* Posts by Bob 5

9 posts • joined 18 Feb 2014

Bosch, you suck! Dyson says VW pal cheated in vacuum cleaner tests

Bob 5

More Dyson spheroids...

I also filter Dyson's claims by my own experience, having been suckered by his "100% suction 100% of the time" ads. into buying one of his machines and found it was nothing of the sort as it contained two inadequately sized dust filters that clogged up in no time. How he gets away with his ads and packaging claims beats me - things like "digital motor" and "no carbon brushes means zero carbon emissions" on the DC31 packaging for instance (http://www.eevblog.com/2010/12/13/eevblog-132-delusional-dyson-marketing/)

He might have a gripe about the unrealistic EU testing regime, but I don't see his claim against Bosch's energy saving feature has any merit at all. Varying the machine's power to suit the needs of the job seems an eminently sensible feature to me. Sour grapes, methinks...

Radio wave gun zaps drones out of the sky – and it's perfectly legal*

Bob 5

Re: Hmmm... I smell an Instructables...

Just take a microwave oven, take the door off and frig the door interlock, point it at the sky, fit a drone drone detector and bob's your aunt's husband - an automatic drone free environment.....(and you'll get the odd free fried pigeon into the bargain).

Laughing gas and rubber: A recipe for suborbital flight?

Bob 5

Re: The soldering on the wirewrap area

Quite right about the heatsink area - and what looks at first glance like two big blobs of solder appears to me to be two chip capacitors to ground, probably to reduce regulator noise and to ensure stability.

Yahoo! blames! MONSTER! email! OUTAGE! on! CUT! CABLE! bungle!

Bob 5

Re: Yahoo! Mail!


Unfortunately where I live I have little or no choice of supplier, however, you don't have to use BT email or the dreadful Homehub. Just set up an Imap gmail account or two in your email client, get yourself a Billion router, (or whatever your preference is), and away you go, just forget BT's accessories.... Mind, you're still stuck with BT's 'customer service'....

Microsoft WINDOWS 10: Seven ATE Nine. Or Eight did really

Bob 5

Stick or bust?

Just built a new desktop using W7. I think I'll stick with it until 2020 as W10 looks on the face of it like a half-assed attempt to merge W7 and W8 in a panic response to a predictable user revolt. Why this obsession to do everything with one OS anyway? You just end up with an OS that does lots of things poorly but nothing well, full of lots of obstructions, annoyances and background bloat that I for one don't want. Still, as long as you can consign all those damn tiles to the recycle bin it may have possibilities I suppose.....

Are you broke? Good with electronics? Build a better AC/DC box, get back in black with $1m

Bob 5

Re: Why does it have to be solid state?

Mmm - a 2KVA M/G set the size of a laptop - now there's a REAL challenge...


Bob 5

In the 70s I had a 25" colour TV that consumed 250W. Now I have a 55" colour TV that consumes 43W. Similarly standby power consumption on devices like TVs has reduced from tens of watts a decade or two ago to normally less than a watt now, (Last time I checked, European directives specified 0.5W/1W max. standby power depending on application), so energy waste is being tackled and there is no doubt standby powers can be further reduced to microwatt levels. TV/Radio etc settings can be stored in NVRAM leaving only a micropower infra-red receiver functioning powered by a micropower capacitive coupled low loss psu awaiting the wake-up command.

In a switch mode psu, burst mode can only reduce consumption at low output levels by reducing switching losses - the efficiency of any psu at zero output is still 0% - the aim is, as always, is to reduce the standby consumption.

Unreliability caused by frequent heat cycling of intermittently powered devices is something that has to be eliminated by design - the aim being to make it unnecessary to permanently power a device to prolong its reliability - that is sooo wasteful. In my experience such unreliability isn't a great problem anyway - my TVs, computers, radios etc are all turned off when not in use and I have not experienced any untoward failures. Remember in electronic devices there are items that have a limited life, in particular standard electrolytic capacitors, (e.g. motherboard capacitors.....), so in such cases any unreliability caused by heat cycling could be more than offset by the life gain of switching off when not in use. Check the manufacturers rated life of electrolytic capacitors - you may be surprised.

'Polar vortex' or not, last month among the warmest Januaries recorded

Bob 5

Are we tilting at windmills....


Let's look at a couple of indisputable facts:

1) The Global Mean Surface temperature has increased by about 0.8°C since the beginning of the 20th. century. (NASA GISS data).

2) The percentage of CO2 in the atmosphere has increased to approximately 400 parts per million, (or to put it another way, 0.04%). This level of CO2 is c. 24 times less than the noble gas argon in the atmosphere.

As I understand it the problem with current climate theory is that there is no reliable science that links 0.04% of CO2 in the earth's atmosphere to a significant affect on radiative forcing. (This could explain the failure of the infamous 'hockey stick' projection).

Is human activity still responsible for that increase of the above mentioned 0.8°C in the global mean surface temperature? Possibly, but perhaps the situation may not be as simplistic as a simple link between CO2 levels affecting radiative forcing which seems to get all of the world's attention at great cost.

Consider for instance that every single fossil fuelled family sized automobile travelling down the motorway/freeway/autobahn at say 75mph has to dissipate c. 15Kw* (15x 1Kw, 1-bar electric fires...), worth of waste energy due to the inefficiencies of the internal combustion engine without even considering trucks, coaches, trains, planes etc. This could go a long way to explain the c. 2°C temperature difference between urban and rural areas. This is just one small example of the possible influence of Direct Energy Wastage on climate change. (There is a better correlation between the rise of the automobile than the industrial revolution on the increase in global mean surface temperature).

In the end, of course, everything comes down to population growth, (7 billion and counting towards doom), and the associated demands for food, goods, services, mobility and energy usage.

*Say 30bhp to maintain 75 mph @ 30% engine efficiency = (0.746x30)Kw = c.22Kwx70%=15Kw wasted power dissipated to atmosphere as thermal energy.

Samsung flings sueball at Dyson for 'intolerable' IP copycat claim

Bob 5

Re: Dyson overrated

Washable HEPA filters? Not mine...They may have changed the design, but the HEPA filters in my two upright Dysons were paper and not washable. When my machines lost suction after a few months use, ("100% of the suction, 100% of the time" - I don't think so...), I first removed the totally clogged 6" foam filter, (inadequate surface area for the job IMHO), washed that, dried it and replaced it and wondered why the wife was still whinging, so prised off another cover with a screwdriver at great risk of breaking the plastic and found a clogged paper "Lifetime" HEPA filter inside, took it out and threw it away - job done. At least now there's only one filter to clog up after a few month's use, and don't get me started about broken clutches and split hoses... My old Hoover Senior from the 60's was better. It even had a light on the front, and was made of sturdy aluminium.... and before you ask, much to my regret I gave it away to the local scouts after falling for the Dyson hype. Bags clog and filters clog - not much difference, really.


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