current monitor circuit - filtering/rectification?

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1

Hi guys,

I have been trying to design a circuit to convert the output of the current transformer ECS1030-L72 https://www.sparkfun.com/products/11005, sold by sparkfun, to a voltage usable by an ADC or arduino. I’ve modified the circuit discussed in this thread: https://forum.sparkfun.com/viewtopic.ph … 5&start=15 to sort of work with the ECS1030-L72. Below is my LTspice simulation and diagram. As you can see, the output is still a little fuzzy.

How would I go about filtering that residual ac noise out? Any other suggestions to make this work properly?

How about other options to get this to interface with a micro controller easily?

How would I have to adapt this circuit for nigher current sensors by EChun? I’m assuming no modification is necessary, it would just decrease the measurement resolution.

I’ve seen the openenergymonitor example and others, but I’d like to have the rectification happen before the input.

Thanks

current+to+voltage+circuit.jpg1311×636 36.4 KB
https://lh3.googleusercontent.com/-eRmm … ircuit.bmp

current+to+voltage+response.jpg1311×636 37.9 KB
https://lh3.googleusercontent.com/-odSd … sponse.bmp

I should add that the op amp is being powered by ±5v and the current source is in place of the current transformer and output and AC signal.

2

Increase C1 or add another LPF. Be wary of the loading issue.

https://forum.sparkfun.com/viewtopic.php?f=14&t=37405

3

Mee_n_Mac:
Increase C1 or add another LPF. Be wary of the loading issue.

https://forum.sparkfun.com/viewtopic.php?f=14&t=37405

Thanks for the suggestions. I’m not sure about how it would work in real life, but in the simulator increasing or decreasing the C1 value has the effect of:

  1. increasing the ac waveform allowed to pass

  2. scaling of the overall output

  3. changing the reaction time of the circuit

All of these things are expected except number 1. Any ideas?