Single Phase Motor - non VFD speed control

Thread Starter


Joined Aug 22, 2012

im new here (and in electronics), i was thinking about building a coil winder. the motor would come from this induction motor that i have around (single phase).

one of the features i would like to have in a winder is soft start and controllable speed.

to my understanding, controlling the speed of this type of motor is done either by VFD or by more sophisticated means like PWM microcontroller which are A. beyond my budget and B. way way beyond my know how.

until i came across this page:

so the question is, in the first circuit, what is P2-P6? these are connections to the power outlet and the output, but im not familiar with these slashed circles thingie, mind if someone can elaborate?

secondly, the circuit connects directly to the mains, this circuit safe? can someone with experience with this chip can point to a safer circuit?

thank you...


Joined Apr 2, 2009
I believe they are off board connections.
They connect via wires to more bulky components tht are mounted off the board or to connections mounted on to the cover or chassis.