Wish to build 2 speed controllers.
1 - for universal motor, brush type, 4A, 230v.
2 - Invert battery DC 12v to 230v ac and vary it for a 3ph 1/2 hp ac motor.
Appreciate any help, suggestions and advice.

 

Are these open or closed loop controllers you are trying to build ?

 

1. You can try something like this - http://www.acdcmotor.info/ac-motor-control-schematic/

2.3 phase motors need a VFD (variable frequency drive) controller.