Thanks Flypaper 2 that explains it well. I now understand what the relation is between them. I had no idea the prop could control the amp draw like you said. With this "wattmeter" is this function usually on a multi meter or is it a specialist tool. Does it get wired in series or parrallel to read the draw and wired at what position in the circuit? Thanks for your patience. Thankyou also to coasre air I will go through that information......much happier now!!!!!