[time-nuts] Clocking a PIC16F628A from a Rubidium Standard

[Kevin Rosenberg]

On Nov 26, 2011, at 10:36 AM, Don Latham wrote:
> Come on, folks. never hook anything directly to the power line. The
> source is just too stiff. Use an opto. I used fiber optic isolation with
> my big DC power supply.

I don't disagree on isolation. I will say that Atmel's (and presumably 
Microchip's) app notes don't give much information on safe construction.

Tom wrote a nice page showing a safer-than-average construction for sipping
AC main voltage through high resistance:

   http://www.leapsecond.com/pages/ac-detect/

Kevin