I have an E1405. The Dell power supply is rated at 19.5VDC at up
to 4.62A (90W), but I measured current flow at 3A with a mostly
discharged battery. Does that supply ever deliver more?
I also have a fine regulated 65W supply capable of delivering
19.5VDC at 3.3A all day long. It's a tiny, high quality
switcher, that would be very nice for traveling, etc. It would
be trivial to make a connector.
On May 19, 9:35 am, ego <j...@freud.id> wrote:
> I have an E1405. The Dell power supply is rated at 19.5VDC at up
> to 4.62A (90W), but I measured current flow at 3A with a mostly
> discharged battery. Does that supply ever deliver more?
It can, it only produces what the notebook needs.
>
> I also have a fine regulated 65W supply capable of delivering
> 19.5VDC at 3.3A all day long. It's a tiny, high quality
> switcher, that would be very nice for traveling, etc. It would
> be trivial to make a connector.
>
> Has anyone used such a thing?
Basic question: Does the 90w power supply work? Does it power the
laptop?
If it does: leave it alone.
Splicing connectors does work, but some of the home done jobs I've
seen scream 'fire hazard.'
paulmd@efn.org wrote:
>
> On May 19, 9:35 am, ego <j...@freud.id> wrote:
> > I have an E1405. The Dell power supply is rated at 19.5VDC at up
> > to 4.62A (90W), but I measured current flow at 3A with a mostly
> > discharged battery. Does that supply ever deliver more?
>
> It can, it only produces what the notebook needs.
>
> >
> > I also have a fine regulated 65W supply capable of delivering
> > 19.5VDC at 3.3A all day long. It's a tiny, high quality
> > switcher, that would be very nice for traveling, etc. It would
> > be trivial to make a connector.
> >
> > Has anyone used such a thing?
>
> Basic question: Does the 90w power supply work? Does it power the
> laptop?
>
> If it does: leave it alone.
>
> Splicing connectors does work, but some of the home done jobs I've
> seen scream 'fire hazard.'
There's a question whether the power supply also does regulation or not,
and battery overcharging. Since the AC-powered laptop when OFF typically draws
1/2 watt, which is maybe running the LED in the power supply mostly,
I suspect the power supply itself has some smarts.
Always add an inline fuse at the power supply sized for the capacity of
the wire, as noted. That's the wire that heats up to glowing when there's
a short, even though the power supply is perfectly happy and well within rated
current draw.
(I have a 20A 12v supply powering about 30 wall-wart-sized devices in my
receiver system, with 1/4 to 1/2 amp fuses on each device separately. The
12v supply otherwise would be very happy to burn down the house if something
went wrong.)
--
Ron Hardin rhhardin@mindspring.com
The laptop determines the current (up to the limits of the supply), not
the power supply. There likely are situations in which the laptop would
take more than 3 amps.
If the connector to the power supply is just a standard coaxial (2-wire)
connector, you could put an approprate connector on your power supply
and it would likely work.
However, there is a "catch" ... some Dell laptops have "intelligent"
power supplies that somehow "communicate" with the laptop, and the
laptop will not work with non-Dell power supplies. I'm not sure how
this works, but I've seen multiple reports of this behavior on various
(not all) models.
ego wrote:
> I have an E1405. The Dell power supply is rated at 19.5VDC at up to
> 4.62A (90W), but I measured current flow at 3A with a mostly discharged
> battery. Does that supply ever deliver more?
>
> I also have a fine regulated 65W supply capable of delivering 19.5VDC at
> 3.3A all day long. It's a tiny, high quality switcher, that would be
> very nice for traveling, etc. It would be trivial to make a connector.
>
> Has anyone used such a thing?
Hmmm... well, if I were doing such a thing, I'd put an AC
digital communication signal atop the DC power, then use code to
enable the laptop to "talk" with the supply. But that shouldn't
be necessary if the laptop simply varies the load, and the
supply intelligently responds to it.
I think a current limiter would be appropriate, just to be safe.
Barry Watzman wrote:
> The laptop determines the current (up to the limits of the supply), not
> the power supply. There likely are situations in which the laptop would
> take more than 3 amps.
>
> If the connector to the power supply is just a standard coaxial (2-wire)
> connector, you could put an approprate connector on your power supply
> and it would likely work.
>
> However, there is a "catch" ... some Dell laptops have "intelligent"
> power supplies that somehow "communicate" with the laptop, and the
> laptop will not work with non-Dell power supplies. I'm not sure how
> this works, but I've seen multiple reports of this behavior on various
> (not all) models.
>
>
> ego wrote:
>> I have an E1405. The Dell power supply is rated at 19.5VDC at up to
>> 4.62A (90W), but I measured current flow at 3A with a mostly
>> discharged battery. Does that supply ever deliver more?
>>
>> I also have a fine regulated 65W supply capable of delivering 19.5VDC
>> at 3.3A all day long. It's a tiny, high quality switcher, that would
>> be very nice for traveling, etc. It would be trivial to make a connector.
>>
>> Has anyone used such a thing?
You don't need a current limiter. And your original post ("I measured
current flow at 3A with a mostly discharged battery. Does that supply
ever deliver more?") makes it clear that your understanding of the
electronics involved is minimal.
ego wrote:
> Hmmm... well, if I were doing such a thing, I'd put an AC digital
> communication signal atop the DC power, then use code to enable the
> laptop to "talk" with the supply. But that shouldn't be necessary if the
> laptop simply varies the load, and the supply intelligently responds to it.
>
> I think a current limiter would be appropriate, just to be safe.
>
>
>
> Barry Watzman wrote:
>> The laptop determines the current (up to the limits of the supply),
>> not the power supply. There likely are situations in which the laptop
>> would take more than 3 amps.
>>
>> If the connector to the power supply is just a standard coaxial
>> (2-wire) connector, you could put an approprate connector on your
>> power supply and it would likely work.
>>
>> However, there is a "catch" ... some Dell laptops have "intelligent"
>> power supplies that somehow "communicate" with the laptop, and the
>> laptop will not work with non-Dell power supplies. I'm not sure how
>> this works, but I've seen multiple reports of this behavior on various
>> (not all) models.
>>
>>
>> ego wrote:
>>> I have an E1405. The Dell power supply is rated at 19.5VDC at up to
>>> 4.62A (90W), but I measured current flow at 3A with a mostly
>>> discharged battery. Does that supply ever deliver more?
>>>
>>> I also have a fine regulated 65W supply capable of delivering 19.5VDC
>>> at 3.3A all day long. It's a tiny, high quality switcher, that would
>>> be very nice for traveling, etc. It would be trivial to make a
>>> connector.
>>>
>>> Has anyone used such a thing?
> -----Original Message-----
> From: Ron Hardin [mailto:rhhardin@mindspring.com]
> Posted At: Saturday, May 19, 2007 1:12 PM
> Posted To: alt.sys.pc-clone.dell
> Conversation: Making a power supply for a Dell laptop
> Subject: Re: Making a power supply for a Dell laptop
>
> paulmd@efn.org wrote:
> >
> > On May 19, 9:35 am, ego <j...@freud.id> wrote:
> > > I have an E1405. The Dell power supply is rated at 19.5VDC at up
> > > to 4.62A (90W), but I measured current flow at 3A with a mostly
> > > discharged battery. Does that supply ever deliver more?
> >
> > It can, it only produces what the notebook needs.
> >
> > >
> > > I also have a fine regulated 65W supply capable of delivering
> > > 19.5VDC at 3.3A all day long. It's a tiny, high quality
> > > switcher, that would be very nice for traveling, etc. It would
> > > be trivial to make a connector.
> > >
> > > Has anyone used such a thing?
> >
> > Basic question: Does the 90w power supply work? Does it power the
> > laptop?
> >
> > If it does: leave it alone.
> >
> > Splicing connectors does work, but some of the home done jobs I've
> > seen scream 'fire hazard.'
>
> There's a question whether the power supply also does regulation or
> not,
> and battery overcharging. Since the AC-powered laptop when OFF
> typically draws
> 1/2 watt, which is maybe running the LED in the power supply mostly,
> I suspect the power supply itself has some smarts.
>
> Always add an inline fuse at the power supply sized for the capacity
of
> the wire, as noted. That's the wire that heats up to glowing when
> there's
> a short, even though the power supply is perfectly happy and well
> within rated
> current draw.
>
> (I have a 20A 12v supply powering about 30 wall-wart-sized devices in
> my
> receiver system, with 1/4 to 1/2 amp fuses on each device separately.
> The
> 12v supply otherwise would be very happy to burn down the house if
> something
> went wrong.)
> --
> Ron Hardin
Don't forget that a Dell power supply communicates with the laptop. I
have two almost identical power supplies (one for the I6000, one for the
I9300). If I plug the I6000 power supply into the I9300, it gives me a
warning in Windows that the power supply is not the proper 90W power
supply and that I can either shut down and charge OR use the computer,
not both.
Making a power supply for a Dell laptop 
Linear Mode
