Silicon Chip 2007-12.pdf

(18141 KB) Pobierz

:6$ZN

~O/800SSGdd

.os8s

03I\Ol::Jddif lSOd lNll::Jd

,00992 O£O,LL

20 Restoring A Vintage TV Set

Whats it like to restore a 50-year-old vintage black-and-white TV set? Here's

how an old AWA Model

229

was brought back to life

by Timothy Stuart

44 Review: Rohde

Schwarz FS300

SM300 Test Gear

We take an in-depth look at Rohde

Schwarz' new FM300 Spectrum

Analyser and SM300 Signal Generator

by Mauro Grassi

~1?0~@@ts9

m~~D@j

10 Signature Series Kit Loudspeaker System

Based on Fountek ribbon tweeters and Peerless drivers, these are the best kit

speakers we have ever heard

by Russell Storey

Leo Simpson

Restoring A Vintage AWA

TV Receiver

Page

20.

30 Infrared Audio Headphone Link For TV

you have trouble understanding what's being said on the TV unless the

volume is cranked way up? This project lets you listen in without disturbing

anyone else

by Jim Rowe

64 An Enhanced 45-Second Voice Recorder Module

Improved design can be easily set up to record two, four or eight different

messages for random-access playback or a single message for 'tape mode'

playback

by Jim Rowe

78 PIC-Based Water-Tank Level Meter; Pt.2

Building the two versions (basic

telemetry) plus installation and calibration

- by John Clarke

Infrared Audio Headphone

Link

Page

30.

90 Playback Adaptor For CD-ROM Drives; Pt.2

Assembling the PC board, assigning the remote control keys, testing and

troubleshooting

by Mauro Grassi

@@~0D @0D~WiJQiJ£5

It's all in a day's work

by the TV Serviceman

48 Serviceman's Log

72 Circuit Notebook

(1) In-Car Charger

Switcher For An SLA Battery;

(2)

Temperature-Controlled

Fridge Fan;

(3)

Simple Water Pump Controller;

(4)

Low-Current Stable

Clock Source;

(5)

Quiz Adjudicator Has No Pushbuttons;

(6)

Buck

Boost

Regulator;

(7)

Doorbell Circuit With Zero Standby Current

Enhanced 45-Second Voice

Recorder Module

Page

64.

97 Vintage Radio

Kriesler

11-595-

Valve Dual- Wave Mantel Receiver

by Rodney Champness

@)@[})0[?{3OUU@QiJts9

Publisher's Letter

Mailbag

Order Form

Product Showcase

104 Ask Silicon Chip

107 Notes

Errata

110 Market Centre

siliconchip.com.au

DECEMBER 2007

PubliSher'S Letter

Electric cars are viable

right now

Peter Seligman's articles on "How to Cut Your

Greenhouse Emissions"

the July, August

Septem

ber issues certainly stirred up some controversy. One

good thing about that is that it clearly demonstrated

that the simplistic solutions often bandied about in the

popular press are not workable. Making large cuts to

greenhouse gases is neither easy nor simple.

Much of the controversy stirred by Peter Seligman's

articles revolved around his conclusion that electric cars were not a useful ap

proach when most of the power stations are coal-fired, as they are in Australia.

Quite a few people disagreed but went on to quote figures drawn from overseas

sources where the power generation mix is quite different to here. Even so, there

have been disagreements about the estimated efficiency of electric vehicles. A

representative letter in that vein is included in the Mailbag pages this month.

For our part, we are very attracted to the concept of electric vehicles and do

believe that a modern electric car employing similar technology to the much

vaunted Tesla Roadster would be quite successful. In fact, we think such cars

should be on Australia's roads in large numbers right now, in spite of the fact

that they would ultimately draw their electricity from mostly coal-fired power

stations. In any case, it is unlikely that any new power stations in Australia will

be coal-fired. They are far more likely to be gas-fired since they are much more

efficient and put out considerably less greenhouse gases for the electricity they

generate. So with future Australian electricity supplies likely to be much cleaner,

we should be planning for electric vehicles.

In the meantime, consider the potential advantages of electric vehicles

they

were in Australia right now. In heavy traffic or on the open road, they generate

no pollution at all. They would not contribute to Australia's growing import bill

for oil and petrol. When stopped, they are silent, apart from the possibility of a

ventilation fan running. And when driving along the road, there is virtually no

noise at all, apart from that generated by the tyres, suspension and any wind

noise. That is a pretty attractive proposition. More importantly, such a car would

require virtually no regular maintenance and very few visits to the local garage

for costly service - no oil changes or engine service - just check the tyres and

the water level for the windscreen washers. Now that is attractive.

Sure, batteries are an expensive component in an electric vehicle's first cost

but if NiMH or Lithium-ion batteries are used, they should last for many years.

In fact, wear in the motor should be very low, so electric vehicles could be very

long-li ved.

Sadly, there are only a handful of electric cars on the road in Australia and to

om knowledge, virtually all of these have been built by enthusiasts. In fact, the

Australian Electric Vehicle Association (AEVA) had a recent field day in Sydney

and a number of such vehicles were on display. But sadly too, they were all far

shy of what can be achieved with technology presently available in Australia.

For example, they all used lead-acid batteries and DC motors (not brushless)

without regeneration. Significantly too, most of them would be dicey in a major

collision and none had air-conditioning.

By contrast, it would be possible to put together a consortium of Australian

suppliers right now, to manufacture a world-class electric vehicle with good

performance and range, able to accommodate four people and their luggage and

with full crash safety. I wonder if any of our local car manufacturers is actually

working on such a project right now. I hope so.

Leo Simpson

SILICON

CHIP

si/iconchip. com.

Letters and emails should contain complete name, address and daytime phone number. Let

ters to the Editor are submitted on the condition that Silicon Chip Publications PtyUd may

edit and has the right to reproduce in electronic form and communicate these letters. This

also applies to submissions to "Ask SILICON CHIP" and "Circuit Notebook".

Solar effectiveness

is regional

A number of readers have comment

ed that I appear to have condemned

electric cars in my article "How to

Reduce Your Greenhouse Gas Emis

sions, Pt.3" (SILICON CHIP, September

Z007). Electric cars are quite advanta

,geous in countries or regions where

the electricity produced generates

less than about 0,9kg of CO

per kWh.

Victoria averages about 1.4kg/kWh

and the Australian average is about

1.0kg/kWh.

In the USA, the average is about

0.7kg/kWh, so electric cars would be

better there than petrol. For Australia

at present, gas-powered cars may be

the best option since, apart from being

relatively low in CO

emissions, they

reduce our dependency on foreign

oil.

In the case of solar hot water heating,

there are several factors which deter

mine whether a booster is required

and what sort ofbooster is appropriate.

To give some examples: if you live in

Victoria, with high CO

per kWh and

your solar system supplies only 60%

of the energy, then a gas booster is

appropriate. In Tasmania, most of the

electricity is hydro and so even though

the solar fraction is lower, electricity

produces the lowest greenhouse gas

emissions.

you live in the sunnier areas of

Australia, where the solar fraction can

be very high or 100%, again electric

ity may be the best. So essential1y the

decision is based on solar insolation

(how sunny your location is), your

usage level and the "dirtiness" of the

electricity supply you would use to

heat the water.

Peter Seligman,

Essendon, Vic.

Electric cars are

cleaner than petrol

I would like to dispute Peter Selig

man's conclusions in his article on

"How to Cut Your Greenhouse Emis

sions" on page 20 of the September

Z007 edition. Peter claims that a

mains-recharged electric car gener

ates more CO

than a petrol car. His

conclusion is only true if petrol car

efficiency is better than ZO%. I contend

that petrol car efficiency is closer to

1Z% rather than the Z5% that Peter

claims.

In justification, a typical smaU car

uses 7 litres/100km at 90km/h on

highway cycle and 8.5 litres/100km

on city cycle. On highway cycle, this

motor uses 1 litre of petrol (10kWh) to

generate 1.7kWh at the wheels; ie, 17%

efficiency. On a city cycle, because

of frequent braking, its efficiency is

much lower at around 5-10%. As

suming 60% city and 40% highway

usage, the average petrol efficiency is

1Z% so

only generates an average of

l.zkWh/litre of petrol used.

Using Peter's CO

equivalence fig

ures of Z.6kg/l for petrol and

1.35kgl

kWh for mains-generated electricity,

let us now compare the amount ofCO

generated by a petrol car per litre used

and by an electric car generating the

equivalent power of l.zkWh.

In a petrol car, one litre of petrol

Australia on the right

wavelength with digital radio

I wish to comment on the letter

concerning DAB+ in the September

Z007 issue of SILICON CHIP. It's a

shame a letter writer has attacked

Australia's plans for digital radio

without the facts and without being

prepared to put their name to their

opinion.

Commercial radio broadcasters

have every confidence that Australia

can successfully lead the way with

digital radio. We have a long history

of innovation that has seen radio

adapt and floutish over the years

despite the advent of technologies

such as TV, CD players and the in

ternet. The development of portable

and in-car listening, the introduction

of top 40 music formats, talkback ra

dio, pioneering live news and sports

reports from the scene, interactivity,

streaming online and radio podcasts

are examples of the way radio has

continually evolved both its content

and distribution over the years. Dig

ital radio is the next step.

The decision to go with DAB+ was

not driven by "bureaucracy" but by

radio stations who understand what

listeners want. DAB+ technology al

lows us to offer exciting new features

and a multitude of content that just

isn't possible with AM and FM.

We should be proud that Australia

was the first country in the world to

switch on a high power DAB+ test

- but we are far from alone. Trials

have been conducted in Italy, Czech

Republic and France, while many

other countries including Canada,

Hungary, Israel, Kuwait, Malaysia,

Malta, New Zealand and China are

making preparations for

tria~s

and

launches. DAB+ is our opportunity

to move the industry forward and

those who don't embrace this change

will most likely be left behind. If

our anonymous critic would like to

come out from behind the cloak of

anonymity then we can make sure

he or she is acquainted with the

facts of digital radio, both here and

globally, and will thus be equipped

to make, in the future, an informed

comment.

Joan Warner,

Chief Executive Officer,

Commercial Radio Australia.

SILICON CHIP

siliconchip.

COm.

Updated

Prawnlight

thought you might be

Atmel's AVR, from

JED in Australia

JED has designed a range of

single board computers and

modules as a way of using the

AVR

without SMT board design

interested in my adaptation

of the Prawnlight featured

in the January 2005 issue.

This was one of those

projects that

was going

to do when a trip to the

The new Prawnlight uses a cut

down trailer tail-light assembly

coast was looming. By the

and a LED auto lamp.

time that happened, Oat

ley Electronics were out of

As you can see, the unit is virtual

stock of the kit so

found an alter

native. Fortunately, newer bright ly the same as the January 2005 ver

sion with the exception of the bright

LEDs have become available and

by using a cut-down trailer tail-light LED assembly, which at around $20

assembly, a similar Prawnlight soon is cheaper than the original kit. Care

is needed when sawing/cutting off

took shape.

tried this "vith just one of these the excess portion of the trailer light

housing.

Superbright LED lights for cars and

One thing different is that the

it is very bright. They have a direc

LED assembly is polarity-sensitive

tional beam of

15°

which is fine for

whereas the incandescent is not.

a torch function.

also tried it as a

used a permanent marking pen to

replacement for overhead lights in

label each end.

a pop-top caravan but there's not

Now all

need is a dark night and

enough side light which is a pity

as they draw one-fifth the current an outgoing tide. Roll on summer.

Murray Solomon,

of incandescent globes and remain

Cheltenham. Vic.

cool.

generates 2.6kg of CO

and 1.2kWh

of power at the wheels. With an elec

tric car, assuming 90% efficiency of

charger and 90% efficiency of control

electronics combined with dynamic

braking, if we recharge the batteries

from the mains, then 1.2kWh at the

wheels requires us to input 1.5kWh

from the mains. So the electric car

generates 1.35 x 1.5

2kg of CO

for

1.2kWh at the wheels.

This is completely the opposite con

clusion to Peter Seligman's example

whereby he claims "Less CO

is gener

ated using a mains recharged electric

car compared with a petrol car."

Peter Kay,

Dromana, Vic.

CHIP magazine has been a major factor

in our group's prosperity.

Please accept our best wishes. We

look forward to the same great relation

ship for the next 20 years.

Gary Johnston,

Silverwater, NSW.

The AVR570 module (above) is a way of

using an ATmega128 CPU on a user base

board without having to layout the intricate,

surface-mounted surrounds of the CPU, and

then having to manufacture your board on

an SMT robot Iline.lnstead you simply layout

a square for four 0.1" spaced socket strips

and plug in our pre-tested module. The

module has the crystal, resetter, AVR-ISP

programming header (and an optional JTAG

ICE pad), as well as programming signal

switching. For a little extra, we load a OS1305

RTC, crystal and

battery underneath,

which uses SPI and port G.

See JED's www site for a datasheet.

AVR573 Single Board Computer

Congratulations on 20 years

Congratulations on the 20th an

niversary of SILICON CHIP. Its obvious

success is a credit to you and for your

foresight in launching the magazine

originally.

note that EPE magazine is now

reproducing some of your construction

articles and this is surely a compliment

to you and your staff for your excel

lent projects.

Keep up the good work!

Garth

Jenkinson,

Emerald, Vic.

This board uses the AVR570 module and

adds 20 An.lOig. inputs, 12 FET outputs, LCOI

Kbd, 2xRS232, 1xRS485, 1-Wire, power reg.

etc. See www.Jedmicro.com.aulavr.htm

$330 PC-PROM Programmer

This programmer plugs into a PC printer

port and reads, writes and edits any 28 or

32-pin PROM. Comes with plug-pack, cable

and software.

Best wishes for

another 20 years

On behalf of all staff at Jaycar Elec

tronics, Electus and Soanar,

would

sincerely like to congratulate you

and your staff on 20 years of "well

done".

am flattered that you mention

Jaycar in your November editorial. It

must be said, of course, that SILICON

siliconchip.com.au

Possible error in Variable

Speed Drive circuit

don't know if

have this analysis

correct but

have gone through the

Variable Speed Drive circuit on page

93 of the October 2007 issue and

Also available is a multi·PROM UV eraser

with timer, and a 32/32 PLCC converter.

JED Microprocessors Pty Ltd

173 Boronla Rd, Boronia, Victoria, 3155

Ph. 03 9762 3588, Fax 03 9762 5499

www.jedmicro.com.au

DECEMBER 2007

Plik z chomika:

system-f

Silicon Chip 2007-12.pdf

Plik z chomika:

Inne pliki z tego folderu:

Inne foldery tego chomika: