Yes, there is still an air core but the formula is the same as that used for an air core only.
Reluctance=(length/cross-section)x (1/mu)
It seems for an air core only the length should be
2 times the length plus 2 times the distance at each end. But I don't see this anyplace...
The URL below adds iron to an air core solenoid to reduce
the reluctance and increase force.
The author calculates the reluctance of an air core as R1.
He then calculates the reluctance of two iron end plate washers as R2 and R4.
Then the iron tube around the air core as R3.
He then adds...
My thoughts of driving an existing device (120v 60hz)
at different frequencies has been disappointing.
The efficiency is very poor as I move away from 60hz.
Not much vibration anywhere except 60 hz, even though
the voltage remains constant.
I have a solenoid with a 5/8" hole in the center...
Glad to hear you have .0001 working.
Is the hard drive "voice coil" you talk about the head drive mechanism?
I think low noise is an important characteristic to work towards.
I would like to see the pictures of .0001.
I bought a 25 watt stereo amplifier last night at
radio shack for...
Regarding complex waveforms; I question how much
effect they would have. My reasoning is, the coil (inductor) is trying to smooth the waveform that you apply and the mass you are moving will be slow to respond to force and continue movement when force is removed.
You mentioned a 1 to 5 watt...
I'm curious how you arrived at 80hz as being the sweet spot. (Maybe I should say how accurate is your research and did it cover a wide demographic?) I was thinking variable frequency from 25hz to 300hz, with variable power. I also wonder about sine, square and triangle wave drive. I've...
