rad0 wrote:
> I want to put a little pic circuit board on an electrically actuated
> ball valve.
>
> First I thought I would use 12vdc, and use a hefty wall wart.  But
> here you end
> up needing upto 3 or 4 amps.  And this I don't quite see how you
> could do on a circuit board.  Yes/no ??

Sure, just use wider traces.  If this is a one-off, you can manually solder
wire accross specific tracks.

> I would like to have something that I can plug into the wall that will
> give me 110 vac for the valve and 5vdc for my pic.

There are many many power supplies that can give you 5V for a PIC from
110VAC.  Tap off the input of the power supply to get the 100VAC directly.

> Say I want to build this from scratch.  I will need a transformer and
> then rectify the stepped down ac into dc.

That's one way.

> (Or can you just buy something like this in one package?

There are a huge variety of off the shelf power supplies available.  Look at
the Jameco catalog for starters.

You need more information to decide the best solution:

Is this a one-off or a volume product?  If volume, how many, what lifetime?

What is the total maximum current draw you need at 5V?

Does the circuit need to be isolated from the AC line?

How does the PIC know when to turn the valve on and off?


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