Shopsmith Forums

Posted: **Fri Dec 17, 2021 10:47 pm**

The reason for the 'paradox' is that universal motors create 'back emf' that limits running current. That 'back emf' is directly related to rpm.

Thus a motor running slow because of reduced voltage will draw more current. A pulsing controller helps reduce this and allows greater torque.

All this is a gross simplification.

Posted: **Fri Dec 17, 2021 11:50 pm**

JPG wrote: ↑Fri Dec 17, 2021 10:47 pm All this is a gross simplification.

It provides some credible explanation for the behavior. It also shows that a speed controller can be a two headed monster, producing more heat and slowing a cooling fan.

Posted: **Sat Dec 18, 2021 1:11 pm**

My angle grinder has a variable speed trigger ??????? not sure of any benefit this would add ?

Shopsmith Forums

Anyone use a HF router speed control with an angle grinder?

Re: Anyone use a HF router speed control with an angle grinder?

Re: Anyone use a HF router speed control with an angle grinder?

Re: Anyone use a HF router speed control with an angle grinder?