I did a Google search of 'single supply op amp' and came upon this thread. The original post could have been written by me today as this is exactly my dilemma. I implemented a Voltage to Current converter using a 741 Op amp with a single 24 V supply and it is not working correctly. The lower the voltage input, the more incorrect the output current is. I am assuming this is related to the common mode voltage or the single supply operation. (I'm not an analog wizard by any means.) It is good at 4.7 volts on the input. (I only have two input voltages in this application, 1 volt and 4.7 volts).
Then I read the posts in this thread and realized that the load that I will be driving goes to ground so this won't work for me. So my question becomes, "How do I implement a voltage to current converter with a 24 VDC supply and 5 VDC supply that will drive a grounded load?" The XTR110 is looking better all the time but the cost is more than I had hoped for. Any suggestions will be greatly appreciated!!