02-12-2013, 12:27 PM
(02-12-2013, 10:56 AM)Refugee Wrote: What you are saying Lawrence is correct for each side of each vane.
The vane also has another side to it and there is only has one answer to this.
While the change is taking place on one side the opposite change is taking place on the other side so they should balance out.
This even applies to the spacing between the stator and the frame all be it negligible.
"While the change is taking place on one side the opposite change is taking place on the other side so they should balance out."
In distance terms yes but surely not in capacitance terms.
Take one rotor plate and the two adjoining stator plates, that is in effect two capacitors in parallel (C1 + C2) If the distance between the stator and the two fixed plates is equal then the capacitances of C1 and C2 will be equal, lets say they are 100pf each when the rotor is fully engaged with the two stator plates, the total capacitance will be 200 pf.
If the distance between the rotor and one of the stator plates eg: C1 (100 pf) is reduced by 50% then C1's capacitance will roughly double to around 200 pf (ignoring edge effect etc) That's the same value as C1 + C2 as originally stated, meanwhile there still remains the capacitance of C2 which has now diminished in value due to the plate spacing being increased by 50% but that value still has to be added to the new value of C1 which results in a different total value to the original.
50% is an extreme example to illustrate things.
Lawrence.
