Harold Hallikainen wrote:

>We currently have several products running off an unregulated external
>12VDC power supply (wall wart). Inside our product, we run through a
>1N4001 for reverse polarity protection, then 1n LM7805 to regulate to +5V
>(to run the PIC!). Upcoming California Energy Commission regulations
>outlaw these external power supplies (due to lack of efficiency and
>standby power). We could replace these with 12V regulated switchers, but
>that is pretty inefficient. What I'd like to do is replace them with
>external 5V switchers, yet continue to allow the use of the old power
>supplies. It would be great if there were an LDO equivalent of the TO-200
>LM7805 with reverse polarity protection (so I could get rid of the diode
>and its drop). Anyone aware of a drop-in replacement?
>
>THANKS!
>
>Harold
>
>
>  
>
We switched over to the LM2940 a long time ago.  The dropout is .5v and 
has built in reverse battery protection.

Bill
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