Electric Drawer Opener: Choose Magnet, Find Current Strength

[johann1301]

Im planning to build a drawer which can be opened using an electric switch. I've thought of perhaps using a strong servo to push the drawer, hydraulics or an electromagnet. But i think the simplest and cheapest solution would be to attach a strong magnet on the back of the drawer, and setting up a wire with a high current running through it behind the drawer. This current is controlled by the electric switch. When the current is on there will be a magnetic force acting on the magnet, and thus on the drawer.

I know that the force on the drawer from the wire needs to be about 20N or more. Does anyone know how strong of a magnet i must buy, how high the current must be?

 

[berkeman]

Im planning to build a drawer which can be opened using an electric switch. I've thought of perhaps using a strong servo to push the drawer, hydraulics or an electromagnet. But i think the simplest and cheapest solution would be to attach a strong magnet on the back of the drawer, and setting up a wire with a high current running through it behind the drawer. This current is controlled by the electric switch. When the current is on there will be a magnetic force acting on the magnet, and thus on the drawer.

I know that the force on the drawer from the wire needs to be about 20N or more. Does anyone know how strong of a magnet i must buy, how high the current must be?

What do you mean by "open the drawer"? Do you want it to just pop open by a few inches so you can pull it the rest of the way open? Or do you want it to roll all the way out like a CD player drawer?

If just popping open would work, you can use a spring for the last few inches of closing the drawer, and have an electric latch that releases the drawer so the spring pops open a bit.

If you want it to roll all the way out, I'd recommend using a setup like the CD payers use. Pushing a button causes the drawer to roll all the way out, and either pushing the button again or pushing the drawer a little makes it retract back in.