>
> Someone told me a while ago that I can do without the expensive =
> transformer, diode bridge and regulator to get  5V power from a 220 - =
> 250V AC line to drive a PIC with some other components like a relay, =
> triac, leds etc.=20
>
> I remember them talk about caps and zeners..=20
>
> (I am use to the XFormer and the well known 78L05 method)
>
> Can sombody help me with a plan

Microchip has a application note on a transformless power supply. The PDF can
be found here:

http://search1.microchip.com/ie/appnote/category/pic16/91008a.pdf

Now here's my stearn warning in all caps:

NOTE THAT THIS DESIGN AS WITH ALL TRANSFORMERLESS DESIGNS HAVE A DIRECT
CONNECTION TO THE HOT AC LINE. CARELESS HANDLING OF SUCH A CIRCUIT CAN RESULT
IN SERIOUS INJURY OR DEATH! TREAT ALL PARTS OF THE CIRCUIT AND ANY DEVICES
CONNECTED TO IT AS HIGH VOLTAGE AC!

Note you'll have to pay attention to the reactance of the cap because the
voltage is doubled.

Good Luck.

BAJ

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