Magnetic Radiation

It is tough to get much range from a solenoid.  To double the distance ya' gotta square the power.  At some point you are looking  at a linear motor or some other soln.

One idea is to use a lever to increase travel.

Another idea is to use a short high current pulse to get maximum range. Once the actuator has pulled in, the holding current can be reduced.

Maybe you could even mount a second coil behind the first coil, once the actuator is pulled in enough with the first coil, activate the second coil and deactivate the first coil. The coils can overlap if needed.

Hi Les,

I got the impression from your question that you are using an open coil and that you are not talking about the travel of a plunger but rather the extent that the magnetic field extends radially from the coil. Is this so?

John

To be fair, you are describing a small linear motor, in a sense

Forever and ever?

Hello yes this is the case i.e. from a coil and core how do I achieve the maximum range ?  Given I have limited power i.e. a 12V battery.

I think, but don't know, If I pick the right core material it will help, not sure about geometric shape.

regards

Les C

Hi Les,

Could you use a boost converter to increase the voltage above the 12V available from the battery?

Best Regards,

Rachael

Hi

a boost convertor is something I had considered jumping from 12 to 24V but if I could find another way then I would take the most cost effective / reliable way.  Do you have in mind a circuit you have used to do this ?  I have had a trawl around the net but there are so many circuits out there I cannot evaluate them all and I would like the device to be as reliable as I can make it.

Les Collier wrote:

 

Do you have in mind a circuit you have used to do this ?

12V to 24V step up is a fairly common thing to want to do so there will be lots of circuits for this around. You've not given us too much detail on your coil, how much current does it draw from your existing 12V supply? This will affect the choice of converter IC. There are lots of cheap ready made converters available if you want to try an off the shelf solution, something like this maybe just to do some initial testing: http://www.ebay.co.uk/sch/i.html?_from=R40&_trksid=p2047675.m570.l1313.TR0.TRC0.H0.X401127469617.TRS0&_nkw=401127469617&_sacat=0

Be warned, you get what you pay for and often things like this which are cheap aren't good for a reliable long term solution. Test the theory with something like this and then look for a more permanent solution after you have proof of concept.

Can you draw a diagram of what you are trying to do, or at least explain it better. Generally speaking magnetism is not a long range phenomenon (ie it's pretty weak once you are separated from the source by a distance equivalent to the size of the source, eg the flux from a solenoid is pretty low once you are 1 solenoid length away from the end.) - if we understood what you are trying to do it might be possible to help a bit better.

MK