Recently, I did a simple test recommended by Eric Dollard on the Rotary Electrostatic Converter built by Chris Carson. It is recommended to look at the below post first before watching the video on the recent test.
The capacitor was sped up with a DC motor and then a potential transformer was turned up to about 4500 volts DC and this potential was applied to 1/2 of the capacitor to see if the electrostatic lines would try keep the rotating capacitor plates in phase with the stationary plates. If so, then it should increase the load on the DC motor and reducing it’s speed.
The video is here and there are some more tests to come relating to this: