Power in the field

[LewisM]

It's time to finally go mobile for imaging, as I can no longer stand the light pollution I must suffer at home. So, today I scurried off to Jaycar.

Got myself a decent pure sine wave inverter, and then off to Supercheap Auto for another powerpack. One Powerpack for the mount and camera, one for the laptop.

Is there anything else I should get power wise? Maybe a powered USB hub? Definitely going to have to go dew heater now too, since I think taking the travellling hair dryer may drain the batteries a little fast

[tlgerdes (Trevor)]

Get a decent deep cycle battery of about 100ah, not one of those power banks

[LewisM]

The ones I got are both 17aH, and I have fully drained one once - it was easily greater than 12 hours, and that was running an NEQ6.

I will get a deep cycle though - been meaning to for a while.

I just hope the inverter I got is decent - paid $139 for it, on clearance.

[LAW (Murphy)]

One of the guys I was speaking to up at Astrofest said he was powering his laptop from a 12V battery using a converter from Jaycar. It was more efficient than an inverter as it just boosted the voltage up to 15V or whatever laptops require through a DC-DC transformer.

I haven't been able to find one but it might be worth looking into if the inverter drains your batteries too quick (or if you get sick of the noise).

[naskies (Dave)]

Originally Posted by LAW

One of the guys I was speaking to up at Astrofest said he was powering his laptop from a 12V battery using a converter from Jaycar. It was more efficient than an inverter as it just boosted the voltage up to 15V or whatever laptops require through a DC-DC transformer.

I haven't been able to find one but it might be worth looking into if the inverter drains your batteries too quick (or if you get sick of the noise).

Here you go:

http://www.jaycar.com.au/productView.asp?ID=MP3324
http://www.jaycar.com.au/productView.asp?ID=MP3472

[2stroke (Jay)]

Originally Posted by LAW

One of the guys I was speaking to up at Astrofest said he was powering his laptop from a 12V battery using a converter from Jaycar. It was more efficient than an inverter as it just boosted the voltage up to 15V or whatever laptops require through a DC-DC transformer.

I haven't been able to find one but it might be worth looking into if the inverter drains your batteries too quick (or if you get sick of the noise).

As naskies posted, lol man they sell these nearly everywhere well computer hardware shops, dse ect, most people who go camping these days have oneNo doubt that an inverter in the field will eat through amps like mad.

Just watch out with usb hubs and bandwidth lewis, if your got your cam and guide cam plugged into the hub it has to share 1 usb 2 connection and could leave with artifacts from your imager if download rate isn't set right and also leave you with issues with your guide cam. I think some hubs that are usb 3 can dived the bandwidth up but you would want to read-up on that first, though make sure your your using a usb3 port on your notebook as well lol.

Another thing i'am going to do is replace all ciggerate sockets with 3 pin lockable canon sockets and jacks, i'am sick to death of the dam things disconnecting with a small bump or pull.

With your notebook turn the wifi off, this will save a lot of power and dim your screen which you would want to do anyhow. You may also be able to get an extended cell battery for your notebook so look it up for your model.

If your making a weekend of it on a reg basis you could even look at solar battery charges which arn't that extremely costly as long as your getting your use out of them. Grab another jump pack as well pending on your time and remember not to run them dead flat, as thats a great way to kill aicd lead based battery's.

If your using a dslr get a dummy 12volt battery convertor pack to save buying more dslr battery's and risking having no power to take your. images with.

Another great tip your iphone or htc ect can be used as a wifi router so if you need to download drivers ect its a handy thing to have, WARNING: watching porn for long periods may damage your site and drain your battery.

[LewisM]

I looked at the DC-DC coupler, but the ones at Jaycar are rated to 6A max. I was a bit concerned as my Laptop is 6.8A - should that really matter??? I felt safer using a pure sine wave inverter as at least then the DCconverter for the laptop regulates it.

My electronics knowledge can be written onto a match head

[Barrykgerdes]

It is interesting how everyone seems to insist on a pure sine wave from their AC supply when it comes from some sort of an inverter but forget that after the AC gets into the set it is turned back into DC with a simple filter/negative feed back system and used to generate a HF square wave to drive a transformer that can supply a range of voltages for subsequent rectification back to DC.

Barry

[LewisM]

I know, but the amperage limitations made me think otherwise

If I am wrong, i will happily take it back and get something half the price

[Bassnut (Fred)]

Originally Posted by Barrykgerdes

It is interesting how everyone seems to insist on a pure sine wave from their AC supply when it comes from some sort of an inverter but forget that after the AC gets into the set it is turned back into DC with a simple filter/negative feed back system and used to generate a HF square wave to drive a transformer that can supply a range of voltages for subsequent rectification back to DC.

Barry

Square waving invertor outputs straight into a rectifier/large cap can cause large currents spikes and noise, let alone a horrendous power factor. Inefficient.

[2stroke (Jay)]

It will be fine lewis, worst cases windows uses power saving features when it detects it cant draw enough from it, though 6.8amps is only a safe max the psu is built at not what your notebook really draws. Unless your got sli 680m's i doubt you will have any issue what so ever.

[naskies (Dave)]

Powered USB hub is a good idea - the vast majority of my USB problems disappeared once I started using one. I use a Jaycar regular to step down from 12V down to 5V.

Once you factor in the mount, dew heaters, USB power, cooled cameras, laptop, light box, etc you'll probably want a decent sized battery. Keep in mind that cold weather, high current, and long wires will all drop the battery voltage - some things go a bit funny below 12V, like my EQ6.

You'll also want keep your usage at say max half the capacity (preserves battery life and keeps the voltage reasonably high).

[RobF (Rob)]

Lewis, just make friends with Ron at Cambroon, and you can have a much darker sky and 240V. Ron posts most months in the Star Parties area.

Dave is right how your power requirements grow as time goes by. A decent battery>40AH and DC convertor very handy in the long run if you really do want to be able to go anywhere. A decent charger essential too. On the other hand, my 2008 jump start pack is still handy for backup, has rescued my wife twice with a flat battery and is good for a 12V hair dryer on wet nights.

[naskies (Dave)]

I knew I was in trouble once I got the genset... having a space heater and electric kettle at the push of a button under dark skies is pure luxury

[rogerco (Roger)]

Check out these from Altronics:-

http://www.altronics.com.au/index.as...item&id=M8627A
http://www.altronics.com.au/index.as...=item&id=M8990

Re inverters, modified square wave will generally be ok for plugging a laptop power supply brick into assuming your laptop is the sort that has a external power supply. If its the sort that have internal power supply then pure sine wave may be better but modified square wave may not give any problems.

[LewisM]

Went and bought this one: http://www.jaycar.com.au/productView.asp?ID=MP3472

Kept the inverter too - could come in handy with the hairdryer after all

Thanks everyone.