Well... It is possible to design these things so that they are quiet. I have put many designs through FCC and CE certifications, with emissions so low that they are asking me "Is that thing on?" :) Two layer boards, no expensive shielding or suppression. It takes careful design of the PCB and component selection. But you're right, there's a bunch of crap out there. I tested one that ran 30dB over the FCC class A limit from 0.1 to 400+ MHz.
________________________________________ From: [email protected] [[email protected]] On Behalf Of Alan Melia [[email protected]] Sent: Monday, June 27, 2011 2:28 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Transformers At the risk of incurring John's wrath ......:-)) The trouble with the so-called green switch-mode "transformers" is they pollute !! .............the radio spectrum!! We still have LF BC services in Europe and an LF amateur band.The noise floor has risen by nearly 20dB in the past 10 years, due to badly designed equipment, and/or badly policed EMC regs. Iron core transformers didn't give these problems. It also affects many radio clock syncs from MSF on 60kHz (there I managed to get an on-topic comment in :-)) ) Alan G3NYK ----- Original Message ----- From: "Chris Albertson" <[email protected]> To: <[email protected]>; "Discussion of precise time and frequency measurement" <[email protected]> Sent: Monday, June 27, 2011 9:02 PM Subject: Re: [time-nuts] Transformers > On Mon, Jun 27, 2011 at 12:18 PM, J. Forster <[email protected]> wrote: > > One of the big networks ran a program on "being green" a couple of years > > ago and suggested that the "energy crisis" could be solved by unplugging > > iPod chargers. > > In the US "Standby Power" is about 5% of total. But standby includes > things like instant on TV sets and computers in sleep mode not just > iPod and cell phone chargers. So if you actually unplugged devices > not in use the most we'd save is 5%. That's a lot but not nearly > enough to solve the world's energy problems. But 5% is nothing to > ignore. It is exactly the same as taking one house in 20 completely > off the grid. > > Getting back to iPods. Technology can help. Apple's latest battery > charger uses 30 milliwatts in standby (after the batteries are > charged) while the industry average is 10 times that much at about > 300 mw. The trouble is that these new chargers are complex and > cost more to make. > -- > > Chris Albertson > Redondo Beach, California > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
