I am wondering if a resistor in series to power supply V+ make a practical current source or not ?

 

I am wondering if a resistor in series to power supply V+ make a practical current source or not ?

Yes. A current source is simply a voltage with infinite output impedance.

 

I am wondering if a resistor in series to power supply V+ make a practical current source or not?

Yes. No. Maybe. It all depends on what you mean by "practical current source." If you'd give us more information on what you are trying to do, and what constitutes "practical" for your purposes, then perhaps we can give you an answer that makes some sense.

 

I want to feed 1 mA current to temperature sensor PT1000.

 

I want to feed 1 mA current to temperature sensor PT1000.

If that's the case, then you need a precision current source; simply putting a resistor in series with the power supply voltage almost certainly WILL NOT deliver adequate accuracy and stability.

Here are some links to information that may help you:

Precision Interface for RTDs
Solutions Search-- Resistance Thermal Device (RTD)
Precision Temperature Sensing with RTD Circuits
Images for "constant current source for RTD"