Potentiometer connection

[Alecs26]

Hi,

I have a stupid question about the connection of a potentiometer on a DAQ card.

The potentiometer schematic is given here:

http://cjoint.com/?fAr4hPu3td

The voltage Vcc and the ground is given by the card. The card also measure the voltage Vo with an analog input. I am afraid that the Vo voltage reading by the card will short-circuit the resistance connected to the ground and that all the current will pass through the card. If it is not the case, why it does not happen ?

Thank you very much,

Jack Rander

[Alecs26]

Here is the circuit, without the web link...

[AnalogKid2DigitalMan]

Which DAQ card are you using? DAQ cards typically have very high input impedances, on the order of 100's of Megohms up to 10's of Gigohms. Except for the USB-600x serries which is a meager 144Kohms.

Thus, the DAQ will shunt very little current from the source.

-AK2DM