LM1881 sync stripper power and grounding questions

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BazookaBen
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LM1881 sync stripper power and grounding questions

Post by BazookaBen »

So I want to make a custom RCA to VGA adapter with a LM1881 chip to use with my Extron RGB. Since I'm not hacking the connector for any game cables, can I can use 5v from a USB cell phone charger? Also, where should I connect the ground for the cell phone charger, Pin 4 or 6?

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For background on what I'm doing: I have one of those general purpose AV cables that has component and composite connectors, and connections for the Wii, 360, and PS. With this I can play 15hz RGB on my PVM. But for games that I need to scale from 480i to 240p with the Extron, I'll need the LM1881 on the composite line. It would be a lot easier for me to make a seperate adapter instead figuring out a way to get 5V from every cable (I don't really want to buy a bunch of SCART cables just for this project).
RGB0b
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Re: LM1881 sync stripper power and grounding questions

Post by RGB0b »

Pin 4:

http://www.retrorgb.com/syncstripperdiy.html

I've never tried using 5v from USB/phone charger, but I assume it it'll work. I'd just suggest using a lower-amp charger, such as using an iPhone charger, not an iPad one.
Last edited by RGB0b on Thu Oct 09, 2014 8:07 pm, edited 1 time in total.
22point8
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Re: LM1881 sync stripper power and grounding questions

Post by 22point8 »

I've made one powered by USB 5v to a mobile phone charger. With pin 8 alone PS1/PS2/XBOX didn't sync, with USB alone no sync, with both pin 8 and the USB I got those console to work (never had any trouble with wii/megadrive 1).

I followed mmmonkeys guide and attached 5v and ground to the points on the circuit board, along with a ground going to the scart and another to the DSUB connector, and 5v from pin 8 to to board.
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BazookaBen
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Location: North Carolina

Re: LM1881 sync stripper power and grounding questions

Post by BazookaBen »

Thanks guys. Didn't see that RetroRGB guide before, it shoudl be helpful. Hope it works out and the grounds from seperate sources don't cause a problem.
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BazookaBen
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Location: North Carolina

Re: LM1881 sync stripper power and grounding questions

Post by BazookaBen »

Update: Works fine.

You can even just use the USB port from the Wii to power it.
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