Two issues: 1) Large resistors results in large attenuation. This circuit attenuates 120VAC to ~5V for the microcontroller. 2) You would need to un-ground all of the components (USRP + PC + you) and float everything to somewhere around 60V
-----Original Message----- From: discuss-gnuradio-bounces+evan=syndetix....@gnu.org [mailto:discuss-gnuradio-bounces+evan=syndetix....@gnu.org] On Behalf Of John Ackermann N8UR Sent: Tuesday, February 21, 2012 1:45 PM To: George Nychis Cc: discuss-gnuradio Subject: Re: [Discuss-gnuradio] discussion on USRP-->Wall Socket for Power Line Comms On 2/21/2012 3:00 PM, George Nychis wrote: > Okay! So apparently there is some interest in power line communication > for GSoC. But, what we would want to do is already have a safe way of > connecting the USRP in to the wall socket for the student(s), and for > the future of GNU Radio and USRP power line communications development. > > So, as a goal of this thread I'd like to get some feedback on how we can > make this possible. Ideally, something off-the-shelf would be great, > providing the highest amount of safety for those experimenting with it. Here's a very simple approach: http://leapsecond.com/pages/ac-detect/ There was a bunch of discussion about this on the time-nuts mailing list, and some folks suggested changes for increased safety (including putting two resistors in series so that if one fails short -- which is a very unusual occurrence -- there's an extra layer of protection. But in general, with large value resistors the current is limited to a very safe level -- and it's current that kills, not voltage. John _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
