Re: [N8VEM-S100:3951] Re: Power distribution across an S100 Board and voltage issues with TO-3 Regulators..

[Rob Doyle <radi...@gmail.com>]

On 6/4/2014 8:54 AM, John Monahan wrote:
> I agree with Tom, In general I never (fall for) cheap Chinese chips on
> eBay. But I have to say, UTSource seems to be an exception.  I’ve gotten
> probably about 6 packages from them over the years. Not yet,
> V-regulators, but in every case the chips were 100% fine, and on the
> surface definitely appeared to be the genuine article. Some (video
> chips)were  in their factory packages.
>
> It seem like there is a flood of 323k knockoff’s out there.    I have
> actually been using 78H05’s   These are 5V, 5A regulators. Yes I know
> overkill for our boards. But I happen to have an old stock of them
> here.  Perhaps we should search around for these.
>
> I like Ian’s idea of checking out used parts stores. I have not done
> that in a while. I think I going to drop by a local one here ,
> http://www.weirdstuff.com/ for anybody that lives in the bay Area.
>
> John

I think a far better answer would be to start including a switching
power supply option (in addition to the LM323K) when designing new
boards. A builder could stuff the board either way. Something like:

http://www.digikey.com/product-detail/en/LM2576T-5.0%2FNOPB/LM2576T-5.0%2FNOPB-ND/212636

http://www.ti.com/lit/ds/symlink/lm2576hv.pdf

At $2.83, it saves money and heat.

We could probably design a little tiny circuit board that could adapt
the LM323K footprint to this switching power supply design for retrofit
uses.

Rob.