MARKET CENTRE
Cash in your surplus gear. Advertise it here in SILICON CHIP
KEEP YOUR COPIES OF
FOR SALE
PCB MANUFACTURE: single to multi
layer. Bare board tested. One-offs to
any quantity. 48 hour service. Artwork
design. Excellent prices. Check out our
specials: www.ldelectronics.com.au
LEDs, BRAND NAME and generic
LEDs. Heatsinks, fans, LED drivers,
power supplies, LED ribbon, kits, components, hardware, EL wire. www.ledsales.com.au
tronixlabs.com - Australia’s best value
for hobbyist and enthusiast electronics
from adafruit, DFRobot, Freetronics,
Raspberry Pi, Genuino and more, with
same-day shipping.
PCBs MADE, ONE OR MANY. Any format, hobbyists welcome. Sesame Electronics Phone 0434 781 191.
sesame<at>sesame.com.au
www.sesame.com.au
WANTED
WANTED: EARLY HIFIs, AMPLIFIERS,
Speakers, Turntables, Valves, Books,
Quad, Leak, Pye, Lowther, Ortofon,
SME, Western Electric, Altec, Marantz,
McIntosh, Tannoy, Goodmans, Wharfe
SILICON CHIP
AS GOOD AS THE DAY
THEY WERE BORN!
ONLY
95
$
1P6LUS
p&p
A superb-looking
SILICON CHIP
binder will keep
your magazines in
pristine condition.
* Holds up to 14 issues
* Heavy duty vinyl
* Easy wire inserts
ORDER NOW AT
www.siliconchip.com.au/shop
dale, radio and wireless. Collector/
Hobbyist will pay cash. (07) 5471 1062.
johnmurt<at>highprofile.com.au
KIT ASSEMBLY & REPAIR
KEITH RIPPON KIT ASSEMBLY &
REPAIR:
* Australia & New Zealand;
* Small production runs.
Phone Keith 0409 662 794.
keith.rippon<at>gmail.com
VINTAGE RADIO REPAIRS: electrical mechanical fitter with 36 years
ex
p erience and extensive knowledge of valve and transistor radios.
Where do you get those
HARD-TO-GET PARTS?
Where possible, the SILICON CHIP On-Line
Shop stocks hard-to-get project parts,
along with PCBs, programmed micros,
panels and all the other bits and pieces
to enable you to complete your
SILICON CHIP project.
SILICON CHIP
On-Line SHOP
www.siliconchip.com.au/shop
Professional and reliable repairs. All
workmanship guaranteed. $10 inspection fee plus charges for parts
and labour as required. Labour fees
$35 p/h. Pensioner discounts available on application. Contact Alan
on 0425 122 415 or email bigal
radioshack<at>gmail.com
DAVE THOMPSON (the Serviceman
from SILICON CHIP) is available to help
you with kit assembly, project troubleshooting, general electronics and custom design work. No job too small. Based
in Christchurch, NZ but service available Australia/NZ wide. Email dave<at>
davethompson.co.nz
ADVERTISING IN MARKET CENTRE
Classified Ad Rates: $32.00 for up to 20 words plus 95 cents for each additional word. Display ads in Market Centre (minimum 2cm deep, maximum 10cm deep): $82.50 per column centimetre per insertion. All prices include GST.
Closing date: 5 weeks prior to month of sale. To book, email the text to silicon<at>siliconchip.com.au and include your
name, address & credit card details, or phone Glyn (02) 9939 3295 or 0431 792 293.
ing it is not so very different from your
design? (N. M., Northern Ireland)
• Some microcontrollers are much
more susceptible to interference than
others. For the Hall Effect input,
maybe a low-value filter capacitor
would remove glitches. Connect a
10nF capacitor between Hall Effect
output and ground (assuming a 10kΩ
pull-up resistor). Also, the supply
to the Hall Effect unit should be filtered with a 100Ω resistor and filter
siliconchip.com.au
capacitor (100µF). Make sure the
microcontroller supply is filtered well
with 100nF capacitor across supply
pins.
We are not aware of how you programmed the Arduino. Dwell needs to
be the period that the coil is energised,
but with a fixed delay before the next
predicted firing. So a period counter
is required to continuously count the
period between each firing and then
to start to charge the coil so that fir-
ing occurs after the dwell period at the
next firing point.
So the dwell starts before the next
spark as predicted by the period counter. The period counter is updated on
every firing so as to keep up with RPM
changes.
Often when programming, you can
develop this in stages starting with
maximum dwell, then firing for a fixed
period (1ms) before the coil is re-energised. The coil needs protection from
January 2017 103
