Connect Laptop to TV with VGA out?

W

washington.steven

I dont have s video. But is it possible to take the VGa out and connect
it to my TV with the standard 3 round plugs (two audio one video....red
white and yellow) I'm not sure the names of the cables connected to the
TV (the red, white, and yellow ones) I'd like to brush up on that vocab
as well :p

Thanks in advance.
 
P

paulmd

I dont have s video. But is it possible to take the VGa out and connect
it to my TV with the standard 3 round plugs (two audio one video....red
white and yellow) I'm not sure the names of the cables connected to the
TV (the red, white, and yellow ones) I'd like to brush up on that vocab
as well :p

Thanks in advance.

Sure, it's a standard part. VGA to RCA. You can probably pick it up
locally. Keep in mind that the television is a *very* low resolution
compared to a PC monitor.



http://www.computercasesandcables.com/ccc/CV-25120?mv_pc=froogle
http://www.monoprice.com/products/search.asp?keyword=2509

http://froogle.google.com/froogle?hl=en&q=vga+to+RCA&btnG=Google+Search&lmode=online&scoring=r
 
P

Paul

I dont have s video. But is it possible to take the VGa out and connect
it to my TV with the standard 3 round plugs (two audio one video....red
white and yellow) I'm not sure the names of the cables connected to the
TV (the red, white, and yellow ones) I'd like to brush up on that vocab
as well :p

Thanks in advance.

According to this, there are two ways this can work. One way, is the
chipset in the laptop, would need a graphics mode where it actually
outputs a composite video signal on one of the output leads. An interlaced
output mode would be part of the solution (as TV is interlaced and not
progressive scan).

The second method does not rely on any "magic" modes in the graphics device
and is called "scan conversion". With "scan conversion", the VGA
device need only meet standard VGA output modes, to be converted.
Getting a composite video output signal, on one of the RGVHV signals
on the VGA cable, is not standard.

http://www.epanorama.net/phpBB2/viewtopic.php?t=1862

Note that one of their cabling examples is this one:

http://www.pccables.com/70717.htm

The advert says "used on _some_ Dell laptops". While the cable is
cheap, the chipset has to have the appropriate output mode to allow
such a cheap cable to work.

This web page shows how a cheap cabling solution might work. The
circuit here, uses resistors to simply sum the signals from the
VGA connector. As long as the video chip puts out upside-down sync
signals, then a crude black&white picture appears on the TV set.

http://www.epanorama.net/circuits/vga2tv/composite_adapter.html

Scan converters start at around $100 and move up. Due to the limits of
TV video bandwidth (especially via a composite signal), you might find
text at 640x480 to be pretty bad. I cannot read text from my video card
that has composite and Svideo output. Viewing a movie might be OK.

Composite (one 75 ohm video signal, like the yellow connector) and
Svideo (luminance and chrominance via four pin DIN connector) are likely
limited to about 4MHz bandwidth or thereabouts. It is possible that
component video RGB (three coax cables) type method could have more
bandwidth than that (haven't seen specs so dunno). A TV set intended
for component video, might be much higher quality than the old TV sets
that only had composite and Svideo. But the interfacing issues remain the
same - unless the chipset on the computer side of things, has had
special modes added for outputting a signal to those standards, then
a cheap cable won't work. Scan conversion devices can make a difference.

If the manual or the technical documentation for the laptop specifically
mentions support for the $13 cable, then it is worth a try. In terms of
having a general tool in your tool belt, to handle any computer going to
TV sets. try a scan converter instead. And not the cheapest one. Pick a
midrange one.

http://aver.com/ppd/comparison_averkey.pdf

There is some more info here. Epanorama tends to use popups, so be prepared
for a few garbage windows when you visit here.

http://www.epanorama.net/links/videocircuits.html

Another page here:

http://ruel.net/pc/tv.tuner.converter.htm

Paul
 

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