On 2/11/2011 8:47 AM, RJ Kanary wrote:
I could be wrong about this {Imagine THAT.}, but I feel
the reasoning behind the armature resistance is best explained
thusly..............
There is going to be a MAJOR inrush current nailing the armature at
every start if these resistors are not present.That can't be an approach
to long life and prosperity. :(
Secondly those armature resistors provide a smoother, more controlled
launch, but were never intended to be a long term speed selecting device.
Right, but on a Craftsman tractor both items are covered by the clutch transmission. You spin up the motor, then let the clutch in and the belts take the hit. That's how gas engines do it.
For total win-ness you could use a relay to interlock the clutch such that it won't allow the motor to "start" unless the clutch is down (and brake is on). Oddly enough Craftsman tractors have this in the "Start" function to crank the motor. So you would just put in this rule:
Latch-in contactor for motor is tied to "Start" key position, then runs. You have to have clutch in and be stopped. Then drive around. If you get off the seat without the clutch in, or if you turn off the motor, the contactor drops out. Also if you get off the seat with the motor running, the contactor drops out.
That way you get all the right and proper safety features. That is where you should focus controller efforts, because if you fall off an Elec-trak it will *STOP*. If you fall off a gas Craftsman it will stop too.
C