[R-390] AC Line Monitoring Musings

[Drew Papanek]

John (JLAP) wrote:

  " Who has, if I may ask, a permanent and effective mon..
   system to moniter line voltage and current..Is it
   common in use, and how could it most simply be done,
   to still supply useful info..?"

Most such systems nowadays are PC based with a plug-in card.  You may not 
care for the half a kilobuck price tag for card and software, however (at 
least for the systems I've seen).

One could easily assemble a voltage monitoring system using an RS-232 
computer-controllable DVM (about $60 from RadioShack, more from other 
sources).  The DVM connects via a standard cable to a PC's serial port and 
includes software for the PC.  I don't know if the software performs 
periodic data logging.  (Perhaps a job for a little QBasic code and that old 
386 you've got sitting around collecting dust.)

For those truly fanatical about power quality, a UPS or power conditioner 
(intended for PC systems) would serve well.    The better units charge an 
internal battery continuously from AC input power and deliver AC output from 
an internal inverter continuously powered by the battery so the AC output is 
essentially unaffected by line input variations.

Of course, all that hardware generates more RF hash & trash to interfere 
with listening...

Drew

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