>How much current does the PIC and interface chips consume?
>Can you separate the LED and other high currents from the
>5V supply consumed by the PIC?

A past version of the project used about 10-15mA with a 78L05 from the
nominal 12V supply, but I would like to get it down if I can by using a
switcher. Normally the LEDs are used as minimal confidence indicators, so
are not very bright at all, and I expect to use high brightness ones to get
to 2-3mA per LED.

>My standard approach for these types of project is to power
>the PIC and related stuff from a small linear supply.  Most
>of my stuff needs only 5mA or so @ 5V.

yeah, this is why I referred to the 78L05, which is how I have doe it in the
past, but if I can find some reasonable way to get the 10mA at 5V to be a
lower current at the 12V, without going overboard on cost, then I would like
to try.

>The high current stuff runs from the un-regulated supply.

Oh, sure, but with a wall wart as the unregulated supply under this
scenario, I would like to stabilise the supply further out. If it is
practical to use the same regulator, then well and good.

>This works well for most of my projects but certainly not all.
>But it may be worth investigating.

This is more of an investigation to see if an existing system can be
improved in various aspects, while updating the design to make it ever more
frugal in the basic configuration.

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