Pulster fixe(s) and rework

Andy Green andy at openmoko.com
Wed Mar 4 20:49:45 CET 2009


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Somebody in the thread at some point said:
| Johny Tenfinger wrote:
|> On Wed, Mar 4, 2009 at 08:32, Joerg Reisenweber <joerg at openmoko.org>
wrote:
|>>> * Change the led transistor power hungry stuff
|>> Guys, this has been fixed for *ALL* FR ever sold!!!
|> No, no, no. You are right only for GTA02v6. On GTA02v5 (which I have)
|> this has been fixed only for orange and blue LEDs under POWER button.
|> Red AUX button is still power hungry - it is eating 50mA.
|
| Your mentioned 50mA for the AUX LED is ridiculous. It would burn out
| with this high current. Normal LEDs only use ~20mA and low current LEDs
| ~2mA. 50mA would be for a higher power led which isn't build into the
| freerunner.
| And when you are on battery the AUX led is off by default and even if it
| blinks (like i modified my led behaviour) it isn't really much it uses.

Johnny Tenfinger is right despite it sounds strange.  On some or all A5s
there is no base current limit resistor on the bipolar transistor used
to light the AUX LED.

This "50mA" fault current then flows not through the LED (which has a
reasonable series current limit resistor), but through the GPIO IO cell
and the driver transistor base.

- -Andy
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