Detect 10V...To.. 260V AC/DC with HCPL-3700
Unfortunately, this is not possible with the same resistors. The input does not detect voltage but current. To switch on, approx. 2.4 mA current required.

So in its current state (2x47k) it will turn on around 240V.


This is just enough to detect 230VAC, but not for lower voltage.
For 10 V, the maximum external resistance would be 2k.


So it can be used in a narrow voltage range. On the data sheet, this figure shows the voltage at which it switches on and off with a given resistor.
At 94k (2x47) these values ​​are approx. 240V and 120V.

So it can be used very well to indicate e.g. the presence of 230V, but is not suitable for signaling a wide voltage range (10V ... 230V).