Thanks, good info like always. Chetan Bhargava http://microz.blogspot.com On Wed, Sep 19, 2018 at 7:42 AM RussellMc wrote: > Extremely useful 34 page manual on using Fisher & Paykel "smart drive" BL= DC > motors as BLDC motors - not quite so trivial as it might seem :-). > The NZ originated F&P direct drive motors are available in surplus washin= g > machines and other domestic equipment in a number of countries worldwide = - > USA included. I recently encountered one in an LG washing machine so they > may be even more widespread in other than F&P machines. > > These motors are widely used as wind turbine and water-power alternators > and somewhat less widely used as motors for ebikes, and other application= s > that will benefit from high torque low RPM direct drive motors. > Applications could include lathes, potting wheels (example given in > manual), gate openers, ... numerous position and variable speed control > applications. > > This manual explains the various versions liable to be encountered in > surplus equipment and how they can be driven using off the shelf brushles= s > motor controllers. A far better treatment than usually encountered. > Their results seem to be "somewhat empirically biased" (a la Edison) but > still useful. > > > https://drive.google.com/file/d/0BzVDBix3S_qbNU1YWmZwTUFsQ2s/view > > Not mentioned in the manual (I think) is the fact that the motors can be > rewired from having coils highly serial connected to series-parallel or a= ll > parallel arrangements (per phase) allowing lower voltage higher current > applications. > > As supplied the motors use ferrite magnets (a cost / performance tradeoff > decision) and produce outputs typical;ly in the 300 - 1200 Watt range. . > Conversions to neodymium magnets produce powers in the 2 to 3 kW range an= d > attendant cooling challenges. The table on page 10 allows power outputs t= o > be assessed. > Power ~=3D nm/10 x RPM. > So 29 nM at 460 RPM =3D~ 1300 Watts > The 1200 RPM, 24 nm claim is suspect but may be true =3D 2880 Watts !!! > Section 4.5 on page 12 suggests rather less power (as expected). > -- > http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist > --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .