Hi all,
I am driving 10 relays of 5v operated, with the microcontroller,and uC also operates o the 5V spply . So single 5V supply is to be used for both. Now say all 10 relays will drive simoultaneously then current spike will generate and it may appear on the microcontroller syppy too. So to protect uC i am planning to use and inductor in series in between them . So that spike will not appear at the controller input pin . So please suggest that which value of inductor should be used in this case?

Baban

Check the attached pdf file for inductor calculation.

also make sure you have diodes across the relay coil.
inductor_cap_esd_design_in_switch_regulator.pdf