amp set resistor

[Don C]

If I can't find a resistor that is the correct resistance is it better to be higher or lower? My motor is 5.5amp (I get 172K) if I can't get a 172k resistor would it be better to use a 120k or a 200k.

[ger21]

Whichever one gives you LESS current. Don't supply the motors more than their rated current.

[Don C]

Thanks, I'll use 120k resistors

[freak_brain]

stack them together in series......simply stack them up, R1 + R2 = your needed value. If you run them in parallel you need to do a little more math. Actually a lot more

R1*R2
R1+R2

So, if you have two resistors, R1 = 2 and R2 = 3

2*3=6
2+3=5
6/5=1.2

1.2 is the answer


I believe this to be correct but I am far from and electronics guy. I just keep digging until I find the answers I need, lol

Allen

[Mariss Freimanis]

Motor current is not a precision setting. 172K is close enough to a standard tolerance 180K resistor that it would make no practical difference. + or - 10% is good enough for motor current set.

Mariss

[ViperTX]

freak brain

Your calculations are correct...for more then 2 resistors I always use 1\Rt = 1/R1 + 1/R2 + 1/R3.......calculator makes it nice....everything is the reciprocal...

[Dan Mauch]

Use the 120K. It will set the current lower but it will be safer and it will prevent you from demagnitizing the stepper motor.
Dan