Hi All,

I am doing some tests.

1. Low battery test, I use a poewr supply to replace the battery of
device, the testing result looks good and correct.

2. I need to test the charging behavior, I still connect the power
supply instead of battery of device, when I plug in charger, however,
the voltage of power supply goes to 5V ( however, I set to 2.8V
originally ), it should be the USB charger voltage, is there any
problem ?

It seems some current limitation, and the device will detect the
current is already smaller than the expection, cut off charging
current, is that correct ?

Thanks!
Boki.

On 14 May 2007 19:58:06 -0700, Boki <bokit@ms21.hinet.net> wrote:

Boki!!! How's it hanging?
Always a blast to decipher your posts..

Can your power supply sink current?
I think most power supplies source current.
I suspect the USB charger is overriding the power supply.
In other words the power supply may not control an external V greater
than its setting..

For example..IIRC in a linear supply, the pass transistor will shut
off if an external V is greater than the power supply V setting.

I don't know the best way to fake a battery...
Maybe a shunt regulator..???
D from BC