i got a power supply question

[ljoe1969]

i found a power supply and i want to know if it will work on a xylotex driver.

input 120 vac 50/60 hz 8 amps

output 24v 75 va

anyone tell me if this will power my xylotex board or should i look for another power supply?

[balsaman]

The input must be 0.8 amps. Output will be around 3 amps. What motors are you using. What is the current rating of them. Unless they are very small steppers you need a little bigger supply.

Eric

[ljoe1969]

i got them with the driver from xylotex. the 116in/oz that is come with the kit.

[balsaman]

It will be nip and tuck. See if you can find a little bigger one, or ask Xylotex to be sure.

Eric

[ger21]

THis would be a little better.
http://cgi.ebay.com/ws/eBayISAPI.dll...category=32720

It's a little pricey, though. If you're not in a hurry, you can usually get a liitle higher output for less money. This cost $135 new, though.

Gerry

[bcromwell]

If you are look for a cheap way to get pretty good power,

I took 3 PC power supplies that where rated for 12 amps on the 12v Feed and 15 amps on the 5v feed, I took and put them in series, Which give me 12+12+5 = 28V at 12 amps, and I picked up the power supplies for 5$ each at a computer surplus shop. They only thing you have to do to get this to work is to remove the 3rd (bottom) prong off each power supply so they will have a floating ground, and becuase I had a metal case, I used double stick tape as a dielectric to keep the three ps's from touch each other and the case.

It's not near as clean as some of the toroidal power supplies, but like I said I am only out 15$, and switching power supplies are very efficient.

[Mr.Chips]

bcromwell
I'm not electrical at all and don't understand putting 3 PC PS in series. Could you supply a little drawing.
To me in series means the output of one is fed to the input on the next... I understand the output, but don't know where the input would be.

This seems like a very inexpensive way to arrive at 28V and 12 amps.
Hager

[abasir]

Something like below I believe

[bunalmis]

No no no

You can not connect 3 PC power supply.

Serial connection not possible. Load can not equal share by 3 Smps and poor PS goes shutdown.

Also If you pull power from 12v but dont pull power from 5v, PC goes shutdown.

[abasir]

Have to wait for bcromwell connection diagram then
May be depend on PS type also?

[limbo]

If I understand correctly from the Xylotex datasheets these steppers are 13W each (2 coils of 6.5W). Suppose the drivers have 70% efficiency (a bit conservative), this means 18.6W draw from the supply per stepper. For three steppers this totals at 55.8W (roughly 2Amps), so I think you'll get away with using your original powersupply. Why not try first and measure the total current, before investing in another supply?

John

[bcromwell]

Originally posted by bunalmis No no no You can not connect 3 PC power supply. Serial connection not possible. Load can not equal share by 3 Smps and poor PS goes shutdown. Also If you pull power from 12v but dont pull power from 5v, PC goes shutdown.

abasir's Picture is exactly correct, And Any PC PS should be fine,

Yes you can connect 3 PS's together IF you make them have floating grounds (On the AC Side) and they can't ground to each other (IE, Since most PC PS's have metal cases, They can't touch each other).
Your amperage will be what ever the lowest rated amperage Leg in the series, IE, If you have 2 PS's rated at 5amps@12V and the last PS is rated at 6amps@12V you would end up with 36V@5amps.

Since my xylotex board will not handle 36V, I only used the 5Volt leg on the 3rd PS, so that I would end up at 28. You cannot just serial connect the 12V and the 5V on the SAME PS because they use a shared common ground.

I have been running my xylotex board with this config for over 3 months now and it works great..

Also If you pull power from 12v but dont pull power from 5v, PC goes shutdown.

To solve this I just used a 2 5V light bulb fixtures and one 12V Bulb, from radio shack, as a indicator light, Because if One PS out of the 3 is off the system still works, but with the lose of volts the steppers slow down, so the lights are nice to have.

I will post pictures of my PS when I get home.

Bryan