How many Amps does a complete imaging set up pull??

[Gargoyle_Steve (Steve)]

Can anyone tell me how many amps you pull when you have your mount, laptop, main imaging & viewfinder cams, etc - everything you set up when imaging - what kind of amperage do you use??

Alternately if you know how long you can run off a battery setup (assuming it is running everything) and how many amp hours your battery is let me know.

Much appreciated!!

[[1ponders] (Paul)]

Just a telescope and I can run for 3 or 4 nights (15Ah) , even with slewing. Running a laptop, a few hours. Include heaters HA! yeah right.

If you really want to know, have a run around at duckadang and add it all up

[KG8]

Funny thing is this. We will spend thousands on cameras, thousands on laptops, and thousands on mounts and scopes. Yet will we spend $300 or $400 on a good set of high amp-hour deepcycle batteries? NO WAY!

If you get yourself three 70Ah marine batteries from supercheap you can run it all for nights on end* and your electric blanket** to boot.




*(for at least 3~4 nights... or so)
**(depends on the setting on the electric blanket)

[GrahamL]

Yes a friend mentioned that once KG8.. I think he said these batteries are made to be drained and recharged while most others arn't ?.I do recall the price bit though ,thats a fair bit of cash to splash .

[Omaroo (Chris Malikoff)]

I use Bosch 120A/H deep cycle batteries which cost me last time, if I remember correctly, around the $230 mark from our local Battery World.

Nightstalker - deep cycle are designed to run LOWER than your typical standard cranking battery, but should not repeatedly be taken to lower than 40% charge. They are able to be run this low (11.8-12.2v) some hundreds of times without loss of performance. I also run my car fridges off these with great success.

A 120A/H battery is heavy, a 70A/H less so...... and it would do most telescope/laptop/camera/heater applications for several nights.

[Gargoyle_Steve (Steve)]

I'm more interested in how much actual current it will drag running off a 240v AC supply, to calculate how many complete setups you can safely to run off a single 10A 240v lead at one time, but I appreciate the answers so far anyway.

[KG8]

Well my EQ6 in full flight pulls 2.1A
A good set of heaters for a big scope 2A
Laptops are rated at around 1~2A
An inverter will waste 1/4A
I Have no idea about cameras

I wouldn't run more than say 2 or 3 setups off that 10A lead. And don't forget that any 240V supply will chew current in its transformer so you have to factor that in.

[gbeal]

Steve,
I use a single 240V AC lead, via an RCD, to where I image.
It feeds a multi block with 4 plug outlets. From this I run:
2 plugs for the monitor and PC case.
1 for the SBIG camera power supply.
1 for an AC transformer to power the mount, dew heaters, and any other 12 volts systems I need. (this is via a homebrew RCA splitter, feeding one RCA 12 volt in ,and up to 4 RCA out).
Typically the 12 volt stuff is just the mount and heater unit, but occasionally other items like the StarMate are plugged in.
No problems with all this, and contrary to how Ponders handles his cables, mine is quite tidy. We have lots of horses nearby, and none have choked, LOL.
All is housed/fitted in a roll out TV trolley, so it is all but plug and play.
Gary

[Karls48 (Karl)]

Hi Steve
You cannot calculate load on your 240V lead by adding 12V amperage. If you want to know how much of current your set-up draws from 240V you must first convert your low voltage load to the Watts. So if your mount draws maximum 2A from your power supply – 2A x 13.8V= 27.6W and so on for all your equipment connected to your power supply. Then add it. Your power supply, if it is linear type will have only about 50% efficiency. That means that if your total load drawn from power supply is 100W, actual load on 240V supply is 200W. Switch mode power supplies are more efficient at 70 to 90% efficiency. Current drawn from 240V supply = Total low voltage Watts / 240V
Your 10A 240V power lead can supply safety 2400W. I don’t think that your set-up uses more then 1/10 of rated power capacity of your 240V lead.

[[1ponders] (Paul)]

Well out at that lovely Queensland Camp site last year from a single wall plug to a 4 point safety pack there were 6 or 7 setups (if not more) running with np.

[Gargoyle_Steve (Steve)]

Thanks for all the replies guys, much appreciated indeed.

I remember well those electrical octopusses at Astrofest last year Paul, and I have often wondered how close to the limits those outlets had been pushed.

I reckon allowing 3-4 full imaging setups running from a single 240v extension cord shouldn't be a problem at all, with plenty of current carrying capability to spare.

For those interested in why a visual observer (& complete non-imager) like myself would be asking this type of question, please read on....

http://www.iceinspace.com.au/forum/s...ad.php?t=22315

A little shameless promotion never hurt anyone!

[ballaratdragons (Ken)]

Steve, alternatively you can now buy very small, VERY quiet generators that will run several items. I saw a really tiny almost silent one at the Telstra van a few months back, and it was running all the vans lighting and 4 computers! I had to stand right next to it to even know it was running, and even then I could hardly hear it.

[Dietmar]

hi Steve,

in my observatory I use this equipment when I am at "full-speed" imaging:
http://www.stargazer-observatory.com/equipment.html

according to measuremwnts
the mount (tracking speed)
the CCD - it`s a Starlight X-press - surely the best solution for an observatory like mine, that is run by solar power. the SBIG cams are so hungry,...4-5 amps slolely!
the driver
the laptop
consumes some 4-5 amps
the most hungry guy is the laptop...
I also use 2 solar panles to charge a 88Ah car-accumulator, that provides everythng except the laptop with power.
for the laptop I use a smaller 33 Ah accumulator that needs to be charged every 3rd night I`m in the obs.
I start with a full laptop power and when this is "dry" I remove it after having plugged in the external powersupply.



BTW: I think I got one for You:
http://www.stargazer-observatory.com/sounds/stars.wav

[higginsdj]

Well my 14" setup.....
Scope - 0.75amp at 12v tracking, 3amp at 12 v full speed slew
Camera A - 1.5amp at 5v and 0.5amp at 12 v
Camera B - 0.75amp at 12 v
Dew Heater A - 5amp at 12 v
Dew Heater B - 1amp at 12 v
Computer (can't remember what the computer and monitor pull - but this should be pretty standard from one computer/monitor to the next)

(12v power is supplied by a 240v-12v power supply from DSE though the cameras have their own 240v-12v adapters)

Cheers

[h0ughy (David)]

Originally Posted by [1ponders]

Well out at that lovely Queensland Camp site last year from a single wall plug to a 4 point safety pack there were 6 or 7 setups (if not more) running with np.

until I plugged in my 1200watt hairdryer

[h0ughy (David)]

btw my DSLR cooled camera pulls 3-4 amps continuously

[erick (Eric)]

It only took two hairdryers (and two gotos, and a computer or two and an electric blanket inside an eyepiece box) to blow the circuitbreaker at Snake valley last month! Think my hairdryer was ripping 1800 watts from the cable! We had to become dueling hairdryers, alternating!

Originally Posted by h0ughy

until I plugged in my 1200watt hairdryer

[Gargoyle_Steve (Steve)]

Thanks guys, your replies are very much appreciated!

[rumples riot]

if you buy a 15 amp lead it can carry that many amps before it gets hot. 15 amps is a lot of current and the average setup would not come anywhere near that, even with an active cooling system running.