A200 power input spec

[KM_krazy]

bacs57 wrote:

I intend to use 4 of 1.5v AA alkaline batteries. Do you think that there would be any particular problem with this? I believe that the alkalines are usually more stable for a longer period than NiMH's before 'sudden death'.

If I were you I would use Energizer Lithium batteries. The last up to 7x longer than alkaline, and they operate much better in cold (if you would be doing that) they are more expensive, but considering they last so much longer they are almost cheaper in the long run. They are also lighter :G

[Phranque]

KMA200:

That's most interesting and useful information, thanks for all your efforts. I don't think the A200 has any motors to worry about soI would have pegged the maximum current consumption at about 250m/a - apart from when charging the flash, so I would have been miles out (or kilometres if you are metric). The LCD doesn't seem to use all that much, with a difference of only 30-40mA when it's on.

One interesting thing I THINK I found when fiddling with my broken plug was that the A200 closed down if it was presented with five fully charged NiMH cells - which when just off charge were getting on for 8 volts. I can't be sure that this was happening as the plug was giving me problems but if this is right the camera really needs the 6volts specified plus or minus very little and a suitable NiMH pack would need a simple stabilisation circuit to work at all.

[Phranque]

KMCrazy

Hi - I wasn't even aware of these lithium-iron * cells so thanks. They are certainly more expensive over here (UK). An AA size is £5.30 plus tax EACH - with a rating of 2900maH, whereas a pack of FOUR of their industrial alkalines at 2500maH costs just £2.36 plus tax and a box of 40 GP alkalines with no published capacity rating £9.79 plus tax. It's an expensive business.

I suppose what you're saying is that if the chips are down and you are out of power is wouldn't matter if they cost £100 each as long as you got the camera working again, and I'm sure many a photographer would agree with that.

* Is that REALLY 'lithium-iron' ? My catalogue people are not all that technical and will print any old thing. They are listed as 1.5volts though, not like a Li-ion.

[KMA200]

I finished playing with the RadioShack Universal Rechargeable Ni-MH Power Pack and it works fine. I should mention that it comes with
- case with belt clip
- long cord and 5 plugs (and with a 3 to 9V range it may come handy for some other devices like PDA, CD player … )
- the AC charger is built-in + car adapter
- charge spec says 3650 mAh
- battery power indicator to know when it's low
- great price (20$ in Canada ... probably less than 15 in US)


for details, see

http://support.radioshack.com/produc...47&Reuse=N

p.s.: I don't know about quality, it looks well built... time will tell

[celsius]

:arrow:Slightly related...I got my A200 on Thursday and left fora weekend of college baseball on Friday and of course forgot the charger and spare battery at home.I took picturesall Friday night and Saturday thenreally wanted to download the pictures to view and share onmy tabletpc while out of town, but by then the A200battery was low/red... so, Saturday nightI went into Radio Shack and sure enough they had a compatible AC adapter:

http://www.radioshack.com/product.as...%5Fid=273-1696

I held my breath (and removed the compactflash) when I hooked it up but it seemed to work just fine. Adjustable to 6V, its rated at 2A and has an interchangable tip that fit. $25US. (Just gotta be careful with that volt switch!)

Pictures turned out great, BTW. I'll append some to the A200 pictures thread in a couple days.
http://www.stevesforums.com/forums/v...highlight=a200

-Chad

[A-lex]

hmm

NiMh's surely need voltage stabilisation, which can be done in two ways, linear (40-50% max effeciency)and non-linear (PWM up to 80% of effeciency). linear method is much easier, reguires 1 cheap IC (LM317) and 1 resistor, but it's drawbacks are that at least 5V difference is needed between input and output for effective work, so you'll need 12V DC at input, to get highly stabilised 5V at output. this is 8 nimh-s instead of 4 The second way is to use PWM (Pulse width modulated) stabiliser, which can be done in various ways, but will require at least 1 IC, 3-4 capacitors, couple of resistors and an Cmos transistor. the estimated part cost is about $10, and build time - depends on you.

So, why I hold such a long speech?

A pair of 2500Mah NiMH batteries costs $6 here. you'll need at least 2 pairs ($12) in case of PWM, and 4 pairs ($24) in case of linear stabiliser. add parts cost, assembly time and so on...

On the other hand, Lenmar's replacement of EN-EL1 costs about $17 here, so I think now you understand what I mean



I may wrote some words wrong, english is not my native language, sorry for that.

[MikeAusA200]

I agree - I just bought an ENEL1 clone for FIVE dollars US from Canada via ebay and it works fine. It is just so much more convenient to have internal batteries.

Normal Linear regulators have a drop of TWO volts but Low dropout regulators only have a 0.1 volt drop. So you could use a 6x NiMH cell (7.2 volt nominal) pack witha cutoff voltage of 6.6 volt. Or you could use a 7.2 volt (2 cell) LiIon or Li Polymer pack with a nominal cutoff of 6.0 volts. At these low voltage drops there is littel adavantage in using Switchmode regulators.

Mike