remote DC iris controll

[jaafe 0]

Hi.

For industrial application I need to remotely controll a DC iris lens.

I tried to do that using the electronic circuit attached, and connecting the drain and control to V1 and V2 terminal, but the result was not acceptable at all, becouse I was not able to have a perfect control of iris, ie it opens and closes too fast.

Does anybody have any suggestion for my poupose?

I dont need to take control signal from camera, but i want to control it by myself using an ecectronic circuit.

 

Thank you very much for your help

Antonio

[zmxtech 0]

try a linear Pot

[jaafe 0]

Hi zmxtech and thank yuo for your fast replay.

Sincerely I used a linear pot!

Anyway do you think this scheme should be successfully?

Maybe I should try to use a different set of resistors?

 

Thank you again

[zmxtech 0]

play around with the voltage divider and values maybe a 10k pot -im sure if you used a 10 turn trimmer you could get it just right.

 

you plug it into the camera some lenses have manual trim also

 

z

[Squiffy 0]

Try an antilog potentiometer. You could also try two diodes on the wiper in inverse parallel, a technique used in music keyboards for pitch-bend wheel potentiometers.

[Kiwi 0]

This is unlikely to work accurately with the voice-coil style actuator found in a DC iris. You would be much better off buying a lens with a motorized iris. Some Computar electric zooms are configured like this, older ones in particular.