Allen Bradley type EJ coil operation

I was just curious if anyone could tell me how the Allen Bradley economizing contactor/relay coil "EJ" works? They list it as an "Electronic Coil" and it initially consumes 17 watts to pull in and drops to 1.7 watts to hold in. I am familiar with the electro-mechanical version of this that uses an economizing contact that drops out when the relay pulls in but how does the "Electronic" version operate. I cant find any literature anywhere on this anywhere. Thanks for listening.

John

I found a product profile page on the coil, but it's in Japanese . Google translate helps a little. I think I read something about a timer circuit. I'm guessing in uses 17 watts for a certain period of time and then restricts the current after that.

"product profile page()":http://literature.rockwellautomation.com/idc/groups/literature/documents/pp/100-pp028_-ja-p.pdf

Thanks Zachary.