Need help from anyone with a Toshiba AC laptop adapter

Hi again,

I was having problems a few weeks ago with a Toshiba Satellite laptop.
Now I believe the AC adapter might be failing.

I've tested the adapter with a digital voltmeter. The adapter is
rated at an output of 15v DC, but the voltmeter only gets 14.98v, and
this is not under ANY sort of load except the voltmeter.

I've heard from some people that this voltage is normal, but I've
tested nearly a dozen other working power plugs around my house, and
all of them tested at much higher voltages than what's on their
labels. I believe the load of a laptop would drag down the adapter so
badly that it finally shuts down (which is what it's doing at the
moment).

I was hoping someone would have a spare, definetly-working AC adapter,
model PA2450U, and could test the voltage with a DC voltmeter and let
me know the readings, I would really appreciate it, thanks.

Dan

dstvns

In article <>, wrote:

> Hi again,
>
> I was having problems a few weeks ago with a Toshiba Satellite laptop.
> Now I believe the AC adapter might be failing.
>
> I've tested the adapter with a digital voltmeter. The adapter is
> rated at an output of 15v DC, but the voltmeter only gets 14.98v, and
> this is not under ANY sort of load except the voltmeter.
>
> I've heard from some people that this voltage is normal, but I've
> tested nearly a dozen other working power plugs around my house, and
> all of them tested at much higher voltages than what's on their
> labels. I believe the load of a laptop would drag down the adapter so
> badly that it finally shuts down (which is what it's doing at the
> moment).
>
> I was hoping someone would have a spare, definetly-working AC adapter,
> model PA2450U, and could test the voltage with a DC voltmeter and let
> me know the readings, I would really appreciate it, thanks.
>
> Dan



The adapter is rated 15VDC. Anything from 13.5VDC to 16.5VDC is
acceptable. The margin for error in components is 10% plus or minus. In
this case, the margin for error is 1.5VDC.

The problem is not your AC power adapter.

Ghost

On Tue, 06 Jan 2004 00:26:11 -0500, dstvns <> wrote:

>Hi again,
>
>I was having problems a few weeks ago with a Toshiba Satellite laptop.
>Now I believe the AC adapter might be failing.
>
>I've tested the adapter with a digital voltmeter. The adapter is
>rated at an output of 15v DC, but the voltmeter only gets 14.98v, and
>this is not under ANY sort of load except the voltmeter.
>
>I've heard from some people that this voltage is normal, but I've
>tested nearly a dozen other working power plugs around my house, and
>all of them tested at much higher voltages than what's on their
>labels. I believe the load of a laptop would drag down the adapter so
>badly that it finally shuts down (which is what it's doing at the
>moment).

Test it with a load. If there is no easy way to use the laptop itself
as a load, a lightbulb of the appropriate wattage should work. This
may be a bit tricky to determine, however, as the resistance of a
lightbulb changes as it heats up, but you should be able to measure
the cold resistance with your digital meter (15 VDC is unlikely to
heat a 120 VAC filament appreciably), and the appropriate resistance
is calculated by dividing the VDC by the current in mA and multiplying
by 1000, or dividing the VDC by the current in A. The higher the
wattage of a bulb, the lower the resistance. Also, most switching
supplies will regulate at between 10-20% of full load anyway. If you
can't get within range with a 120 VAC lightbulb, try something in the
24 volt range, or 2 12 VDC automotive bulbs connected in series.

Tom

>
>I was hoping someone would have a spare, definetly-working AC adapter,
>model PA2450U, and could test the voltage with a DC voltmeter and let
>me know the readings, I would really appreciate it, thanks.
>
>Dan

Tom MacIntyre

On Wed, 07 Jan 2004 04:43:27 GMT, Barry Watzman
<> wrote:

>It's a 15 volt adapter, use a 12 volt light bulb, e.g. an automobile
>light bulb(s).

My thinking was to use a bulb/bulbs rated higher than the output of
the adapter, so as not to harm the bulb, but I suppose 15 VDC wouldn't
destroy a 12 VDC bulb, at least not the first time it's used in this
way....unless the bulb's resistance was off enough so as to affect the
adapter's regulation so that it goes to 20+ VDC.

Tom

>
>Tom MacIntyre wrote:
>> On Tue, 06 Jan 2004 00:26:11 -0500, dstvns <> wrote:
>>
>>
>>>Hi again,
>>>
>>>I was having problems a few weeks ago with a Toshiba Satellite laptop.
>>>Now I believe the AC adapter might be failing.
>>>
>>>I've tested the adapter with a digital voltmeter. The adapter is
>>>rated at an output of 15v DC, but the voltmeter only gets 14.98v, and
>>>this is not under ANY sort of load except the voltmeter.
>>>
>>>I've heard from some people that this voltage is normal, but I've
>>>tested nearly a dozen other working power plugs around my house, and
>>>all of them tested at much higher voltages than what's on their
>>>labels. I believe the load of a laptop would drag down the adapter so
>>>badly that it finally shuts down (which is what it's doing at the
>>>moment).
>>
>>
>> Test it with a load. If there is no easy way to use the laptop itself
>> as a load, a lightbulb of the appropriate wattage should work. This
>> may be a bit tricky to determine, however, as the resistance of a
>> lightbulb changes as it heats up, but you should be able to measure
>> the cold resistance with your digital meter (15 VDC is unlikely to
>> heat a 120 VAC filament appreciably), and the appropriate resistance
>> is calculated by dividing the VDC by the current in mA and multiplying
>> by 1000, or dividing the VDC by the current in A. The higher the
>> wattage of a bulb, the lower the resistance. Also, most switching
>> supplies will regulate at between 10-20% of full load anyway. If you
>> can't get within range with a 120 VAC lightbulb, try something in the
>> 24 volt range, or 2 12 VDC automotive bulbs connected in series.
>>
>> Tom
>>
>>
>>>I was hoping someone would have a spare, definetly-working AC adapter,
>>>model PA2450U, and could test the voltage with a DC voltmeter and let
>>>me know the readings, I would really appreciate it, thanks.
>>>
>>>Dan
>>
>>

Tom MacIntyre

On Wed, 07 Jan 2004 21:26:10 GMT, Barry Watzman
<> wrote:

>Not only will 15 volts not destroy a 12 volt automobile bulb, but the
>actual voltage in an automobile is quite a bit higher than 12 volts or
>even 12.6 volts, in fact it's just about ..... 15 volts (with the engine
>running, the alternator puts out MORE than 12.6 volts to keep the 12.6
>volt battery charged).

Right...sometimes I forget the small details. The alternator is
usually regulated to about 13.8 volts or so, I think.

On a related note, a former co-worker used to use, as a dummy load for
audio amplifiers testing at full power, so as not to have to tolerate
the dB's, used, as a dummy load...an element from an electric stove.


Tom

>
>
>Tom MacIntyre wrote:
>
>> On Wed, 07 Jan 2004 04:43:27 GMT, Barry Watzman
>> <> wrote:
>>
>>
>>>It's a 15 volt adapter, use a 12 volt light bulb, e.g. an automobile
>>>light bulb(s).
>>
>>
>> My thinking was to use a bulb/bulbs rated higher than the output of
>> the adapter, so as not to harm the bulb, but I suppose 15 VDC wouldn't
>> destroy a 12 VDC bulb, at least not the first time it's used in this
>> way....unless the bulb's resistance was off enough so as to affect the
>> adapter's regulation so that it goes to 20+ VDC.
>>
>> Tom
>>
>>
>>>Tom MacIntyre wrote:
>>>
>>>>On Tue, 06 Jan 2004 00:26:11 -0500, dstvns <> wrote:
>>>>
>>>>
>>>>
>>>>>Hi again,
>>>>>
>>>>>I was having problems a few weeks ago with a Toshiba Satellite laptop.
>>>>>Now I believe the AC adapter might be failing.
>>>>>
>>>>>I've tested the adapter with a digital voltmeter. The adapter is
>>>>>rated at an output of 15v DC, but the voltmeter only gets 14.98v, and
>>>>>this is not under ANY sort of load except the voltmeter.
>>>>>
>>>>>I've heard from some people that this voltage is normal, but I've
>>>>>tested nearly a dozen other working power plugs around my house, and
>>>>>all of them tested at much higher voltages than what's on their
>>>>>labels. I believe the load of a laptop would drag down the adapter so
>>>>>badly that it finally shuts down (which is what it's doing at the
>>>>>moment).
>>>>
>>>>
>>>>Test it with a load. If there is no easy way to use the laptop itself
>>>>as a load, a lightbulb of the appropriate wattage should work. This
>>>>may be a bit tricky to determine, however, as the resistance of a
>>>>lightbulb changes as it heats up, but you should be able to measure
>>>>the cold resistance with your digital meter (15 VDC is unlikely to
>>>>heat a 120 VAC filament appreciably), and the appropriate resistance
>>>>is calculated by dividing the VDC by the current in mA and multiplying
>>>>by 1000, or dividing the VDC by the current in A. The higher the
>>>>wattage of a bulb, the lower the resistance. Also, most switching
>>>>supplies will regulate at between 10-20% of full load anyway. If you
>>>>can't get within range with a 120 VAC lightbulb, try something in the
>>>>24 volt range, or 2 12 VDC automotive bulbs connected in series.
>>>>
>>>>Tom
>>>>
>>>>
>>>>
>>>>>I was hoping someone would have a spare, definetly-working AC adapter,
>>>>>model PA2450U, and could test the voltage with a DC voltmeter and let
>>>>>me know the readings, I would really appreciate it, thanks.
>>>>>
>>>>>Dan
>>>>
>>>>
>>

Tom MacIntyre