"Michael Black" <et472@ncf.ca> wrote in message
news:Pine.LNX.4.64.0811251133080.8452@darkstar.exa mple.net...
On Tue, 25 Nov 2008, M.I.5¾ wrote:

>
"Jerry" <Hello@spammers.com> wrote in message
> news:ggg0cm$8f2$1@news.motzarella.org...
>> "BillW50" <BillW50@aol.kom> wrote in message
>> news:ggfdme$rfq$1@nntp.motzarella.org...
>>> Adrian C wrote on Mon, 24 Nov 2008 23:20:59 +0000:
>>>> BillW50 wrote:
>>>>
>>>> Although if you were going to use it anyway, I would throw three
>>>>> rectifier diodes in series with one of the lines. This will knock the
>>>>> voltage down by 2.1 volts.
>>>>>
>>>> I wouldn't do that. The diodes will get rather hot if the machine is
>>>> pulling a lot of current - and the failure mode of high current
>>>> rectifiers is often to short themselves. Then you leave with the
>>>> original problem - running too high a voltage, which will not be kind
>>>> to
>>>> the laptop.
>>>>
>>>> Put a wanted request out on FreeCycle. There are a lot of AC adaptors
>>>> people keep in storage after their old laptop breaks, gets lost, run
>>>> over by the 4WD, etc...
>>>
>>> Interesting, I've done it all of the time without any ill effects at
>>> all.
>>> You need to purchase diodes with a tolerance 30% higher than you need.
>>> And you shouldn't have any problems whatsoever. That is what they told
>>> me
>>> when I was getting my electronic engineering degree. And it has worked
>>> in
>>> my decades of experience as well.
>>>
>>> --
>>> Bill
>>> Asus EEE PC 8GB 1GB SoDIMM Adata 16GB
>>> Windows XP SP2 and Xandros Linux
>>
>> Wow, that must have been a shocker at your graduation. I would have
>> thought they would have wished you good luck instead of telling you
>> "throw
>> three
>> rectifier diodes in series with one of the lines. This will knock the
>> voltage down by 2.1 volts.
>>
>
> Actually, using diodes to drop a voltage by small amounts is a good way of
> doing it as the volt drop across the diode is fairly constant over a wide
> current range.
>
It's hardly a novel trick, it's been done enough times. Indeed, one
reason you see so many diodes in the schematics of what's inside
integrated circuits is because the scheme is used to drop voltage,
diodes using up less space on the chip than resistors.

Michael

Whoa....what's all this talk about integrated circuits and rectifier diodes?
I got my BSEE in 1955 and VR Tubes are the only way to go. Integrated
Circuits????...give me a 5U4, a honking big Power Transformer, a few
electrolytic caps, a choke and a pile of wirewound resistors any day. For
mobile appications nothing beats a Leece-Neville belt driven alternator with
a rectifier stack mounted behind the grill for cooling purposes.

olfart wrote on Tue, 25 Nov 2008 13:34:50 -0500:
> Whoa....what's all this talk about integrated circuits and rectifier diodes?
> I got my BSEE in 1955 and VR Tubes are the only way to go. Integrated
> Circuits????...give me a 5U4, a honking big Power Transformer, a few
> electrolytic caps, a choke and a pile of wirewound resistors any day. For
> mobile appications nothing beats a Leece-Neville belt driven alternator with
> a rectifier stack mounted behind the grill for cooling purposes.

When I got my BSEE in '76, mine was the last class that included tube
theory. Kind of sad to see it not taught anymore. As I though it did
well as a base to move on to solid state. :)

--
Bill
Asus EEE PC 8GB 1GB SoDIMM Adata 16GB
Windows XP SP2 and Xandros Linux

"BillW50" <BillW50@aol.kom> wrote in message
news:gghh03$r50$1@nntp.motzarella.org...
> olfart wrote on Tue, 25 Nov 2008 13:34:50 -0500:
>> Whoa....what's all this talk about integrated circuits and rectifier
>> diodes? I got my BSEE in 1955 and VR Tubes are the only way to go.
>> Integrated Circuits????...give me a 5U4, a honking big Power Transformer,
>> a few electrolytic caps, a choke and a pile of wirewound resistors any
>> day. For mobile appications nothing beats a Leece-Neville belt driven
>> alternator with a rectifier stack mounted behind the grill for cooling
>> purposes.
>
> When I got my BSEE in '76, mine was the last class that included tube
> theory. Kind of sad to see it not taught anymore. As I though it did well
> as a base to move on to solid state. :)
>
> --
> Bill
> Asus EEE PC 8GB 1GB SoDIMM Adata 16GB
> Windows XP SP2 and Xandros Linux

The last all tube computer I worked on was the largest one of it's kind in
1960. We designed and built the GIRDHS for Convair and The B-58 Hustler
program. Buried underground in FT Worth, TX it was slightly bigger than a
football field and I can't remember how many tons of AC were required to
cool the **** thing. I think we dimmed every light in FT Worth every time we
fired it up. Before we ever really got it up and running at full steam they
scrapped the B-58 program and went to ICBM's.
Now ..."those were the days" LOL

olfart wrote:
> "BillW50" <BillW50@aol.kom> wrote in message
> news:gghh03$r50$1@nntp.motzarella.org...
>> olfart wrote on Tue, 25 Nov 2008 13:34:50 -0500:
>>> Whoa....what's all this talk about integrated circuits and rectifier
>>> diodes? I got my BSEE in 1955 and VR Tubes are the only way to go.
>>> Integrated Circuits????...give me a 5U4, a honking big Power Transformer,
>>> a few electrolytic caps, a choke and a pile of wirewound resistors any
>>> day. For mobile appications nothing beats a Leece-Neville belt driven
>>> alternator with a rectifier stack mounted behind the grill for cooling
>>> purposes.
>>
>> When I got my BSEE in '76, mine was the last class that included tube
>> theory. Kind of sad to see it not taught anymore. As I though it did well
>> as a base to move on to solid state. :)
>
> The last all tube computer I worked on was the largest one of it's kind in
> 1960. We designed and built the GIRDHS for Convair and The B-58 Hustler
> program. Buried underground in FT Worth, TX it was slightly bigger than a
> football field and I can't remember how many tons of AC were required to
> cool the **** thing. I think we dimmed every light in FT Worth every time we
> fired it up. Before we ever really got it up and running at full steam they
> scrapped the B-58 program and went to ICBM's.
> Now ..."those were the days" LOL

I worked on aircraft radar on an old tube radar for the first few
months. They told me that to not to get too involved with it, as I would
never see it again. And I never did. Then spent the next 4 years working
on the AWG-10A missile control radar system. The computer systems were
made by Westinghouse and the VTAS by Honeywell. Both were high tech
small and especially the VTAS. Which was the same computer used for the
Apollo moon missions. About the size of a small desktop and millions of
hair thin wires everywhere on the backside of the motherboard. Had about
10 cards plugged into the topside. Both computers were programmed by
paper tape. The only tubes I saw there was CRTs, Klystrons, and Megatrons.


--
Bill
Asus EEE PC 8GB 1GB SoDIMM Adata 16GB
Windows XP SP2 and Xandros Linux

In article <4DDWk.653$QX3.95@nwrddc02.gnilink.net>, "Ray" <rayj.balt@DELTHISverizon.net> wrote:
>My friend has lost the power supply to her IBM Thinkpad T43.

Considering the T2x through T4x bricks can easily be purchased for $15 - $20
on eBay (they're all the same, although there are two different amperage
ratings and lots of different part numbers), why take the risk?

Art

"Arthur Shapiro" <art.shapiro@unisys.com> wrote in message
news:gghs24$1jds$1@si05.rsvl.unisys.com...
> In article <4DDWk.653$QX3.95@nwrddc02.gnilink.net>, "Ray"
> <rayj.balt@DELTHISverizon.net> wrote:
>>My friend has lost the power supply to her IBM Thinkpad T43.
>
> Considering the T2x through T4x bricks can easily be purchased for $15 -
> $20
> on eBay (they're all the same, although there are two different amperage
> ratings and lots of different part numbers), why take the risk?
>
> Art

Best answer of the bunch.

It might. The issue is the voltage, 18.5 is dangerously high for a
device expecting 16v. You might get away with it but there is risk.


Ray wrote:
> My friend has lost the power supply to her IBM Thinkpad T43.
>
> The bottom of the laptop says we need power of 16v and 4.5 amps.
>
> I have an old HP Pavillion power supply which fits the connector but the
> power is 18.5v and 4.9amps.
>
> Would it do any damage if I try this alternative power supply?
** Posted from http://www.teranews.com **

"BillW50" <BillW50@aol.kom> wrote in message
news:gguhe2$pvj$1@news.motzarella.org...
> The unknown warrior wrote on Fri, 28 Nov 2008 11:38:32 +0000:
>> BillW50 wrote:
>>
>>> When I got my BSEE in '76, mine was the last class that included tube
>>> theory. Kind of sad to see it not taught anymore. As I though it did
>>> well as a base to move on to solid state. :)
>>
>> Tubes (or valves to us English), are still used to this day, and probably
>> will be for the forseable future. Getting a couple kW from semiconductors
>> is no mean feat, but can be done. Getting a couple of MW from
>> semiconductors is simply not possible, but tubes can manage it on a
>> continuous basis.
>
> Yes this is so true. And I thought everybody except Americans used valves?
> And the device that most people have in their homes that still has a valve
> (aka tube) is a microwave. I believe it is called a klystron tube (aka
> valve).
>

You believe wrong. It is a magnetron.

"olfart" <olfart65@excite.com> wrote in message
news:6p324dF67im4U1@mid.individual.net...
>
> "BillW50" <BillW50@aol.kom> wrote in message
> news:gghh03$r50$1@nntp.motzarella.org...
>> olfart wrote on Tue, 25 Nov 2008 13:34:50 -0500:
>>> Whoa....what's all this talk about integrated circuits and rectifier
>>> diodes? I got my BSEE in 1955 and VR Tubes are the only way to go.
>>> Integrated Circuits????...give me a 5U4, a honking big Power
>>> Transformer, a few electrolytic caps, a choke and a pile of wirewound
>>> resistors any day. For mobile appications nothing beats a Leece-Neville
>>> belt driven alternator with a rectifier stack mounted behind the grill
>>> for cooling purposes.
>>
>> When I got my BSEE in '76, mine was the last class that included tube
>> theory. Kind of sad to see it not taught anymore. As I though it did well
>> as a base to move on to solid state. :)
>>
>> --
>> Bill
>> Asus EEE PC 8GB 1GB SoDIMM Adata 16GB
>> Windows XP SP2 and Xandros Linux
>
> The last all tube computer I worked on was the largest one of it's kind in
> 1960. We designed and built the GIRDHS for Convair and The B-58 Hustler
> program. Buried underground in FT Worth, TX it was slightly bigger than a
> football field and I can't remember how many tons of AC were required to
> cool the **** thing. I think we dimmed every light in FT Worth every time
> we fired it up. Before we ever really got it up and running at full steam
> they scrapped the B-58 program and went to ICBM's.
> Now ..."those were the days" LOL

Luxury.

I remember the old spark gap transmitters, and having to tap the coherer on
the receiver to get a signal. Things went down hill when the bright
emitters came along.

BillW50 wrote:

> When I got my BSEE in '76, mine was the last class that included tube
> theory. Kind of sad to see it not taught anymore. As I though it did
> well as a base to move on to solid state. :)
>

Tubes (or valves to us English), are still used to this day, and
probably will be for the forseable future. Getting a couple kW from
semiconductors is no mean feat, but can be done. Getting a couple of MW
from semiconductors is simply not possible, but tubes can manage it on a
continuous basis.

The unknown warrior wrote on Fri, 28 Nov 2008 11:38:32 +0000:
> BillW50 wrote:
>
>> When I got my BSEE in '76, mine was the last class that included tube
>> theory. Kind of sad to see it not taught anymore. As I though it did
>> well as a base to move on to solid state. :)
>
> Tubes (or valves to us English), are still used to this day, and
> probably will be for the forseable future. Getting a couple kW from
> semiconductors is no mean feat, but can be done. Getting a couple of MW
> from semiconductors is simply not possible, but tubes can manage it on a
> continuous basis.

Yes this is so true. And I thought everybody except Americans used
valves? And the device that most people have in their homes that still
has a valve (aka tube) is a microwave. I believe it is called a klystron
tube (aka valve).

--
Bill
Asus EEE PC 8GB 1GB SoDIMM Adata 16GB
Windows XP SP2 and Xandros Linux

"BillW50" <BillW50@aol.kom> wrote in message
news:gguhe2$pvj$1@news.motzarella.org...
> The unknown warrior wrote on Fri, 28 Nov 2008 11:38:32 +0000:
>> BillW50 wrote:
>>
>>> When I got my BSEE in '76, mine was the last class that included tube
>>> theory. Kind of sad to see it not taught anymore. As I though it did
>>> well as a base to move on to solid state. :)
>>
>> Tubes (or valves to us English), are still used to this day, and probably
>> will be for the forseable future. Getting a couple kW from semiconductors
>> is no mean feat, but can be done. Getting a couple of MW from
>> semiconductors is simply not possible, but tubes can manage it on a
>> continuous basis.
>
> Yes this is so true. And I thought everybody except Americans used valves?
> And the device that most people have in their homes that still has a valve
> (aka tube) is a microwave. I believe it is called a klystron tube (aka
> valve).
>

You believe wrong. It is a magnetron.