RGB(GREEN SYNC) to RGB(HV SYNC)

[WMT]

-I know that RGB(HV) is the same with RGB(GREEN SYNC) exept the second does not have seperate horizontal/vertical sync wires it comes along with the green.
Is it possible to read the green sync and convert it to RGB(HV)?
By this way we can get good picture from stand alone dvds with RGB output.

Just a thought!Can it be done?I will also ask a friend of mine that works as an electronic engineer but it is to late now,i will have to wait until tomorrow but this thing is on my head all afternoon so i had to post it.

 

[Remy]

Hi,

You can use a EL4583 from Elantec/Intersil to separate synchro signal from green video signal, but you will need to add a buffer between the green+sync signal and the input of the EL4583, if not, the color balance might turn to green without this buffer.

http://www.intersil.com/data/fn/fn7173.pdf

One resistor must be changed(680K at 15khz interlaced pal, other value in vga mode) if you change the video mode(maybe a multi -turn trim pot can help if you use different video mode).

Rémy

 

[WMT]

Thanx a lot Remy!

Your replay is exactly what i wanted to know!I reed carefully the pdf and your replay but i think i will need help with this as there are somethings i do not know.I am good with electonics but this is something very new and i must try harder to figger out the external components.The el4583 is a very interesting IC i would say.Do you think i might find it in a local electronic part shop easily or it will be available only at intersil.com?Have you done this allready?If yes any instractions would be wellcome, IF you have the time to replay any.I think if it works at list we will not have to have a pc on to watch a dvd!I know that it will not be like native vga from a graphic card but it will be much better than composite and svideo threw a video to vga adapter that i am carently using with not so good results,(composite is not watchable and svideo nearly ok but not good).

Thanx and have a nice day Remy.

 

[WMT]

ok!

Everything is at your homepage!Lets see if i manage to build it Remy!!!(sync seperator v2.2)

 

[Remy]

Hi WMT,

I buy EL4583 on this french site http://www.radiospares.fr/ maybe you can find a similar web site in your country.
The circuit on my web site(sync separator v2.2) is a RGB+video composite to RGB+HV(or RGB+ pure composite sync) converter, to connect european dvd players to some crt or dlp/lcd projector, some projector don't like to sync with a video composite signal from scart, they only accept pure sync signal without video data. I have starded to build a RGsB to RGBHV converter for linux ps2 kit sync on green out to standard vga RGBHV. I'll add the design soon on my www, juste have to add a "buffer mode" opamp between green signal and the input of the EL4583. It will be tested next week.

Rémy

 

[Remy]

You can try too the LM1881, less sophisticated, but can handle higher sync frequency. I'll do a pcb for this sync separator in RGsB >RGBHV mode if want

http://cache.national.com/ds/LM/LM1881.pdf

Rémy

 

[WMT]

Tomorrow i will see what i will be able to find.I think el 4583 is a little difficult to find but i will try!lm 1881 is easier to find.I wait until you test your constraction and tell me the results!If it works well then you are the man!!!If you have time and you think that lm1881 will also do the job then please send me the diagram for it.Do you think that the RGsB to RGBHV will be similar good as the RGBHV from the pc when watching dvd's?

Sorry if i ask a lot!!!

 

[Remy]

Hi WMT,

This circuit only modify the sync signal, not the video signal, no risk to "damage" it. I've tried today morning the circuit on a test board, it works I tried it with a ps2 with linux kit, output 800*600 at 50Hz, image seem to be perfect, no flickering, color balance is ok, good black level and no saturation in white level. I'll draw the pcb this evening. For the opamp, i use a Elantec LT1398, but you have difficulty to find it, i'll search in other brand for a similar opamp.

Rémy

 

[WMT]

Hi Remy.

-I bought the LM1881 today but no luck with the LT!
So if you can find a similar one from another brand i will huppily
built the kit!
Thanx a lot Remy for everything.