Minimum power requirements to update firmware?

[David]

My new Classic arrived and wanted to update the firmware.  The QA Checklist was dated 11/9/11.  My question is can I power the Classic with a 12V wall wart to update the firmware and if so what would the amp requirements be?  The reason for this is that I only have VMWare with Windows Vista on my 27" iMac and I wanted to avoid hauling it into the basement where the classic would be installed in order to update it there.. especially with my swollen knee! 

Thanks.

[boB]

Hi David.

Yes, you can power it off of a wall wart or any DC supply from 10V up.  A 12V DC wart should be perfect.

9 Volts may be a wee bit too low.

boB

[epsgunner]

I tried a 200ma 12v wall plug and got a flickering screen..

Can anyone confirm what the minimum mA required to get power up enough to bring up the screen all the way??

I can get a 12v 500ma or 12v 750ma.. but it would be good to know which one to get.

[boB]

I tried a 200ma 12v wall plug and got a flickering screen..

Can anyone confirm what the minimum mA required to get power up enough to bring up the screen all the way??

I can get a 12v 500ma or 12v 750ma.. but it would be good to know which one to get.

The flickering display is exactly what happens when you don't have quite enough power to run the Classic or to get it to start up (surge).
It will try to turn on and turn itself off and repeat that as you saw it do.

Your 200 mA wall wart can supply a power of    12V X 0.200 A  = 2.4 watts

I would agree that 200 mA at 12V is too week, but barely.

12V X 0.500 = 6 watts which should be fine.

There is somewhat of a surge when it first powers on and a battery doesn't have a problem with that.

12V at 500 mA should be enough to keep that Classic going, but not maybe not enough momentary surge to turn it on, then you can increase the surge capability of the wall wart with a filter capacitor across that output.  That way, the Classic can use the energy
stored in the capacitor just to get over that surge and the wall wart would keep it going after that.

12V DC at 750 mA should be fine I would think and probably without any added capacitor.

I would go with the 12V at 750 mA wall wart to make sure.

I go to second hand stores and buy wall warts for this type of thing.  Sometimes I find one that is like, 30 volts DC which  also works well.  The current can be fairly low at that DC voltage.

boB

[epsgunner]

I found a nice Class 2 model thats 1 amp @ 12v for $10.. thank you for the info

I will report back when I get it hooked in with the results..

[epsgunner]

The 1000ma (aka 1 amp) 12V adaptor I got works fine.. lights it all up good..

This one said flatbed scanner on it.. so maybe check your junk pile folks for that old scanner wall-wart..