Engineering What are alternative techniques for starting a DC motor from rest?

[PRoberts1244]

Having been asked to identify two methods of starting a DC motor from rest, I am struggling to get anything on the internet apart from Rheostats. Does anyone know of another technique that can be adopted for DC motor start-up?



no equations required



Knowing that the aramture when the DC motor is running, produces a back EMF that acts in resistance to the applied voltage and this field collapses or is not present once stationary. The problem lies with techniques that resist the applied voltage in order to allow the motor to start running and finally the armature back EMF up and running, therefore eliminating the need of the starter.

Ideally a viable technique would incorporate some form of power electronics. I am not necessarilary lloking for the answers but more of a point in the right direction.

 

[NascentOxygen]

Try a google search. This note says, "There are five main types of reduced voltage starters ..." so might give you some ideas for further research.

http://www.globalspec.com/learnmore/motion_controls/motors/motor_starters_accessories/dc_motor_starters

This note examines three methods, and models them on a simulator. http://www.google.com.au/url?sa=t&rct=j&q=%22dc%20motor%22%20starting&source=web&cd=24&ved=0CFIQFjADOBQ&url=http%3A%2F%2Fwww.ijens.org%2FVol%252011%2520I%252002%2F115302-6464%2520IJECS-IJENS.pdf&ei=dq7gTpC2GeepiAeXrunIBQ&usg=AFQjCNG-ehblBAeLV-DuMSXoYnfNI2X6dw&cad=rja