Can anyone help me with obtaining a circuit diagram to build the above
please. Required for an LCD T/V. I live in the United Kingdom and the boat
is on the Great Ouse near Huntingdon.
Thankyou

mack wrote:
Can anyone help me with obtaining a circuit diagram to build the above
please. Required for an LCD T/V. I live in the United Kingdom and the boat
is on the Great Ouse near Huntingdon.
Thankyou


You did not say how many amps you need or what supply you will give it.
Try Maplin to start with
http://www.maplin.co.uk/Search.aspx?...15m1&source=15

"Bozo" wrote in message
...
mack wrote:
Can anyone help me with obtaining a circuit diagram to build the above
please. Required for an LCD T/V. I live in the United Kingdom and the
boat
is on the Great Ouse near Huntingdon.
Thankyou


You did not say how many amps you need or what supply you will give it.
Try Maplin to start with
http://www.maplin.co.uk/Search.aspx?...15m1&source=15

The boat supply is 12 volts DC - but when charging i.e engine running, this
can rise to above 14 volts, this would no do an LCD T/V a lot of good. T/V
takes less that 5 amps DC - hope this makes my request a bit clearer. I wish
to build not buy.

Actually a 60 watt load is a lot for a non switching regulator to do.
You don't want a switching type on a boat as it interferers with the radios.

I think your best bet is :
http://www.nteinc.com/specs/900to999/pdf/nte933.pdf
I have used this in airplanes with good luck before.

NOTE! USE a BIG heat sink!! it will get hot. If it gets too hot the device
will auto shutdown.

Captain Joe




On 15-Jan-2007, "mack" wrote:

The boat supply is 12 volts DC - but when charging i.e engine running,
this
can rise to above 14 volts, this would no do an LCD T/V a lot of good. T/V

takes less that 5 amps DC - hope this makes my request a bit clearer. I
wish
to build not buy.

On Tue, 16 Jan 2007 00:53:10 GMT, wrote:

Actually a 60 watt load is a lot for a non switching regulator to do.
You don't want a switching type on a boat as it interferers with the radios.

I think your best bet is :
http://www.nteinc.com/specs/900to999/pdf/nte933.pdf
I have used this in airplanes with good luck before.

NOTE! USE a BIG heat sink!! it will get hot. If it gets too hot the device
will auto shutdown.

Captain Joe

The NTE933 is not a good choice for this application - the minimum
input/output differential (AKA dropout voltage) is 2.6 volts - on a
car or boat 12 volt system, this means that the NTE 993 regulator will
only be working as a voltage dropper, and not as a regulator.

I think that the only solution for the OP is a switching regulator
that can both buck and boost the input voltage.



--
Peter Bennett, VE7CEI
peterbb4 (at) interchange.ubc.ca
new newsgroup users info : http://vancouver-webpages.com/nnq
GPS and NMEA info: http://vancouver-webpages.com/peter
Vancouver Power Squadron: http://vancouver.powersquadron.ca

Peter,

I don't think that will be a problem for the display, most of them will
handle a low voltage condition
without a problem but a switching type will interfere with the radios. Plus
it is beyond a first time do it yourself project.

Captain Joe


On 15-Jan-2007, Peter Bennett wrote:

Actually a 60 watt load is a lot for a non switching regulator to do.
You don't want a switching type on a boat as it interferers with the
radios.

I think your best bet is :
http://www.nteinc.com/specs/900to999/pdf/nte933.pdf
I have used this in airplanes with good luck before.

NOTE! USE a BIG heat sink!! it will get hot. If it gets too hot the
device
will auto shutdown.

Captain Joe

The NTE933 is not a good choice for this application - the minimum
input/output differential (AKA dropout voltage) is 2.6 volts - on a
car or boat 12 volt system, this means that the NTE 993 regulator will
only be working as a voltage dropper, and not as a regulator.

I think that the only solution for the OP is a switching regulator
that can both buck and boost the input voltage.



--
Peter Bennett, VE7CEI
peterbb4 (at) interchange.ubc.ca
new newsgroup users info : http://vancouver-webpages.com/nnq
GPS and NMEA info: http://vancouver-webpages.com/peter
Vancouver Power Squadron: http://vancouver.powersquadron.ca

On Tue, 16 Jan 2007 07:36:11 GMT, wrote:

Peter,

I don't think that will be a problem for the display, most of them will
handle a low voltage condition
Not always the case, my LCD TV (nominally 12v) will handle 17v but
loses sound at about 11.3v
without a problem but a switching type will interfere with the radios. Plus
it is beyond a first time do it yourself project.
Agreed

Richard

Nb "Pound Eater" Parkend G+S

"mack" wrote in
:

The boat supply is 12 volts DC - but when charging i.e engine running,
this can rise to above 14 volts, this would no do an LCD T/V a lot of
good. T/V takes less that 5 amps DC - hope this makes my request a bit
clearer. I wish to build not buy.


Makes no difference, whatsoever, unless some idiot switches the battery
switch to OFF with the CHARGER OR ENGINE RUNNING!

The 12V input to ANY LCD TV or other electronic device made in the last
30 years is a voltage regulator or DC to DC converter that converts
whatever crap you feed it to what the TV needs, regulated to rock stable
voltage no matter what the input does from 10-20 volts, easy.

This oh-we-gotta-have-a-rock-steady-power-source nonsense comes from the
Rock-Steady Power Supply Company, LLC., who's gotta sell this crap to
stay in business. The worst stupidity is small computers, who have
switching power supplies that really don't care what you feed them, as
long as it's over about 80VAC. The computer, first, rectifies whatever
AC, pulses, spikes, buzzes, sparks, even DC fed to it and charges a few
filter caps in parallel to whatever HVDC it can get, then feeds the DC to
a highly regulated DC-DC switching regulator that turns that into highly
filtered, perfect DC that varies not over a huge range of input garbage
and load current. (I don't care if my UPS is a square wave, as long as it
runs to keep that input coming when the power company fails.)

Lionheart has a massive LCD TV made by some unknown, no-name Korean
manufacturer running straight off the house battery panel. I'm sucking
DC from the starboard DC lighting circuitry, which just happened to have
wires hanging out where we took the light down and put the TV on a swing
arm mount so we can use it for a big video monitor for The Cap'n off the
laptop. It has worked fine for many years....(c; The dock has cable!

Still not convinced? Plug the wall brick into any AC outlet and measure
the 12VDC output of it. What? You say it's over 16V open circuit! WOW!

Larry
--
Extremely intelligent life exists that is so smart they never called
Earth.

"Larry" wrote in message
...
"mack" wrote in
:

Makes no difference, whatsoever, unless some idiot switches the battery
switch to OFF with the CHARGER OR ENGINE RUNNING!

The 12V input to ANY LCD TV or other electronic device made in the last
30 years is a voltage regulator or DC to DC converter that converts
whatever crap you feed it to what the TV needs, regulated to rock stable
voltage no matter what the input does from 10-20 volts, easy.

rest of rant snipped

Larry, this is over-generalized.

I have first hand experience with expensive touchscreen LCD's from Xenex.
These were 24V screens and a 90-240V adapter was supplied. 12 were installed
in a 96' motor yacht and they all fried (backlight) within 6 weeks. Turns
out they could not stand 28.8V of a fully charged battery bank, so we
installed 24/24V DC/DC converters.

Meindert

"Peter Bennett" wrote in message
news.com...
On Tue, 16 Jan 2007 00:53:10 GMT, wrote:

Actually a 60 watt load is a lot for a non switching regulator to do.
You don't want a switching type on a boat as it interferers with the
radios.

I think your best bet is :
http://www.nteinc.com/specs/900to999/pdf/nte933.pdf
I have used this in airplanes with good luck before.

NOTE! USE a BIG heat sink!! it will get hot. If it gets too hot the
device
will auto shutdown.

Captain Joe

The NTE933 is not a good choice for this application - the minimum
input/output differential (AKA dropout voltage) is 2.6 volts - on a
car or boat 12 volt system, this means that the NTE 993 regulator will
only be working as a voltage dropper, and not as a regulator.

I think that the only solution for the OP is a switching regulator
that can both buck and boost the input voltage.


A while back there was some discussion regarding the decrease in life of LED
lights if you ran them on the charging voltage of 14 volts vs a lower
voltage. Voltage reduction solutions were discussed. The potential problem
with the lack of sufficient voltage differential to properly activate a
voltage regulator was discussed and a couple of folks pointed out there are
low-dropout regulators that will work with a differential of only 0.4 volts.
Don't know about the power handling ability of these though.