SILICON CHIP
Publisher & Editor-In-Chief
Leo Simpson, B.Bus.
Editor
Greg Swain, B.Sc.(Hons .)
Technical Staff
John Clarke, B.E.(Elec.)
Robert Flynn
Advertising Manager
Paul Buchtmann (02) 982 9553
Regular Contributors
Bryan Maher, M.E . B.Sc.
Jim Yalden, VK2YGY
Garry Cratt, VK2YBX
Jim Lawler, MTETIA
John Hill
Jennifer Bonnitcha, B.A.
Bob Young
Photography
Bob Donaldson
Editorial Advisory Panel
Philip Watson, MIREE, VK2ZPW
Norman Marks
Steve Payor, B.Sc., B.E.
SILICON CHIP is published 1 2 times
a year by Silicon Chip Publications Pty Ltd. All material
copyright (c). No part of the contents of this publication may be
reproduced without prior written
consent of the publisher. Kitset
suppliers may not photostat articles without written permission
of the publisher.
Typesetting/makeup: Magazine
Printers Pty Ltd, Rozelle , NSW
2039.
Printing: Macquarie Publications
Ltd, Dubbo, NSW 2830.
Distribution: Network Distribution
Company.
Subscription rates: currently
$42 per year (12 issues) inside
Australia. For overseas rates,
refer to the subscription page in
this issue.
Liability: Devices or circuits
described in SILICON CHIP may be
covered by patents. SILICON CHIP
disclaims any liability for the infringement of such patents by the
manufacturing or selling of any
such equipment.
Address all mail to: Silicon Chip
Publications Pty Ltd, PO Box
139 , Collaroy Beach , NSW
2097 . Phone (02) 982 3935 .
Fax (02) 982 9553.
ISSN 1030-2662
2
SILICON CHIP
PUBUSHER'S LETTER
Power lines and
the environment:
a touchy subject
During the month of March, the ABC program "Countrywide" had a
segment about a rural community in New South Wales protesting
about high voltage power lines crossing their land. Now this subject
has been discussed to some extent in the June 1989 issue of SILICON
CHIP and my attitude in the past has been to dismiss most claims about
the effects of power lines on human beings. But the power lines in the
Countrywide program were of a totally different magnitude and I
couldn't help feeling some sympathy for the protesters.
Forget the whacky claims made about power lines in the past which
have generally been concerned with voltages of up to lOOkV AC or
more. It is difficult to conceive that these have any biological effects or
if they do, they must be very small. But what if the voltage on the
power lines is 600,000 volts AC and the current is thousands of amps?
What if the voltage gradient is high enough to light up fluorescent
lamp tubes carried by people walking under those power lines? What
if you are a farmer cultivating crops every day with those power lines
passing overhead? Wouldn't you feel just a trifle edgy? I know I would.
Apart from the dangers, real, imagined or unquantified, who really
wants those monstrous gantries marching across the landscape,
especially if you own the land? And I can think of a third reason why
the farmers would not want those extremely high voltage power lines
close by.
Think of the effect they could have on TV and radio reception. Corona discharge at 600,000 volts AC is a dandy of a problem. That's why
you see very high voltage cables hanging in pairs or groups of three or
four - it simulates a much larger cable diameter and thereby cuts
down corona discharge.
No, the more I think about it, the more I am sympathetic to the
farmers. We all need electrical energy but maybe the real cost of
transmitting it at such extreme voltages is just too high. Maybe the
time has come when such high voltages are no longer politically acceptable. Maybe we should accept the slightly higher losses of transmitting electrical energy at lower voltages and then put the power lines
underground. It is not cheap or easy but it has been done before.
In the future there is no doubt that all large engineering projects
will be subjected to much greater scrutiny with regard to their effect
on the environment, on people's health and well-being, and on safety.
High voltage transmission lines certainly come into this category and
if they are subject to much closer questioning, then that is probably a
good thing.
Leo Simpson
