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Form,

Has anybody tried powering thier HP50g using an Apple power block (or one of the many aftermarket products) intended for an I-Pod? They way these calculators kill betteries, it would be great to be able to use the power block as a power supply.

From my limited understanding of these devices, they only provide the operating voltage of a USB connection without any of the data lines being connected.

I'm suffering a little bit of chicken-ites. After reading about the damage caused by HP chargers being used without the re-chargable batteries installed I'm hesitent to just try it.

Very Respectfully,

David

how would this work?

I never had the impression the 49G+ or 50G drew power thru the USB connection.

Les

Hi Les.

The 49G+ was not capable of being powered through the USB, but the 50G is.

You can see it by yourself: press [ON]-[F] then [8] to enter the battery evironment and

you'll see it switching between "battery" and "USB" if you plug out or in

a USB powered cord to the 50G.

Hope this helps.

Best regards.

Giancarlo

I have a 49G+, not a 50G.

If that is the case, then I think the iPod power block should work and be safe for the calculator. If the current carried through a USB connection doesn't fry the iPod, and if the Griffin powerblock is intended to replicate that delicate power source, it shouldn't cook the calculator either.

Les

I'll test the Griffin Powerblock when I can.

I haven't tried other power supplies with the 50g, but note that the 50g requests 50mA from the USB port. I expect that any source that can supply at least 50mA at 5V should work for powering it from the USB port.

Another possibility is that two of the pins of the "4-pin USB" port used for the serial connection are supposed to connect directly to the battery, so it should be possible to power it through that port too, as long as at least one AAA cell is removed. If rechargeable cells are used, it should be possible to to connect an appropriate charger / battery eliminator through the serial port.

Of course the nominal purpose of the battery connection at the serial port is to optionally provide power to anything the user cares to connect to the serial port. I don't know whether power is available from the serial port while the calculator is being powered from only the USB port; but I rather doubt it.

Regards,
James

PS:

On second thought, although the 50g requests 50mA from the USB port, I don't know how much it actually draws; I expect somewhat less. But I guess that supplies intended for music players are probably rated to supply at least that much.

Regards,
James

Hi Les,


Quote:
If the the current carried through a USB connection doesn't fry the iPod

Having too much "Current" can never fry anything. Too much voltage can. The Current rating on a power supply is the maximum amount of current that the power supply can provide at a certain voltage. The device using the power supply determines how much current will be attempted to be drawn from the power supply. If the device tries to draw more current than the power supply can provide, then, depending upon the regulation ability of the supply, the voltage will drop and the supply can overheat or malfunction.

As long as the power supply is rated at the corrent voltage and has, as a minimum, the required current rating, then the power supply can be used. Of course, polarity is very important. Make sure you don't get it reversed.

The nice thing about devices being powered through the USB connector, is that there is no way to get the polarity wrong. And any of the USB power devices can be used. I use the Griffen power cube with the USB cable to power my Ipod, Dell Axim, and a MIO GPS unit. I also have a Belkin USB lighter plug adapter that lets every thing be used in the car.

Bill

Yet another reason why I should get a 50g, which regrettably is not cheap in Canada.

I would have multiple uses too for a Griffin powerblock (iPod, Palm, etc.)

Les

I contacted Griffin and here is thier response:


Quote:
Hello,


We have not tested it with that unit, so we cannot guarantee that it will work,
but it outputs the standard 5volts required for USB operation. So it should
work.


Thanks,


JR

Griffin Technology
Tech Support



I'm still waiting for a response from HP. I think it should work, but since I'm not a gamblin man, I'm not willing to bet my HP on it. I'll wait for HP's anser first,

Very Respectfully,

Dave

I finally got an answer from HP: They were unable to test the 50g with an Apple Powerblock because they couldn't figure out how to connect it. I've not seen the Apple Powerblock, but they said its connector is not standard USB.

I tested my 50g using a Griffin model 17B061001 AC power supply. It has a standard USB output, 5.0V 500mA. Using the ON+F6, then option 8, I was able to verify it would switch to USB power using the Griffin PS.

I also took the AAA batteries out, and connected to the Griffin, the 50g worked.

After my test, I verified the operation of the USB connection, it suffered no apparent damage.

I think we have a winner!

Very Respectfully,

David