Hi Robert, Thank you for the reply. Your question is an interesting one.
We usually sit in the reverb chamber during immunity testing, and observe product and image quality for essential performance. Lately, as a general practice I have been bring a wide band receiver with me during testing (antenna off) for monitoring. I have seen odd things happen, like the power amp going into some of "odd mode" (with no rf applied,) generating a wide-band hissing noise, (forward power meter reading zero watts.) The solution was power cycling the power amp... The GFI tripping has been observed by another test lab using different signal generators & amps. My testing is showing quite a bit of variability in GFI sample to sample. (I got home last night at 1:45 am.) Regards, Dave Garnier From: Robert A. Macy [mailto:m...@california.com] Sent: Saturday, January 14, 2006 1:54 PM To: Garnier, David S (GE Healthcare) Cc: emc-p...@ieee.org Subject: Re: RFI breakers being tripped during RF immunity testing David, Did you check the obvious, that a jump in amplitude occurs when the modulation is switched on? A wild transient? Knowing how GFI are made, I'm surprised this has not been a problem noted here before. - Robert - On Fri, 13 Jan 2006 18:26:26 -0600 "Garnier, David S (GE Healthcare)" <david.garn...@med.ge.com> wrote: > Hello everyone, > > I have been testing a product that has a ground fault interrupter > (GFI) circuit breaker in it, I am wondering if anyone else has had > similar experiences with products containing GFI circuit breakers? > > During RF immunity testing, at 5 V/m to 10 V/m level, within a > frequency range of 800-900 MHz, the GFI breaker immediately trips when > AM modulation is switched on. (I can think of a number of mechanisms > for this behavior, the least of which are, dissimilar metal junctions > in the neutral panel sense wire.) > > There are a few manufactures that make GFI IC's, such as Fair-Child > and National Semiconductor, both which use a liberal amount of diodes > (on the die) to allow powering the IC directly off the AC line. > (Don't need no stinking power transformer in these > designs!) ;-) > > These GFI's aren't quite as interesting as the new ARC detection > breakers... Either way, this has been an interesting experience. > > Thanks to all that reply. > > Dave Garnier > - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to emc-p...@ieee.org Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@ptcnh.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: emc-p...@daveheald.com All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
