REQ: Motor soft start design information.

[pico]

Hi friends,
Where can I find motor soft start design information. For 3-phase and single phase.

Thanks.

 

[solvarg]

Hi friends,
Where can I find motor soft start design information. For 3-phase and single phase.

Thanks.

Look here:
https://www.st.com/stonline/products/support/motor/index.htm

Regards

 

[pico]

Hi solvarg,
I want the soft start circuit design priciple not the motor itseft. Anyway thank for your help.

 

[flatulent]

maximum current

In the old manual switch days you would have taps on the transformer feeding the motor. You would start at the lowest voltage and the current would drop as the motor reached steady state speed. You would then go to the next higher voltage tap and wait for the speed to rise and the current to drop. There were special relay circuits that would automate the process.

I suspect that you could do the same thing with triacs and raise the conduction angle.

 

[pico]

Thanks flatulent,
Would you please give me some more information.
What percentage of voltage that I could start and then raise it to 100 % within how many second?