Anyone know of a site that describes DC motor tradeoffs? I know torque is proportional to current and turns, and there are practical problems with wire size and resistance that limit number of turns, etc. Lets say I have a 3 pole armature and a 7 pole armature wound with the same number of turns and wire size. Will they have the same torque? Which one will have greater rpm? I know the inductance goes up with turns. Seems like there should be a rule about L/R time constant and RPM somewhere in the rule of thumb list. Some big hefty motors cant be PWMd faster than a kilohertz or so... is this because of large L?
- posted
17 years ago