# magnetism

#### Ashraf Ali

Joined Nov 2, 2007
6
hi,
i would like some advice on the below theoritical circuit.

the circuit has to give an output in the form of magnetic pulses using a electromagnet, so i have thought of employing a counter circuit connecting the output to a power amplifier and finally to a electro magnet,
now when the counter finishes one cycle it would give one impulse which would be amplified and fed to the electromagnet so magnetic field can be produced in the desired pulse mode.

now my doubts are . .
which material to use so i get the optimum intensity of the field,
can i use a trigger circuit between the counter and amplifier,
how to calculate the field equations for the same.

#### Mike M.

Joined Oct 9, 2007
104
hi,
i would like some advice on the below theoritical circuit.

the circuit has to give an output in the form of magnetic pulses using a electromagnet, so i have thought of employing a counter circuit connecting the output to a power amplifier and finally to a electro magnet,
now when the counter finishes one cycle it would give one impulse which would be amplified and fed to the electromagnet so magnetic field can be produced in the desired pulse mode.

now my doubts are . .
which material to use so i get the optimum intensity of the field,
can i use a trigger circuit between the counter and amplifier,
how to calculate the field equations for the same.
As far as the material for optimum intensity goes, try looking into permalloy. What kind of field intensity were you aiming for and what are the maximum size requirements for a magnetic package? Here are some field equations. Note that a large current is required for a relatively low density field. You may want to go with a Neodymium magnet surrounded by a "c" shaped permalloy material attached to a solenoid for greater field density and lower power requirements, unless you need a very short duration pulse.

#### Ashraf Ali

Joined Nov 2, 2007
6
what i am aiming for is a uniform magnetic field anywhere between 0.2 T -0.5 T , generated by electromagnet into a box of area 225 sq cms . . the duration of each pulse can be in the order of 2 - 5 secs . . this set up has to be operational contineously for 2 days at a stretch . .