I'm building a bench to calibrate a device that measures AC currents. As I won't build something accurate, the current will be measured with a current clamp and a multimeter (voltage mode).
For the current load, I first tried a diode bridge with big capacitors and after it, a DC current load (voltage / current converter).
The result is a non sinusoïdal voltage at the clamp output due to the diode voltage which leads to 0 current when the input voltage is less than twice the diode voltage. Like in this screenshot (orange = input voltage, yellow = clamp output (volt)).
The problem is that the multimeter does not integrate correctly the non sinusoïdal voltage of the clamp and outputs a wrong rms value. If I plug the multimeter in-line as an ampere meter, the measure is correct but I need the clamp because I will measure currents that are beyond what the multimeter can do
That's why I want to build a device that operates likes a rheostat. Its resistance should be defined by a microcontroler and the current vaweform should be proportionnal to the voltage waveform. Maximum dissipated power is around 60W (for the purpose of my specific design, I can add a serie resistor to drop the power in the device down to 20W) Input voltage: 6V 50Hz AC sinusoïdal.
How can I do?