Re: [CAD_CAM_EDM_DRO] Re: New to group and need some info

In a message dated 11/14/2002 11:29:00 AM Central Standard Time,
motomann2003@... writes:

> I meant can I use common ground from a parallel pin for the optos on
> a G201 drive, and not worry about wiring a +5Vdc line from the PS to
> the gecko drives?
>

John: I do not know about the G201's---I have had ONLY the G210's, and THEY
can be "customized" (by changing "jumpers" under the aluminum cover) for +5
common, or "ground" common, for the inputs, which are the LED's in
opto-isolators. These draw about 8 to 15 mA of current. It has been MY
experience that SOME PC printer-ports can "source" sufficient current to
light LED's on a bread-board, but I am not sure that "all" PC's can do that!
Almost SURELY not! But I expect "all" can SINK that much current, but that
will mean that the "common" to the Geckos will have to be +5, and I repeat, I
do not know if the G201's can be configured for + common.

As someone else has replied to your question, already, you shouldn't even
THINK about re-wiring "some of the ground pins" on the DB-25 connectors for
+5. This will make your PC NON-standard, and just CONNECTING most "printer
cables" (which have pins 18-25 "shorted") will DAMAGE your PC's 5VDC supply!


It may be a hassle, yes, to "bring out" the +5 from an extra disk-drive
connector, but I assure you, it is WORTH the "hassle", as it will SURELY save
your PC from some expensive, if not "total" damage!!!! Just watch what you
are doing, and do NOT pick the 12 VDC pin! At the risk of sounding
"unkind", I must say this: If you are SO bewildered by this problem that you
must ask, it is quite probable that you do NOT have sufficient experience
with such seemingly-simple little conundrums to even [deleted] with it at
all! Best you DON'T!

For MY Gecko-drives, to insure sufficient DRIVE-CURRENT to those
opto-isolator inputs, AND to "isolate" my PC from the "nasty motor-world", I
used a 74HCT541 CMOS buffer, a ULN2003 driver, and a WHOLE-NUTHER 5VDC supply
(well, there is one in my "periferal" I was cobbling, anyway). Whew! All is
safe!



[Non-text portions of this message have been removed]