Camera Autowinder

This is probably a simple question for the people here but I have a Autowinder for an old film camera and would like to test it. I figure its a stepper motor inside and that it must be triggered by the shutter of the camera.

I did think that this would be a simple make then break circuit as the wind control distance appears to be part of the control dial. Anyway I have metered the pins and they have voltage across them equivalent to the sum of the batteries inserted in to it. Linking the pins does nothing. and there appears to be no other electrical connection as the PD between either pin and any other metal contact to the camera is 0v.

Can anyone help me understand how this may work please?

Here is what the unit looks like http://img814.imageshack.us/img814/6418/29022012104.jpg its the 2 pins on the left of the image that have voltage. If it makes a difference the unit works with a canon A1 and a few other old film cameras.

Thanks in advance

James

Hi James,
As no-one else has taken up the challenge . . .

If you find the winder's manufacturer's name and google it, they may have a website and a "contact us" link for asking technical questions, possibly a datasheet or repair manual they could email you.

Another idea would be to google up some "real" film photography sites, which most likely will have a variety of user forums for sharing information, Possibly there are user forums relating to the cameras (or manufacturers thereof) the unit is designed for.

You could google or look on Ebay for one of the cameras it fits, which might just be going cheap, as I expect digital photgraphy has by now mostly wiped out almost all of the market for film cameras.
(I was a keen photgrapher once, and I have a dozen or so beautiful film cameras and multiple accessories in a couple of boxes in my loft, untouched since I went digital.)

The motor may be an ordinary brushed motor, and the film advance distance limited by the camera mechanism, in the same way it is when you manually wind on, in which case the dial may simply adjust the time to cutoff the motor after winding. But I'm just guessing.

There appears to be another little tab sticking up at the other end from the contact pins. Is that just a locating tab, or does it move, or might it also be a contact ? And what about what might be just a rivet head before that, which could also be a contact ? Does tweaking the spool engagement dog make anything happen ?

If your manual skills and your toolkit (and your sense of adventure !) are up to it, you could delicately disassemble the unit and draw its circuit diagram. In which case you could post pictures of the internals here and ask what any bits are you don't recognise.

Well, that's exhausted all my ideas ! Happy hunting !