nikhil arora said:
I donot know whether it is Rf choke but it is like a 1/2W resistor with color band markings. I donot know it power handling capacity.
Like Nigel has said, this is an rf choke ... a "power inductor" is usually wound on a torrid or bobbin core, and is larger than an rf choke ... here are some pictures (mainly surface mount)
https://images.google.com/images?q=power+inductor ... you can see a power inductor I wound myself in
this picture ... it's the green torrid with white wire wrapped around it
i am using IRF540 and a 2200uF electrolytic capcitor.
The IRF540 is a high voltage medium current transistor, rated for between 80 to 100 volts ... and as such, requires substantial gate drive Vgs of
at least 20v ... most likely your smps controller is not able to drive the switch fully on. You need a "logic level" mosfet, something with a much lowr Vgs requirement ... IRLR, IRLU, IRL, etc... these are all logic level parts compatible transistors, and don't take 20 volts on the gate, instead they generally take under 10, some as low as 1.8
For the output stage, use a lot of smaller caps in parallel instead of one big cap, this will help to reduce your ESR
the input is from battery 6V,4.2Ah and i have connected 1000uF at input.
that sounds fine, again, use smaller caps in larger numbers, try something like four 100uf in parallel