>     Somewhere, sometime, a long time ago, at a job far, far away an ad for
>     a single IC which would convert line voltage to a low current +5V
>     supply with no external components, so it wasn't a buck converter
>     type.  Does anyone know who makes these parts and what the part number
>     is?
>
>     Scott Fink

The Harris HV1205 and HV2405 use a small number of external parts. If the
number of milliamps you need is in the single digits, a rectifier, series
metal-oxide power resistor, and filter cap represent a minimalist solution.
Note that if this powers or is connected to any kind of user interface,
there are very serious safety issues to be considered.

Reg Neale