DC 3,6V to 7.4V regulator (Stepless)

Hi

I'm not all that familiar with electronics, i know a little but i have here a little project wich i'm hoping
to find som help too in here.

1) I need to make a small voltage regulator (stepless) 3,6V to 7,4V and the supply comes from 2 Li-on
chargebel batteries on 3,7V, 1000 - 1200 mAh each, it need to be as small as possible, can it be done by just using a potentiometer in a specified resistance range, and if what range should this potentiometer have ?

2) Along with this voltageregulator, i would like to have a kind of visual measurement, that tells me how many volt the device is putting out, that could be in the best form a one digit display LED or LCD or the alternative maybe 5 LED s that when one light i turned on the regulator is at 3,6V an when all 5
is turned on its 7,4V.
Again it is important that these devices also i as small as possible

I would be very happy and thankful if anyone could help me, and even more if it would be possible to direct me to an onlineshop where i can purchase these items.

I advance many thanks

What's the current of the load?

Hi

That is one of my problems, i don't know the exact current that will flow in the system, but i can tell you that much
that the batteries are used to make a thin flat coil glow (app. ø6-8 mm), a little like a bulb in a car, but ofcourse this coil is
sitting in an open environment and isn't in a vacuum bulb with gas in so its not glowing that much.

It is not possible for me to read the Wattege of this coil, i know for sure that there is no diect data to collect there, and i don't have
the coil yet, is ordered and i think i will recieve it this week.
But one thing i know is the resistance of the coil, and that i 3,6 Ohm, can't we calculate the current from that, i will try here correct me
if i'm wrong Current = Volt / Resistanse <=> Current = 7,4/3,6 = 2,06 A and regulated down to 3,7V it gives 1,03A
I have a digital multimeter and know how to messure current, it may be possible for me to mesure how much current is running
through the coil when its activatet.

But if shuld give a shot at the current, i maybe think if i relate to the car bulb wich is about 55W, if i say that this coil uses lets say
36w the current then it will use 10A

Sorry the last to lines in the post above should have been deleted, i wrote that before i came to my knowledge that
i did know the resistance,