Bad science...
...and good
Techno Talk
Mark Nelson
Fire is a good servant but a poor master. The same can be said for science in general and electronics
in particular, as you’re about to see.
B
y and large, we do not adopt
many new German words into
the English language. That said,
one that I currently have in mind is
Schadenfreude, which has no direct
one-word equivalent in English. In a
nutshell, it means ‘taking pleasure in
someone else’s misfortune’. Needless to
say, mocking the less fortunate is not the
policy of this magazine but on this occasion, I simply cannot not resist drawing
your attention to a strange lapse in another, highly regarded, publication. First,
please see how much ‘bad science’, halftruthery and outright disinformation you
can spot in the following advertisement.
‘Save up to 25% on your electricity
bills by installing a single-phase voltage
optimiser at your home. In-line with CE
regulations, most of the UK’s electrical
equipment is designed to operate most
efficiently at 220-230V. For historic reasons, our electricity is supplied to homes
at an average of 242V but could be as high
as 253V. It is a little-known fact that the
more voltage you apply to an appliance
the more energy it consumes, costing you
more and shortening the life of the device. By matching your voltage supply to
pieces of equipment it is possible to make
a substantial energy saving and prolong
the life of your household appliances.
An Eco-Max Home Voltage Optimiser
will reduce any excess voltage, leaving
you with lower bills and lengthening
the life of your electrical appliances.
The ECO-Max Voltage Optimiser reduces your carbon footprint and saves you
money and helps your electrical appliances last longer’. Wow!
Too good to be true?
People on web forums are not fooled
easily. Crucially, the device may well
reduce your instantaneous power consumption, but only in terms of the rate
of energy usage. It will not reduce, and
may even increase, total energy used.
Things like kettles will take longer to
boil. Incandescent lights will use less
power, but will be pointlessly dimmer.
These optimisers will make no difference
to the power consumption of anything
containing a switch-mode power supply
10
or which are designed to absorb power until a specific function has been
achieved (central heating). These devices, along with power factor correctors,
do have a place in specific industrial
environments, which are metered very
differently to domestic consumers. But
in an ordinary house? I don’t think so.
So where does Schadenfreude come
in? The ‘ethical products’ advertorial
containing this ‘information’ appears
in the 20 March issue of New Scientist
magazine, which has long crusaded
against ‘bad science’. At least this slip
demonstrates that the magazine’s editorial and advertising departments operate
independently!
Another way of saving electricity?
Yes, I am obsessed with circuitry that
works without batteries or mains power.
This month’s clever stuff does that, but
it’s not exactly free, because you have to
buy special parts to make the setup work.
Nevertheless, there’s no ongoing cost
once you have made the initial investment. Energy harvesting is the ‘magic’ that
makes this possible. ON Semiconductor
(www.onsemi.com) is the innovator here
and power switching for smart homes
and buildings is the name of the game.
In a nutshell, harvesting ‘green’ dynamic
energy from the movement and force applied to a press-button switch is how the
setup achieves significant cost savings. It
does this with a wire-free Zigbee connection to offer unparalleled flexibility for
deployment within buildings, requiring
no hardwiring, zero maintenance hassles
and no battery replacement or disposal.
It gets even better. You have the flexibility to install a switch without cabling
anywhere you want, and it will fulfil its
function over the entire length of its service life without maintenance or battery
changes. In contrast to hardwired data
cabling, the self-powered wireless switch
is also attractive for building services because it is easy to retrofit. For example,
you can install new light switches without
having to cut any holes in the wall. The
system is not only for homes and offices,
but also has great potential for industrial
automation, particularly when the time
taken to lay cables is disproportionate to
the application. Here again, the energyharvesting wireless switch serves as a
cost-effective, battery-less alternative to
cable-based microswitches.
Green Alliances
A developer’s kit is available for anyone
planning applications for these green
power modules. In the kit is a Zigbee
Coordinator USB device, which interfaces with the Strata Developer Studio
(a cloud-connected development platform), plus two energy harvesting nodes,
which act as Zigbee Green Power Devices.
Pressing the switch on either of these
devices generates energy that is used to
power the SOC (system-on-chip) 2.4GHz
transceiver device. This also has 640kB
of embedded FLASH memory for program storage, along with 48kB of RAM
for data storage. The energy harvester
itself comprises a simple diode rectifier
bridge, a clamp and a small 56µF storage capacitor. No EMC suppression is
required, thanks to the low energy generated by the switch.
To make these applications truly ecofriendly, you need wireless protocols
that are compatible with the low-power
nature of the switch elements. Available
RF protocols include Bluetooth Low
Energy and the Green Power option promoted by the Zigbee Alliance (http://bit.
ly/pe-jun21-zgb). More at http://bit.ly/
pe-jun21-ons
Whether or not this technology eventually makes it to the mass market or
becomes available to hobbyists is unclear. Currently, ON Semiconductor is
promoting the concept to OEMs, but it’s
something that we shall be watching.
And finally... (at last)
The UK’s Information Commissioner’s
Office (ICO) and OFCOM have recently
outlined a joint plan for tackling nuisance and scam calls for 2021/2022.
This follows a surge in complaints from
September/October to December 2020.
OFCOM saw an 83% increase in the
number of complaints compared with
the same months in 2019 – details at:
http://bit.ly/pe-jun21-ofcom
Practical Electronics | June | 2021
