Motor consumes no charge ?

[Gothic]

This is off topic but still relevant. I like to look through manuals of
old (and new) general mechanisms that are proven to function as was
their original intent. Therefore no guesswork or R&D needed (Which is
time consuming and expensive), just "here is the device" and "this is
the working theory".   

A couple of items "the syncrotech motor" and a diagram of a d.c. 
wattmeter. It,s the working principle that helps to further understand
the mechanics of what is...

syncrotech is found in this pdf along with numerous other devices

http://naca.central.cranfield.ac.uk/reports/arc/rm/2199.pdf

d.c. wattmeter is found in this pdf along with numerous other devices

https://books.google.com/books/about/Electrical_Engineer_s_Pocket_book.html?id=9vQOAAAAYAAJ

the syncrotech is a little bit similiar to this youtube video being that
there is a permanent magnetic field perpendicular to the working field.

https://www.youtube.com/watch?v=pUDnPQY6yJI

[Gothic]

Been looking at DIY electrostatic speakers and how displacement current might play a role.

http://jazzman-esl-page.blogspot.com/2009/12/newest-segmented-esl.html

Edit: if nothing else, they are worth building simply for the realistic sound production