I know that after couple of uses DC Motors we should replace carbon brush because the physical size of carbon
brush will be reduced and it can not do its job!
But let me ask my 3 main questions....
1) Does reducing of physical size means that the resistance is also reducing of carbon brush?
I know that new carbon brush which is unused has bigger physical size than used carbon brush? And according a theory that longer wire has high resistance than short wire. So I think that longer carbon brush might have a high resistance as well!
Am I right?
2) When resistance is reduced down to very small amount will it make a short circuit?
Will it destroy another components of dc motors like rotor or stator or trigger?
Which one could be damaged?
If this is true than tell me how can we prevent this problem?
Does modern drill drivers based on DC Motors or based on Universal Motors have any kind of protection like 5amp fuse?
Is the fuse the best solution?
When we are triggering a universal motor and little spark appears is it OK?
Can you tell me what does it mean?
Does it means that we should replace a carbon brush?
Even when I replaced a carbon brush there was still sparks during triggering!
At one time even little smoke appeared and the universal motor of drill driver was working but suddenly stopped when I was triggering!
Does it mean that problem is inside a trigger?
3) When Drill driver or Universal motor is working with AC 220v and its power is lower like 100watt does it mean that the resistance of carbon brush mist be much higher and higher compare to any another universal motors like more powerful motors which works 220V AC with 1500watt power?
please answer my question on a title!
Does resistance of carbon brushes in DC Motors decreases after couple of uses?