Analog to Digital Converter with electronic switch...

[eren uyanik]

Hello Friends,

This is my first post so first I want to say hello to everyone...

My name is Eren and I am an MSC Mechanical Engineer working at testing engineering.

Electronics is one of my hobbies but never designed my own circuits, only prepared some circuits from schematics.

It is time to step forward and solve my own problem now...

So the circuit I need has to read current from 40 different resistances.

It does not need to be continuous and high sampling rate but needs to get the current values from 40 points and index and send to computer.

I do not want to use a 40 channel analog to digital converter instead I want to use an electronic switch and a 4 channel analog to digital converter, so that I can index the channel and read the current value. So sampling rate will be very low but who needs sampling rate for constant current values anyways

Any suggestions ???

Thank you for sharing your experience and ideas.

 

[OLIVE2222]

Hello Eden,

You can use a so called multiplexer to achieve that. A cd4067, a very popular part, can do the job. It' s a 16 inputs mux, so 3 of them connected on 3 ADC channels will be ok. You can select them simultaneously (pins A,B,C &D), having 3 measurements the switch to then next channels.
Be aware that this kind of components have an internal resistance, can be impacting or not depending of your circuit.

http://www.mouser.com/ds/2/405/cd4067b-82143.pdf

Olivier