Guess what this thing is

[turbo!]

It's a linear motor. Who can guess the era, what kind and what it is used for?



The magnets clam shell over the coil and the thing on the upper right is a back-to-back of IR LED and a dual element CdS sensor.

[Stray Electron]

  I haven't seen that one but we used something similar in the old Burroughs Corp. removable platter hard disk drives.  Disks were 14" in diameter IIRC. Single platter drives were 5Mb IIRC.  This was about 1977.

[CaptnYellowShirt]

A Flux Capacitor?

[Skimask]

https://www.google.com/url?sa=t&source=web&rct=j&ei=3-VRU5niMoamygHM24C4Dw&url=https://www.youtube.com/watch%3Fv%3D3WCvULMRUq8&cd=1&ved=0CCoQtwIwAA&usg=AFQjCNFramL46JglnSwLRyKJ1Dq3W6lFlw&sig2=ZGEeSEuMYR8aKseI3E10Tw

[senso]

High tech analog control flippers machine

[FrankenPC]

https://www.google.com/url?sa=t&source=web&rct=j&ei=3-VRU5niMoamygHM24C4Dw&url=https://www.youtube.com/watch%3Fv%3D3WCvULMRUq8&cd=1&ved=0CCoQtwIwAA&usg=AFQjCNFramL46JglnSwLRyKJ1Dq3W6lFlw&sig2=ZGEeSEuMYR8aKseI3E10Tw

It's not  mine, I SWEAR!

[SeanB]

It is ok, I can send you some spare parts if you need them.

[TerraHertz]

High end 8" floppy disk drive head-seek motor?
With the head assembly running on polished steel slides, with roller bearings.

I'm only guessing this because I've seen a similar arrangement in a big hard drive, and that looks like an 8" floppy drive die casting.

[turbo!]

High end 8" floppy disk drive head-seek motor?
With the head assembly running on polished steel slides, with roller bearings.

I'm only guessing this because I've seen a similar arrangement in a big hard drive, and that looks like an 8" floppy drive die casting.

Nothing to do with data storage.

[NiHaoMike]

Some optical assembly?

[TerraHertz]

Those are definitely spring-hinges at left and right. So there's something off-frame below that moves back and forth perpendicular to the plane of the picture.
Also the coil, if the magnets are mounted above and below it, will move perpendicular to the picture plane.
If those two moving objects are interconnected, they'd probably be linked by some kind of lever-reduction linkage below. Which would suggest the purpose was to achieve very small but precise movements in one plane, while retaining rigidity in the perpendicular plane.

How about... an LP record master disk cutting machine?

[houdini]

part of a precision scale

[han]

Laser Projector?

[turbo!]

Those are definitely spring-hinges at left and right. So there's something off-frame below that moves back and forth perpendicular to the plane of the picture.
Also the coil, if the magnets are mounted above and below it, will move perpendicular to the picture plane.
If those two moving objects are interconnected, they'd probably be linked by some kind of lever-reduction linkage below. Which would suggest the purpose was to achieve very small but precise movements in one plane, while retaining rigidity in the perpendicular plane.

How about... an LP record master disk cutting machine?

Yes to all, except the last one.

part of a precision scale

Yep.

The answer is magnetic balance cell. It works like a triple beam balance or mechanical balance in doctor's office. Instead of moving counter weights around to get it to zero, it pulls on it with an electromagnet.

There's no pointer to show balanced, but it uses a light beam and a slit. A variable current power supply is used to achieve the needed force to balance it out. The current needed to achieve this point is used to determine the weight. 

The magnets themselves drift with temperature. The sensor within the magnet is used to compensate it.

The whole deal is accomplished using a 1980s PID closed loop technology.

[CaptnYellowShirt]

A Watt Balance!

[turbo!]

A Watt Balance!

I just read this:
http://en.wikipedia.org/wiki/Watt_balance

I think its a bunch of gibberish. It says it is a better version of ampere balance, but the description of operation tells me its the same thing.

[Richard Crowley]

According to their explanation, we (engineers, scientists, etc.) have electrical measurements (amps, ohms, volts, watts, etc.) down pretty well and we can precisely measure and reproduce them around our planet.
So their scheme is apparently to transfer that knowledge and reproduciblity to the PHYSICAL world from our ELECTRICAL world where we apparently have it so well off.  So they will ultimately be able to "define" a kilogram (for example) in electrical terms.
At least that is how I understood it from a quick review.

[turbo!]

Here's a diagram of this unit I found online and the picture of  the analogue guts that go with this sensor block. 

The parts in red circles are what you can see in the picture in first post.

Diagram:


Analogue guts:

No idea what the National ME84202 is. Let me know if you guys know.