Hi kinarfi,
I keep touching the heatsink and it does not seem to be getting any hotter but I will leave it overnight to be certain.
The voltage is pretty stable at exactly 5v with minimal load and only dropping to 4.85 at 2 amps load.
Strangely enough the other one I have made which has exactly the same components is a bit different in that it drops to 4.45v at 2 amps. Odd! Is there any way to tweak these switchers?
Also on the schematic 1000uF cap is used but I didn't have a suitable one at that value so I substituted a 2200uF 10v one on both my circuits, could this cause the drop to be more? I was thinking that it would be the bigger the better and also the 10v caps have better ESR than the higher voltage ones.
Al