Geoff,
            What Blair is saying, and I agree,  the 470uF caps on the 
outputs of the
voltage regulators are way too high.  As he said  the norm.is ~ 10uF
and keep the 0.1uF caps in parallel with them

cheers
Dave



>Hello Blair,
>
>I always put the largest capacitors on the input side of the regulators,
>This way when power is cut and the voltage dies, the input should always 
>be a higher
>voltage than the output so i do not worry about loss or upsets
>to power. I have not yet in many years lost an Opamp
>to lightning so being worried about RFI like always
>i do not want any diodes near the input.
>Because you use caps like this should have fuses
>but since these wall converters are protected internally
>(so i understand) I do not worry about shorts.
>caps have a nasty tendency to short when they go bad.


>----- Original Message ----- From: "Blair lade" 
>To: 
>Sent: Tuesday, July 12, 2011 2:24 PM
>Subject: RE: Noise
>
>Geoff,
>
>SNIP
>
>A note about power supplies, the 470ufd caps after the regulators are 
>probably a bit big, National Semiconductor suggest around 10ufd with 
>0.1ufds in parallel and you really should have reverse diodes across the 
>regulators with capacitors this size (see National Semiconductor's 
>application notes for the reasons).
>
>Bypass every chip and every board with 0.1ufds on each rail ( to the local 
>board ground) and typically 1 * 10ufd on each rail to ground on each board 
>if the supply leads are greater than about 6 inches.
>
>blair

__________________________________________________________

Public Seismic Network Mailing List (PSNLIST)

To leave this list email PSNLIST-REQUEST@.............. with 
the body of the message (first line only): unsubscribe
See http://www.seismicnet.com/maillist.html for more information.