+/- 24volts for galvos

[taggalucci]

It can be ok to have DC and AC ground connected, though I wish to preemptively eliminate ground loops.

The key to this is because in my set up with isolated grounds, ILDA pin 25 is connected to DC ground.

[badger1666]

another question, would there be a problem running two dc-dc converters ? one for 5v and one for 12v.
just wondered if i would see the same problem as i had in the past with two different t220 voltage regulators on the same power supply
one would get very hot, never did find out why that would happen, they just seem to fight each other all the time , had to use two supplys in the end

[sbk]

Voltage regulators are wasting the excessive voltage into heat, so a 5V reg will heat more than a 12V one if you power them both from 15V. Good news now is a proper DC/DC don't suffer this problem, they have an efficiency of such 90% within the entire input voltage range they are specified for.

[badger1666]

i hope someone can help me again with the maths thing
i have got a smps500r power supply and the 5v 12a dc-dc converter which i only need 5amps.
is there enough overhead on this power supply to still add more dc-dc converters as i still need 6v @2a
and 12v@ 3 to 4amps
or i could just get away with the 12v @4amps ikf there is not enough room to run both
also i cant find any 6v 2a converter that have a 48v input voltage ? anyone know where i might find one thats small

thanks

[taggalucci]

Hey there,

So

I * V = P

Therefore...

12A * 5v = 60W
2A * 6v = 12W
4A * 12v = 48W

=Total of 120W

Your SMPS can provide 500W so *theoretically* you've got plenty of headroom. Things to bear in mind (with much of this thanks to Dnar)...

Power consumption isn't power available. So you need to get the maximum power consumption figures for each device hanging off your PSU.

Assuming you're using some of this for driving the scanners, the main 24V supply must handle the peak current requirements of the galvo amps with enough extra for the other power drawing devices at maximum. Dnar suggested to me that no more than 80% utilized worst case scenario and to consider the thermal derating of the power supply (normally you can get a graph/specs on the datasheet). So consider the range of operating temperatures and factor in the impact.

[hakzaw1]

I see that quite a few who have been so kind to add help in this thread happen to be on-line-NOW.

I have a few questions especially for Steve as he seems to be very helpful when it comes to CTs. I know my questions will show all how little I know about scanners and the amps --so be it.

if you need more pics just let me know-- likewise if I should just try to cope with these heavy & huge Amps I will deal with that too-- after all CT used them with these 6800s+ back then for a reason--

***********************************

OK-- I got an pair of Legacy CT 6800 scanners via Ebay and the AMPs are HUGE and HEAVY-

not sure why but they are that size but they are WAY too big to fit inside my DIY RGB-

Are they this size for some reason that I cannot imagine? on the back there are a pair of RCA jacks and an 'input' That is the same as the output DMX on my PJs. On the front besides the Power switch and its LED there is a knob for GAIN.

I guess I could still use these amps with the 6800s and just move the driver boards from the back of the rack-mount case that houses the amps and install them inside my PJ case.
And add plugs to make putting it all together easy.

And thus keep the amps in this rack-mount case or move them into something slightly smaller (w/ fans of course)- I would like to use this case for another PJ someday.

But ideally I would like to get good, but smaller amps that can go inside my RGB case.

If I can do that I may want to sell or trade these big amps- I am not sure I will ever have a use for them--Not sure why they needed to be so big either

--< this is the back view of the two RCA jacks and the 'DMX'(looking) jack- they have wires running to the back of the GAIN in the center pic above. And of these black wires also run to each driver and the strip on the left side.( far right pic)


this is my first PJ build and have never worked with CTs before. No doubt however that they are plenty powerful for the CT scanset.

see my pics below and if you need more pics I can take them-- TY in advance for any help.

[hakzaw1]

here are a few more pics

[taggalucci]

Hi Len,

It looks like you have the same amps as I, the CB6580.



In my opinion, these are not particularly large. They're about double the size of the Chivo amps, but worth every ounce and some! Perhaps you are referring to the whole box of tricks you have, not just the amps (1 single amp is pictured above)? The transformers/power supplies will be large and heavy, but these can be swapped for smaller power supplies provided you meet the demands of these amps.

I have swapped the large toroidal linear power supplies for a pair of Meanwell SP-200s hooked up in series to create a dual rail +/-24v power supply.

http://www.computronics.com.au/meanwell/sp-200/

Here's a picture of them in my projector...


Here's a thread that talks about the technical details regarding these amps and appropriate power supply...

http://www.photonlexicon.com/forums/...0-scanner-amps

Let me know if that helps clarify things for you.

Good luck with your build
.

[taggalucci]

PS: If those amps and galvos are in good condition, you've got yourself a damn fine setup! I love my CT scanners, they are so smooth and shit all over the Chivos

[hakzaw1]

So maybe I should just leave the boards where they are & not change a thing- ??

THEY ARE the same - CB6580.
They also sent the manual with foldout schematics. This was from an estate sale so its history is unknown.
Same sale had halF dozen HeNes(All reds, I asked) some other laser items and a remote for an ILT Argon that MAY allow mine to do more than idle at 9mW. Good question for Sam.
They had a spare Y 6800 with driver- mirror attached and I grabed that up when nobody else 'made offer' 99$usd.
SOOO glad I asked the seller about the mirrors- thier pic was of the back of the block and it looked dusty- when it arrived (serperatly ,as I asked they obliged & no extra charge) it seemed unused or very little-

I will not deny I did know know any scanner amps were as big as these. So maybe I should add another rack on top
for the modules and block- there is room in this case for my big PS for the 532.
Just that part weighs 23.5lbs. I will look into swapping out those heavy transformers..
Thanks for the help and the link- I will post up some pics when the fun begins.--Len