Once you find it difficult to turn the magnetic effect off.Very interested in this, when is a reverse pulse necessary?
Once you find it difficult to turn the magnetic effect off.Very interested in this, when is a reverse pulse necessary?
Let me use different words for that: A layer of dust, a few grains of sand, a piece of paper, will make almost zero difference in detecting what seems to be actual contact. As the plate gets within about a half a millimeter, the current will change, a lot, and that's easy to detect.Telling the difference between a few tens of micrometers will be difficult differentiating from true contact.
What do you mean? Is it not possible to build an EM that will alway let go when power is cut?You are making a permanent magnet.
If you have the right non-magnetizable steel. The longer you leave a magnetic field near most iron alloys, the more magnetic it will become. Swipe a sewing needle on a magnet, set it on a floating cork and you have a compass.What do you mean? Is it not possible to build an EM that will alway let go when power is cut?
That works for me. I'm just wondering about detection if it's there for only a millisecond or two. Can that be registered to an arduino?Let me use different words for that: A layer of dust, a few grains of sand, a piece of paper, will make almost zero difference in detecting what seems to be actual contact. As the plate gets within about a half a millimeter, the current will change, a lot, and that's easy to detect.
If you have the right non-magnetizable steel. The longer you leave a magnetic field near most iron alloys, the more magnetic it will become.
If you have the right non-magnetizable steel. The longer you leave a magnetic field near most iron alloys, the more magnetic it will become. Swipe a sewing needle on a magnet, set it on a floating cork and you have a compass.
LOL. You cleared that up nicely!Arduinos work at megahertz speed. A millisecond is like a week to them.
Well, maybe all afternoon.
Yes, I've played with these before. They're super strong, but I can't seem to get the same flux properties of the U shaped mags, meaning, the flux field on the round mags have 90% of their strength right on contact, with little left further away. The Us seem to spread it out a little more, pushing the flux field much further away, good for my application.When you lift with a DC electromagnet, on switch off there is residual magnetization that can retain the object, the traditional method is to give a short pulse in the reverse polarity to release.
H bridge control electronic or relay.
The solid iron core is a little more efficient on DC.
Here is one I have used in the past.
Max.
Yup, I've found that result from experimentation.Another reaction if continuous use heats the electro-magnet, it loses strength and in some cases lose effective lift capability completely for some heavy materials.
Max.
So, how long does it stay magnetized?If you have the right non-magnetizable steel. The longer you leave a magnetic field near most iron alloys, the more magnetic it will become. Swipe a sewing needle on a magnet, set it on a floating cork and you have a compass.
It must be like, years. Have you ever heard of a ship's compass crapping out in the middle of a voyage? Does your Cub Scout compass still work when you're 40 years old?So, how long does it stay magnetized?
You guys are hilarious.It must be like, years. Have you ever heard of a ship's compass crapping out in the middle of a voyage? Does your Cub Scout compass still work when you're 40 years old?
I get away with that because I'm kinda senior here, but some people don't bring their sense of humor and get all fussy with me.You guys are hilarious.
Please compress the file to 800x600 jpg for images and upload to the forum, this photo I already compressed it to 800x600, thanks.I didn't count honestly, as I'm just experimenting but it's gotta be on the order of 300 + ft. It certain is getting warm though. Here's a pic:
View attachment 93539
http://i.imgur.com/pbNzjzK.jpg
by Jake Hertz
by Aaron Carman
by Jake Hertz