Re: Transformerless PSU using a zener/transil to drop voltage

["CWatters" <colin.watters@xxxxxxxxxxxxxxxxxxxxxxxxx>]

<andrea@xxxxxxxxxxxxxxxx> wrote in message
news:465c4e56$0$37196$4fafbaef@xxxxxxxxxxxxxxxxxxxxxx
>
> Hi all,
>
> For a hobby home automation system I need to make a very small, non
> isolated, direct-mains power supply unit regulated via a 7812 IC or such.
> Thus it has to be transformer-less, and since I need to draw something
> like 100mA, even a capacitor (of the kind that do not explode on mains!)
> would be too big. I have two ideas so far to lower the voltage to a range
> acceptable by the 7812:

I'd advise you not to try this. Too dangerous unless you now what you are
doing. Wall warts are as big as they are for a reason.

If you are aware of the risks consider buying an AC-DC converter module
perhaps..

http://www.cdiweb.com/ewave/435