thank you to everyone.  I just ordered a max233A...

Jake Anderson wrote:
> 2xAA and another chip wouldnt fit in the box ;->
>
> -----Original Message-----
> From: pic microcontroller discussion list
> [mailto:PICLIST@MITVMA.MIT.EDU]On Behalf Of Jinx
> Sent: Saturday, April 17, 2004 10:35 AM
> To: PICLIST@MITVMA.MIT.EDU
> Subject: Re: [EE:]TTL to/ From rs232 for 16F628 circuit
>
>
>
>>serial in side) and perhaps provision for external power. as it is
>>though i am in the 10s of hours of run time off a single 9v battery
>
>
> Silicon Chip recently had a project for replacing a 9V with 2xAA
> rechargeables
>
> http://www.siliconchip.com.au/cms/A_100886/article.html
>
> by using the TL499A. I've a few black boxes that use either 6xAA
> or 1x9 that I'm looking at upgrading, particularly those that require
> more than a few mA for extended periods (because of the Iq of
> the circuit)
>
> Full article not online yet but I have a scan of the circuit here
>
> http://home.clear.net.nz/pages/joecolquitt/tl499a.html
>
> Basically the application diagram from the pdf with practical values
>
> The 47uH inductor is 30 turns of 0.63mm enamelled wire (about
> 700mm total) on a Neosid 14.8mm powdered iron core (Neosid
> part number 17-732-22)
>
> TL499A info here
>
> http://focus.ti.com/docs/prod/folders/print/tl499a.html
>
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