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On Wed, 31 Dec 2003 06:25:43 -0500,
hanz wrote:
FOR $55.00 UDS you can my a PW-70A which takes 12v dc and has all the
output for you computer..look at:

http://www.logicsupply.com/product_i...roducts_id/118

I've been running only for 4 months.

Hanz


That will work fine, provided your power requirements are 100W



Jim Richardson wrote:
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On 30 Dec 2003 10:32:28 -0800,
Dan wrote:

"Fred Miller" wrote in message ...

Slightly Off topic but I know someone here can answer the question.

I am trying to run a Dell Inspiron 5100 in my truck using a small inverter
but all I do is blow fuses in the truck. This is a 6 month old Chev 1500 in
excellent condition.

My "brick" 110 V power supply reads:

AC 100-240 V - 103-109 VA 50-60Hz
DC 20 V 4.5 A

What size inverter in watts do I need to use with this power supply?
Can a cigar lighter outlet supply the required power?

TIA for your help.

Whether in a truck or a boat, it's inefficient to convert DC to AC
back to DC. You'd be better off powering a tower or laptop computer
directly from the DC off the vehicle. A trip to Radio Shack should
provide all the parts needed. An AT power supply for a tower computer
has +12V, -12V, +5V, -5V, and ground. For the +12V and -12V, you will
need to filter and regulate the DC feed from your battery bank. The
+5V and -5V can be derived from your filtered 12V side, just step the
voltage down via a stepdown transformer and regulate it. Make sure to
filter the ground as well or gremlins will get your electronics. Now
take the wires from your existing PC power supply and connect them to
your new power supply. This is overly simplified, but I think the
whole project can be built from schematics found in the Radio Shack
project books. Laptops are a little bit trickier. Find the voltage
rating of the battery, then step the 12V DC of the vehicle to the
proper voltage. The tricky part is determining if the voltage
regulator is built into the battery or the laptop itself. You may
have to make the voltage regulator yourself. If you don't need the
regulator, connect your new power supply to the battery contact pads
on the laptop. Just remember that you will definately void any
warranty doing this.

Dan Schiro
M/V Sea Ranch
Pensacola Sail and Power Squadron



In order to use a transformer to step the voltage down, you must by
definition be using AC. A transformer doesn't work with a DC level.


Rather than go to the hassle of designing and building your own
powersupplies, you can buy std AT style supplies that take 12VDC as an
input, but usually in limited power forms, don't try powering your 500W
game monster machine from one. Expect to pay $200 and up for one.

For the laptop, most manufacturers make a 12V car powersupply as an
option. If not, then Targus among others, will happily sell you one.

The downside to low voltage DC of course, is the I2R losses in the
cables, 120VAC may lose some in the translation from DC-AC, but it has
the advantage of low loss with relatively small gauge wire.



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--
Jim Richardson http://www.eskimo.com/~warlock
We aim to please. Ourselves, mostly, but we do aim to please.
Anthony DeBoer

Jim Richardson wrote in message ...
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Hash: SHA1

On 30 Dec 2003 10:32:28 -0800,
Dan wrote:
"Fred Miller" wrote in message ...
Slightly Off topic but I know someone here can answer the question.

I am trying to run a Dell Inspiron 5100 in my truck using a small inverter
but all I do is blow fuses in the truck. This is a 6 month old Chev 1500 in
excellent condition.

My "brick" 110 V power supply reads:

AC 100-240 V - 103-109 VA 50-60Hz
DC 20 V 4.5 A

What size inverter in watts do I need to use with this power supply?
Can a cigar lighter outlet supply the required power?

TIA for your help.

Whether in a truck or a boat, it's inefficient to convert DC to AC
back to DC. You'd be better off powering a tower or laptop computer
directly from the DC off the vehicle. A trip to Radio Shack should
provide all the parts needed. An AT power supply for a tower computer
has +12V, -12V, +5V, -5V, and ground. For the +12V and -12V, you will
need to filter and regulate the DC feed from your battery bank. The
+5V and -5V can be derived from your filtered 12V side, just step the
voltage down via a stepdown transformer and regulate it. Make sure to
filter the ground as well or gremlins will get your electronics. Now
take the wires from your existing PC power supply and connect them to
your new power supply. This is overly simplified, but I think the
whole project can be built from schematics found in the Radio Shack
project books. Laptops are a little bit trickier. Find the voltage
rating of the battery, then step the 12V DC of the vehicle to the
proper voltage. The tricky part is determining if the voltage
regulator is built into the battery or the laptop itself. You may
have to make the voltage regulator yourself. If you don't need the
regulator, connect your new power supply to the battery contact pads
on the laptop. Just remember that you will definately void any
warranty doing this.

Dan Schiro
M/V Sea Ranch
Pensacola Sail and Power Squadron


In order to use a transformer to step the voltage down, you must by
definition be using AC. A transformer doesn't work with a DC level.


Rather than go to the hassle of designing and building your own
powersupplies, you can buy std AT style supplies that take 12VDC as an
input, but usually in limited power forms, don't try powering your 500W
game monster machine from one. Expect to pay $200 and up for one.

For the laptop, most manufacturers make a 12V car powersupply as an
option. If not, then Targus among others, will happily sell you one.

The downside to low voltage DC of course, is the I2R losses in the
cables, 120VAC may lose some in the translation from DC-AC, but it has
the advantage of low loss with relatively small gauge wire.



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Jim,
Good catch about the transformers. A simple analog voltage divider would work.

Jim Richardson wrote in message ...
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Hash: SHA1

On 30 Dec 2003 10:32:28 -0800,
Dan wrote:
"Fred Miller" wrote in message ...
Slightly Off topic but I know someone here can answer the question.

I am trying to run a Dell Inspiron 5100 in my truck using a small inverter
but all I do is blow fuses in the truck. This is a 6 month old Chev 1500 in
excellent condition.

My "brick" 110 V power supply reads:

AC 100-240 V - 103-109 VA 50-60Hz
DC 20 V 4.5 A

What size inverter in watts do I need to use with this power supply?
Can a cigar lighter outlet supply the required power?

TIA for your help.

Whether in a truck or a boat, it's inefficient to convert DC to AC
back to DC. You'd be better off powering a tower or laptop computer
directly from the DC off the vehicle. A trip to Radio Shack should
provide all the parts needed. An AT power supply for a tower computer
has +12V, -12V, +5V, -5V, and ground. For the +12V and -12V, you will
need to filter and regulate the DC feed from your battery bank. The
+5V and -5V can be derived from your filtered 12V side, just step the
voltage down via a stepdown transformer and regulate it. Make sure to
filter the ground as well or gremlins will get your electronics. Now
take the wires from your existing PC power supply and connect them to
your new power supply. This is overly simplified, but I think the
whole project can be built from schematics found in the Radio Shack
project books. Laptops are a little bit trickier. Find the voltage
rating of the battery, then step the 12V DC of the vehicle to the
proper voltage. The tricky part is determining if the voltage
regulator is built into the battery or the laptop itself. You may
have to make the voltage regulator yourself. If you don't need the
regulator, connect your new power supply to the battery contact pads
on the laptop. Just remember that you will definately void any
warranty doing this.

Dan Schiro
M/V Sea Ranch
Pensacola Sail and Power Squadron


In order to use a transformer to step the voltage down, you must by
definition be using AC. A transformer doesn't work with a DC level.


Rather than go to the hassle of designing and building your own
powersupplies, you can buy std AT style supplies that take 12VDC as an
input, but usually in limited power forms, don't try powering your 500W
game monster machine from one. Expect to pay $200 and up for one.

For the laptop, most manufacturers make a 12V car powersupply as an
option. If not, then Targus among others, will happily sell you one.

The downside to low voltage DC of course, is the I2R losses in the
cables, 120VAC may lose some in the translation from DC-AC, but it has
the advantage of low loss with relatively small gauge wire.



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Jim,
Good catch about the transformers. A simple analog voltage divider would work.

On 30 Dec 2003 10:32:28 -0800, (Dan) wrote:

Whether in a truck or a boat, it's inefficient to convert DC to AC
back to DC. You'd be better off powering a tower or laptop computer
directly from the DC off the vehicle. A trip to Radio Shack should
provide all the parts needed. An AT power supply for a tower computer
has +12V, -12V, +5V, -5V, and ground. For the +12V and -12V, you will
need to filter and regulate the DC feed from your battery bank. The
+5V and -5V can be derived from your filtered 12V side, just step the
voltage down....

Dan Schiro

Though it sounds paradoxical, using an ordinary regulator to derive
5 volts from a 12 volt source is normally less than 5/12 efficient or
42% and its the +5 volts output that takes most of the current, if
I recall. (using a resistive voltage divider is even more wasteful
still.....) I'm not convinced you would show a power savings, with
the homebrew DC source approach over a 12/120AC inverter.

There is a way to convert DC sources efficiently though, by using a
buck switching converter. They can show efficiencies in the 90s, but
they cost.....

I liked the packaged DC supply for PCs approach that someone
mentioned. That would be a usable alternative to an inverter, IMO.

Brian Whatcott Altus OK

On 30 Dec 2003 10:32:28 -0800, (Dan) wrote:

Whether in a truck or a boat, it's inefficient to convert DC to AC
back to DC. You'd be better off powering a tower or laptop computer
directly from the DC off the vehicle. A trip to Radio Shack should
provide all the parts needed. An AT power supply for a tower computer
has +12V, -12V, +5V, -5V, and ground. For the +12V and -12V, you will
need to filter and regulate the DC feed from your battery bank. The
+5V and -5V can be derived from your filtered 12V side, just step the
voltage down....

Dan Schiro

Though it sounds paradoxical, using an ordinary regulator to derive
5 volts from a 12 volt source is normally less than 5/12 efficient or
42% and its the +5 volts output that takes most of the current, if
I recall. (using a resistive voltage divider is even more wasteful
still.....) I'm not convinced you would show a power savings, with
the homebrew DC source approach over a 12/120AC inverter.

There is a way to convert DC sources efficiently though, by using a
buck switching converter. They can show efficiencies in the 90s, but
they cost.....

I liked the packaged DC supply for PCs approach that someone
mentioned. That would be a usable alternative to an inverter, IMO.

Brian Whatcott Altus OK

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Hash: SHA1

On 31 Dec 2003 17:37:47 -0800,
Dan wrote:
Jim Richardson wrote in message


snip

In order to use a transformer to step the voltage down, you must by
definition be using AC. A transformer doesn't work with a DC level.


Rather than go to the hassle of designing and building your own
powersupplies, you can buy std AT style supplies that take 12VDC as
an input, but usually in limited power forms, don't try powering your
500W game monster machine from one. Expect to pay $200 and up for
one.

For the laptop, most manufacturers make a 12V car powersupply as an
option. If not, then Targus among others, will happily sell you one.

The downside to low voltage DC of course, is the I2R losses in the
cables, 120VAC may lose some in the translation from DC-AC, but it
has the advantage of low loss with relatively small gauge wire.



Jim,
Good catch about the transformers. A simple analog voltage divider
would work.


The down side to simple voltage devider, is that you have to throw away
a lot of power, whether you are doing it with a linear regulator, a
dropping resistor, or a zener diode, any voltage you don't "use" get's
wasted as heat at the rate of "unwanted volts" X amp draw. Nasty if you
are powering a high draw system like a 5VDC logic board, with 12VDC.

In the case of a computer, your best choice really is either an
inverter, or a DC-DC switching powersupply built for the task. Either,
well done, is going to draw less total power, (by wasting less) than a
linear regulator or voltage divider setup. Unfortunately, they are going
to have other problems which have to be dealt with, most importantly,
being switching noise. Which is pretty critical in the case of a system
on a boat with comm gear. You'll need to take the relevent precautions
to prevent noise coming in the power supply of the radios.


On the other hand, if you have the space and inclination, you could
allways build a motor-generator converter although they are typically
used in situations where you are changing a *lot* of power, and number
of phases and frequencies too.. but you could do it I suppose

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--
Jim Richardson http://www.eskimo.com/~warlock
"Even if you can deceive people about a product through misleading statements,
sooner or later the product will speak for itself." - Hajime Karatsu

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On 31 Dec 2003 17:37:47 -0800,
Dan wrote:
Jim Richardson wrote in message


snip

In order to use a transformer to step the voltage down, you must by
definition be using AC. A transformer doesn't work with a DC level.


Rather than go to the hassle of designing and building your own
powersupplies, you can buy std AT style supplies that take 12VDC as
an input, but usually in limited power forms, don't try powering your
500W game monster machine from one. Expect to pay $200 and up for
one.

For the laptop, most manufacturers make a 12V car powersupply as an
option. If not, then Targus among others, will happily sell you one.

The downside to low voltage DC of course, is the I2R losses in the
cables, 120VAC may lose some in the translation from DC-AC, but it
has the advantage of low loss with relatively small gauge wire.



Jim,
Good catch about the transformers. A simple analog voltage divider
would work.


The down side to simple voltage devider, is that you have to throw away
a lot of power, whether you are doing it with a linear regulator, a
dropping resistor, or a zener diode, any voltage you don't "use" get's
wasted as heat at the rate of "unwanted volts" X amp draw. Nasty if you
are powering a high draw system like a 5VDC logic board, with 12VDC.

In the case of a computer, your best choice really is either an
inverter, or a DC-DC switching powersupply built for the task. Either,
well done, is going to draw less total power, (by wasting less) than a
linear regulator or voltage divider setup. Unfortunately, they are going
to have other problems which have to be dealt with, most importantly,
being switching noise. Which is pretty critical in the case of a system
on a boat with comm gear. You'll need to take the relevent precautions
to prevent noise coming in the power supply of the radios.


On the other hand, if you have the space and inclination, you could
allways build a motor-generator converter although they are typically
used in situations where you are changing a *lot* of power, and number
of phases and frequencies too.. but you could do it I suppose

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--
Jim Richardson http://www.eskimo.com/~warlock
"Even if you can deceive people about a product through misleading statements,
sooner or later the product will speak for itself." - Hajime Karatsu

this might be what someone else was referring to
kit costs about $US32
http://user.gru.net/n4uau/kits/Volta...e/apvb-kit.htm

which isnt as cheap as this which i just bought for $US17.90
http://www.compgeeks.com/additem.asp?invtid=SDR-70W


On Fri, 26 Dec 2003 16:45:01 +0000, Fred Miller wrote:

Slightly Off topic but I know someone here can answer the question.

I am trying to run a Dell Inspiron 5100 in my truck using a small inverter
but all I do is blow fuses in the truck. This is a 6 month old Chev 1500
in excellent condition.

My "brick" 110 V power supply reads:

AC 100-240 V - 103-109 VA 50-60Hz
DC 20 V 4.5 A

What size inverter in watts do I need to use with this power supply? Can a
cigar lighter outlet supply the required power?

TIA for your help.

this might be what someone else was referring to
kit costs about $US32
http://user.gru.net/n4uau/kits/Volta...e/apvb-kit.htm

which isnt as cheap as this which i just bought for $US17.90
http://www.compgeeks.com/additem.asp?invtid=SDR-70W


On Fri, 26 Dec 2003 16:45:01 +0000, Fred Miller wrote:

Slightly Off topic but I know someone here can answer the question.

I am trying to run a Dell Inspiron 5100 in my truck using a small inverter
but all I do is blow fuses in the truck. This is a 6 month old Chev 1500
in excellent condition.

My "brick" 110 V power supply reads:

AC 100-240 V - 103-109 VA 50-60Hz
DC 20 V 4.5 A

What size inverter in watts do I need to use with this power supply? Can a
cigar lighter outlet supply the required power?

TIA for your help.