Didier Juges wrote: > Be careful that if you do not isolate the A/D converter analog circuits from > the USB ground, you may create all sorts of nasty ground loops with the > computer. When dealing with power supplies, it's always best to be isolated. > I do not know enough about USB to know if it can be simply isolated with > opto couplers, but I know that RS-232 is very easy to isolate. So if your > data rate is not great, a serial solution would be easier to implement (even > if you go through a serial-USB adapter for convenience on the PC side) > > Linear Technology, Analog Devices and Maxim have hot side current sense > chips that are accurate and cheap. They are specialized diff amps, not > regular IA. LT for instance has one that has less than 50uV offset (LT1787, > see Design Note 227)
That's a really good point. Thanks for reminding me of the potential ground loop problems. John _______________________________________________ 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.
