"Spehro Pefhany" wrote
>>Yes, actually, for other lens models they replace the name "control" by
>>"damping", could you elaborate more on this subject?
>
> No, as I know virtually nothing about it with 100% certainty. I don't even
> have a lens in front of me, as you do. But I can visualize how the guts
> *could* work.

I was just asking what prompted you to use the word damping and how you 
thought it worked, but Robert Rolf's post gave a good insight on what 
damping means.


>>Well, it was 11pm and I had 3 shots of bourbon 8^D
>
> Might be worth trying again. Sober or not is up to you.

Who said I wasn't sober 8^D  The problem I believe is that I was sleepy


> The voltage across the coil (actually, the current through it) most likely
> is what matters.

That is correct. Yesterday I plugged the psu (5V) directly to the drive coil 
and it fully opened. As expected, the current going through the coil was 
about 25mA.
I was using a pot to reduce the voltage and the resistance of the pot was 
way too high (5 meg), so when I measured the voltage coming out of the pot, 
I could measure 3.5V, but as soon as I plugged it to the coil, it dropped to 
0V.


> I really don't know. It could work either way, with the lens integrating
> the signal from the camera, but I suspect it acts more like a galvo with
> the iris 'positioned' according to the current. You'll soon see what it
> really does, and hopefully tell us.

I don't know what a galvo is, but if there is enough current for the coil, 
then applying positive voltage to drive+, it does open. But that's only half 
of the problem, well, a third really. Now I have to find out how to create a 
"black box" that inputs f-stops and outputs analog signal to implement a 
corresponding aperture on the lens.


> You don't happen to have a full schematic of a compatible camera do you?

No. I'm monitoring ebay to see if I can find a really cheap (broken is fine) 
compatible camera that I can cannibalize (for the mating plug).


Cheers

Padu 

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