This question is to help me with my work in building a VCCS for the excitation signal of an Electrical Impedance Tomography measurement set-up to use with EIDORS. I have only basic knowledge in electrical engineering since I'm a computer science student.
I'm trying to build a similar system as described in this paper for my Electrical Impedance Tomography (EIT) system. In particular, I took this Figure from the paper as a reference for building my test system:
I am generating a sinusoidal excitation signal (10kHz-100kHz) with the AD5930 DDS waveform generator that has a full-scale current output of 3-4mA and 0.56V peak-to-peak.
I want to build an AD8220-based VCCS to generate the EIT excitation signal. However, I don't know how to build a VCCS, especially with the AD8220 instrumentation amplifier, and was hoping someone could help me with that?
The constant AC current should be less than 1mA, for example, around 100uA p-p would be sufficient.
What I have tried so far: I used LTSpice to simulate the following circuit to try and build a VCCS:
However, I don't know how to set and calculate R2 given R_Load and if this really is a VCCS and the right approach to this.