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powerfull, small, 12volt electromagnet
chrisg - 10/7/05 at 07:59 PM

Anybody any idea where I could get one of these?

Thanks

chris


MkIndy7 - 10/7/05 at 09:29 PM

I think Ford Fiestas with Injection have a 12v Solenoid on them to let fuel vapor into or out of the carbon canister in the front wing.

Might be of some use to ya,

Or ya could reveal what secret use its going to have...... so we can suggest a bit better.


jack trolley - 11/7/05 at 06:32 PM

Central-locking solenoids?


johnjulie - 11/7/05 at 06:46 PM

You could try a boot release mech off an old Fiesta etc.
What exactly do you want to do with it?
Cheers Johnj


chrisg - 11/7/05 at 07:21 PM

it's to use on the back of my side screens to stop them flapping.

That's why solenoids are no good.

The idea is to put a piece of metal on the sidescreen which is attracted to the electromagnet fixed to the car when the ingnition is switched on.

Obviously the metal would be released when the ignition is cut, thereby allowing you to get out.

simple and efficient but seemingly impossible!

Cheers

Chris


MkIndy7 - 11/7/05 at 08:59 PM

I likes the thinking, very clever.

Can't you make them, by wrapping wire around a iron core I seem to remember it being that easy at school.

Mercedes and Jags have something similar that pulls the doors and boot closed after you've gently shut them.

Couldn't the solenoids push out and through something to lock the sidescreens and if spring return they'd retract out of the way when the power is cut?


ady8077 - 11/7/05 at 09:18 PM

Hi Chris

I doubt you'd need an electro magnet, i'd have thought the flexy strip magnet you get from model shops for making fridge magnets would do ? its not very strong but should hold it closed?

Adrian


paulf - 12/7/05 at 12:10 PM

I would have thought that cupboard door latches would do the job.RS sell holding magnets which are a round electromagnet but not sure of what operating voltage range they do.
A similiar type of electro magnet is often used in factorys and public buildings to hold fire doors open , the doors shut automatically when the alarm operates
Paul.


clbarclay - 12/7/05 at 04:16 PM

The easy way to an electro magnet is to get a long length of wire and wind your own. The only dificulty is getting the balance of wire diameter, resitance and number of coils.


chrisg - 12/7/05 at 06:45 PM

Thanks for the replies chaps. I've tried the flexy magnet stuff which sort of works i.e some times it holds a little too well and you're trapped and other times it springs off, which is why I thought of a magnet that holds while the power is on.

I found these

link

Do you think they'd be suitable?

If you click on the individual items they have spec sheets, which I can spot with my very limited electrical knowledge that they do a 12 volt one.

I've e-mailed them and I'll let you know

Cheers

Chris


johnjulie - 13/7/05 at 07:46 PM

I think you may have problems with them getting very hot after some time. Keep it simple, use straps and poppers as on the Caterham.
Cheers J&J


splitrivet - 14/7/05 at 05:53 PM

Come on tell the truth Chris its really for attaching to the front of your car and switching on when a bus goes past to save fuel.
Cheers,
Bob


chrisg - 14/7/05 at 06:49 PM

Damn!

busted by Bob!

i've got loads of ideas running round my head after last night's meeting.

Just to explain the side screens are held by a solid hook which goes over the horizontal side of the cockpit, which works very well as a primary fixing, it's just the back that"flaps" too far back for you to reach when strapped in.

I understand that electromagnets work better the other way round i.e on for a short time because of the heat.

I'll keep you informed

Cheers

Chris


MkIndy7 - 14/7/05 at 10:02 PM

Some electro magnets can be energised for years

Those fitted on gas solenoid valves on pipelines (in industry) as emergency knock offs in kitchens etc.

They stay energised 24/7 until somebody hits the knockoffs or the fire alarm is activated.
Admittedly they run pretty hot and probably aren't holding that much pressure open, but they are reliable for a good number of years constant use.


johnjulie - 15/7/05 at 08:13 AM

You have the same problem on the Caterham with the back one, espcially with a harness fitted, but, you get used to reaching round with the opposite arm to open and close it. Is yours out of reach?
Cheers John


MkIndy7 - 15/7/05 at 11:04 PM

Just remembered a cheep source of powerful normal magnets to try.

The 1's that hold the closed till chains up at supermarkets,
occasionally you find that they get stuck to your trolley as you push them through the checkout and end up outside while your packing your car.

Not really sure how this phenomenon happens but there pretty powerful magnets.


chrisg - 19/7/05 at 03:18 PM

I'd probably be better driving the trolley!

Cheers

Chris