robgraham wrote:
Why is that when you are at one's intellectual worst that the more
complex of discussions occur - solution of the world's problems,
etc !!!

This particular one revolved round ac and dc motors - covering single
phase v. 3 ph induction motors and their relative power /torque
capabilities and how they work, which was hard work 45 years after
university, but what triggered the whole discussion was how Bosch can
claim that a lawnmower with a 36v Li-polymer powered dc motor can have
the same capability as a 1700w ac motor. OK 1700w is a comfortable
2hp but single phase induction motors are not too good on torque, and
if I remember that is where dc motors score but are modern ones going
to match a 1700w ac motor ?

Can anyone help or point me at a site on this topic please.

certainly 36v and about 50A is not unusual in the largest 'DC' model
aircraft motors. Mind you there is no such thing as a DC motor.

They are all 3 phase. - a DC brushed motor simply uses a commutator to
generate the AC..

If you are sticking 1700W in, its got to come out as heat, noise or as
shaft power.

I doubt efficiencies are any less on a brushed PM versus induction
motor, ..


Rob