If you can put that resistor circuit as the gain impedance in a opamp,
then you can convert the resistance into voltage.

Francisco



Omer YALHI wrote:

>Hi,
>
>I have the following resistors setup, as the magnet around them moves, B1
>and B2 reed switches close or open, and thus the total resistance changes
>(B3 is for sensing strong magnets and short circuits the system).  I need to
>find out different states of the 3 reed switches.  I am able to do this by
>connecting a capacitor and timing the charge time it takes, thus I can
>differentiate different states.  I do this every 500ms.  I had to use a
>special capacitor not to be effected by the temprature changes.
>
>I am wondering if I can differentiate the switch states by analog reading?
>The current changes but not the voltage; how would I do this?  Note that
>power consumption is extremely important.  With current setup I am down to
>10uA (averaged).
>
>Please let me know if this is a stupid question also.
>
>Thanks in advance.
>
>Omer
>
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