rahulan999
New Member
audioguru, can u explain how can we wind the magnet wire on such a shape??????what has the shape do it with it.Explain?
Follow along with the video below to see how to install our site as a web app on your home screen.
Note: This feature may not be available in some browsers.
audioguru, can u explain how can we wind the magnet wire on such a shape??????what has the shape do it with it.Explain?
If a magnet has a straight bar core then there is only half the magnetic field at one end of the core.what has the shape do it with it.Explain?
It has everything to do with it. The objective is to attract and hold paper clips. A complete magnetic circuit (U or double-U shaped) will probably hold more paper clips than a single ended magnet.what has the shape do it with it.Explain?
A complete magnetic circuit (U or double-U shaped) will probably hold more paper clips than a single ended magnet.
Thank you for the help jpanhalt. I live in Maryland, US but currently I am in Indonesia and I will be in Thailand next week. The competition is 5 months away, so I have some time. I was thinking of going to an iron art shop to get the core.
I want to try putting in some switches to do one electromagnet for maximum lifiting and parellel electromagnets for fast moving. I have a feeling you will still be right, but I have a few months, so I want to try a few prototypes.
I am way out of my leauge on calculating the size of the core as to avoid saturation. I found a good website for this but the concepts are too advanced for me. I will try to post it when I get back to my computer.
When I start building I will make a new thread with pictures, test results, and a summary of what has been discussed so far.
Some questions:
My concern is that a switch might add too much resistance. Do you think 5 switches would add an appreciable ammount? Is there a certain style of switch that is better?
Is there a type of solder that would be good for this application? Low resistance and able to withstand the heat.
I have some old PC heatsinks. Would It be helpfull to dremel them up and use thermaly conductive epoxy to secure them to the upper side of the electromagnet? Or would the wire still fuse at the same current because the lower side would have no help.
Trisorion said:Some questions:
My concern is that a switch might add too much resistance. Do you think 5 switches would add an appreciable amount? Is there a certain style of switch that is better?
Is there a type of solder that would be good for this application? Low resistance and able to withstand the heat.
I have some old PC heatsinks. Would It be helpfull to dremel them up and use thermaly conductive epoxy to secure them to the upper side of the electromagnet? Or would the wire still fuse at the same current because the lower side would have no help.
Now I need to make some circuits to test batteries.
I'd use published specs.
the current may be ~20 amps, most multimeters I have seen max out at 10 amps.
The meter movement in my cheapie analog VOM takes 1 mA to give a full scale reading which translates to 400 mV. Using the 150 mA scale as a voltmeter connects you directly to the meter movement.
Iron coat hanger wire has 6x the resistance of copper wire; sand off the paint and make a load resistor out of one foot of wire or so and tap off the wire to get a full scale reading for whatever meter movement you use.
You only need relative readings.
Careful, the wire gets pretty hot.
Also, volts out vs. amps through for this shunt is pretty non-linear because of the temperature coefficient of resistance for iron. Again, relative readings are what counts.
Power: 1.2 volts 40 amps
Wire 1: .05 ohms 24 amp max
Wire 2: .05 ohms 24 amp max
Wire 3: .025 ohms 48 amp max
Total: 96 amps total