Post by thread:Analog Multiplexer / Switch

Hi All, Looking for a way to measure current in an automobile application. First thoughts were to insert a shunt into the circuit with a very low, but known resistance and measure the drop across the shunt. Assuming a drop in the 50-100mV range, what would be a good way to meausre that? I'd also like to be able to measure the same at about 10-12 points. Could some sort of analog switch be used to select a voltage source? My thoughts were to use an analog switch (isn't the 4066 along these lines?) that could be used to select the voltage source to be measured, but then I recall that some A/D chips also support multiple channels. Would it be better to have multiple 4 channel A/D devices rather than a single A/D device with a 12 way switch? All input greatly appreciated. -- Mitch

I would think it better to have multiple micros out there, and have them all talk to one another on a bus such as RS-485. Andy "Mitchell D. Miller" <spam_OUTmdmiller2TakeThisOuTHOME.COM> on 06/02/2000 01:20:10 PM Please respond to pic microcontroller discussion list <.....PICLISTKILLspam@spam@MITVMA.MIT.EDU> To: PICLISTKILLspamMITVMA.MIT.EDU cc: (bcc: Andrew Kunz/TDI_NOTES) Subject: Analog Multiplexer / Switch Hi All, Looking for a way to measure current in an automobile application. First thoughts were to insert a shunt into the circuit with a very low, but known resistance and measure the drop across the shunt. Assuming a drop in the 50-100mV range, what would be a good way to meausre that? I'd also like to be able to measure the same at about 10-12 points. Could some sort of analog switch be used to select a voltage source? My thoughts were to use an analog switch (isn't the 4066 along these lines?) that could be used to select the voltage source to be measured, but then I recall that some A/D chips also support multiple channels. Would it be better to have multiple 4 channel A/D devices rather than a single A/D device with a 12 way switch? All input greatly appreciated. -- Mitch