= Motor Track =
------



=== Notes ===

 . Tektronix 7000 series oscilloscopes (designed in the 1970s) used 25 KHz switching power supplies

 . Aluminum resistivity from Physics Hypertextbook !ValPolyakov.txt 2004 (missing linefeeds)

|| Temp || Resis  || Skin   || 60 Hz || 10 KHz || 100 KHz ||
|| K    || ohm m  || mm-√Hz ||  mm   ||   mm   ||    mm   ||
|| 200  || 1.6e-8 ||  201   ||    26 ||    2.0 ||    0.64 ||
|| 300  || 2.7e-8 ||  262   ||    34 ||    2.6 ||    0.83 ||
|| 400  || 3.9e-8 ||  314   ||    41 ||    3.1 ||    0.99 ||
|| 600  || 6.1e-8 ||  393   ||    51 ||    3.9 ||    1.24 ||
|| 800  || 8.7e-8 ||  469   ||    61 ||    4.6 ||    1.48 ||


Reactive power supplies resistive drops in the rotor.  Run capacitors on big induction motors supply less than a percent of total power to maintain 90 degrees out-of-phase currents in rotor windings.

Aluminum specific heat is 910 J / Kg-K according to engineeringtoolbox.com (at what temperature???)

According to [[ http://webbook.nist.gov/cgi/cbook.cgi?ID=C7429905&Mask=2&Type=JANAFS&Plot=on#JANAFS | this ]], specific heat increases from about 900 J/Kg-K at 298 C to 1300 J/Kg-K .  The slope steepens near 300 K.