Reading AC Voltage with HCPL3700

Other Hardware General Electronics
1

Anyone is using HCPL3700 for AC reading?

2

What are you wanting to measure?
It looks like that chip only detects if the voltage is above a threshold defined by a resistor.

3

I want to mesure if root mean square (RMS) is more or less than 127.

Can I do this using a HCPL3700?

4

Found this: http://www.micropik.com/PDF/4N25.pdf

4N25 6-Pin DIP Optoisolators Transistor Output

5

jgarcia:
I want to mesure if root mean square (RMS) is more or less than 127.

Can I do this using a HCPL3700?

Ina word no.

6

jgarcia:
Found this: http://www.micropik.com/PDF/4N25.pdf

4N25 6-Pin DIP Optoisolators Transistor Output

The problem with this is the non linear transfer.
If you want to do these measurements you need an opto with two recieving transistors and use the second one as a feed back in an op amp to linearise the transfer.