+/- 24volts for galvos

[LaNeK779]

ok, silly question coming up.

anyone got a suggestion for a "beefy" psu one could use instead of the cheap and not powerfull smps that comes as standard issue with most cheap scanners (the classic +/-24v - 1amp)

could i use two 24v power supplies? is there another trick?

thanks!

[dilbert]

I use 2 x 24 6A supplies in mine to power pretty much everything - scanners, interfaces, cooling etc Just link one + & - out for the common 0v then use the + for +24v & the - for -24v

[Badpip]

As dilbert said, two 24V supplies in series is the way to go.

If size and weight is not an issue, a good ol' linear psu would be great as well

/Thomas

[LaNeK779]

that was quick!!

thanks guys

[hakzaw1]

Can this be handled with just one if it were a better 24V? I will post PIC of mine later.
its a fan Cooled lambda nv-power nv=350
has 15v @16A- 24V @8A -15V @10A. and 5v @10A.

ANY OPINON?
thnx hak

[taggalucci]

Can this be handled with just one if it were a better 24V? I will post PIC of mine later.
its a fan Cooled lambda nv-power nv=350
has 15v @16A- 24V @8A -15V @10A. and 5v @10A.

ANY OPINON?
thnx hak

Hmm, + and - rails from a single PSU? Not without an isolated DC/DC convertor (which is like another PSU anyway).

...unless any more electron-cogniscent folks can enlighten us.

[dilbert]

Nice supply but no - its not suitable with just 1 x 24V rail - you could use a pair of these for entire projector as overkill if you have space.

Can this be handled with just one if it were a better 24V? I will post PIC of mine later.
its a fan Cooled lambda nv-power nv=350
has 15v @16A- 24V @8A -15V @10A. and 5v @10A.

ANY OPINON?
thnx hak

[flecom]

I use +/-24vdc Power One linear supplies... they work great

[Tracky]

Projektor Elektronik.jpg

This is my solution. First I use a ring core transformator 2x18V AC, two peaces of Graetz Bridge and 2x20.000µF. Now I have 2x24V DC with enough current reserve. 2 step I use some power DC DC converter. 5V/30A and 4 peaces adjustable voltage from 9V-12 up to 8A for my TEC driver.

[hakzaw1]

Thanks for all the posts and my apoligy to the OP- not meaning to threadjack you.
But while you had all these great 'helpers' I wanted to learn more and thereby waste less time and money.

maybe this;
its a fan Cooled lambda nv-power nv=350
has 15v @16A- 24V @8A -15V @10A. and 5v @10A.

Should have been wriiten like this..

its a fan cooled Lambda NV-power NV-350
has 15v @16A, 24V @8A, 15V @10A. and 5v @10A.

I do have lot of room on my 13 lb 12"X24" finned bottom base plate(thnx Mike for the great deal$40) also all three of my labbies have a small footprint.

I have a few other regulated PSs that I could use. But buying another is not an affordable option right now.


sorry for all my noobish questions. I use search all I can.


thanks for all the advice


len

[Badpip]

Hmm, + and - rails from a single PSU? Not without an isolated DC/DC convertor (which is like another PSU anyway).

...unless any more electron-cogniscent folks can enlighten us.

That's one way to do it.

Another way is a non-insulated voltage inverter.

...Or a 48V single supply with a rail-splitter.

Both are quite small, but price will most likely be the same as two PSUs anyway.

/Thomas

[LaNeK779]

Thanks for all the posts and my apoligy to the OP- not meaning to threadjack you.
But while you had all these great 'helpers' I wanted to learn more and thereby waste less time and money.

no problem Lem, i also learned from your questions and subsequent answers. that's the whole point!

[hakzaw1]

ha ha you called me--LEM-- I love laser enthuaists meets(LEMs) and considered changing my user name to LaserLemLen ( which would be a little redundant)--lol

len

[LaNeK779]

ha ha you called me--LEM-- I love laser enthuaists meets(LEMs) and considered changing my user name to LaserLemLen ( which would be a little redundant)--lol

len

ha ha ha!!! my apologies! this is my second name-screwup in here. the first one was some time ago, when i called dsli_jon as "john"... i was lucky enough he didn't send an ultra powerfull laserbeam my way

[hakzaw1]

NEW RGB case day one 002.jpgNEW RGB case day one 004.jpgNEW RGB case day one 007.jpgNEW RGB case day one 008.jpgN?P my friend

I still dont know if my lambda PS will take care of everything- hope so- I am running out of space.
my working area is 22X 12 &5/16th inches and none too deep - but no worries about warping os the HS abilities- it is heavy finned and weighs 13 lbs for just the base. end pieces also 1 inch thick counting the fins.

Has a place for two fans on the bottom and 120+ drilled and tapped holes left from the rgb that once lived in it(thanks Mike for the sweet deal @40$)
the opening is 20 MM up from the base and off to one side ( right if facing) I hope to build this with an access door to get to the mounts w/o having to remove the top.

red closest to scanner green in the middle and 445 farthest.
hope i can get 1.5 to 1.8W from it.

lots of help so far thanks to all- too many to mention atm.


cheerz len

[LaNeK779]

i was browsing for some other stuff when i ran into this

http://www.datasheetcatalog.org/data...onics/1317.pdf

check out figure 13. To make a long story short, this chip takes 8 to 36 volts single rail and makes it 4 to 18 volts "symmetrical" (dual) rail

maybe it proves usefull to somebody, as it handles up to 3amps

[-bart-]

That is what they call a railsplitter

Personally I would not use such a device, because current spikes (not uncommon for galvo amps) on the positive rail, might end up as voltage spikes on the negative rail.
And when one rail is shorted, it will wreak havoc on the opposite rail.

[sbk]

And you have to find a +36V power supply which is quite uncommon...

I found this one too which seems nice, a simple +-24V rectifier, HB-Laser are using them for their EyeMagic scanners : http://shop.hb-laser.com/OEM/elektro...ply::3182.html

[LaNeK779]

i don't get it, why do they use two bridge rectifiers?

i think just one will do the trick

something like this simple design (not this one of course, it can't handle high amps)

[sbk]

Yes it's strange, I usually saw only one rectifier. Maybe to have completely independant rails, but I don't see the advantage...

[LaNeK779]

and it also seems way overpriced!! 57 euros for 2 caps, a pcb and the bridge rectifiers?? and the caps are not even audio grade

anyway, i chose the analog way, one heavy 2x18 transformer is sitting on my desk alongside two 10.000uF capacitors and this will power the galvos only, so i'm golden

thanks to bart and sbk for the input on that "strange railsplitter" chip

[sbk]

Yes I believe that as usual, a big part of the price is going to the "engineering" (not really difficult though), PCB manufacturing and benefit for HB
Anyway your transformer will work just fine. 10.000uF caps are a bit overkill but if you have enough space that can't be bad at all

On my side I found and buyed this one, which is an audio grade SMPS and seems great quality especially for the price. Will test it as soon as I receive my EMS7000 scanners

[-bart-]

@*^&%&*%^!!!
Still waiting for my SMPS300R's ....

[Solarfire]

On my side I found and buyed this one, which is an audio grade SMPS and seems great quality especially for the price. Will test it as soon as I receive my EMS7000 scanners

I looked at this one too but ditched it due to the lack of specific data like ripple @ rated power, rise time and such and due to it being a Chinese build.

[mixedgas]

I use massive unregulated linears with crowbar circuits. If something does go wrong, the crowbar kills the power to the amps in about 20 nanoseconds (no, I'm not kidding, moderate size SCRs are fast, and they short the rail till the fuse blows) This is the classic, preswitcher way to power Cambridges, and I use 2 transformers with my choice of 19 or 27 V taps, the transformers are so massive as to be self regulating, I'm no where near core saturation.

Before you scoff, I've had to replace switchers more often then I'd like, if my projector is on switchers, TWO spare switchers travel with me. I hate them. A well designed linear will out live me.

BTW, there are 5 amp versions of LM317, and you can add booster transistors to the LM317 or LM338, just look at the ap note. However do not forget to add the 3 reverse protection and clamping diodes when you do the boost circuits. Some people have published the boost circuits with the diodes removed, this is wrong in so many ways.

Steve