Circuit Project Electronic

This simple adapter can be used to convert Y/C video (S-video) to a composite video. This adapter is useful in cases where your video output device has only S-video output but your signal source accepts only composite video input. This circuit works with both PAL and NTSC video standards.

Y-ground——————+
+———- RCA/composite ground
C-ground——————+

Y————————-+
+——— RCA/composite video
C————||———–+
470pF

This circuit can be quite easily build inside a the S-video connector case if a physically small size 470 pF (ceramic) capacitor is used. Larger capacitor values will also work, but cause picture to become “softer”. The voltage rating of capacitor can be 10V or more.

This circuit works in practice quite well even though the circuit operation is not ideal. This means that impedances and signal levels not matched exactly right, but near enough to work accetably. The picture quality you get from this circuit is is good, but not as good as with best possible composite video output circuitry.

Here is the pinout of the S-video connector shown from the end with the FEMALE PINS (picture is a view on the equipment back/front panel):

1 Y ground
2 C ground
3 Y (luminance+sync)
4 C (crominance)

What if my PC graphics card has a 7-pin S-video connector instead of 4-pin ?

Related Links
More Circuit TV
More Circuit Video and TV

Read more source:
http://www.uashem.com/pageid-482.html
Thank you.