Lost Steps
Posted by
Ejay Hire
on 2000-08-22 05:31:23 UTC
I think the best thing you can do to get this running is to find a local
electronics person with an oscilloscope and buy them a six-pack. There are
too many things that can cause the problems you are having to guess at what
the cause is and have any hope of fixing it cheap.
Things to check with an oscilloscope:
1. 5v Supply - Ground Near the Voltage regulator. In Operation, this
should be a nice straight line. If the filter cap is too small, then it
will jump around some.
2. 37V Supply -Ground Near the Voltage regulator. In Operation, this
should be a nice straight line. If the filter cap is too small, then it
will jump around some.
3. Look at the signal you are recieving from the pc. They should be nice
and square with very little warble.
4. Look at the signal on the motor inputs. It should swing from 0 to 37
volts and back to 0.
... Interjection -- Does anyone know if his board uses PWM?
If you can't find an oscilloscope:
1. You said your cooling fan was AC. Humor me and disconnect it and see if
the problem goes away.
2. How close (Inches, feet)(Same board, different board) is the AC
transformer (or it's leads) to the
A. Step/Direction Inputs of the controller
B. Outputs of the Controller
C. Inputs of the Driver
D. Output to the motor.
Things to know about EMI.
EMI is more likely to be caused by AC than DC, so you want to look at all
your AC (Before the rectifier) circuits first. Additionally, the Power of
any electromagnec field is inversely proportional to distance, so moving the
source of the interference a few inches may cause the problem to go away
completely. EMI is probably not going to induce enough current in one of
the 37V lines to cause the motor to turn. However, It will produce enough
current to give the controller a step pulse, or momentarily flip the
direction bit. It might even induce enough current to cause the driver to
turn on at the wrong time, and any of these would cause the problem you
describe.
The person who is having the problem -> Where are you located?
Good Luck,
Ejay Hire
________________________________________________________________________
Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com
electronics person with an oscilloscope and buy them a six-pack. There are
too many things that can cause the problems you are having to guess at what
the cause is and have any hope of fixing it cheap.
Things to check with an oscilloscope:
1. 5v Supply - Ground Near the Voltage regulator. In Operation, this
should be a nice straight line. If the filter cap is too small, then it
will jump around some.
2. 37V Supply -Ground Near the Voltage regulator. In Operation, this
should be a nice straight line. If the filter cap is too small, then it
will jump around some.
3. Look at the signal you are recieving from the pc. They should be nice
and square with very little warble.
4. Look at the signal on the motor inputs. It should swing from 0 to 37
volts and back to 0.
... Interjection -- Does anyone know if his board uses PWM?
If you can't find an oscilloscope:
1. You said your cooling fan was AC. Humor me and disconnect it and see if
the problem goes away.
2. How close (Inches, feet)(Same board, different board) is the AC
transformer (or it's leads) to the
A. Step/Direction Inputs of the controller
B. Outputs of the Controller
C. Inputs of the Driver
D. Output to the motor.
Things to know about EMI.
EMI is more likely to be caused by AC than DC, so you want to look at all
your AC (Before the rectifier) circuits first. Additionally, the Power of
any electromagnec field is inversely proportional to distance, so moving the
source of the interference a few inches may cause the problem to go away
completely. EMI is probably not going to induce enough current in one of
the 37V lines to cause the motor to turn. However, It will produce enough
current to give the controller a step pulse, or momentarily flip the
direction bit. It might even induce enough current to cause the driver to
turn on at the wrong time, and any of these would cause the problem you
describe.
The person who is having the problem -> Where are you located?
Good Luck,
Ejay Hire
________________________________________________________________________
Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com