double armature การใช้

• Eighteen late " Balao "-class submarines received low-speed double armature motors which drove the shafts directly and were much quieter, but this improvement was not universally fitted until the succeeding.
• By April 2005, the resulting Super . fi 5 Pro, a double armature product, was offered to consumers at $ 250 per pair, and sales of these helped Ultimate Ears to gross more than $ 10 million in 2006.