Thanks for the thoughts!
I guess I didn't mention this is not a one off thing.. I'm looking for something repeatable & manufacturable which is why there is emphasis on low cost.
Willi, I understand your idea but do not think that labor operations can possibly be lower cost than an off the shelf part that is placed my a machine. I apologize for not stating that.. but I did think about your idea of winding my own (well it would be a custom built part)
Ron H,
I agree externally I would need lots of ampere turns but these reed switches are spec'd at 10-15 AT (which isnt alot imo) _but_ this is at a specified distance so some experimentation is required to see how much I have to boost it for my increased distance.
Also I'm not an opto guy!
But I did consider opto-coupled devices.
Klaus, thanks for the info about the iron cored inductor.. I guess air cored is out (I was thinking more turns would be available with this type)
A little more elabortation may be in order,
I'm looking to get extreme capacitive isolation from relay coil driver to the contacts. I can accomplish less than 0.1 pF with an external coil. Incidently, relays are offered with this amount of isolation but they are expensive. This is why I couldn't swing an opto-fet/tran type of device.
Other details: switch can be low voltage (no 100V+ requirement)
must carry 1.0A or better (tough for hi isolation opto devices)
dont' care how long it takes to switch or bounce or any similar antics.
I need life of switch to be > 500e6 cycles. I'll be switching gently (no hot switching)
Sounds like a coil with sufficient strength is the answer.. but how to do it low cost? I've thought about wacky things like using a dummy (but strong) relay as my off-the-shelf pre-built coil driver.. or inductors or somehow permanent magnet but I'm not sure how to move it around in a low cost way..due to reliability, a low cost motor is out.
Thanks for the thoughts guys! If there are other considerations, please share them I think I'm going to go iron core inductor hunting..