More bable
Posted by
Arne Chr. Jorgensen
on 1999-07-23 04:17:47 UTC
Hi,
Thanks for the info on helical gears. I do think they will give a
less play, though.
+ + To Ian: Linux. ++++++++++
Partitions: I am not quite sure of this, but:
I can't recall when they added support for big partitions. You said
that you had 4Gb for Linux.
The boot partition for Linux has to reside inside 2Gb of the start
of the disk. Also any Linux partition can't be more than 2Gb. There
is option for large disk, but if you want to mount a dos partition,
you will save your self from a lot of trouble. Anyway - with Linux
you can mount other disks and partitions, even over networks.
Memory: Your memory is probably not correctly set. If it is a 486,
read some of the old digests on how to do it. If it is a newer one,
recalculate where you set the upper limit. I have also found that
Bios can make some trouble, - it can set aside some shadow memory.
What this is: Bios resides on read only memory, EPROMS. They are
much slower to read, than ram. So what it does is to make a copy in
ram, and use that instead. This speeds up things, but I found some
problem with it under Linux. ( I don't know why )
++ Tracy +++++++
Some of the hardest things to do, - is to set up the video. If you
have trouble with it, you may try to download a newer version of
XFree86. If you take it from a RH5.2, then a lot of newer devices
have no support.
As for books, - some of the best info is found on the system. Look
in the directory /usr/doc/HOWTO - there are subdirectories, like
"other-formats", and mini. The mini's is short and easy. In
"other-formats", you have postscript files, and html.
If you have a browser installed, ( I use Netscape ) - just do:
file:/usr/doc/HOWTO/other-formats/html instead of the normal
http://www.xxxxx -
I have looked at several books, but I have not seen anyone better
than the documents you already find here.
By the way, - ( Have not done this ) - If you mount the dos
partition, - you can copy all the html files to a directory, then
under read all the stuff in Windows. ( If that is easier )
++ Ian : disk space ++++++++
do the command "du" - disk usage. ( man du ) It will give the
space from your current directory. If you want to see all that is
used for a mounted directory, do the command at the root of it.
++ Ian: servo motors +++++++
Sounds as if you have found something nice. The labels GND, A, B,
C, Led+ and led- is an optical encoder. +5v goes to Led+, and led-
goes to ground. But since they have both, it may lack a current
limiting resistor. Watch out ! You should be safe with a 220 ohm
resistor, for a 5volt supply. A,B,C is the quadrature signals from
the encoder, C is probably the index.
Servo motors - is not motors with encoders. There is different
types, but they usually have a tacho generator attached. This may be
the "coil around the shaft". If it don't have brushes, then it is a
AC tacho, else it is DC. All servo motors need some kind of
feedback. The normal thing is a feedback from this generator - back
to the servo amplifier. Then you have the motor running under
closed loop, in this case, - it has a closed loop velocity path. If
the amplifier has an input signal in the range of 0-10V, then the
motor will run the rpm according to this scale. If the rpm drops,
then the tacho voltage will drop, and the amplifier will increase
the output to keep the rpm steady.
A closed loop position mode loop, is either some position feedback
from a variable resistor, or it may be from encoders.
Proffesional servo systems, need both control loops - velocity and
position, + they all have a current loop, so that the amps to the
motor is under control.
++ Randolph: DRO display +++++++++
Remember that a LED display is very easy to read. In many cases, you
will not find anything better.
With a LCD, - you have a limitid viewing angle, - and they are often
useless in daylight, sunshine, or if you use a torch on a cutting
table.
++ Dan: Servo amps ++++++++
Something messes up the drawing in my last email. It will not align
the caracters, but I guess you understood what I was trying to do.
+++++++++++++++++++++++++
I hope this could be to some help for somebody,
//ARNE
Thanks for the info on helical gears. I do think they will give a
less play, though.
+ + To Ian: Linux. ++++++++++
Partitions: I am not quite sure of this, but:
I can't recall when they added support for big partitions. You said
that you had 4Gb for Linux.
The boot partition for Linux has to reside inside 2Gb of the start
of the disk. Also any Linux partition can't be more than 2Gb. There
is option for large disk, but if you want to mount a dos partition,
you will save your self from a lot of trouble. Anyway - with Linux
you can mount other disks and partitions, even over networks.
Memory: Your memory is probably not correctly set. If it is a 486,
read some of the old digests on how to do it. If it is a newer one,
recalculate where you set the upper limit. I have also found that
Bios can make some trouble, - it can set aside some shadow memory.
What this is: Bios resides on read only memory, EPROMS. They are
much slower to read, than ram. So what it does is to make a copy in
ram, and use that instead. This speeds up things, but I found some
problem with it under Linux. ( I don't know why )
++ Tracy +++++++
Some of the hardest things to do, - is to set up the video. If you
have trouble with it, you may try to download a newer version of
XFree86. If you take it from a RH5.2, then a lot of newer devices
have no support.
As for books, - some of the best info is found on the system. Look
in the directory /usr/doc/HOWTO - there are subdirectories, like
"other-formats", and mini. The mini's is short and easy. In
"other-formats", you have postscript files, and html.
If you have a browser installed, ( I use Netscape ) - just do:
file:/usr/doc/HOWTO/other-formats/html instead of the normal
http://www.xxxxx -
I have looked at several books, but I have not seen anyone better
than the documents you already find here.
By the way, - ( Have not done this ) - If you mount the dos
partition, - you can copy all the html files to a directory, then
under read all the stuff in Windows. ( If that is easier )
++ Ian : disk space ++++++++
do the command "du" - disk usage. ( man du ) It will give the
space from your current directory. If you want to see all that is
used for a mounted directory, do the command at the root of it.
++ Ian: servo motors +++++++
Sounds as if you have found something nice. The labels GND, A, B,
C, Led+ and led- is an optical encoder. +5v goes to Led+, and led-
goes to ground. But since they have both, it may lack a current
limiting resistor. Watch out ! You should be safe with a 220 ohm
resistor, for a 5volt supply. A,B,C is the quadrature signals from
the encoder, C is probably the index.
Servo motors - is not motors with encoders. There is different
types, but they usually have a tacho generator attached. This may be
the "coil around the shaft". If it don't have brushes, then it is a
AC tacho, else it is DC. All servo motors need some kind of
feedback. The normal thing is a feedback from this generator - back
to the servo amplifier. Then you have the motor running under
closed loop, in this case, - it has a closed loop velocity path. If
the amplifier has an input signal in the range of 0-10V, then the
motor will run the rpm according to this scale. If the rpm drops,
then the tacho voltage will drop, and the amplifier will increase
the output to keep the rpm steady.
A closed loop position mode loop, is either some position feedback
from a variable resistor, or it may be from encoders.
Proffesional servo systems, need both control loops - velocity and
position, + they all have a current loop, so that the amps to the
motor is under control.
++ Randolph: DRO display +++++++++
Remember that a LED display is very easy to read. In many cases, you
will not find anything better.
With a LCD, - you have a limitid viewing angle, - and they are often
useless in daylight, sunshine, or if you use a torch on a cutting
table.
++ Dan: Servo amps ++++++++
Something messes up the drawing in my last email. It will not align
the caracters, but I guess you understood what I was trying to do.
+++++++++++++++++++++++++
I hope this could be to some help for somebody,
//ARNE