[arm-allstar] power up

[David McGough]

Most data sheets recommend a value of 1uF to 10uF on the INPUT side of the
LM78xx regulators. This needs to be a good quality capacitor (low ESR),
just as Bob mentioned. I typically use a 10uF, 50V tantalum cap on the
input--I've got a big bag of them!

73, David KB4FXC


On Fri, 5 Dec 2014, Andrew Sylthe wrote:

> I typically use a 22 picofarad on the input, and a 10 microfarad on the
> output of the 7805. Is that not the correct way to do things?
> 
> Thanks!
> On Dec 5, 2014 8:29 PM, "Bob" <Bob at fot.com.au> wrote:
> 
> > Hi All
> > When using a 7805 Regulator male sure you put  low ESR capacitors
> > (10microfarad) right on the input and output terminals to ensure it doesn't
> > oscillate
> >
> > Bob
> >
> >
> >
> > On 6 December 2014 10:12:45 "Mark Herson, N2MH" <n2mh at n2mh.net> wrote:
> >
> >  I'm running a pair of BBB's each from its own 7805 voltage regulator with
> >> no problems. One BBB is an Element14 card (which is the Chinese version,
> >> problably what comes from MicroCenter) and the other is the USA version
> >> from Beaglebone.org. No startup problems have been noted at all.
> >>
> >> Of course, when using a 7805 voltage regulator, one must use a good
> >> heatsink. I measured the current draw at 350 mA or so. With an 8 volt
> >> voltage drop, that comes out to about 2.5 to 3 watts that the voltage
> >> regulator must dissapate. This requires a pretty good heatsink.
> >>
> >> 73, Mark, N2MH
> >>
> >> > To: arm-allstar at hamvoip.org
> >> > From: ke2n at cs.com
> >> > Date: Thu, 4 Dec 2014 06:57:55 -0500
> >> > Subject: [arm-allstar] power up
> >> >
> >> >
> >> > Any one else have a BBB Rev C power up problem?
> >> >
> >> >
> >> >
> >> >
> >> > http://elinux.org/Beagleboard:BeagleBoneBlack#Improper_
> >> Power_Down....All_
> >> > Rev
> >> > isions
> >> >
> >> >
> >> >
> >> > I got two units from Micro Center and they both have a really hard time
> >> > getting started.
> >> >
> >> > One unit I got from Spark Fun works fine every time.
> >> >
> >> >
> >> >
> >> >
> >> > Ken
> >>
> >>
> >> _______________________________________________
> >>
> >> arm-allstar mailing list
> >> arm-allstar at hamvoip.org
> >> http://lists.hamvoip.org/cgi-bin/mailman/listinfo/arm-allstar
> >>
> >> Visit the BBB web page - http://www.crompton.com/hamradio/
> >> BeagleBoneBlackAllstar/
> >>
> >
> >
> >
> > _______________________________________________
> >
> > arm-allstar mailing list
> > arm-allstar at hamvoip.org
> > http://lists.hamvoip.org/cgi-bin/mailman/listinfo/arm-allstar
> >
> > Visit the BBB web page - http://www.crompton.com/hamradio/
> > BeagleBoneBlackAllstar/
> >
>