author=poynt99 link=topic=3684.msg71663#msg71663 date=1548597094]
Thanks for the video Brad! (and thanks for not rubbing in your DMM results).
Regarding the scope/meter discrepancy for a moment, what is the AVG CSR2 voltage by manual calculation?
If we assume that you are seeing about 750mVp across CSR2 and using a 5% duty, that would calculate to 37.5mV AVG. This is lower than your meters were indicating, and right around what the scope is saying.
In the video,i was using a 7% duty cycle,which gives an average of 52.8mV.
The meter was showing at 46mV.
I am surprised indeed that the AVG measurements in the CVR's aren't the same. I don't have an explanation as to why.
Well,if you are interested in my thought's,here they are.
With a standard coil,having a steel or ferrite core,when we send a current through the coil the magnetic field is built from a 0 value up. So we start with no field,and then that field begins to build and cut through the windings as the current begins to flow. When we disconnect the current,the field collapses back through the winding's and the current continues to flow in the !same! direction<--this is important to remember.
Now,when we have a PM as the core we already have a magnetic field that exists through the winding's,but where that field is opposite to that of which the coil will produce once energised.
So now when we energise the coil the existing field must first collap's through the windings before the opposite field can be built by the induced current through the coil.
Now,the question is-->when the existing PM field is collapsing,which way will the induced current flow?
Well we know that when the current to the coil is cut off,the inductive kickback current keeps flowing in the same direction. This can only mean that the current produced by the collapsing PMs field through the coil must produce a current flow in the opposite direction to that of the induced current.
Why can we see this reversed current?
Well we can,we just dont know we are looking at it via the extra current at CVR2.
One side of CVR2 is X amount above 0,and the other side of CVR2 is X amount below 0,instead of being a 0 value.
It would seem to me that we have two opposite flows of current meeting at CVR2,or the potential across the coil becomes opposite to that of the supply for a brief period of time.
If we look at the scope shot below,how is the inductive kickback period nearly twice as long as the current input time?.
Anyway,they are my thoughts for what there worth.
In either case, you are measuring more AVG current in CSR2 than in CSR1, so something is different there.
If you have indeed managed to extract some energy from the magnet, perhaps you might consider pausing at this time and investigating further to see if a SS device is possible.
I did post a design for a SS version some pages back on this thread.
I am not sure anyone took up the !theoretical! project?.
Perhaps i will take the time today to give it a shot,while waiting for the rotor to be perfected by Jim.
Brad
Never let your schooling get in the way of your education.