1. I have tried & recorded some results.
2. Snubber circuit is added.
3. I have attached a pdf to show some results:
4. Page 1 shows how circuit is setup i.e how drop across sense resistor is measured by CRO. (circuit says current probe but its where drop is measnured across 5.4ohm resistor.)
5. Page 2 shows voltage & current relationship.
6. Page 3 shows a circuit where I have placed a capacitor in parallel to motor.
7. Page 4 shows its relationship voltage & current relationship.
8. Page 5 shows the capacitor which I had used. I don't know what its exact value. But by checking it at LCR meter, value shows around 2.2uF.
9. Page 6 shows sense resistor (5 resistors in parallel of 27 each) , & how drop across it is measured by CRO. I placed ground wire close to sense tip of probe, so as to have minimum distance.
10. On doing phase control as soon as I try to do it suddenly entire voltage across the motor goes down.
11. What I am planning to do now, is to place a zero crossing detector across sense resistor & will do phase control whenever current goes zero. Will see what happens then.
12. Should I proceed this way or there is any other method?
13.File is available at
http://www.docdroid.net/xn32/design123.pdf.html