Thanks BrianT and mackrackit.
It still seems counter-intuitive to me, but it means that I can have accurate battery readings with less wasted current, so I'm happy.
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Thanks BrianT and mackrackit.
It still seems counter-intuitive to me, but it means that I can have accurate battery readings with less wasted current, so I'm happy.
Last edited by Kamikaze47; - 11th August 2010 at 16:10.
"I think fish is nice, but then I think that rain is wet, so who am I to judge?" - Douglas Adams
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An easy way to understand it without going into thevenin equivalent circuits.
Consider the plus side and the 0 (ground) side of the power source as low impedance sources. In an ideal power source the + side and 0 side will each be zero ohms impedance and as such the PIC sees both the high side resistor and low side resistor going to to zero ohm sources making the value of the resistors parallel.
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Nice explanation!Consider the plus side and the 0 (ground) side of the power source as low impedance sources. In an ideal power source the + side and 0 side will each be zero ohms impedance and as such the PIC sees both the high side resistor and low side resistor going to to zero ohm sources making the value of the resistors parallel.
Dave
Always wear safety glasses while programming.
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...or put a largish capacitor accross the pic pin and use the ESR of the cap as your source impedance!
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