[Gta04-owner] Battery removal with USB plugged in
Dr. H. Nikolaus Schaller
hns at goldelico.com
Thu Sep 27 20:00:55 CEST 2012
Am 27.09.2012 um 19:46 schrieb Gilles Filippini:
> I've tried removing the battery with the GTA04 connected to my box by
> USB. It works correctly up to the PIN code step, but it instantly goes
> off afterward.
> Is this expected? It used to work fine with GTA02.
Yes. More or less.
The reason is that the system draws more current than the USB
power supply provides as soon as the UMTS module is fully
powered up. This happens just after you enter the PIN and the
radio link to the base station is established.
It should depend on the antenna type and distance to the best
base station (far away = must have higher transmit power).
According to the specs the power supply of the UMT module
must be able to provide 2 Amperes in this case.
A similar case is by enabling WLAN+Bluetooth. This also raises
the power demand beyond some limits.
It may just be good luck that it did work on the GTA02.
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