Machsupport Forum
Mach Discussion => General Mach Discussion => Topic started by: Pythagoras on December 19, 2008, 12:59:04 AM
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Hi guys, I just bought a SS and 4 Geckodrives.
Where do I get the 5 volts from to drive the Geckodrives?
Can I get that from the USB port or will that cause it to close down.
I am a newbie again, since I have previously used a Rutex setup
Regards Benny
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Benny, I prefer to power the SS externally so I use a line from the computers power supply to do that and you could use that to power the Geckos.
If you you are using a BOB then they often have 5V outputs as well.
Not sure how much draw the Geckos have but would think USB would be adequate but then again some computers are weak on the USB, are you having problems with the SS dropping comms?
Hood
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Thanks Robin for the reply, you are just the man I was hoping would answer.
I am not using a BOB (I'm a risk taking, money saving scab) Should I ?
As for drop outs, I wouldnt' know yet. Ive only just installed mach and tested it on the bench. Nothing other than the USB connection. The lights ae doing as they should be.
Why do you power your SS externally?
Do you know much about computer power supplies? Do they have the 5 volts regulated out of the case or is that done on the mother board.
Two ex admins hey :)
Benny
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I use external power as I just dont trust USB power for anything :D Had many an external HDD work fine on one computer and then the next doesnt have enough guts in the USB to power it.
Computer power supplys produce all of the voltages internally, well that is if we are talking desktop PCs and not Laptops. On the desktop PSU the molex connectors that go to devices such as PATA HDD and CDROMs etc have both 5V and 12v, 5v is the red wire and 12v the yellow and Black is 0v. You can also get 7V there if you wish to power a fan that is too noisy on 12V but too slow on 5v, just use the 12V and 5v lines rather than one of them and the 0v :) The ATX connector also has 3.3v and usually -12v and all voltages from the PSU are regulated and usually fairly good regulation at that even on the cheapos (should be music to your ear ;D ) You also have a 5V standby voltage on the ATX connector that is present even when the mobo itself is powered down, all the rest of the voltages just come on when the power good signal from the mobo is present.
Hood
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Thanks Robin
:D :D :D
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Thanks Robin
:D :D :D
The funny thing is, you think I was making a joke. Sadly I was not :)
Before Robin hits back, I best tell you my name is really Benedict.
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So I suppose your nickname shall be Arnold?
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So I suppose your nickname shall be Arnold?
And yours "Uncle"
Blow it, I was hopig to make this a good thread to be used as a reference for others. Oh well.
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And yours "Uncle"
Blow it, I was hopig to make this a good thread to be used as a reference for others. Oh well.
Not when Sam gets involved...... ;)
Dave
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Benny, think you messed up when typing your name, should the T not be a few letters back ;D
Hood
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Seconding everything Hood said and adding that USB power caps at something like 500ma (per port).
I can't speak for all computers, but my laptop's reaction to drawing too much power was to simply SHUT OFF the juice to the port! Not pretty.
PC power supplies are regulated very well, methinks and they are dirt cheap. I'm using an old one that can no longer run a motherboard, but still puts out a nice steady 5v and 12v. You can just jumper the 'ready' or 'power good' (per Hood's post) pins on the motherboard plug and the power supply will switch on a and run by itself.
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I saw somewhere that the common wire for the 5 volts and the steppers power should be the same.
Does that mean I can't use two seperate power supplies, one for the 5 volts and another for the steppers?
One more thing, how much tollerance with the 5 volts have I got. The computer power supply I have seems to pt out 5.5 volts. Will that fry the SS or Geckos?
Could that mean the power supply is on its way out?
BTW can a moderator please delete all the previous bullsh1t posts in this thread, as I havnt been back long enough to warrant the afterhours, let your hair down and play with the lads stuff.
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I think it is normal practice to have all of your 0V connected to provide a common reference point, whether that be from 2 different 5v supplies or a 12v and a 5v etc unless I suppose they are on separate sides of opto isolation. Then again I am no expert at this so maybe wait for someone else to chime in.
Usually computer PSUs have a tolerance of 5% or less, your seems to be nearer 10% but I presume that is unloaded, if you put a load on it will probably come closer to 5V. Cant remember exactly what voltage Greg said was too much but its definitely on his forum if you do a search, think 10% should be acceptable but less would obviously be better.
Hood