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.

That chip is going out of production. Supertex (http://www.supertex.com) has a
range of really cheap chips that can do the job. The HV9120 is around $1.80.
You will need a choke, or a transformer depending on the safety level.

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