On Fri, 5 Jun 2015, g wrote: > On 06/05/2015 04:16 PM, Michael Hennebry wrote: >> On Fri, 5 Jun 2015, g wrote: > <<>> > >> As I understand it, GFI sums the currents going into each prong. >> If the sum is not close enough to zero, it breaks the circuit. > > not quite. see; > > https://en.wikipedia.org/wiki/Residual-current_device I should have written "into two prongs". I have a "headset" that works now. I'd forgotten that I bought it and still do not remember why. Apperently it's a "universal all-in-one stereo earset". Despite the name, it does have a usable miocrophone. -- Michael hennebry at web.cs.ndsu.NoDak.edu "SCSI is NOT magic. There are *fundamental technical reasons* why it is necessary to sacrifice a young goat to your SCSI chain now and then." -- John Woods