How do SGL Imagers cable up power for their CCDs and laptops at dark sites.

[focaldepth]

How do SGL Imagers cable up power for their CCDs and laptops at dark sites.

(Usual disclaimer about dumb questions...)

OK here is the back ground..

I currently image from my roll off roof shed with the luxury of mains power.

My SXVR H18 CCD is very fussy about power and likes its own SX 240v-12V PSU.

I've now been to 2 star parties and have been spoilt by dark skies, Keilder next.

Now, I know that I am over thinking this, having an electronics back ground but connecting lots of gear to a 12V (13V ish) battery and a laptop via a step up converter and a USB powered guider bolted to a common ground with the CCD and Mount, just sounds like a disaster waiting to happen. Ground loops, noise, leakage currents.....

CCD cameras are too expensive to find out the hard way.

I already have a 12V Lesure battery and plenty of Cigar lighter splitter sockets and a 12V laptop supply. I have ordered 12V-12V converter to try.

So the question is, do you all just plug it together and it all works or are there steps you take to ensure a star point for ground or ensure isolated floating power supplies etc.

Thanks in advance for any ideas.

[focaldepth]

I have just stumbled across,

http://starizona.com/acb/ccd/settingupcomp.aspx

which advocates running the CCD of a separate 12V supply.

That makes sense to me. Is this what SGL members do?

[carastro]

I only go to campsites that have hook up.

Carole 

[focaldepth]

I only go to campsites that have hook up.

Carole 

I like lateral thinking . Unfortunateley, so far, I have booked too late or there was none. I am on the drop out EHU list for Keilder though.

I am still interested in how people wire it up though.

[digitaltre515]

I've got two 12v battery supplies, and a 24,000mAh external battery for the laptop.  Heaters plug into one supply, camera and scope to the other, larger one.  I run ferrite core isolators on all my cables at both source and destination ends of the cable.  Haven't seen a problem yet.

At home it's all on mains, with the 12v coming from a regulated power supply.  Still run the ferrite cores, though.  I made a wire harness of sorts for the rig, so i don't have to run cables all over.  Makes setup and teardown quicker, and keeps it all neater.

Also, in that wire harness, I cut the heater cables so the heaters can be seperated from the harness for stoage.  I soldered in XT60 connectors for the break.  This also lets me power the heaters from RC LiPo batteries, if I want or need to.

[focaldepth]

I've got two 12v battery supplies, and a 24,000mAh external battery for the laptop.  Heaters plug into one supply, camera and scope to the other, larger one.  I run ferrite core isolators on all my cables at both source and destination ends of the cable.  Haven't seen a problem yet.

At home it's all on mains, with the 12v coming from a regulated power supply.  Still run the ferrite cores, though.  I made a wire harness of sorts for the rig, so i don't have to run cables all over.  Makes setup and teardown quicker, and keeps it all neater.

Also, in that wire harness, I cut the heater cables so the heaters can be seperated from the harness for stoage.  I soldered in XT60 connectors for the break.  This also lets me power the heaters from RC LiPo batteries, if I want or need to.

Thanks for that, that is the sort of thng I was thinking. It just felt wrong to connect everything into one 12V cigar splitter. I was thiking about ground connections but forgot about killing the RF with ferrites. In my shed I have most things on their own PSU and it works as expected.

Time for a blank sheet of paper.....can't beat good practice.......

[Uranium235]

On a side note, run the CCD power cable separately from the data cables (ie: down the other side of the OTA), as they can cause interference with USB cables.

[digitaltre515]

On a side note, run the CCD power cable separately from the data cables (ie: down the other side of the OTA), as they can cause interference with USB cables.

Yes. But the ferrite cores do a pretty good job at isolating noise from stray contact. Good ones, not the little tiny ones.

Sent from my XT1254 using Tapatalk

[Physopto]

I use two batteries. One does the Dew heaters and Mount, the other does  the rest.  

But I also use 12 volt to 12 volt DC convertors. CDD on one Mount on another. Focuser and A.O. on another. Computer on its own step up supply.

I will be at Kielder you are welcome to see it if there.

Derek

[focaldepth]

I use two batteries. One does the Dew heaters and Mount, the other does  the rest.  

But I also use 12 volt to 12 volt DC convertors. CDD on one Mount on another. Focuser and A.O. on another. Computer on its own step up supply.

I will be at Kielder you are welcome to see it if there.

Derek

Thanks I would like to see your solution but plan to have a working setup by then as I DON'T want to get some dark sky imaging done. (I do really, that was for the cloud gods )

I am glad to see that I was thinking on the right lines.

[focaldepth]

On a side note, run the CCD power cable separately from the data cables (ie: down the other side of the OTA), as they can cause interference with USB cables.

Yes good idea. I need to get some good subs to try your image processing from SGLX. Thanks for that lesson.

[m.tweedy]

If you can use at least 2 batteries.

I use one soely for the mount because if that dies everything is finished for the night. I have used a 50Ah one all night.

dew banks can take a lot of your battery life. You will soon find out what i mean if you get to Kielder. So I use a second for them.

In he past i have not used a CCd but it draws minimum power compared to the bands and I would be temted tp put them together with them and get a more powerful battery for them say minimum 85Ah

THE BIG THING ESPECIALLY AT KIELDER WHEN IT CAN GET SUB ZERO IS INSULATION. put the batteries into something like a cool box because it keeps them warm.

[focaldepth]

Great, so based on advice and gear to hand, and some cheap ebay stuff, I plan on my 110AH Leisure (back breaker) battery for the mount, heaters and and laptop PSU. CCD on its own 15AH Lithium battery and guider off USB power. Scatter a few well placed ferrites around, consider a stabilised DC-DC (with Crowbar) for the CCD and I should be sorted.

 

Add in an aluminiumised bubble wrap tea cosy to keep the batteries snug and happy then route cables carefully before taking images.

 

Thanks all some good ideas.

 

[Physopto]

CCD battery may need to be larger, but that depends upon what power it takes for the cooling. If you can keep the battery on charge whilst using the CCD then fine. Same for the main battery try to keep charged whilst in use. 110 ah lead acid batteries will only give out about 50% before the voltage goes below 12.4 volts at the battery. If a long cable is used their can be up to a 1volt drop in it easily. This would then only be delivering around 11.4 volts at the equipment under load. Even leisure batteries do not like being discharge this far too often, before irreversible damage is done to the battery. Your CCD may not work below 11volts. So keeping the batteries charged at all times is the best method.

Have fun.

Derek

[focaldepth]

Just for reference, my planned power budget is as follows (measured this morning)

From the 110Ah Battery

HEQ5 0.32A (Sidereal)

Heaters 1A at 50%

AstroTrack 0.25A

Laptop 3A (5A max) including guider

Total = 4.6A

From the 15Ah Lithium

CCD 1.1A (Max) via DC-DC converter

So I am hoping I can last 3 nights without a recharge at Keilder.

[Physopto]

I will be very surprised if you can. The dc/dc converters are about 85 to 90 efficient so the 1.1 amp will be about 1.2 to 1.3 amps. So expect possibly 2 nights. The other at 4.6 amps might get the same, ish! Before the battery gets below half charge. Remember the battery will not hold its charge so well when cold, AND it does get really cold there at times. Your heaters may use a lot more than you think at those temps.

It is not hard to recharge during the day there. Steve the resident site manager (Kielder shop owner) will let you charge up at the on site " warm room". I believe there is now a new room built this year. Better to charge than run out during a really good nights viewing/imaging.

Derek

[focaldepth]

OK thanks, a topup may be in order then, if we actually get a few clear nights that is. I do have a solar panel but may not have room in the car for it.