I replaced yet another compact fluorescent lamp (CFL) in our house last night.  I have been meaning to track our personal MTBF of these things because they seem to fail all too easily – well before the service life of at least 6,000 hours.  I actually ended up putting in some standard incandescent bulbs in as replacements although they seem to fail prematurely as well.  This time I have kept the receipt to monitor the lifetime of the new bulbs.

I took the failed lamp to the workshop to investigate the failure mode, along with my small collection of other CFLs that had failed.

First up is the Woolworths Essentials CFL.  I think I tried to complain to Woolworths about these things but I never heard back.  I don’t think there is any data on their lifetime available from Woolworths.  After taking the lamp base apart I discovered that one of the lamp filaments was open circuit.  There was also quite noticeable deposition on the inside of the tube. This deposition is probably tungsten that had boiled off the filament.  There are two capacitors on the circuit board that are probably polyester greencaps which are now quite a dark colour indicating that they had built up a lot of heat.

The next one I inspected was a Philips Genie 11 watt model.  I gave it an initial test to see if it was actually blown (it was in my to-do pile for some time). The CFL tube gave a brief flash at switch on in the same way that some incandescent do when they blow.  After taking this one apart I found that the the mains filter capacitor (4.7μF at 400V) had almost vented.  Capacitor failures due to venting (caused by a build up of internal pressure during overheating due to the ESR) are a common fault in switched mode power supplies.  These power supplies operate at frequencies in the order of 20 kHz so if they have poor quality capacitors the heating due to ESR is significant (Ohms Law, ripple current, heat dissipation and all that). Heating due to ESR is much less at a 100 Hz ripple frequency so the failed capacitor must have had a really high ESR value.  The capacitor is one of the cheap brands that come out of China so it’s failure is no surprise.  As for the failure mode I can only guess that the capacitor ESR slowly increased, the lamp may have somehow shut down due to over temperature, and then when I turned it on from cold the high ripple voltage caused the switching transistors to fail by both being in conduction at the same time.  Someone has reverse engineered the electronics of some CFLs and you can check out the circuits on this page.

The last one I looked at was from Ecobulb, a New Zealand company, although the lamps themselves are manufactured overseas of course.  Given the lack of debris and signs of heat discoloration his one did not look like it had had much use.  The switching transistors had shorted and an RFI coil was open circuit.  The coil essentially acted as a fuse.  My guess is that this one failed because it was used on a dimmer circuit.  Hmmm, that gets me thinking about the design of the electronics in these CFLs.  There is no reason why the designers could not have put in a low voltage cutout in the circuit.  Oh, silly me that would cost extra and affect the profits!

Eventually I hope to wire the whole house for 12 volt lighting and then use 12 volt LEDs in all of the lamp fittings.  This is a much more elegant, versatile,  and efficient way of lighting.  Single step down transformer (switched mode of course), ease of battery backup, ability to hook into PV panels would be a few of the advantages   I’ll keep you posted.

Incidentally, Interwaste do CFL recycling and I think they actually pioneered fluorescent lamp recycling in New Zealand.

The Huffington Post have done a photo essay of the high level of consumption in the United States.

The photos are mind-boggling when you think that it is only a very small part of the total amount.  Here at Ecotech Services we offer a recycling service for selected items

I have asked the question of how much technology do we really need in a previous post.  I now have to question the need for electric pencil sharpeners.

So what is hard about sharpening pencils? What is wrong with the low tech options of a hand cranked model?  Even that is overkill in my opinion.  The small hand operated type works just fine.

An electric pencil sharpeners needs all sorts of materials that need to be mined,  transported, refined, transported again, manufactured into the final product, shipped around the world, and then purchased by the customer.  And what happens to it when it is at the end if its useful life?  It should be recycled but at present that is not likely to happen here in so-called clean-green New Zealand.  An electric pencil sharpener also contains embodied energy, a proportion of which will be from fossil fuels.

So here we are, squandering the future of Earth on unnecessary items such as electric pencil sharpeners.

Now I am no luddite – that is obvious since I repair and own all sorts of high tech stuff – but I have to question just how far do we go with all of this electronic technology?  Most of us are buying and using it so we obviously want to have it.  But do we need it?  Is it being forced on us by seductive marketing and the pressure of keeping up with the Joneses?

What prompted these thoughts was my discovery here on our roadside of a discarded vacuum cleaner hose (of all things) from some unknown brand of machine.  I was interested to discover that it had a remote control with three buttons built into the hand piece of the hose.  As an electronics tech my professional interest was aroused.  My first thought was how does it interface to the vacuum cleaner?  Does it have a set of contacts on the hose end?

It turns out that there were no wires or contacts at the vacuum cleaner end of the hose.  So I unclipped the bezel surrounding the buttons – a simple matter of of using a small screwdriver as a lever in a slot on the bezel edge – and a circuit board assembly dropped out.  It had some water damage but I could see that it was a little battery powered RF transmitter and a bit of control circuitry. The buttons still work because the LED comes on when they are pressed, and the battery is reading about 2.5 volts.

If I had the actual vacuum cleaner I could have repurposed the remote control into something else.  Unfortunately it would probably have a very poor range because it only ever has to transmit the length of the hose and it is only powered by a CR2032 cell.

So all this effort has been put into designing and manufacturing this little gizmo to improve the owners vacuum cleaning experience. Or has it? Just how useful was it over its short lifetime?  Given the materials and the unsustainable energy that went into making it, that these things are not likely to be recycled, and the relatively short useful lifetime of vacuum cleaners, it all makes a mockery of environmental protection.

This is a little off topic but as an electronics tech who is keen on conserving the many endangered species I occasionally ponder the use of electronics technology to do the job of controlling predator numbers.  Here in New Zealand there are a number of really bad mammalian predators, the stoat being one of the worst but rats, mice, feral cats, and possums add to the problem.

The use in New Zealand of the mammalian pesticide 1080 (sodium fluoroacetate) is really contentious and the media have recently been banging on about the by-kill of the kea, a unique, endemic, clownish, intelligent alpine parrot.  It is a valid concern but the pest problem is really bad and 1080 is the most cost effective option.

One of the newer mechanical technology methods of trapping stoats and possums is a pneumatically operated skull crusher developed by goodnature.

It looks like a really good idea and because it only needs to be checked once a month it is a more cost effective way of controlling pests.

I want to go a step further and have a completely automatic trap for all pest species that never needs to be maintained.  A big ask you may say. Well I say that if we have flown to the Moon, to Mars, and sent space probes to beyond our Solar system (and I say that we have to all of you Moon landing conspiracy theorists) surely we can trap a few animals in the bush.

So how would it work?  Since facial recognition software is now old hat it will be easy to develop species recognition software.  So all we need to do is to mount a camera in a trap and when the target pest is recognised some method of killing it is activated (perhaps mechanical but I like the idea of electric shock).  A trapdoor is then opened and drops the now dead pest on the forest floor.  The trap will then reset itself for the next baddie.

The trap could be powered by a solar panel, although this will not be very effective under the shady bush canopy.  Maybe the weight of the pest as it falls out of the trap could be used to drive a small generator?  Hmm, maybe not.  Could be prone to mechanical failure.  Modern electronics can be made to run on the smell of an oily rag so powering the trap may not be too much of an issue.

One problem is that the trap could be stolen by some nasty individual that thinks it might be worth a bit of money.  There was a case last year some time where a very expensive and specialised wildlife monitoring camera was stolen from a remote part of a protected area here in Christchurch city.  As well as being a financial cost it set the scientific work back a bit.

I like delving into the realm of “conservation technology science fiction” and I have been dreaming up a few scenarios.  We could employ a fleet of airborne drones with image sensing for pests and lasers deployed to zap them.  Hmm, that sounds quite feasible to me.  How about an army of nanobots that swarm over the land to seek out pests and then somehow kill them?  And then dismember them into individual molecules rather than having the carcase left behind to disrupt the ecological balance.

Now we really are talking science fiction! A bit like Michael Crichton’s book Prey.

Last week I was asked, as a favour, to look at a portable electric heater that was not turning off (a potentially unsafe condition). It was less than two years old and came with a two year warranty. The heater looked like it had hardly been used, probably because the owner spends time overseas. Unfortunately the sales receipt was not available so the retailer would not replace it.  The box had a sticker of $49.95 on it but they apparently sold for as low as $6.00 so the retailer had no idea how much to refund.  (Hmm, but why would they not simply replace it?)

The heater was marketed by Kent, a well known New  Zealand company.  When I approached them they were unsympathetic and they did not supply spare parts for the unit.  So I decided to have a go at fixing it.  It turned out that the rotary on/off selector switch, which I managed to dismantle, had been assembled incorrectly at the factory.  One of the switch contacts was laying at 90 degrees to the position it should have been in and therefore always making a closed circuit.  I doubt that it could have become dislodged during use so it looks like production and quality control both failed on this failed unit!

Speaking of faulty goods I chanced across this video clip about a shoddy Chinese made USB hub (I think the presenter may be a fellow New Zealander).

A really bad bit of Chinese electronics

Not a video on my usual subjects this time… This 4 port USB hub has to be the worst bit of electronics I’ve ever seen come out of China. China has revolutionized the electronics industry by delivering useful products to the world at previously unbelievably low prices but at the bottom of the market, some of the stuff they ship is absolute crap.

It is of shocking quality (pardon the pun) and was faulty from new. Politicians, consumers, and manufacturers are all complicit in this sad state of affairs. Consumers demand cheap products, manufacturers make cheap products, and politicians (as well as government agencies to some degree) allow it to happen.

Consumers and the environment are loosing out.

The sales of smartphones topped one billion units in 2013.  That’s a lot!  That means one out of every seven people on the planet purchased one last year.  Gee, if only I could get to repair a millionth of that volume my profits would look pretty damn good!