Chopperp Guru Joined: 03/01/2018 Location: AustraliaPosts: 1040
Posted: 08:42am 23 Sep 2021
We did this when I was at Uni back in the 90's. Played with a big DC motor. We would lower the field current to make it go faster & raise the field current to slow it down. Had to record & plot everything.
The reason being (if I remember correctly) is that with a lower field current, a lower back EMF is generated & the armature current rises, speeding up the machine, if possible to regain the equilibrium & vice versa.