I recently discovered an old furnace motor tucked away in a corner. Brushless DC, continuously variable speed, three phase drive (three transistor pairs), 18 poles. Very smooth ramp up and down, very quiet running. Hundreds of watts, 5 A internal fuse.
It was replaced under warranty and they didn't take the dead one away. Tore it apart. 240 Vac input, bridge, two 1000 uF / 200 Vdc caps in series, and one of them blew after about 2 years. The replacement has run for about 15. GE developed the motor for Carrier, for $5 million development cost.
ak
It was replaced under warranty and they didn't take the dead one away. Tore it apart. 240 Vac input, bridge, two 1000 uF / 200 Vdc caps in series, and one of them blew after about 2 years. The replacement has run for about 15. GE developed the motor for Carrier, for $5 million development cost.
ak