geoff wrote:
In message zPe9o.22696$hp4.8069@hurricane, John
writes
"The Natural Philosopher" wrote in message
...
Grimly Curmudgeon wrote:
We were somewhere around Barstow, on the edge of the desert, when the
drugs began to take hold. I remember robgraham
saying something like:

Why is the lower powered DC machine equal in capability with the much
higher powered AC driven mower? Is it in the mower design or are
modern DC motors (I'm presuming they are stepper motor type design)
that much more efficient and powerful?

The DC motor might be geared down and is running at its most effective
speed.

all mortors will be geared.

But the thing is a leccy motor will draw what it has to until its
reaches
some limit.

Ypu probably only need a couple of hundred watts on a 12" or so
rotary to
cut a shortish grass. Its when you hit the rough stuff. Ive got a 3.5bhp
briggsie and that will stall on rank grass. Even the 13bhp one will as
well. But that's a 48" cut.

So no difference on light duties. The 1700 watter will be running at a
couple of hundred same as the battery one. The mains will 'go up to'
1700
which the battery one probably won't, although its deeply possible on
short bursts to pull 80A out of a 12v lead acid of mower type
dimensions.
which is well over a brake horse.


Not all motors are geared.


No, but mortors might be


All electric motors used in lawnmowers will be geared.

Otherwise the mower blade tips would be supersonic long before the motor
was up to sensible efficiency.