spearte circuits

[maor]

Hello,
i have source of 0-5v output and he has Rin of some Mega ohms and the source has maximum current of 20mA. and i have a destiniation of 0-5v input and he has Rin of some Kohms. i want to connect between the source and the destination with oprocoupler, and i want that when i give, lets say, 3v in the source i will get 3v in the destination
( if i give 2.5v in the source i will get 2.5v in the destination). can you tell me which optocoupler to use and how the circuit looks like?

Thank you,

 

[Colin Mitchell]

Why do you want to use an opto-coupler?

 

[maor]

Because i have a machine (mks 247d) with 25 pin connector with four diffrent grounds and i want to connect it to the arduino mega2560 and separate the arduino and the machine circuits because i have 4 diffrent grounds.

 

[Martaine2005]

maor,
Did you come up for air? I cannot read that!!