What Dave and I both "assumed" was that you were measuring DC currents.Originally Posted by DavyJones
The part about an A/C signal would have helped in the beginning.
Being that the heat gun is mainly a resistive load, you could get a much closer reading by finding the highest (peak) voltage and multiply by 0.707, which gives the R-M-S value of a perfect sine wave. Then convert to current.
The heat gun also has a fan, which is an inductive load, so you'll never get a perfectly "accurate" reading with the 0.707 multiplier. But since the fan is only a small portion of the load it would be closer.
But I doubt the eventual use of your project will be measuring the current from heat guns. And the type of load makes a HUGE difference.
If you'll be primarily measuring motor currents, the wave forms will NOT be sine, and .707 will not even come close. In that case, there is only one way to go.
Run the signal from the current sensor into an R-M-S converter. Don't bother trying to do it in software. I like the LTC1966, but it's a really tiny chip and isn't great for hobby use cause they're too hard to solder.
There are several other chips available that do the same thing. But for sure you will need an R-M-S (Root Mean Square) reading for any inductive loads.
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