#1  
Old 27-02-2008, 06:17 PM
Zuts
Registered User

Zuts is offline
 
Join Date: Mar 2007
Location: sydney
Posts: 1,427
SBIG External Power Help

Hi Guys,

I have an SBIG ST2000 XCM. I want to use it away from mains. I already have a 24 amp hour battery. The SBIG has the standard 90 to 240 volts AC adaptor.

What is the best way to use the battery power without destroying the camera

Thanks
Paul
Reply With Quote
  #2  
Old 27-02-2008, 06:22 PM
skwinty's Avatar
skwinty (Steve)
E pur si muove

skwinty is offline
 
Join Date: Dec 2007
Location: Cape Town
Posts: 494
Hi Paul
I would use an inverter.
They are reliable and stable as well as being reasonably priced.
You would select one based on output wattage required.
Regards
Steve
Reply With Quote
  #3  
Old 27-02-2008, 08:20 PM
Dennis
Dazzled by the Cosmos.

Dennis is offline
 
Join Date: May 2005
Location: Brisbane
Posts: 10,866
The SBIG mains adapter for my ST7E delivers both 12Vdc and 5Vdc so I’d second Steve’s recommendation of a good quality inverter.

Cheers

Dennis
Reply With Quote
  #4  
Old 27-02-2008, 10:19 PM
Zuts
Registered User

Zuts is offline
 
Join Date: Mar 2007
Location: sydney
Posts: 1,427
Quote:
Originally Posted by skwinty View Post
Hi Paul
I would use an inverter.
They are reliable and stable as well as being reasonably priced.
You would select one based on output wattage required.
Regards
Steve
Thanks Steve, I was thinking of that but hopefully a SBIG user will chime in and tell me what they do.

Paul
Reply With Quote
  #5  
Old 28-02-2008, 12:02 AM
skwinty's Avatar
skwinty (Steve)
E pur si muove

skwinty is offline
 
Join Date: Dec 2007
Location: Cape Town
Posts: 494
Quote:
Originally Posted by Zuts View Post
Thanks Steve, I was thinking of that but hopefully a SBIG user will chime in and tell me what they do.

Paul
Hi Paul
If your sbig camera requires 2 voltages then your only other option is 2 batteries wired directly to the camera. If the camera requires one voltage then you would have to wire one battery directly to the camera.
See Dennis's post 3.
The advantage of using an inverter is that you dont have to connect anything other than the original plugs and power supplies to the camera.
This will minimise any undue damage to the camera.
A battery will not have any short circuit or over current protection should something go wrong whereas the sbig power supplies should at least be voltage and current regulated affording you some level of protection.
(unless you purchase a suitable powertank which may or may not have this protection)
IMHO a decent quality inverter is the only sensible solution to operating away from the mains supply.
Regards
Steve
Reply With Quote
  #6  
Old 28-02-2008, 04:35 AM
gbeal
Registered User

gbeal is offline
 
Join Date: Oct 2004
Location: New Zealand
Posts: 4,299
Sorry mate, I only use AC, as where I image there is power, and this powers the mount, and the PC. SBIG do make a 12 volt power supply.
Reply With Quote
  #7  
Old 28-02-2008, 05:00 AM
montewilson's Avatar
montewilson (Monte)
Registered User

montewilson is offline
 
Join Date: Apr 2007
Location: Sydney
Posts: 374
I use a generator. Honda 2000i far from cheap but perfect for this equipment. It is bigger than I need. Honda make smaller ones at the same quality level.

You could consider a $100 Bunnings generator. Despite what many say, I got a year and a half of work from one and the computers/cameras weren't upset by it as long as you didn't introduce large sudden loads to the generator such as switching on a monitor or tv while imaging.

Get a couple of those cheap 25m extension cords too and put the generator 50m away and the already reasonably quiet exhaust from the generator is not an issue. You will need to mix 2 stroke oil for the cheap gen sets.

You could buy one, try it with all your equipment connected and if it doesn't suit you, quickly return it. Basically if you are getting in to serious CCD's and you want to go all night, batteries are no longer the answer.
Reply With Quote
  #8  
Old 28-02-2008, 10:55 AM
Zuts
Registered User

Zuts is offline
 
Join Date: Mar 2007
Location: sydney
Posts: 1,427
Hi Guys,

Thanks for all the replies. I may go with the field unit from SBIG, but a bit exe.

Another alternative would be a 1800va UPS as sold for pc's (142 bucks from MSY). What do people think about this option. Also my current battery pack is 12 amp hour. For a 1800 va UPS does this mean it is 18 amp hour and are the batteries inside a UPS the same as the standard car starter batteries with the same charging and power supply characteristics?

Thanks Paul
Reply With Quote
  #9  
Old 28-02-2008, 12:27 PM
turbo_pascale's Avatar
turbo_pascale (Rob)
Registered User

turbo_pascale is offline
 
Join Date: Apr 2006
Location: Melbourne, Australia
Posts: 350
I'm sure someone else which chime in, but the risks of an inverter could be a bit of a problem. If they don't generate a good true sine wave, you could screw with the electronics. SBIG cameras are not the cheap $50 TV from your local discount store.

I'd ring/email Peter Ward @ atscope and get his advice directly. Many years ago I asked the same question, and was put off an inverter (but don't have the details handy). Don't skimp with this stuff unless you're happy to risk a very expensive paperweight.

That's just my 2c worth - ask someone who knows the gear inside out!
Reply With Quote
  #10  
Old 28-02-2008, 04:15 PM
skwinty's Avatar
skwinty (Steve)
E pur si muove

skwinty is offline
 
Join Date: Dec 2007
Location: Cape Town
Posts: 494
Hi Paul
If you go the UPS way remember that the UPS is basically an inverter.
With regards to the sine wave issue the points to remember are:
1. 24amp/hr DC battery powers the inverter producing 220VAC.
2. 220VAC powers the standard SBIG power supplies.
3. The standard SBIG power supply produces the DC voltages for the camera.

Hence any variation the sine wave quality of the inverter would have no impact on the DC voltage produced by the SBIG supplies. The inverter could produce a square wave or a saw tooth wave and still not affect the DC voltage produced by the SBIG power supply.

Good Luck in your quest for field power.
Regards
Steve
Reply With Quote
  #11  
Old 28-02-2008, 05:01 PM
skwinty's Avatar
skwinty (Steve)
E pur si muove

skwinty is offline
 
Join Date: Dec 2007
Location: Cape Town
Posts: 494
Hi Paul
I looked at the SBIG field power supply and for peace of mind you should rather use this.
12VDC Power SupplyThis optional power supply converts 12VDC from a battery to the 5VDC and 12VDC required by the camera. It is for operating your ST-7/8/9/10/2000 camera from a battery in the field, or anywhere there is no convenient AC power. Part # 50388

I dont know what the cost is but this power supply does not use an inverter.
It will use voltage dividers and regulators as it only needs to convert DC to DC.
Regards
Steve

Another reason for suggesting an inverter was because you could use it to power other accesories (such as laptop etc) as well as the camera. Inerters are not as risky as some would suggest unless it is heath robinson.
Reply With Quote
  #12  
Old 28-02-2008, 06:07 PM
Zuts
Registered User

Zuts is offline
 
Join Date: Mar 2007
Location: sydney
Posts: 1,427
Hi Steve,

Thanks, yes, as I said in a previous post I am considering the SBIG field converter but is is rather exe at 230 AUD.

I really dont want to damage/lessen the life of my camera so I am trying to find out what other SBIG users use in the field.

Failing this i will probably get the SBIG converter.

Paul
Reply With Quote
  #13  
Old 28-02-2008, 07:01 PM
skwinty's Avatar
skwinty (Steve)
E pur si muove

skwinty is offline
 
Join Date: Dec 2007
Location: Cape Town
Posts: 494
Quote:
Originally Posted by Zuts View Post
Hi Guys,

Another alternative would be a 1800va UPS as sold for pc's (142 bucks from MSY). What do people think about this option. Also my current battery pack is 12 amp hour. For a 1800 va UPS does this mean it is 18 amp hour and are the batteries inside a UPS the same as the standard car starter batteries with the same charging and power supply characteristics?

Thanks Paul
Hi Paul
Some more info re: your questions (albeit from a non sbig owner).
VA means a ratio between volts and amps.
1800VA means that at 1800 volts the current will be 1 ampere.
At 180 volts the current will be 10 ampere.
The battery will not be the same as a car battery which is a lead acid battery. It would probably be a Lithium , Cadmium , Nickel or Metal based battery.

A 12amp/hour battery of any type means that the battery will provide 12 ampere for 1 hour or 1 ampere for 12 hours.
The charging rates will differ from battery type to battery type.

Hope this is of some use to you.
Regards
Steve
Reply With Quote
  #14  
Old 28-02-2008, 08:14 PM
Karls48 (Karl)
Registered User

Karls48 is offline
 
Join Date: Jan 2006
Location: Sydney
Posts: 753
This is true only for resistive load. If there is any inductance or capacitance in the circuit then it has to be calculated as I x U x cos phase angle. VA rating alone does not give you information how much power it can supply or for how long.
Reply With Quote
  #15  
Old 28-02-2008, 08:29 PM
skwinty's Avatar
skwinty (Steve)
E pur si muove

skwinty is offline
 
Join Date: Dec 2007
Location: Cape Town
Posts: 494
Quote:
Originally Posted by Karls48 View Post
This is true only for resistive load. If there is any inductance or capacitance in the circuit then it has to be calculated as I x U x cos phase angle. VA rating alone does not give you information how much power it can supply or for how long.
Hi Karl
This is true only for resistive loads refers to which statement?
Agreed the impedance of a alternating current circuit plays a significant role in circuit analysis but at the end of the day ohms laws still apply.
Regards
Steve
Reply With Quote
  #16  
Old 29-02-2008, 07:50 AM
higginsdj's Avatar
higginsdj
A Lazy Astronomer

higginsdj is offline
 
Join Date: Mar 2006
Location: Canberra
Posts: 613
I have an ST-8E and ST-9E. The ST-8E has a mains supply adapter and the ST-9E has a 12v/Battery power supply adapter both from SBIG.
Reply With Quote
  #17  
Old 01-03-2008, 11:28 AM
Zuts
Registered User

Zuts is offline
 
Join Date: Mar 2007
Location: sydney
Posts: 1,427
Quote:
Originally Posted by higginsdj View Post
I have an ST-8E and ST-9E. The ST-8E has a mains supply adapter and the ST-9E has a 12v/Battery power supply adapter both from SBIG.

Hi Guys,

Thanks for all the replies. I should get the SBIG field unit but I cant wait the month it will take. So i will get a 300 watt sine wave inverter from Jaycar and another battery pack. If anyone thinks this is really dumb please tell me quick as i will be going soon to pick one up.

Thanks Paul
Reply With Quote
Reply

Bookmarks

Thread Tools
Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT +10. The time is now 02:56 PM.

Powered by vBulletin Version 3.8.7 | Copyright ©2000 - 2019, Jelsoft Enterprises Ltd.
Advertisement
Lunatico Astronomical
Advertisement
Meade Australia
Advertisement
Celestron Australia
Advertisement
SkyWatcher Australia
Advertisement
Bintel
Advertisement
NexDome Observatories
Advertisement
OzScopes Authorised Dealer
Advertisement
Astronomy and Electronics Centre
Advertisement