usb power question

[Perris Calderon]

so I have a usb gps with a linux operating system, I have no idea which linux but I'll research to see if I can find out

anyway, it's powered from the cigarette lighter and I am wondering if the same power cord can be used with my pocket pc since that's usb charged also

does the os recognize voltage and adjust?

are the voltages common because of common processors?

thanx for the info in advance

 

[LeeJend]

Usb standard dictates 5V voltage, voltage limits, power quality and maximum draw of 5W.

The pocket PC should not try and draw more than 5W so it should work. Skim thorugh the manual for the pocket PC and see if it says anything different.

The cigarette lighter plug adapter should specify it has a 5V, 5W output on the case. If it doesn't it may put out a higher voltage that could damage the pocket PC.

The GPS and Pocket PC manuals should specify what is expected on the power interfaces.

When all else fails. Can you plug either device into your dektop and recharge it? If yes, they both will work off of the USB standard.

Standards are great, unfortunately not everybody follows them...

Personally I would get a meter and measure the output from the USB charger with it plugged in if you can. Those pins are not real accessible. I fit reads under 6V with no load on it then you should be safe.

 

[Perris Calderon]

Usb standard dictates 5V voltage, voltage limits, power quality and maximum draw of 5W.

The pocket PC should not try and draw more than 5W so it should work. Skim thorugh the manual for the pocket PC and see if it says anything different.

The cigarette lighter plug adapter should specify it has a 5V, 5W output on the case. If it doesn't it may put out a higher voltage that could damage the pocket PC.

The GPS and Pocket PC manuals should specify what is expected on the power interfaces.

When all else fails. Can you plug either device into your dektop and recharge it? If yes, they both will work off of the USB standard.

Standards are great, unfortunately not everybody follows them...

Personally I would get a meter and measure the output from the USB charger with it plugged in if you can. Those pins are not real accessible. I fit reads under 6V with no load on it then you should be safe.

thanx leejand, that answers the question perfectly, yes, both get charged from laptop

 

[Taurus]

Usb standard dictates 5V voltage, voltage limits, power quality and maximum draw of 5W.

i thought it was 500mA, so 2.5W..?

edit:

The USB specification provides a 5 V (volts) supply on a single wire from which connected USB devices may draw power. The specification provides for no more than 5.25 V and no less than 4.75 V (5 V±5%) between the positive and negative bus power lines.[10] Initially, a device is only allowed to draw 100 mA. It may request more current from the upstream device in units of 2 mA up to a maximum of 500 mA.