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Old 29-08-2006, 12:46 PM
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Striker (Tony)
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12 volt power supply for Canon DSLR ??????

I can not find a 12 volt power supply but I do have the 240AC power supply that plugs straight into the camera battery supply.

What I was wondering...I know the battery's are 7.4v and range from 600MAH to 1800MAH depending on what quality battery you buy.

My question is can you use a 12 volt power supply that has adjustable voltage and change it to a preset of 7.5v 1000mah...would the .1 of a volt make any difference.

To me it sounds ok in theory but am I missing something.
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Old 29-08-2006, 01:30 PM
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Pretty Sure you are safe Tony...

Canon batteries are 7.2V nominal - probably closer to 8V fully charged. The Canon ac adapter puts out 7.8V - I use a dc-dc convertor fron Dork S that puts out 7.5V to drive my 20D. That is either connected to a 12v mains adatper (with surge protection) or a 12v 7AH battery depending on location.
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Old 29-08-2006, 08:39 PM
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Tony. NiCad or NiMh batteries are both 1.2 volts nominal. They are considered 'dead' at 1.0/1.1 volts, but straight off the charger can be anything up to 8.4/8.7 volts which slowly reduces. (6 X 1.2 = 7.2 volts, 6 X 1.45 = 8.7 volts).
It depends entirely upon what the manufacturer has set the charger cut off voltage at. Normally around 1.4 volts per cell, which gives you 8.4 volts.
(I state 1.45 volts because that is/was considered as the fully charged battery cutoff point).
If you are going to buy/use any, 240 volt or 12 volt to 9/7.5/6/4.5/3 volt power supply, then please make sure it is a 'Switch Mode' or regulated one.
The 'normal' (insert cheaper here), tranformer type '240 to 12/9/etc, plug packs' are not regulated & can put out a lot more voltage at low loads than you require. I've seen/measured some at up to ~17/20 + volts when supposedly putting out just 12 volts on 'no load'. The lower settings also show this tendency.
(Must Be Switch Mode/Regulated).
This one is a 240 volt plug pack from Jaycar > #MP-3031 (Adj Volt @ 1.25 Amps), @ $45.
OR this one is Dc to Dc converter #MP-3014 (Adj volt @ 1.5 Amps), @ $24.95.
This is from a 2005 cataldog. Might have changed since.
HTH. L.

Last edited by RAJAH235; 29-08-2006 at 09:03 PM.
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Old 29-08-2006, 09:04 PM
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Will check it out...thanks Rajah.

I suppose those cheap cigarette lighter 12 volt power supply I was thinking off that can be changed from 1.5V all the way up to 12V are not regulated.
adjustable 1.5 - 12V 1500MAH.

No good I suppose.

If not suitable any chance of a link when you get time.
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Old 29-08-2006, 09:22 PM
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Hi Tony, The #MP-3014 unit is just such a beast & is Switch Mode. (Ummm, I would not have posted otherwise). Plugs into the lighter skt.
The Plug Pack #3031 is here > http://www1.jaycar.com.au/productVie...Max=&SUBCATID=
I cannot find (does not come up on their search engine), the 12 volt Converter...Must be new # or deleted line???....Give em a call??
Jaycar in Aspley, 1322 Gympie Rd., Ph. 3863 0099
L.

Last edited by RAJAH235; 29-08-2006 at 10:59 PM.
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Old 30-08-2006, 07:28 AM
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Hi Tony, dont know if this is of any use but I use one with my Pentax, havent checked if there is a connector for the Canon. (can check tonight if you are interested)

Charge from mains, car or a 12v battery. Can supply 3V/5V/6V/7.4V not sure how long it would last drawing 7.4 but I just left it connected to a 7AH 12v battery.

http://www.interbatteries.com.au/pro...oducts_id/2836
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Old 30-08-2006, 10:46 AM
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Thanks Chris.

I checked with Jaycar today..they have regulated swithmode cigarette power supply with adjustable 7.5V for $25.

I dont understand the section about regulated only while on 24V....Rajah will this do the job.
http://www.jaycar.com.au/productView...=&SUBCATID=665
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Old 30-08-2006, 04:38 PM
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Tony. What the (12 volt output etc etc) means, is simply that the output will not be accurate if run on a 12 volt battery.
The regulator chip requires the input voltage to be about 2.5 volts above the output voltage otherwise the chip will not 'regulate' correctly. Works fine on all the lower settings with 12 volts input.
That 2 Amp unit is a good choice.
HTH... L.
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