This is only a preview of the October 1994 issue of Silicon Chip. You can view 33 of the 96 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. Articles in this series:
Items relevant to "Beginner's Dual Rail Variable Power Supply":
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PRODUCT SHOWCASE
PIR detectors
from DSE
Passive infrared detectors are becoming cheaper and their uses more
varied. They are used to detect movement and are most commonly found
in alarm systems, automatic doors and
lighting systems.
The sensor consists of two infrared
elements on a single substrate which
is heated to operating temperature.
One element is exposed to incoming
infrared radiation with the other
protected. With a static background,
the amount of infrared radiation
seen by the exposed element remains
constant, but when a body moves
across the background, it alters the
amount of heat seen by the element,
causing a voltage shift between the
two elements.
Placing a Fresnel lens in front of the
sensor maximises the change in heat
seen by breaking the background into
zones. As a person moves across the
sensor's field, he or she moves from
zone to zone causing a pulsing heat
signal to be seen by the exposed element. This difference is detected by
the electronics and if enough pulses
are detected in a set time the detector
opens a relay to indicate that it has
seen movement.
People are not the only sources of
heat, so care has to be taken when
installing the detectors so that sources
of heat do not lead to false triggering.
Common sources of false triggering
are direct sunlight, air conditioners
and heaters. Stickers can be placed on
the inside of the Fresnel lens to blind
particular zones from the source of
interference.
Three PIR detectors are available
from Dick Smith Electronics. The first
Low cost
video enhancer
If your VCR is in tiptop condition
you probably have no need for a
video enhancer but if you want
to dub between VCRs or want to
send video signals over a longish
cable, then this SuperBooster II
model from Jaycar may be for you.
It has controls for video boost and
the stereo audio levels and will
provide a maximum video gain of
two (+3dB).
Note that it does not boost the
video high frequencies which
would enhance picture detail. If
you want a detail enhancer. Jaycar
has another model, the JVE-1.
84 Silicon Chip
The video enhancer is powered
by an external 9V 200mA DC
plugpack (not supplied) and sells
for $39.95 (Cat. AV-6500). It is
available from all Jaycar Electronics stores.
(DSE PIR detector) is a budget version
and has a fixed 90° field of view. The
sensitivity is adjustable and a LED
gives visual indication of detection to
help with setup procedures. A tamper
switch inside detects any attempt that
is made to open the case. The detector
needs a 12V supply and has an N/C
(normally closed) alarm output (Cat.
L-5011).
The second detector (Everspring
180 degree PIR) is a half hemisphere
in shape and uses mirrors above the
sensor to gain a 180° view. It can have
the Fresnel lens mounted vertically or
horizontally to tailor the field of view
to wide or tall.
Four lenses are included to provide
further response tailoring and are
la
belled wide angle, long distance,
pet and curtain. Detection pulses are
counted over a time frame to minimise
false triggering. Tamper protection and
LED indication are also included. The
unit needs a 9-16V supply and has
N/C tamper and alarm outputs (Cat.
L-5015).
The last detector (Ir-tec IR-820 PIR)
has three different Fresnel patterns
in its lens to detect motion. The patterns are designated wide angle, long
range and finger curtain. Stickers are
included to mask out any zone that
has a source of interference. The
sensor can also be moved in relation
12-PPM laser printers
from Hewlett Packard
SILICON CHIP SOFTWARE
Now available: the complete index to
all SILICON CHIP articles since the first issue in November 1987. The Floppy Index
comes with a handy file viewer that lets
you look at the index line by line or page
by page for quick browsing, or you can
use the search function. All commands
are listed on the screen, so you’ll always
know what to do next.
Notes & Errata also now available:
this file lets you quickly check out the
Notes & Errata (if any) for all articles published in SILICON CHIP. Not an index
but a complete copy of all Notes & Errata text (diagrams not included). The file
viewer is included in the price, so that you can quickly locate the item of interest.
The Floppy Index and Notes & Errata files are supplied in ASCII format on a
3.5-inch or 5.25-inch floppy disc to suit PC-compatible computers. Note: the File
Viewer requires MSDOS 3.3 or above.
ORDER FORM
Hewlett-Packard has introduced
two new 12-page-per minute (PPM)
laser printers that are 30-40% faster,
on average, than their predecessors.
Called the HP LaserJet 4 Plus and
HP LaserJet 4M Plus, these printers
feature 600 x 600 dots per inch (dpi)
resolution and a 12-ppm print engine
with a 25MHz Intel i960 RISC processor with cache, advanced memory
management and other performance
enhancements.
HP's Memory Enhancement technology (MEt) effectively doubles
the printer's memory and enables
it to print more complex pages with
stand
a rd memory in PCL, while
u s e rc o n f i g u r a b l e i n p u t / o u t p u t
(I/O) buffering allows the printer to
accept print data faster, returning
control of the host computer to the
user sooner.
The resource-saving feature retains
downloaded fonts, logos, forms and
macros, eliminating the time normally
needed to download this information
again when switching between PCL
and Postscript. Job overlap enables
the printer to process one print job
while it is printing another. This
re
sults in faster printer throughput
when multiple jobs are sent to the
PRICE
❏
Floppy Index (incl. file viewer): $A7
❏
Notes & Errata (incl. file viewer): $A7
❏
Alphanumeric LCD Demo Board Software (May 1993): $A7
❏
Stepper Motor Controller Software (January 1994): $A7
❏
Gamesbvm.bas /obj /exe (Nicad Battery Monitor, June 1994): $A7
❏
Diskinfo.exe (Identifies IDE Hard Disc Parameters, August 1995): $A7
❏
Computer Controlled Power Supply Software (Jan/Feb. 1997): $A7
❏
Spacewri.exe & Spacewri.bas (for Spacewriter, May 1997): $A7
❏
I/O Card (July 1997) + Stepper Motor Software (1997 series): $A7
POSTAGE & PACKING: Aust. & NZ add $A3 per order; elsewhere $A5
Disc size required: ❏ 3.5-inch disc
❏ 5.25-inch disc
TOTAL $A
Enclosed is my cheque/money order for $A__________ or please debit my
❏
Bankcard
❏
Visa Card
❏
MasterCard
Card No.
Signature_______________________________ Card expiry date______/______
Name ___________________________________________________________
PLEASE PRINT
Street ___________________________________________________________
Suburb/town ________________________________ Postcode______________
Send your order to: SILICON CHIP, PO Box 139, Collaroy, NSW 2097; or fax your
order to (02) 9979 6503; or ring (02) 9979 5644 and quote your credit card number
(Bankcard, Visa Card or MasterCard).
✂
to the lens to alter the response pattern. A gauge on the PC board helps
in alignment.
LED indication is jumper selectable
and can be turned off once setup is
complete, thereby not letting an intruder know that he has been detected.
Tamper protection and pulse counting
are also included. The detector needs
9-16V and has N/C tamper and alarm
outputs (Cat. L-5014).
These PIR detectors sell for $39.95,
$59.95 and $89.95 respectively and
are available from all Dick Smith
Electronics stores.
October 1994 85
printer, particularly if the jobs alternate between PCL
and PostScript.
The HP LaserJet 4M Plus printer offers improved greyscale capability when printing in Postscript. The result
is reduced visual banding so transitions in grey tones
appear smoother and more even, while scanned images
are reproduced with better detail.
The new LaserJet comes standard with 2Mb of RAM
while the LaserJet 4M Plus includes 6Mb of RAM. Addi
tional memory can be used in both printers to increase
I/O buffer space for faster return to the user's application
and for saving of downloaded fonts, forms and macros.
The HP LaserJet 4 Plus and 4M Plus are upgradable to
66Mb and 38Mb, respectively.
For further information on HP products and services,
phone 131 347 (toll free, no STD area code required).
Ultra-thin toroidal
transformers from Tortech
Conventional toroidal transformers are readily available from several sources in Australia but if you want to
place a toroidal transformer with a reasonable high VA
rating in a one-unit high rack case, you have a problem.
Or at least you did, until now. Pictured above are two
toroids, one a conventional unit and one an ultra-thin
unit measuring only 20mm thick and having a rating
of 50VA.
Want to know more? It is available from Tortech Pty
Ltd, 24/31 Wentworth Street, Greenacre, NSW 2190.
Phone (02) 642 6003.
Replace your mouse
with a tablet from DSE
Dick Smith Electronics has two new graphics tablets
to improve your CAD and drawing ability on the PC. The
Acecat II is a high resolution digitising tablet with up to
2000 line per inch (LPI) resolution.
Using the supplied
WinTab multi-pointer
software driver, the tablet
can be used alongside a
standard mouse or trackball in the Windows environment as a template
overlay for easy tracing of
existing drawings or creating freehand drawings.
86 Silicon Chip
For CAD users, the tablet
uses "absolute" positioning
which means that where you
point on the tablet is exactly
where your cursor will appear on the screen. This, it is
claimed, makes the selection
of icons and drawing faster
than using a conventional
mouse or trackball.
The programmable 2-button
stylus comes with replaceable
tips on either a 5-inch square
or 12-inch square tablet. The
right mouse button is on the
barrel of the stylus and is controlled by your index finger,
while the left mouse button is
actuated by pressing the stylus
more firmly on the tablet. The
smaller tablet is about the size
of a mouse pad and can be
used in the palm of the hand or
on the desk, whereas the larger
tablet is intended for desk use.
Supplied with five software
drivers and various testing
utilities, the Acecat II can be
software configured to suit
your favourite program and
connects to any serial port.
The Win Tab driver appears
as an icon in the Windows
envi
r onment and may be
clicked on to change parameters such as tracking areas,
tablet sensitivity and button
configurations.
The smaller tablet (5 x
5-inch) retails for $199 and
the larger (12 x 12-inch)
sells for $399. Both come
with a quickstart guide and
comprehensive user's manual.
For more information, contact
the Dick Smith Electronics
store nearest you.
Beyer kick drum
microphone
The new TG-X mic from Beyer
Dynamic is designed primarily
for close miking of kick drums in
re
cording and live performance
applications. It is also useful for
miking high sound pressure levels
such as musical instruments.
The heart of the microphone
uses a pressure gradient dynamic
transducer with a hypercardioid
pattern. The capsule has a quoted
frequency response of 15Hz to
18kHz (no dB limits). The microphone body is constructed of diecast zinc with a matt black finish
and it is fitted with a standard
3-pin XLR connector.
Standard accessories are a
mic clip and padded carry bag.
Options include a range of mic
and boom stands and cables with
Neutrik jack and
XLR connect ors.
Recommended retail price of the
Beyer TG-X 50 is
$495. For more information, contact
Amber Technology, Unit B, 5 Sky
line Place, Frenchs
Forest 2086. Phone
(02) 975 1211.
October 1994 87
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