Video switcher system design

[R110]

sony video switcher diagram

Hi
I want to design a video switcher system, It should switch 12 input video signals.
Do any body have any shcematic circuit diagram or any other usefull info.
By the way if I want to design a video buffer with the IC AD826 , what configuration do you recomend?

 

[padspcb]

video switch

Hi
I've seen some projects using simple cmos switches. they work.
with some simple circuit, an ye o'l cga controler and some ram you can also build an osd for time & channel. you can use a pic to display, switch, timer stuff etc.
there are many solutions for displaying multi channels, but deppends on cost.

 

[aNdreiBuuu]

Use M@xim video switches... worksgreat, and U'll see on m@xim page some app notes.
if U want to use simple cmos switches u'll need 3 for each channel and a Not gate one in the middle coupled to earth and the other 2 at in and out...
//a

 

[R110]

I've seen a professional video switcher manufactured by sony, called PRESELECTOR.
I my design I 've used a buffer network ( using AD826 as a video buffer) and a switch network ( using two analog switcher 74hct4051 that are controlled by microcontroller 8951 and a video amplifier for amplify the gain of the signal.
My problem is that there is not any good video buffer IC . so that I have to use AD826 because I can make the buffer network by using just 8 of them. I'm looking for a suitable circuit diagram of a video buffer

Do you have any suggestion?

By the way, thanks for your replys

 

[aNdreiBuuu]

take a look at:
h**p://para.m@xim-ic.com/compare.asp?Fam=Vid_Buff&Tree=Amps&HP=AmpComp.cfm&SORD=190&FT_190=1094&ITEMLIST=110343,110356,110360,110362,110363,110364

//a

 

[R110]

Hi
Thanks alot, it was wonderful. Now I have a new question.
I've encountered with a kind of RF noise when I was testing my system, I think this noise was because of the enviroment's radiation. How can I solve this problem?
Do you have any recomendation?

Kind regards

 

[Dragon]

Hi R110.
I used a Maxim Ic Max440 and I have similar problems of noise, and I put a 75R resistor to unused inputs and the problem was solved.

 

[R110]

I've used 75 ohm resistor, it does not solved this problem . when I test it in laboratory there is no noise, But in the main room it has problem of noisi.
Thank you very much for your attention any way.

<font size=-1>[ This Message was edited by: R110 on 2001-10-20 09:35 ]</font>