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Low dropout 12V voltage reg


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#1 Wavess

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Posted 16 August 2011 - 07:31 AM

Hi, I´m using this pcb for my okto 12V fpv gear, I have a 4S main battery to power everything there

https://www.mikrocontroller.com/index.php?main_page=product_info&cPath=65&products_id=576&zenid=6c04586999fb3fbf977f51b8f416e313

I didn´t notice since last few days that while flying fpv, I lost fpv video. The problem is that the suggested Volt regcuts feeding to 12V at about 13.5V, very dangerous to use this voltage regulator for fpv.

I was thinking on using Linear LM 2940 12V low dropout, since it will never quit feeding the fpv gear, below a certain voltage in, it will output the same volts than it has in.

Do you know a better option than this reg (non linear more efficient) to use for this application?

Edited by Wavess, 16 August 2011 - 07:33 AM.

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#2 Kilrah

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Posted 16 August 2011 - 01:54 PM

4s->12V is rather tricky as the end voltage is identical. I think I'd go with a linear LDO too. 15->12 at nominal charge level isn't all that bad in terms of loss.
Otherwise you have the Anyvolt Micro that will take anything and turn it into anything (it will still provide 12V even if main battery voltage becomes lower than that), but watch out for the 500mA limit on both input and output.

I just use a separate 3s pack for video.

Edited by Kilrah, 16 August 2011 - 01:55 PM.


#3 Wavess

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Posted 17 August 2011 - 05:25 AM

ok thanks a lot kilrah, IŽd go with lm 2940 12V 1A route.
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