According to your text, it looks like your circuit needs around 20mA... small switching power supplies can fit inside a small wall wart plastic case. I may be redundant, but why not using a regular wall wart 110/220 - 5Vdc - 50mA, small and simple. Wagner. John Perkinton wrote: > > I need a space saving power supply for powering a pic chip and very little > other components from the mains directly which will work in any country. > I've been looking at the Harris Semiconductor HV-2405E which RS Components > can supply, but due to the size on inline power resistor (5W) the heat > disapation is very high, no use for plastic enclosures. Has anyone any other > ideas, or should I just use a 240V-12V transormer, a bridge rectifier, a 35V > 470uF cap, and a 7805. This seems to work well on both 240V and 110V, but is > rather large, or does anyone know of a supplier of ultra small transformers.