DC-DC Isolator

[gillesfan]

OK new circuit

Output is lovely and clean as before until i attach it to the STE then it becomes messy but in a different way

I will replace the 741s

 

[BobK]

Why the resistor between the buffer and the ADC?

I have a feeling the drops you are seeing are due to the voltage drop across that resistor when the ADC is sampling.
Bob

 

[gillesfan]

i put it in for protection
should i try it without?

I will try with the other op amps

 

[gillesfan]

Tried it with other op amps and its much worse, gain drops off massively when connected to the IL300

I wish i understood things better

 

[gillesfan]

OK

It works.

I am using the LM741 as the input as in the last diagram, but it turns out the ADC is not used as a voltage follower but essentially measures resistance between two pins. Thus if i connect directly these two pins to 5 and 6 ofthe IL300. I get a response which covers 70% of the range.

Ideal.

Thank you so much for your help

 

[gillesfan]

Just in case anybody wonders...