Congratulation to you and your team that 1,730 members have registered in this forum. It shows that every topic starter gets almost an accurate answer of his question from the professionals in electrical engineering in this forum.
I am very thankful to Marke and others that they have provided a chance to juniors like me to seek the best knowledge in this forum.
I came cross a special device consisting of an electronic card firing a series of transistors which themselves are connected to the stator windings. The rotor of the motor is connected to a series of resitors through a series of contactors. I am told that when powered, the motor ramped slowly to rated speed similar to a soft starter. This application is used on a hoist unit.This is a japanese invention according to the description I can read on the box.
This equipment is now faulty and literature is unavailable.
Any guess on this technology?