I was just playing around and came up with a rather stupid CCR. As you can see the base current modifies the slope = effective resistance. The IV characteristics seem fairly constant. The resistances range from about 5k to
300k which easily can be changed by modifying the resistor values.I'm sure the circuit can be simplified and optimized... anyone care to give it a try? Seems like it might be possible to use some form of circuit topology to get a nice VCR and/or CCR that works over a wide ranges of voltages, currents, and resistances that an be floating.
I haven't found anything but JFETs for VCR's and they tend to have small resistances(max I've seen is about 10k) and cannot be "floating"(at least not without more complexity/cost).
I did find
for a CCR that supposedly has a wide functioning range of parameters but seems a bit complex and costly. I'm looking something, not a digital pot, that can replace a pot... or rather be controlled by a pot as I need a single pot to control multiple sites.
Of course I have no clue if the circuit in I came up with actually works. Just did some IV analysis on an idea and played around with it until I got slopes that dependent on the base current. So please no flames...