Different between AC and DC magnetic field.
I need to set up a test system to measure the operating magnetic field emission of the products. I know there are 2 type of operating magnetic field which will be emitted from the product in operating mode which is DC magnetic field and AC magnetic field. So, what is the different between this two?
Basically, the difference between an AC and DC magnetic field are that a DC magnetic field emanates from the earth naturally that is what allows a compass to find magnetic North; while AC magnetic fields emanate from man made electrical systems (power lines, transformers, computers, and anything with an electric motor). I would say that the type of field you are going to be measuring is going to be an AC magnetic field, unless you are testing MRI machines which do create there own DC field. This is a very brief description lacking many details. There are many sources out there that can better explain the differences between AC and DC magnetic fields. I hope this helps.
Andrew:
As you noted the most prevalent DC or quasi-DC magnetic field is the result of the earth’s magnetic field, but as you further noted DC or more correctly uni-directional magnetic fields can also be produce by man-made sources as noted in your reference.
Any time current flow through a wire a magnetic field is generated. If that current is Direct Current the resultant magnetic have a constant orientation. If the current is AC or alternating current the the magnetic field will vary in direction and intensity, hence the term AC magnetic field. This is also known as radio frequency radiation. It can vary in frequency in Extremely Low Frequency all the way up to Extremely High Frequency [1]
Niel Leon
engineering.com
An excellent and free series of PDF manuals on anything electronic are the Navy Electricity and Electronics Training Series (NEETS) manuals. I am posting the specific guide to your question here but there about 23 different manuals and they are all available online!
