is there dc current source ,i searched it for along timebut i couldn’t find it
If you have a model number for the part try a google search on “fritzing part part_number” but it looks like that mostly finds the various current sensor modules.
There are various regulator(s) in the parts bin. Not sure what kind of DC power you are looking for… Can you elaborate?
A current source is usually an inverted voltage regulator, it varies the voltage to keep the output current constant instead of the other way around.