Chwiliodd Google a chael hyd i'r isod. Yn anffodus, doedd dim gair am darddiad y term.
 

Brown-out .... What is it?

Brown-out is a condition of lower than normal power line voltage being supplied by your local utility or generating equipment. This condition may be short term (minutes to hours) or long term (1/2 day or more). A power line voltage reduction of 8 - 12% is usually considered a Brown-out.

Berwyn
----- Original Message -----
From: [log in to unmask] href="mailto:[log in to unmask]">Geraint Lovgreen
To: [log in to unmask] href="mailto:[log in to unmask]">Berwyn Prys Jones
Sent: Wednesday, February 05, 2003 3:12 PM
Subject: "brown-outs"

sgen i ddim syniad be ydi "brown out" - rhyw fath o ddiffyg trydanol a ddigwyddodd yn America yn 2001???