From: Jerry Van Baren <gerald.vanbaren_at_smiths-aerospace.com>
Date: Mon, 7 Feb 2005 10:53:02 -0500

[IDC]Dragon wrote:
>>Matthias is using a 9+v charger which, according to the FAQ, gives him
>>about
>>140mA current into the Archos. The problem is, this is only slightly more
>>than is necessary just to run the AJR (and less than needed when the disk
>>spins up). With a limit of 40% duty cycle (24/60), his charger is falling
>>behind.
>
>
> The Recorder hardware can measure both the cell voltage and the DC input
> voltage, and could derive the charging current from that. Perhaps the duty
> cycle should be a function of this?
>
> Jörg
>

Hi Jörg,

I'm confused.

1) In adc.h I see the comment:
#define ADC_EXT_POWER 7 /* The external power voltage,
V=X*0.0148 */

2) On the schematics, I see the raw power coming in, going through a 82K
resistor and clamped by a zener to 2.7v.

3) In power.c, I see (cutting out the #ifdefs):
bool charger_inserted(void)
{
     /* Recorder */
     return adc_read(ADC_EXT_POWER) > 0x100;
}

I'm having a hard time reconciling the three pieces of information.
What am I missing???

Thanks,
gvb
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Received on 2005-02-07