This is only a preview of the September 2014 issue of Silicon Chip. You can view 35 of the 104 pages in the full issue, including the advertisments. For full access, purchase the issue for $10.00 or subscribe for access to the latest issues. Items relevant to "Create Eerie Music With The Opto-Theremin, Pt.1":
Items relevant to "A Wideband Active Differential Oscilloscope Probe":
Items relevant to "Mini-D Stereo 10W/Channel Class-D Audio Amplifier":
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LED Causes Car Computer False Alarm
I’m hoping you can help me with
a small problem I have. I recently
had installed an after-market radio
in my BMW X5 and this included
a rear-view camera. The camera
replaces one of the number-plate
lights and has a LED for lighting the
number plate.
The problem is that because of
the lower power consumption of
the LED, the car computer thinks
the number-plate light is blown and
constantly brings up a warning of
“check number plate light” on the
dashboard.
I’m guessing I would need to put
a resistor either in series or parallel
with the LED to get the car computer
to stop nagging me. Can you suggest
a suitable resistor value and should
it be wired in series or parallel? (B.
A., Margate, Tas).
• A 100Ω 5W resistor should be
suitable and should be wired across
the original number plate light connection (not across the camera LED).
Presumably this would also be the
power connection for the camera.
What’s probably happening is that
the current drawn by the camera that
includes the LED is insufficient for
the car computer to accept that the
bulb is not blown.
If a 100Ω 5W resistor doesn’t solve
the problem, use a 47Ω 10W resistor. The resistor should be mounted
so that its heat can be dissipated
without burning any plastic parts.
Mounting it in a small diecast box
would be best and you should ensure
that the leads are insulated from
the case.
The resistor should be secured
against the box to heatsink it. Some
heat resistant epoxy such as JB Weld
can be used to affix it to the case or
you could attach it using suitable
brackets.
Advertising Index
Altronics......................................... 3
Aust. Exhibitions & Events............ 57
Blamey & Saunders Hearing.......... 5
Core Electronics........................... 33
element14.................................... 69
Embedded Logic Solutions.......... 66
Emona Instruments...................... 67
Front Panel Express....................... 9
Futurlec.......................................... 6
Gless Audio................................ 103
Hammond Manufacturing............... 9
Hare & Forbes.......................... OBC
HK Wentworth (Electrolube)......... 65
Icom Australia.............................. 11
Iconic PCB................................... 60
Jaycar .............................. IFC,49-56
Keith Rippon .............................. 103
Keysight Technologies.................. 73
period. An LM3909 can flash a LED
while drawing low current. You can
purchase the IC and get a data sheet
from www.futurlec.com/Linear/LM3909Npr.shtml
BFO wanted for
shortwave listening
Did SILICON CHIP or “Electronics
Australia” ever do a project for an
external BFO to use with a shortwave
receiver? This would resolve amateur
SSB transmissions for listeners.
A useful addition to your web page
would be the ability to search for
projects, using supplied keywords. Of
course, someone has to index the lot.
(D. H., via email).
• We have a very comprehensive
search facility on our website. Just
go to the home page, hover over “Articles” and you will get a choice of
searches: contents, word etc.
If you type “BFO” into the word
search you will get nine results at
www.siliconchip.com.au/Articles/
WordSearch and the relevant one is at
November 2010 at www.siliconchip.
com.au/Issue/2010/November/Highperformance+shortwave+converter
This takes you to a preview of the
November 2010 issue. The relevant
item is in the Circuit Notebook pages
of that issue under the title “High Performance Shortwave Converter”. This
is suitable for AM and SSB reception
from 6MHz to 17MHz.
Note that to access this article, you
SC
need to buy the full issue.
KitStop............................................ 6
LD Electronics............................ 103
LEDsales.................................... 103
Lintek Pty Ltd............................... 63
Master Instruments.................... 103
Mastercut Technologies................ 68
Microchip Technology................... 19
Mikroelektronika......................... IBC
Ocean Controls.............................. 8
QualiEco Circuits Pty Ltd............. 59
Quest Electronics....................... 103
Rohde & Schwarz........................ 71
Satcam......................................... 70
Sesame Electronics................... 103
Silicon Chip Binders..................... 84
Notes & Errata
Playing USB-Stick & SD/MMC Card
Music Without a PC, January 2012:
on page 86, the article states that
the Tenda TD896 requires two 2-pin
JST leads for the audio outputs and
a 3-pin JST lead for the earphone/
speaker outputs. However, the two
2-pin JST headers/leads are for the
earphone/speaker outputs while the
104 Silicon Chip
3-pin header/lead is for the audio
(line level) outputs.
40V Switchmode/Linear Bench Supply, April-June 2014: the parts list
swaps the part numbers for Q6 and
Q7. Q6 is the BC327 and Q7 is the
BC337. This is shown correctly on
the circuit and parts layout diagrams
and on the PCBs we supply.
Silicon Chip Online Shop........... 102
Silicon Chip Subscriptions........... 31
Silvertone Electronics.................. 83
Soltronico Pty Ltd......................... 70
Tronixlabs Pty Ltd....................... 103
Virtins Technology.......................... 7
Wiltronics...................................... 10
Worldwide Elect. Components... 103
siliconchip.com.au
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