Notes & Errata
Touch Lamp Dimmer, June 1989:
As noted in the article, the revised version of the SLB0586 does
not require diodes D1 and D2 but
they will not affect circuit operation if they are left in. However,
now that the revised chip has
been released, as SLB0586A, it
has been found not to work in the
circuit as published. To make it
work, two components must be
changed. The 680k0 resistor
must be swapped for a 0.33µF
capacitor while the .0022µF
capacitor should be swapped for
a 1ookn resistor. These components will fit without any
modifications to the PCB pattern
being required. If your kit has
the original SLB0586 IC, no circuit changes are necessary.
Studio Series 32-Band 1/3 Oct-
ave Equaliser, March, April
1989: one of the four 220µF electrolytic capacitors shown on the
main equaliser in the wiring
diagram (Fig.1(b} on page 48 of
the April issue} is reversed in
polarity. The capacitor in question is connected to pin 4 of IC2.
Ultrasonic Car Burglar Alarm,
July 1989: the wiring diagram on
page 63 shows one side of the
siren connected to chassis. It
should connect to + 12V, as
shown on the circuit on page 61.
Garbage Reminder, August
1989: the .047 µF supply bypass
capacitor shown between IC6
and IC7 on the wiring diagram of
page 50 is shown as 0.1µF on the
circuit of page 49. The value is
not critical though and either
0.lµF or .047µF is OK.
Advertising Index
Allied Capacitors .... .... .. .... .... 65
Altronics ...... .. ...... .. ....... 46-49
Arista Electronics ............. .. .. 1 7
Banksia Information Tech ...... 89
Board Solutions .. .... .. ... .......... 9
Dauner Electronics .. .. .. .. . .. ... 1 3
David Reid Electronics ..... 56,57
Dick Smith Electronics ..... 68-73
Electronic Solutions .. ..... . 14, 15
Elmeasco .... ..... .. .. ..... .... .. OBC
Geoff Wood Electronics ..... .. IFC
Harbuch Electronics .. ... .. ... .. . 94
Hycal Instruments .. .... .. .. ...... 13
Jaycar Electronics .. .. .. .... 36-39
80-83
J.V. Tuners .. ... ............. .. ..... 94
Kepic .... ... .. .... ... .. ........ .. .... . 95
Novocastrian Electronics .... .. 1 9
PC Marketplace ....... .. ..... ..... 31
Pelham .. .. .. .................... .. . 112
Power-Sonic Corp .... .... ..... . IBC
Philips Test & Measurement .. 89
RCS Radio ... .... .. ...... .. .. .. ... 102
Rod Irving Electronics .. ... 96,97
WIA .. .. .. .. .... .. .... ............... 103
tell me where I can get one?
SILICON CHIP is a great magazine.
I like the Vintage Radio section and
the Serviceman's Log. What happened to the Technology Letters?
(A.R., St George, Qld}.
• Tunnel diodes have become
very rare. In the 1960s they were
regarded as the wonder diode but
very largely they look to have been
a solution looking for a problem.
Their special claim to fame is that
they have a "negative resistance"
characteristic which enables them
to be used as amplifiers or
oscillators right up to microwave
frequencies.
Now, most of the applications for
tunnel diodes appear to be fulfilled
by more conventional devices such
as microwave transistors and Gunn
diodes.
General Electric was at one time
the major manufacturer of tunnel
diodes but this is no longer the case.
However, we have been in contact
with the agents for General Electric, GEC Components, and they
have indicated that they may be
able to source tunnel diodes, depending on the type number and quantity required. If you want to make
further enquiries, you can contact
GEC Components by phone on (02}
887 6222 or by fax on (02} 805 0272.
Remote Control ctd from page 8
secure and military designers are
constantly searching for better
ones. Some of the more complex included frequency hopping, chopped
chirp, exotic encoding and above
all else, making the vehicle as intelligent as possible, so that it can
perform its task with as little outside assistance as possible.
All of this and more will be
discussed in columns to come.
There'll be simple explanations
covering the installation of the
equipment into models, care and
feeding of nicads, and the correct
use of servo arms, plus the exotic. It
should be a lot of fun. See you next
month.
~
The Way I See It ctd from page 90
ly turned up in disposals stores for
50c each or three for a dollar!
"As far as I could see, the only
thing the power transformer did
was to operate the pilot light. A
single wire ran to the nest of pots
and another to the circuit board,
PC Boards
Printed circuit boards for SILICON
CHIP projects are made by:
• RCS Radio Pty Ltd, 651
Forest Rd , Bexley, NSW 2207.
Phone (02) 587 3491 .
• Jemal Products, 5 Forge St,
Welshpool, WA 6106. Phone
(09) 350 5555 .
• Marday Services, PO Box
Avondale, Auckland,
NZ. Phone 88 5730 .
19-189,
being soldered, of all things, to the
piece of PCB foil spelling out the
manufacturer's part number!
"What does a friend do in this
situation? Does one protest that the
$300 miracle healing machine is
just a con and refuse to proceed
any further with the farce?
"Knowing the lady as I did, I
replaced the crunched diodes with
three new ones and assured her
that they were a close equivalent to
the originals. And of course, as
soon as she turned it on, she noticed
the difference!"
K.W. observes that "thousands
of electronic enthusiasts have pulled apart discarded computer
boards. How many can claim that
they've actually repaired one?" ~
OCT0BER1989
111
