David Lord <sn...@lordynet.org> wrote: > David Lord wrote: >> David J Taylor wrote: >>> OT: GPS18x LVC failure >>> >>> My GPS18x LVC stopped working a couple of days ago. There appears to >>> +5V going into the unit, and the serial output is stuck around -5V >>> with no signs of data on the 'scope. Garmin have accepted the unit > > I'm guessing you hit (-) rather than (+), otherwise something > odd as with my unit the supplies are +5V and 0V, output spec > is 0V to +5V. Where was the -5V generated? If the -5V was real > then it would indicate some sort of internal fault.
No, it is normal for an RS232 output to output positive and negative voltages. Where was the -5V generated? Internal to the device. Using a DC-to-DC convertor, often a charge pump using some diodes and capacitors. This is not a fault. _______________________________________________ questions mailing list questions@lists.ntp.org https://lists.ntp.org/mailman/listinfo/questions