Contents
Vol.31, No.6; June 2018
SILICON
CHIP
www.siliconchip.com.au
Features & Reviews
14 AgBots – robots working on the farm of tomorrow!
You’ve seen how drones have made inroads into agriculture but there are many
different types of autonomous and robotic vehicles already making a farmer’s life
easier, more productive and requiring less labour – by David Maddison
77 Degen’s wind-up or solar-powered AM/FM/SW radio
Just in case the world goes to pot, this little radio will keep going! AM, FM, SW,
Bluetooth, voice recording . . . it’s got everything you could want – including
being powered by a solar cell, a wind-up generator or USB – by Ross Tester
80 El Cheapo Modules 17: 4GHz digital attenuator
Programmable over a range of zero to 31.5dB in 0.5dB steps, this attenuator
module can reduce signal levels in a circuit to manageable levels. And it costs
less than a couple of cups of coffee! – by Jim Rowe
Constructional Projects
24 The USB Flexitimer: accurately timed switching
If you need highly accurate switch timing – from milliseconds to many
days – the Flexitimer will do it, switching anything on or off as you decide.
Program it on-board or via your USB port – by John Clarke and Nicholas Vinen
32 Wide-range digital LC Meter: FARADS and HENRIES!
This outstanding new LC meter deserves pride of place in your test equipment
arsenal! It’s Arduino-based, cheap to build, has a digital display and there’s even
a snazzy case available for it! WOW doesn’t do it justice – by Tim Blythman
44 Switch on or off anything with a Temperature Switch
You can turn just about anything on or off if it gets too hot or too cold – and two
sets of relay changeover contacts makes it really flexible. All you need to set it
up is your multimeter – by John Clarke
64 800W (+) Uninterruptible Power Supply (UPS) Part II
It has certainly set tongues wagging: this month we show how to construct our
new highly versatile UPS. It will cost you much less than a commercial design
and you can expand it as you need – by Duraid Madina and Tim Blythman
Imagine robots that go out into
the field, sow them, weed them,
fertilise them and even harvest
them! Imagine no more: it’s
happening now – Page 14
Set the time –
from ms to
days – and
turn just
about anything on or
off as you require – Page 24
You really
need this
one on
your work
bench: an
Arduino
Digital LC
meter that looks
as brilliant as it works! – Page 32
Something getting too hot or too
cold? Control it
with our new
Temperature
Switch – it’s
extremely
versatile
– Page 44
Your Favourite Columns
58 Serviceman’s Log
Servicing “proper” stereo amplifiers is satisfying – by Dave Thompson
85 Circuit Notebook
(1) Atari Punk Console 4-16 step synthesiser/sequencer
(2) Use your phone to capture glitches on a scope
(3) Low-cost automotive ammeter
(4) PICAXE-based millisecond reaction time
(5) Servomotor tester
90 Vintage Radio
1952 Astor GP/PS Hybrid Portable – by Graham Parslow
Everything Else!
2 Editorial Viewpoint
4 Mailbag – Your Feedback
siliconchip.com.au
42 SILICON CHIP Online Shop
96 Product Showcase
97
103
104
104
Ask SILICON CHIP
Market Centre
Celebrating 30 Years
Advertising Index
Notes and Errata
Here’s our superb new 800W (+)
UPS: this month we show you how
it all goes together – Page 64
Is this the perfect “preppers”
AM/FM/SW radio:
charge it by
winding it up
– or put it out
in the sun!
– Page 77
June 2018 1
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