[time-nuts] Downloaded HP"s SmartClock / Size of Lucent modules.

[Didier Juges]

Clearly off-topic, but hopefully it will stop here...

The Dell supplies use a 3 wire cable and have a resistor in the power
supply connecting the 3rd wire to ground. The value of that resistor tells
the laptop the current capability of the supply (they have various models
between 3.0 and 4.5A) so that the laptop can determine if it will have
enough current to run. This is mostly applicable when the laptop is plugged
into a docking station, because the current demand is then quite a bit
higher. If the laptop cannot read the resistor value, it may refuse to run
(or ask you to press F1 to force it to run anyhow) The 3rd wire is pretty
small (because it carries negligible current) and it is sometimes the first
one to break. You are then left with a perfectly usable 19.5V power supply
that cannot power a Dell laptop but that is fine for many GPSDO and Rb
oscillators :)

Didier KO4BB


On Sun, Dec 28, 2014 at 10:11 PM, Gerhard Hoffmann <dk4xp at arcor.de> wrote:

> Am 29.12.2014 um 00:39 schrieb Dr. David Kirkby (Kirkby Microwave Ltd):
>
>> 2)  Can anyone with these $150 two-part Lucent boxes tell me the size of
>> them.
>>
>>
> The box itself:  65mm high, 152 mm deep, 244 mm wide
>
> Front plate:  76 mm high, 274 mm wide
>
> Just a little bit to big to fit into a 4 HU 19" box ( for both).
>
> (still doing a night shift on the 5->10MHz doubler, filter & 5 chan.
> distrib amp for it.
> Or 4 chan 10 dBm 10 MHz & one 1pps on SMA )
>
>
> BTW I once bought a generic chinese power supply as a fallback solution
> for my Dell laptop.
> That turned out not to work because Dells talk to their PS. Nobody else
> seems to do that.
> It now powers my Lucent duo.
>
> I saw that the PS has an additional 12V input. That may ease the task of
> emergency power
> from a lead or Li-IronPhosphate battery.
>
>
> regards, Gerhard
>
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