREs also?

so with 1.75inch poles and 1.75 inch (diameter frame), I have a coil ID of 1.75in and an OD of 5.5in. The coils can be as long a reasonable. The electromagnet needs to be able to operate for at least 5 min at a time with say 20 min inbetween, pulse operation won't work.

I've really not been clear, so please excuse me, I'm usually never this bad. What I need is a electrolmagnet capable of nearly saturating a rubber with 29% iron particles. I've seen journal articles where a air gap (nothing inbetween the poles) flux density of 0.45 T was sufficient to get to the...

Didn't see the last part of your reply. I'm going to have a double lap shear fixture inbetween the poles. The fixture is attached to a high frequecy horizontal tensile tester. The specimen is going to be some soft rubber with iron particles, 30% iron 70% rubber (MRE magnetorheological...

Thanks MJR2, I'm sorry but I meant 0.6T not 2T. Could I wind the coil by hand? Also I plan on running the electromagnet for 20 min periods with say an hour break. I could calculate the heat transfer and all of that, but in your opinion will the coil I described above be able to handle say...

I'm very sorry, for calculations above ID =1" OD=8"