MechMate CNC Router Forum

MechMate CNC Router Forum (http://www.mechmate.com/forums/index.php)
-   701. Motor Drives (http://www.mechmate.com/forums/forumdisplay.php?f=14)
-   -   How to calculate resistor needed for gecko drives (http://www.mechmate.com/forums/showthread.php?t=2902)

Richards Fri 09 July 2010 10:56

For the G201, G203, or the G203v stepper drivers, the formula is:

47 X Amps / ( 7 - Amps) = Resistor.

So, for your motor:

47 X 5.6A / ( 7 - 5.6A) = 188K resistor.

A 180K or a 200K 1/4 Watt resistor would work fine ( or any other resistor that is +/- 5% of 188K).

Red_boards Tue 13 July 2010 07:03

What a timely post. I was looking at this earlier.
For the MK 9801's:
(47 * 4.1)/(7-4.1) = 66.5 kOhm
Fantastic - this is 4x what I got earlier using the same calculation! A lot to be said for re-reading and re-calculating (and thinner fingers).

Kobus_Joubert Tue 13 July 2010 12:39

Buy the UIM drivers. Amps are set with a onboard potentiometer...no more looking for resistors.;)

Richards Tue 13 July 2010 15:52

The Geckodrive G201X uses an internal dip switch for selecting current limiting resistor values. It has most of the features of the G203v but costs less, $114 plus shipping.

litemover Sun 12 May 2013 23:23

Hey Mike,

I was reading the manual and it actually states 47*I/ (7-I). That would be inductance no? Just confirming because on the G203V manual, it specified Inductance as part of the formula, not amps. Any ideas why?

Thanks,
chris

Gerald D Mon 13 May 2013 03:46

From http://en.wikipedia.org/wiki/Electric_current:

The conventional symbol for current is http://upload.wikimedia.org/math/d/d...7f9b147d7f.png, which originates from the French phrase intensité de courant, or in English current intensity.[3][4] This phrase is frequently used when discussing the value of an electric current, but modern practice often shortens this to simply current. The http://upload.wikimedia.org/math/d/d...7f9b147d7f.png symbol was used by André-Marie Ampère, after whom the unit of electric current is named, in formulating the eponymous Ampère's force law which he discovered in 1820.[5] The notation travelled from France to Britain, where it became standard, although at least one journal did not change from using http://upload.wikimedia.org/math/0/d...4d143e1257.png to http://upload.wikimedia.org/math/d/d...7f9b147d7f.png until 1896.[6]

litemover Mon 13 May 2013 04:16

Awesome explanation Gerald. Thanks for that! Very educational! :D

Tom Ayres Tue 14 May 2013 17:34

Gerald, I don't know if you or wiki contains more knowledge.:D

smreish Wed 15 May 2013 08:52

...Gerald.


All times are GMT -6. The time now is 03:09.

Powered by vBulletin® Version 3.8.3
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.