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DIY SCART to VGA

Discussion in 'Cables & Switches' started by wiredcharlie, Mar 27, 2005.

  1. wiredcharlie

    wiredcharlie
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    I started reading this thread just before I bought my TH37PW7. I was struck by the almost unanimous recommendation of the JS-Technology SCART to VGA box, in fact I almost decided to buy one! Then I started to look into what this box and other similar products like the SyncBlaster actually do.

    Basically the RGB signals from the SCART just need to be connected directly to the same signal pins on the VGA. ie the video does not need to be changed at all. The Plasma VGA does however require separate Horizontal and Vertical Sync signals.

    So, I started trying to find a simple way to build a Sync Separator for myself.

    The result is a small is this:
    [​IMG]

    It is powered from pin 8 on the SCART - which I expected not to work properly!

    This is my scribbled circuit diagram:
    [​IMG]

    The circuit is based around the Intersil EL1883 IC and more info can be found here:

    http://www.intersil.com/cda/deviceinfo/0,0,EL1883,0.html

    This is quite a new chip and generates proper Horizontal Sync pulses. According to the data sheet it is also Macrovision compatible!

    My only testing has been with a Hauppauge DEC-2000 Freeview box and my Panasonic plasma. Results are perfect!

    If anyone knows a bit about electronics and wants to have a go I would be happy to help.

    Tony
     
  2. chienmort

    chienmort
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    The difference between scart and VGA is that VGA has TTL level (5V high impedance) separate H+V syncs and Scart (RGBs) has composite low impedance (0.3V 75ohm) syncs. So both Keene and JS have a built in sync separator.

    Make sure that your unit can accept video frequencies via VGA before spending or building.

    BTW the circuit looks good!
     
  3. wiredcharlie

    wiredcharlie
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    Good point.
    The signal spec will be listed as 625(575)/50i in the Plasma display manual. This means 625 lines (575 visible lines)/ 50hz interlaced. The horizontal (line) frequency is 15.625KHz and the vertical frequency is 50Hz.

    Tony
     
  4. Vikash

    Vikash
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    excellent. do you have a larger schematic, and/or component diagram to follow. I'll be giving this a go to get my new PW6 going :smashin:
     
  5. wiredcharlie

    wiredcharlie
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    Have a look at this:

    http://www.intersil.com/data/fn/fn7010.pdf

    The only addition I've made is to protect the IC from overvoltage by putting a zenner diode across the supply, plus a 1ohm series resistor.

    If you look at my scribbled circuit, scart pin 19 is shown as S19 etc and D-type pin 13 is D13 etc.

    I suspect the only circuit value that is absolutely critical is the 681K resistor from pin 6 to GND - see the pdf.

    Plug pinnouts here:

    http://www.hardwarebook.net/connector/av/vga15.html
    http://www.hardwarebook.net/connector/av/scart.html

    The IC is a surface mount component. I carfully soldered it to small wires plugged into an ic socket (tricky). Then soldered the ic skt to the scrap of veroboard I built the circuit on.

    Tony
     
  6. Davidgilmour

    Davidgilmour
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  7. wiredcharlie

    wiredcharlie
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    For a mass produced item, yes. For a "Cottage Industry" niche product, maybe not.

    Tony
     
  8. geewhizz

    geewhizz
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    So the question is ::: are you going to be selling them ?? :cool:
     
  9. Vikash

    Vikash
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    Tony, where did you get the IC's from? I've orded a few samples so let see what happens.

    I'm doing a few kits at the moment, so if this really is as good as the £100+ commercial equivelents, then I see a possibility of getting a kit and PCB's made to sell.

    Here's a mic preamp kit I'm doing at the moment:
    http://www.vikash.info/audio/pim/micpre.asp
     
  10. Vikash

    Vikash
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    Hi Tony,
    I've got the chips and will have a go. The PDF mentions RSET as 681K for NTSC. Is this what you used, or did you adjust it for PAL as I assume would be required?
     
  11. magge

    magge
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    This is really interesting compared to the expensive alternatives!!!

    Did you figure out if you infact have to tweak the resistor for PAL? I read the EL1883 specs and I got the impression that the resistor had to be tweaked for different resolutions aswell?

    Is the output of the EL1883 H/V sync in a compatible voltage level for the VGA connector side?

    I'll try building one or more of these if Intersil will give me sample chips. If I can make it work I think this thread has saved me $$$. Great info, thanks! :thumbsup: :)

    ...now all I need is to find a DIY IR repeater kit. :)
     
  12. dvd_chemist

    dvd_chemist
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    my name is David and I'm an electronics complete newby.

    Nonetheless I'd like to build a cable similar (I think) to the one you shown in the thread "DIY SCART to VGA".

    The objective is to use a new LCD monitor (which I still have to by and which probably will be the SyncMaster 2032BW http://www.samsung.com/uk/products/m...0pebsfvedc.asp) to watch dvds from a dvd player (with scart, s-video and rgb outputs).

    Actually I see in the techincal details of the 2032BW monitor, that the accepted "Signal Input Video Signals" are:
    - Analog RGB, DVI
    - Sync. Type Separate H/V, Composite , SOG
    and that the "Input Connectors" are:
    - D-sub, DVI-D

    So I don't really know if I require a sync separator as you put in your cable or if I can simply connect the scart output pins to a VGA pins...
    ... well, I told you, I'm a coplete newby; please, be understanding, I didn't mean to bother you too much.

    I'd be pleased if you could give me some advice on how to obtain what I need...if I managed to explain it...'bout which I'm not really sure...

    Well, if you have some time, I'd really be thankful if you could answer me.


    Thanks in advance anyway.

    David
     
  13. choddo2006

    choddo2006
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    If you buy a standard monitor you may well find it cannot accept the horizontal sync frequency of 15.625KHz - the spec will normally state what freq range it can accept over VGA
     
  14. dvd_chemist

    dvd_chemist
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    thanks for your fast reply.

    I'm sorry but I still don't understand well.
    The frequencies in the specifications at this page: http://www.samsung.com/uk/products/monitors/lcd/designer/ls20pebsfvedc.asp
    are:
    Horizontal Frequency(kHz) 30 ~ 81
    Vertical Frequency(Hz) 56 ~ 75

    The 15kHz frequency you mentioned is the normal output from a dvd player?

    What should I do then to see an image from a dvd player on such a monitor?

    Can you please check the specs of the monitor (see link above) and tell me what would you do to be able to see a dvd from a normal dvd player?

    thanks in advance, also for being understanding.

    David
     
  15. freeman

    freeman
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    Don't you need something like this?
     
  16. dvd_chemist

    dvd_chemist
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    Thanks for replying, in fact I do need something like that, at least logically speaking.

    But it cost more than the monitor itself...
    Actually I found a similar device for much less:

    http://www.playtronics.it/product.p...+S-VIDEO+------>+VGA+MONITOR+PC+CRT+LCD~.html

    What I thought, reading this old thread, was that I could build myself a cable doing the conversion with an "enough simple" circuit...

    Unfortunately I wasn't able to contact wiredcharlie, who built something which seemed to me close to my need (cheap and effective selfmade cable).

    Thanks,

    D
     
  17. ntsc443

    ntsc443
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    Hello, i want to build scart to vga (or video i think it's simplier) adapter to connect Philips SLV3100 TV link to Home cinema projector. I have made connector, but it worked for about 10 seconds and video disapeared, tryed second time and result was the same. Maybe you have schemes or something, that might help me? I'll be very thankful, Basketball championship has began so, I hope that I can watch these games in my home cinema. I'm from Lithuania
     

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  18. ntsc443

    ntsc443
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    Deleted
     
    Last edited: Sep 16, 2009
  19. ntsc443

    ntsc443
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    Sugestions? :confused:
     
  20. Vikash

    Vikash
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    Anyone get this working?
     
  21. ntsc443

    ntsc443
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    Still in progress...
     
  22. ntsc443

    ntsc443
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    Done, but without scart adapter. I just opened AV link box and found, that it receives wireless video and it goes like simple RCA to another converter and then i get Scart. Simply disconnected that converter and got this system running. Now i can wach TV in my home cinema :) :clap:
     
  23. RascalRuss

    RascalRuss
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    Hi Guys,

    I know this is a really really old thread now, but does anyone have the wiring diagram for making the JS RGB to VGA project that is discussed??

    Cheers

    Russ
     
  24. MarkTaylor

    MarkTaylor
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    Just for clarity, the JS product is a commercial item, it was mentioned in passing at the start of the thread but the rest has nothing to do with JS.
     
  25. RascalRuss

    RascalRuss
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    Yes sorry,I was just refering to JS as the type of box
     

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