Re: [CAD_CAM_EDM_DRO] Gecko 5V supply

Gentlemen,

Where can you get cheap 5volt wall warts? I see the 4.5 and 6 volt ones all
the time, but 5v? They seem to run around $25.00 USD. I can get a used PC
power supply for 5-10 USD. And that is a regulated power supply with a
chord and power off switch.

Tom Eldredge

Tom Eldredge

Tom Eldredge

----- Original Message -----
From: Alan Marconett KM6VV <KM6VV@...>
To: <CAD_CAM_EDM_DRO@yahoogroups.com>
Sent: Monday, April 02, 2001 1:16 PM
Subject: [CAD_CAM_EDM_DRO] Gecko 5V supply


> Hi Jesse, Brian, Mariss,
>
> I just might have to disagree a little with that statement! Most U.S.
> cars have the negative side of power connected to the frame of the car!
> The negative side of a PC's power supply is connected to the chassis
> ground (probably at one point). On the other hand, the series connected
> 120 or so lead-acid cells in the battery wells on the submarine I was on
> WAS floated from "chassis" ground! The electricians were VERY careful
> not to short out one of THOSE cells!
>
> (and on Brian's post)
> The PC's 5v power available through the joystick connector PROBABLY has
> a fuze (The better boards), just like the keyboard port is supposed to.
> As the traces on a PCB are quite thin, I doubt if you'd be able to pull
> 25A anyway. But a good warning!
>
> NOT that I consider PC power the best choice. Several years ago, I was
> rigging up a driver for a stepper motor system (wires strung all over
> the office), and had one external open frame power supply driving the
> stepper fall into another (where's that cat). When I came in the next
> day, flipping on the power gave me a big flash! :>( I fried the driver
> module, the CY525 controller, and the parallel port board. The PC
> finally came up after I removed the fried parallel board. It limped
> along, and really didn't run right after that (it was subsequently
> retired).
>
> The lesson: you NEED isolation from the PC! I suggest a 5v wall wart,
> and leave the PC's 5v for things like joysticks, mice, hand scanners and
> keyboards.
>
> Yes, I'd have to agree with Mariss! Not much electrocution danger from
> 5v. And I must say, the Gecko's are GREAT DRIVES! I just wired up my
> first pair of 201's, and found them to be VERY easy to use! Much easier
> then the SD200's I had seen in the past. Although I mounted the pair on
> a 6x6x1.5" finned heatsink, they run perfectly cool (37v, 2A)! I did
> find out that I'll need a LOT more steps to make them spin FAST! Guess
> I'll be going to EMC on a Pentium faster then I thought! (But how does
> one get the little covers off? Even after pulling off the terminal
> blocks, it only slides back so far. Wouldn't want to bend it!). Again,
> I am greatly impressed by these drives! Thank you Mariss!
>
> (An idea)
> Did you know, "Surplus" 24v linear power supplies, with "fried"
> regulators, are available cheap, and with the regulation stripped out,
> can provide about 37v for a stepper driver! Try to find one with a 6A
> rating, 4A might get by.
>
> Alan KM6VV
>
>
> jesse wrote:
> >
> > On DC power circuits neither side is grounded. So both the + or - buss
has zero potential to ground. Years ago when I was running
> > diesels generating DC power for electrolytic hydrogen it was normal
to feel the bolted buss connections looking for hot spots.
> > It took watching someone else doing this a few times before starting to
do it. Just don't grab both busses at the same time.
> > I would have to do some checking before I did this on electronic
systems.
> > Jesse
> >
> > mariss92705@... wrote:
> >
> > > Hi,
> > >
> > > Most PCs have a game port. The +5VDC is available on pin of the game
> > > port. You cannot electrocute yourself off of 5 volts even if you put
> > > the wires in your mouth and stand in a tub of salt water. Haven't
> > > tried it myself but I am sure.
> > >
> > > Mariss
>
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