# Controlling a mechanical shutter with an electromagnet

I'd like to drive a pair of mechanical shutter / apertures with an electromagnet. For those curious, we're using a shutter from Edmond optical. For the particular application, I'd like to design a compact actuator to drive it. (I had considered just hacking a camera lens with a shutter, but couldn't find one that was large enough for my needs).

So at present I am thinking about attaching a neodymium magnet to the lever of the shutter and then using a series of electromagnets to push it between open and closed. Which all leads to my first question: how can build compact electromagnet?

It seems like the steps involved are to find a solenoid and then to drive it with a decent voltage difference. I wonder if anyone could recommend a good small solenoid for such purposes. Does it make more sense to roll my own with an iron core and insulated wire?

My second question is more open-ended: can you think of a better way to drive such a shutter? How would you design the shutter motor?

@tyblu the shutter needs to be open or closed in about 500 microseconds (but exactness is not important).

@bt2 a solenoid is interesting, are you thinking of hitting the lever and letting momentum carry it across to the close position?

• You can buy solenoid motors, is that what you are talking about here? I would think it much easier to buy a solenoid motor than create your own. You can search by stroke and power. I'm guessing you don't need much of either.
– bt2
Commented Jan 19, 2011 at 5:32
• How quickly does it have to open and close? Commented Jan 19, 2011 at 5:34
• Shutter != Aperture. A shutter has two states - Open and Closed, and cycles between the two very fast. An aperture, (which is what you linked), often will never fully close, and has degrees of openness, related to the size of the opening. If you want to control a shutter, an single electromagnet will suffice. If you want to control an aperture, more is involved. Commented Jan 19, 2011 at 6:10