Lee Hart wrote: > > Rod Hower wrote: > > > > > Motor rpm is limited by available Voltage. > > > > That applies to DC motors. Less common AC induction motors RPM is > > dictated by the frequency generated by the inverter. > > > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> > > > > You can also do this with DC motors, it's called field weakening. > > Or, a series motor with a light load. No-load, they will run so fast > that they can self-destruct!
Apply 100V to a DC motor with no load, it will do x RPM. Apply 200V to it, and it will do 2x RPM. Apply any voltage to AC motor, and unless frequency is >0 it will not run, load or no load. That is the difference. > To be strictly correct, motor rpm is indirectly limited by voltage for > all motors -- AC or DC. More strictly - voltage limited from the high RPM side. Victor > -- > Lee A. Hart Ring the bells that still can ring > 814 8th Ave. N. Forget your perfect offering > Sartell, MN 56377 USA There is a crack in everything > leeahart_at_earthlink.net That's how the light gets in - Leonard Cohen
