Coming up in Silicon Chip
Underground Mapping, Pipe Inspection and Leak Finding
Dr David Maddison explains the numerous techniques and devices which can
be used to find wires, pipes and other structures underground. In some cases, it
is possible to build a complete map of everything near the surface. This is critical
when digging in urban or suburban areas, to avoid damaging existing services
or, in the worst case, starting a fire or a flood!
4G Remote Monitoring Station
It’s often necessary to know what’s going on in a remote location, such as whether
your boat battery is low, or if it is taking on water. Now that 2G is gone, and there’s
talk of 3G being phased out, this is best done via 4G. Our new Arduino-based
remote monitoring station can send updates over 4G mobile data or via SMS,
and can even be used to switch things on and off at a distance.
Micromite Air Quality Monitor
An easy-to-build device which measures the concentration of Volatile Organic
Compounds (VOCs) in the air and displays it on a colour LCD, both as a numeric
reading (in parts-per-billion) and as a graph, showing how it changes over time.
Use it to monitor your home, office, or anywhere else that you might experience
poor air quality.
Low-cost Hifi Bookshelf Speaker System, Pt.2
These medium-sized bookshelf speakers are made from a sheet of plywood
and a couple of drivers from Altronics. While they are quite cheap to build, they
certainly don’t sound cheap! And if you build the optional subwoofers, using a
similar construction method, you get decent bass too, plus bonus speaker stands.
Low-distortion Direct Digital Synthesiser
This two-channel digital signal generator can produce very low distortion sinewaves
across the audio frequency band (20Hz-20kHz), plus several other waveform
shapes. The output levels are independently adjustable over a wide range, and
the channels can also be phase-locked with a 0-360° phase offset.
Note: these features are planned or are in preparation and should appear
within the next few issues of Silicon Chip.
The February 2020 issue is due on sale in newsagents by Thursday, January
30th. Expect postal delivery of subscription copies in Australia between January
28th and February 14th.
Advertising Index
Altronics...............................81-84
Ampec Technologies................. 19
Dave Thompson...................... 111
Digi-Key Electronics.................... 3
Emona Instruments................. IBC
Jaycar............................ IFC,53-60
Keith Rippon Kit Assembly...... 111
LD Electronics......................... 111
LEACH PCB Assembly............... 5
LEDsales................................. 111
Microchip Technology................ 65
Ocean Controls........................... 6
RayMing PCB & Assembly.......... 8
Rohde & Schwarz.................. OBC
SC Micromite BackPack............ 69
Silicon Chip Binders............... 111
Silicon Chip Shop...............90-91
Silicon Chip Subscriptions..... 109
Switchmode Power Supplies....... 7
The Loudspeaker Kit.com......... 67
Vintage Radio Repairs............ 111
Wagner Electronics..................... 9
Notes & Errata
Discrete pump timer, Circuit Notebook, November 2019: the diodes are all shown correctly orientated, however the anode
(“A”) and cathode (“K”) markings have all been swapped. Also note that the 12V version of the Cyclic Pump Timer was in the
July 2017 issue, not July 2016.
45V 8A Linear Bench Supply, October-December 2019: in the PCB overlay diagram (Fig.6) on page 70 of the November issue, the types and labels for diodes D5 and D6 are swapped. D5 is on the left and should be a 1N5404 type, while D6 is closer
to the edge of the board and should be an SB380. The PCBs supplied for this project have the same error on their silkscreen
printing. The circuit will still function correctly if both diodes are SB380s.
LoRa Chat Terminal, Circuit Notebook, August 2019: the connections from IC2 to the LCD12864 display module are incorrect. The correct connections are: 1) pins 1-8 on IC2 go to pins 7-14 on the LCD; 2) pins 23-25 on IC2 go to pins 15-17 on the
LCD; 3) pins 26-28 on IC2 go to pins 4-6 on the LCD.
112
Silicon Chip
Australia’s electronics magazine
siliconchip.com.au
