Positivity follows
the gloom
Techno Talk
Mark Nelson
Is the premature death of LED lamp bulbs purely the result of user ignorance, or just the latest variant
of a worldwide swindle that has been going on for nigh on a century? But on the bright side, is a Li-Fi
revival possibly just around the corner?
T
here are some people who
are convinced that the LED lamp
bulbs of today (or at least some of
them) are a swindle. In their opinion,
these bulbs fail to deliver their claimed
brilliance, get dimmer as they age or give
up the ghost altogether long before the
stated lifetime. Often, this is the result of
user misunderstanding or unintentional
mistreatment. A helpful and informative
web page at https://bit.ly/pe-jun22-led
goes a long way towards providing the
user enlightenment that the industry
should have provided – or maybe decided was in their interest to stifle!
It’s not the first time!
Oddly enough (or perhaps entirely predictably if you’re a conspiracy theorist),
there’s a precedent for short-changing
buyers of lamp bulbs, and it began just
two years short of a century ago. In those
days, bulbs had the same form factor,
used exactly the same bayonet and screw
fittings and performed exactly the same
function – only less efficiently. The sole
major difference was that the bulbs were
incandescent, as were their users when
they discovered that most of the bulbs on
sale were intentionally and deliberately
designed to fail prematurely!
To quote researcher Markus Krajewski,
‘On 23 December 1924, a group of leading international businessmen gathered
in Geneva for a meeting that would alter
the world for decades to come. Present
were top representatives from all the
major light bulb manufacturers, including Germany’s Osram, the Netherlands’
Philips, France’s Compagnie des Lampes,
and General Electric from the US.’ But
this was not a social event, but strictly
business. They had come to Switzerland
to found a worldwide cartel that they
named Phoebus, after a sun god in Greek
mythology. Enlightenment was, so to
speak, its goal, but not in terms of classical education. Its stated aim was the
‘development of lighting’, but the sole
beneficiaries were members of the cartel,
who set out to dominate the worldwide
market for lamp bulbs by nominating
agreed production quotas for each manufacturing member in its assigned territory.
8
Competition from non-member companies soon put paid to the cartel’s dreams
of world domination. Krajewski reported
that, ‘As the cartel continued its policy
of artificially elevated prices, competitors spotted a golden opportunity to
sell cheaper, if often inferior-quality,
goods. Particularly threatening was the
flood of inexpensive bulbs from Japan.’
In the end, the chaos caused by the approach of war made it impossible for the
cartel to continue and it was dissolved
in 1939. However, its work was not in
vain. Although it was perfectly possible
to make a lamp bulb that could burn for
2500 hours, the cartel decided that their
members’ bulbs should last only 1000
hours, which was hardly in the interest
of consumers and a strategy that today
we could call planned obsolescence.
New life for Li-Fi?
Back in 2013, the technical press was
abuzz with reports on ‘Li-Fi’ – an electro-optical version of Wi-Fi. Prof Martin
Dawson, Director of Research in the
University of Strathclyde’s Institute of
Photonics, confidently declared: ‘This
is technology that could start to touch
every aspect of human life within a
decade. Imagine an LED array beside
a motorway helping to light the road,
displaying the latest traffic updates and
transmitting Internet information wirelessly to passengers’ laptops, netbooks
and smartphones. This is the kind of
extraordinary, energy-saving parallelism that we believe our pioneering
technology could deliver.’
Well, yes. To be fair, there’s still a year
left, so Li-Fi could still fulfil this prediction – just. And to remind you, Li-Fi is
not just optical Wi-Fi but comes with
higher capacity and fewer technical hangups. However, a clever notion needs a
killer application to become a winner,
and ten years ago, Li-Fi was very much
a solution looking for a problem. Now
(or soon) its time may finally have come.
Lightbulb moment
Cast your mind to the burgeoning
number of autonomous (self-driving)
cars and other road vehicles. Then
consider the vital need for dependable collision-avoidance mechanisms,
many of which rely on 100%-reliable,
split-second vehicle-to-vehicle (V2V)
communication. What a no-brainer
– isn’t this exactly what radio is for?
Think again; we’re talking about safety-critical situations for which you
need acutely low-latency and no risk
of signal corruption. Optical communication is far more secure, says Mike
Sandyck, product marketing manager
with international semiconductor manufacturer Onsemi. ‘Brake lights could
be modulated to let the vehicle behind
know that the brakes have been operated – this would be instant, but with
RF a delay could be disastrous. RF is
easily intercepted, while the localised
nature of light adds to security.’
He continues: ‘Modulating the light
intensity or frequency of LED-based
lighting allows data to be transmitted
in much the same way as an RF carrier
wave is modulated. This opens up applications including light-based Wi-Fi
style networking [Li-Fi] and underwater
usage. The ability to transmit data via
light requires little if any power over
and above what is needed for the LEDs
and installation costs are low because,
in many cases, the lighting is already in
place. While the flickering of the lights
can be easily detected by a receiver, the
frequencies used are imperceptible to
humans due to their persistence of vision, so there is no user impact with
this technology.’
Looks like we got us a convoy
Truck manufacturer Scania’s future vision of Europe’s freight transport is of
sleek convoys or ‘platoons’ of trucks
travelling autonomously and synchronously along green corridors of ‘smart’
roads. Says the company’s senior business analyst Fredrik Callenryd, ‘We
would see autonomous trucks travelling
in road trains in the foreseeable future,
with drivers navigating only when they
leave these green corridors, to travel to
the depot, for example.’ If he is right,
V2V communication will be the key enabler and Li-Fi could be the killer app!
Practical Electronics | June | 2022
