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TB October 3rd 03 11:16 PM

2x12v in series to power laptop
 
Would it be possible to have the house and engine batteries conected in
series to give 24v, step this down to 18v to power the laptop. Then tap
off each battery for normal 12v service. Sorry if this is a dumb
question but I need a dc supply as the inverter interferes with the ssb
radio when receiving weather faxes.
Tony


Glenn Ashmore October 3rd 03 11:46 PM

2x12v in series to power laptop
 
Go to Radio Shack and get a 19V cigarette lighter converter.

Or he http://www.powerstream.com/ADC.htm


TB wrote:
Would it be possible to have the house and engine batteries conected in
series to give 24v, step this down to 18v to power the laptop. Then tap
off each battery for normal 12v service. Sorry if this is a dumb
question but I need a dc supply as the inverter interferes with the ssb
radio when receiving weather faxes.
Tony



--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com


Doug Dotson October 3rd 03 11:54 PM

2x12v in series to power laptop
 
I owuld either run off of the laptops batteries while recieving FAXs then
recharge them at another time. Or find a small inverter that doesn;t make so
much noise.

Doug

"TB" wrote in message ...
Would it be possible to have the house and engine batteries conected in
series to give 24v, step this down to 18v to power the laptop. Then tap
off each battery for normal 12v service. Sorry if this is a dumb
question but I need a dc supply as the inverter interferes with the ssb
radio when receiving weather faxes.
Tony




TB October 5th 03 03:47 PM

2x12v in series to power laptop
 
That sounds a lot simpler. So this converter is not an inverter then?

Glenn Ashmore wrote:

Go to Radio Shack and get a 19V cigarette lighter converter.

Or he http://www.powerstream.com/ADC.htm


TB wrote:

Would it be possible to have the house and engine batteries conected
in series to give 24v, step this down to 18v to power the laptop. Then
tap off each battery for normal 12v service. Sorry if this is a dumb
question but I need a dc supply as the inverter interferes with the
ssb radio when receiving weather faxes.
Tony





Splitpair October 5th 03 11:50 PM

2x12v in series to power laptop
 
Or this
http://www.mpja.com/productview.asp?product=12974+PS

SP



"TB" wrote in message ...
That sounds a lot simpler. So this converter is not an inverter then?

Glenn Ashmore wrote:

Go to Radio Shack and get a 19V cigarette lighter converter.

Or he http://www.powerstream.com/ADC.htm


TB wrote:

Would it be possible to have the house and engine batteries conected
in series to give 24v, step this down to 18v to power the laptop. Then
tap off each battery for normal 12v service. Sorry if this is a dumb
question but I need a dc supply as the inverter interferes with the
ssb radio when receiving weather faxes.
Tony







johnh October 6th 03 02:00 AM

2x12v in series to power laptop
 
Or this one
http://www.idot.com/TheStore/Desktop...stat us=green


"Glenn Ashmore" wrote in message
...
Go to Radio Shack and get a 19V cigarette lighter converter.

Or he http://www.powerstream.com/ADC.htm


TB wrote:
Would it be possible to have the house and engine batteries conected in
series to give 24v, step this down to 18v to power the laptop. Then tap
off each battery for normal 12v service. Sorry if this is a dumb
question but I need a dc supply as the inverter interferes with the ssb
radio when receiving weather faxes.
Tony



--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com




Gw October 6th 03 04:06 AM

2x12v in series to power laptop
 
Watch out if you get the radio shack adapter it puts out +12 volts on
the plus side referenced to ships ground and - 7 volts on the - side
referenced to ships ground for 19 volts. If you want to connect
anything else to your computer that is using ships ground then you
have 7 volts between them and you get an arc maybe blow some stuff up,
for those that want to argue with this just read very carefully the
warning on page 9 (I think, been a while, maybe page 5) of the manual
it is criptic but it is a warning. I had a customer with one of these
and he blew up his 900 dollar ptc-pro sailmail modems!! So I
investigated and found that they move the negative down from the
input reference.

Watch out !

It is good for running your laptop and for charging batteries but you
must disconnect it before you hook anything else up to the computer.
Charge up the battery then disconnect it. Then connect your fax and
radio stuff.

GW




Glenn Ashmore wrote in message ...
Go to Radio Shack and get a 19V cigarette lighter converter.

Or he http://www.powerstream.com/ADC.htm


TB wrote:
Would it be possible to have the house and engine batteries conected in
series to give 24v, step this down to 18v to power the laptop. Then tap
off each battery for normal 12v service. Sorry if this is a dumb
question but I need a dc supply as the inverter interferes with the ssb
radio when receiving weather faxes.
Tony


TB October 6th 03 05:39 PM

2x12v in series to power laptop
 
I do connect the GPS to the lap so It looks as though this may be an
issue. I do run on charged batteries at the moment but the used thinkpad
that i use will run less than 2hrs on a fully charged battery. I tried
our local Radio Shack for the converter this morning with no luck. I
will check their web site for the part#
Tony

Gw wrote:

Watch out if you get the radio shack adapter it puts out +12 volts on
the plus side referenced to ships ground and - 7 volts on the - side
referenced to ships ground for 19 volts. If you want to connect
anything else to your computer that is using ships ground then you
have 7 volts between them and you get an arc maybe blow some stuff up,
for those that want to argue with this just read very carefully the
warning on page 9 (I think, been a while, maybe page 5) of the manual
it is criptic but it is a warning. I had a customer with one of these
and he blew up his 900 dollar ptc-pro sailmail modems!! So I
investigated and found that they move the negative down from the
input reference.

Watch out !

It is good for running your laptop and for charging batteries but you
must disconnect it before you hook anything else up to the computer.
Charge up the battery then disconnect it. Then connect your fax and
radio stuff.

GW




Glenn Ashmore wrote in message ...

Go to Radio Shack and get a 19V cigarette lighter converter.

Or he http://www.powerstream.com/ADC.htm


TB wrote:

Would it be possible to have the house and engine batteries conected in
series to give 24v, step this down to 18v to power the laptop. Then tap
off each battery for normal 12v service. Sorry if this is a dumb
question but I need a dc supply as the inverter interferes with the ssb
radio when receiving weather faxes.
Tony




Leanne October 6th 03 07:22 PM

2x12v in series to power laptop
 

"TB" wrote in message ...
I do connect the GPS to the lap so It looks as though this may be an
issue. I do run on charged batteries at the moment but the used thinkpad
that i use will run less than 2hrs on a fully charged battery. I tried
our local Radio Shack for the converter this morning with no luck. I
will check their web site for the part#


I think we went through this a month or two ago. Take a look
at www.lindelectronics.com Check out the inverters converters
or what-have-you listed down the right side of the window.

Leanne B
S/V Fundy




TB October 14th 03 01:23 AM

2x12v in series to power laptop
 
I see, so do you think that a 12v DC to 16V DC converter is the answer then?
Tony

Mad Dog wrote:

Yes, using a 6V battery in conjunction with some very extensive
series-parallel
connections and battery isolators you could theoretically design such a
circuit.
But lets consider the source of the interference, alternators are used
insted of generators
on car and boat engines because they are lighter and smaller but alternators
produce alternating current (A/C).
A full wave bridge rectifier consisting of trio diodes is used to convert
A/C into D/C
and a regulator governs output from 13.8 to 14.6VDC.
what a concept huh, anyway the rectifier leaks a small amount of A/C
current into
the regulated D/C.
this small amount of A/C current (700 millivolts) is infamously known as
A/C ripple.
In the D/C world you can call it dirty power because it will infect every
D/C appliance
and electronic gadget that you have turned on.
A/C ripple in a D/C circuit produces NOISE and INTERFERENCE and premature
component failure.
To compund things you are a inverter which inverts the already dirty DC
current back
into a modified square wave which resembles AC current.
****'s gittin deep over here...........
let me know if i'm going to fast 4 ya, what you need to do is condition or
filter the Dc
current before it reaches the intended circuit.
There are 3 types of electrical storage devices: condensers,capacitors and
batteries.
condensers store dc, capacitors store AC and you know what batteries do.
Gittin to the point a capacitor mounted in a DC circuit will block AC while
allowing DC
current to pass, hence we have effectively filtered the DC current.
there are also different types and sizes of capacitors, depending on it's
intended purpose.
keep in mind that DC current flows pos. to neg. thru the battery and
negative to positive thru
a circuit so what this means is grounds are just as important if not more so
than the positive wire.
Several companies make line conditioners for your purpose, but i have always
built my own using large banks of oil-filled electrolytic capacitors wired
in series to handle the demand
for heavy current draw.
Hopefully i have not confused you or gave you a headache as i now have
one..........
but instead given you some insight as to why some DC components dont
function as intended
when operated from rectified AC current.
--
Mad Dog

"TB" wrote in message ...

Would it be possible to have the house and engine batteries conected in
series to give 24v, step this down to 18v to power the laptop. Then tap
off each battery for normal 12v service. Sorry if this is a dumb
question but I need a dc supply as the inverter interferes with the ssb
radio when receiving weather faxes.
Tony






Mad Dog October 14th 03 03:23 AM

2x12v in series to power laptop
 
Yes, using a 6V battery in conjunction with some very extensive
series-parallel
connections and battery isolators you could theoretically design such a
circuit.
But lets consider the source of the interference, alternators are used
insted of generators
on car and boat engines because they are lighter and smaller but alternators
produce alternating current (A/C).
A full wave bridge rectifier consisting of trio diodes is used to convert
A/C into D/C
and a regulator governs output from 13.8 to 14.6VDC.
what a concept huh, anyway the rectifier leaks a small amount of A/C
current into
the regulated D/C.
this small amount of A/C current (700 millivolts) is infamously known as
A/C ripple.
In the D/C world you can call it dirty power because it will infect every
D/C appliance
and electronic gadget that you have turned on.
A/C ripple in a D/C circuit produces NOISE and INTERFERENCE and premature
component failure.
To compund things you are a inverter which inverts the already dirty DC
current back
into a modified square wave which resembles AC current.
****'s gittin deep over here...........
let me know if i'm going to fast 4 ya, what you need to do is condition or
filter the Dc
current before it reaches the intended circuit.
There are 3 types of electrical storage devices: condensers,capacitors and
batteries.
condensers store dc, capacitors store AC and you know what batteries do.
Gittin to the point a capacitor mounted in a DC circuit will block AC while
allowing DC
current to pass, hence we have effectively filtered the DC current.
there are also different types and sizes of capacitors, depending on it's
intended purpose.
keep in mind that DC current flows pos. to neg. thru the battery and
negative to positive thru
a circuit so what this means is grounds are just as important if not more so
than the positive wire.
Several companies make line conditioners for your purpose, but i have always
built my own using large banks of oil-filled electrolytic capacitors wired
in series to handle the demand
for heavy current draw.
Hopefully i have not confused you or gave you a headache as i now have
one..........
but instead given you some insight as to why some DC components dont
function as intended
when operated from rectified AC current.
--
Mad Dog

"TB" wrote in message ...
Would it be possible to have the house and engine batteries conected in
series to give 24v, step this down to 18v to power the laptop. Then tap
off each battery for normal 12v service. Sorry if this is a dumb
question but I need a dc supply as the inverter interferes with the ssb
radio when receiving weather faxes.
Tony




Ron Thornton October 14th 03 02:08 PM

2x12v in series to power laptop
 
Mad Dog,

Nothing in your post is correct. Best leave this to the E techs and
engineers.

Ron


Mad Dog October 14th 03 05:43 PM

2x12v in series to power laptop
 
Well Ron, please be so kind as to correct me..........
--
Mad Dog

"Ron Thornton" wrote in message
...
Mad Dog,

Nothing in your post is correct. Best leave this to the E techs and
engineers.

Ron




Mad Dog October 14th 03 05:49 PM

2x12v in series to power laptop
 
No, a step-up transformer is not the answer......why does he need 16V.
the original post mentions a need for 24VDC, 18VDC,12VDC and interference
of weather faxes when inverter is turned on.
--
Mad Dog

"TB" wrote in message ...
I see, so do you think that a 12v DC to 16V DC converter is the answer

then?
Tony

Mad Dog wrote:

Yes, using a 6V battery in conjunction with some very extensive
series-parallel
connections and battery isolators you could theoretically design such a
circuit.
But lets consider the source of the interference, alternators are used
insted of generators
on car and boat engines because they are lighter and smaller but

alternators
produce alternating current (A/C).
A full wave bridge rectifier consisting of trio diodes is used to

convert
A/C into D/C
and a regulator governs output from 13.8 to 14.6VDC.
what a concept huh, anyway the rectifier leaks a small amount of A/C
current into
the regulated D/C.
this small amount of A/C current (700 millivolts) is infamously known

as
A/C ripple.
In the D/C world you can call it dirty power because it will infect

every
D/C appliance
and electronic gadget that you have turned on.
A/C ripple in a D/C circuit produces NOISE and INTERFERENCE and

premature
component failure.
To compund things you are a inverter which inverts the already dirty DC
current back
into a modified square wave which resembles AC current.
****'s gittin deep over here...........
let me know if i'm going to fast 4 ya, what you need to do is condition

or
filter the Dc
current before it reaches the intended circuit.
There are 3 types of electrical storage devices: condensers,capacitors

and
batteries.
condensers store dc, capacitors store AC and you know what batteries do.
Gittin to the point a capacitor mounted in a DC circuit will block AC

while
allowing DC
current to pass, hence we have effectively filtered the DC current.
there are also different types and sizes of capacitors, depending on

it's
intended purpose.
keep in mind that DC current flows pos. to neg. thru the battery and
negative to positive thru
a circuit so what this means is grounds are just as important if not

more so
than the positive wire.
Several companies make line conditioners for your purpose, but i have

always
built my own using large banks of oil-filled electrolytic capacitors

wired
in series to handle the demand
for heavy current draw.
Hopefully i have not confused you or gave you a headache as i now have
one..........
but instead given you some insight as to why some DC components dont
function as intended
when operated from rectified AC current.
--
Mad Dog

"TB" wrote in message

...

Would it be possible to have the house and engine batteries conected in
series to give 24v, step this down to 18v to power the laptop. Then tap
off each battery for normal 12v service. Sorry if this is a dumb
question but I need a dc supply as the inverter interferes with the ssb
radio when receiving weather faxes.
Tony








Mad Dog October 14th 03 10:03 PM

2x12v in series to power laptop
 
I'm still waiting with baited breath.........
I've been wrong before and i probably will be again,
but prove yourself please!
--
Mad Dog

"Mad Dog" wrote in message
...
Well Ron, please be so kind as to correct me..........
--
Mad Dog

"Ron Thornton" wrote in message
...
Mad Dog,

Nothing in your post is correct. Best leave this to the E techs and
engineers.

Ron






Ron Thornton October 15th 03 02:44 AM

2x12v in series to power laptop
 
Mad Dog,

I was hoping one of the younger guys would step up to the plate cause I
don't think deeply about this stuff any more and I hate writing long
posts, but here goes.

Using a 6 volt battery can be done quite simply with a double pole
double throw switch. When in charge mode the 6v negative is connected
to the 12v negative and the 6v positive is connected to the 12v positive
thru a dropping resistor of suitable size. When in the 18v supply mode
the 6v negative is switched to the 12v positive and the 6v positive is
switched to the 18v output. Monitor the 6v on charge and switch to 18v
output when the 6v is charged. One of the 6v Kiddy car batteries at
WalMart would probably be enough.

The source of the interference, according to Tony, is the inverter.
This has nothing to due with the alternator.

A full wave bridge rectifier has four diodes.

AC ripple is the primary frequency of the alternating current source
used for conversion of AC to DC. Virtually all power supplies have some
of it no matter how much filtering is done and most appliances and
components will handle it unless it is at ridiculous levels which
usually means something in the power supply failed. The "dirty DC" as
you call it, has little or no thru put in an inverter. It is quite
isolated by the circuitry and the toroidal transformer used in most
modern inverters.

For about the last 75 years condensers have been components of
refrigeration equipment. In electronics, condenser and capacitor are
now the same thing. Only the auto industry still calls them condensers
(supprise, supprise).
Capacitors do not store AC. A capacitor does not block AC, it blocks DC
and passes AC.

The current flow thru the battery is irrelevant. Equal current flows
thru the negative (ground) and the positive.

A properly designed filter would dramatically reduce your need for such
large oil filled capacitors. A DC filter is comprised of capacitance
(C), reactance (R) and inductance (L). You get some filtering at low
loads with large C only because the circuit has some residual R and L,
but not much. The C component could be cut down considerably by adding
R and L but this requires some specific knowledge of electronics design
to achieve.

I believe you are confusing ripple with switching transients that come
from solid state junctions such as the transistors used in inverters and
the diodes in the alternator. These are much higher in frequency than
the 60 hertz of the AC line or the 15 to 20 thousand hertz of most
inverters (alternators are in between I believe) and will propagate as
radio waves. These frequencies could be coming into Tony's ssb by air
as easily as on the supply line. The cures, short of buying another
(probably more expensive) inverter could be to make sure the inverter
case has a good ground path ( in the engineering lab, we used braid
instead of wire, something to do with the way rf propogates on wire),
shield the inverter with another grounded enclosure and add small
capacitors (.001, .0001 mmf) between the output to ground hopefully
shunting to ground the offending interference.

Regards, Ron


Mad Dog October 15th 03 11:35 PM

2x12v in series to power laptop
 
(The source of the interference, according to Tony, is the inverter.
This has nothing to due with the alternator.)

Since the inverter produces a modified square-wave from the DC
coming off the alternator it certainly could....

(A full wave bridge rectifier has four diodes.)

I said it uses trio diodes...

(AC ripple is the primary frequency of the alternating current source
used for conversion of AC to DC.)

Standard AC cycles at the rate of 60 cycles per second,
AC ripple voltage is a small amount of AC mixed in with DC source,
usually 700 millivolts or less.

( The "dirty DC" as you call it, has little or no thru put in an inverter.
It is quite
isolated by the circuitry and the toroidal transformer used in most
modern inverters.)

The output from a amplifier or inverter can only be as clean as the input...

(The current flow thru the battery is irrelevant. Equal current flows
thru the negative (ground) and the positive.)

Current flows in 1 direction thru a circuit :negative to positive...

(A properly designed filter would dramatically reduce your need for such
large oil filled capacitors. )

I needed a large bank for the high current draw in my circuit...
not intended for use in this matter, just an example.

( The cures, short of buying another (probably more expensive) inverter
could be to make sure the inverter case has a good ground path ( in the
engineering lab, we used braid
instead of wire, something to do with the way rf propogates on wire),

I agree 100%, chassis grounds are critical, especially on inverters and
transceivers or any piece of electronics for that matter.
Copper braid is used because RF current travels on the surface of a
conductor rather than thru it like AC/DC.
They call it the "skin effect".

Thank you for your reply, it is nice to converse with someone of equal
talent
and interest.
I feel we have knowledge that could bestow the fellow group members,
However i am new here and i will lay low with open ears.
--
Mad Dog
KG4LBD

714 Sandpile,
The Mad Dog wavin' good bye
"Ron Thornton" wrote in message
...
Mad Dog,

I was hoping one of the younger guys would step up to the plate cause I
don't think deeply about this stuff any more and I hate writing long
posts, but here goes.

Using a 6 volt battery can be done quite simply with a double pole
double throw switch. When in charge mode the 6v negative is connected
to the 12v negative and the 6v positive is connected to the 12v positive
thru a dropping resistor of suitable size. When in the 18v supply mode
the 6v negative is switched to the 12v positive and the 6v positive is
switched to the 18v output. Monitor the 6v on charge and switch to 18v
output when the 6v is charged. One of the 6v Kiddy car batteries at
WalMart would probably be enough.

The source of the interference, according to Tony, is the inverter.
This has nothing to due with the alternator.

A full wave bridge rectifier has four diodes.

AC ripple is the primary frequency of the alternating current source
used for conversion of AC to DC. Virtually all power supplies have some
of it no matter how much filtering is done and most appliances and
components will handle it unless it is at ridiculous levels which
usually means something in the power supply failed. The "dirty DC" as
you call it, has little or no thru put in an inverter. It is quite
isolated by the circuitry and the toroidal transformer used in most
modern inverters.

For about the last 75 years condensers have been components of
refrigeration equipment. In electronics, condenser and capacitor are
now the same thing. Only the auto industry still calls them condensers
(supprise, supprise).
Capacitors do not store AC. A capacitor does not block AC, it blocks DC
and passes AC.

The current flow thru the battery is irrelevant. Equal current flows
thru the negative (ground) and the positive.

A properly designed filter would dramatically reduce your need for such
large oil filled capacitors. A DC filter is comprised of capacitance
(C), reactance (R) and inductance (L). You get some filtering at low
loads with large C only because the circuit has some residual R and L,
but not much. The C component could be cut down considerably by adding
R and L but this requires some specific knowledge of electronics design
to achieve.

I believe you are confusing ripple with switching transients that come
from solid state junctions such as the transistors used in inverters and
the diodes in the alternator. These are much higher in frequency than
the 60 hertz of the AC line or the 15 to 20 thousand hertz of most
inverters (alternators are in between I believe) and will propagate as
radio waves. These frequencies could be coming into Tony's ssb by air
as easily as on the supply line. The cures, short of buying another
(probably more expensive) inverter could be to make sure the inverter
case has a good ground path ( in the engineering lab, we used braid
instead of wire, something to do with the way rf propogates on wire),
shield the inverter with another grounded enclosure and add small
capacitors (.001, .0001 mmf) between the output to ground hopefully
shunting to ground the offending interference.

Regards, Ron




Ron Thornton October 16th 03 01:37 PM

2x12v in series to power laptop
 
Thanks Mad Dog. It's nice to have an exchange of ideas and disagreement
without being called a moron. I appreciate your civility.

I don't think your garbage in, garbage out theory applies to inverters
as it does with amplifiers. In the next week or so I'll run some
inverters off a trashy DC supply and let you know what comes out. Now
where did I put that oscilloscope?

Regards, Ron


Mad Dog October 17th 03 04:34 PM

2x12v in series to power laptop
 
Ten-4 neighbor..keep me posted
--
, Mad Dog

"Ron Thornton" wrote in message
...
Thanks Mad Dog. It's nice to have an exchange of ideas and disagreement
without being called a moron. I appreciate your civility.

I don't think your garbage in, garbage out theory applies to inverters
as it does with amplifiers. In the next week or so I'll run some
inverters off a trashy DC supply and let you know what comes out. Now
where did I put that oscilloscope?

Regards, Ron





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