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Entries by Alan W (113)


Lumens not Watts

LED lighting

Amazing how time flies, isn't it? Since I wrote an item in 2014 on What is the kiloWatt hour, light bulbs based on light-emitting diodes have matured and are now universally available, and sales easily outstrip those pesky CFLs (compact fluorescent lights). They have virtually replaced halogen lights too, which are being made obsolete despite being more efficient than traditional bulbs. The UK vendor CPC listed 1,330 LED bulbs on its web site but only 141 CFLs, so it's obvious which was the market has headed.

The same principles of kWh power consumption costs apply, but LEDs are far more efficient than halogen bulbs, thereby costing even less to run, to the point that running costs become negligible. LED bulbs might have a fraction of the running costs of traditional incandescent bulbs, but they are pricier to buy - and budget-priced ones use the cheapest components which can fail very quickly. So I try to choose reputable branded ones like Osram, Philips or Crompton.

Lumens not Watts

In olden days (before ~ 2017) we chose firebreathing tungsten filament light bulbs based on their wattage. Everyone knew a 60W was general purpose, 40W for smaller light fittings and 100W for larger ones. A 150W bulb was the largest readily available. They were horribly inefficient (< 5%) and therefore made much better room heaters than sources of light.

Today, instead of considering 'wattage', output is described increasingly using Lumens.

For starters, a 42W halogen bulb is equivalent to 55W in 'traditional' light bulb terms and has a light output of typically 630 lumens. A popular 5-6 Watt 470lm LED bulb equates to an 'old' 40W bulb or thereabouts.  A larger 9-10 Watt 800lm LED bulb roughly equals an 'old' 60W bulb or so.

In other words, popular LED bulbs are typically selling as 6 Watt / 470 lumens (old 40 Watts), 9 Watt/ 800 lumens (old 60 Watts) or 14 Watt/ 1500 lumens  (100 Watts).

I found this very helpful guide from Integral LEDs useful.

We'll eventually get used to buying bulbs based on Lumens, not wattage. Doubtless the price will continue to drop and happily, power consumption will be increasingly negligible.

My preferred source of LED bulbs is TLC-Direct who offer great service including some very hard to get LED bulbs as well as plenty of electrical hardware.


35mm slide viewers

A 35mm slide viewer to avoid!

I’ve a collection of 35mm slides, many of sentimental value – in my view there’s no substitute for viewing original and evocative pictures on the actual film that captured a scene for posterity, like playing back a treasured tape recording of some original sound tracks hailing from bygone years.

To preserve images for the future it’s easy enough to scan them onto disk or upload to the cloud, but I think that simply flicking through a slideshow of JPEGs on a screen isn’t the same as seeing ‘the real thing’. I used my legacy Microtek Scanmaker 8700 to scan twelve 35mm slides at a time onto hard disk, but how best to view the slides themselves periodically, though?

The obvious answer is to use a battery-powered slide viewer, so for starters I tried a Hama slide viewer model DB 54. It’s a compact 2 x AA powered thing containing a filament light bulb and plastic lens, and I have to say it proved to be a complete waste of money. Here’s why: the plastic lens was of such poor optical quality that it distorted the image like crazy; I had never seen such a bad example of pin-cushioning and the centre of the image suffered from a mini-magnifier type effect. It was hopeless. Secondly, the small torch bulb produced a mediocre, dimly lit, yellowing image that detracted even more from the quality of the image.  No, the Hama DB 54 was not for me and mine’s headed for the recycling bin.

Then I remembered that, actually, I had in fact bought one of these some years ago and thought the same of it then. I’d sent it back. Catch me once, shame on you – catch me twice, shame on me!

Scouring the web for alternatives I found a neat LED 35mm slide viewer branded as PhotoLux SV-2.  Desirable features include a real glass lens and x2 magnification and it uses daylight-temperature white LEDS for a light source. It’s 2 x AA powered – and it proved infinitely better than the Hama.

To demonstrate the problem of distortion I made a 35mm transparency slide based on a simple grid and photographed the results, which speak for themselves.

Slide viewed through the Hama DB 54 [click to see]Same viewed through Photolux SV-2 LED viewer [click to see]Test slide demonstrating distortion of Hama DB 54 slide viewer [click to see]Same grid viewed in Photolux SV-2 [click to see]

You can buy the Photolux SV-2 from Amazon. For more intensive use the Photolux SV-3 handles negative strips as well as slides, has a push-button slide collection tray and is x3 magnification, needing 4 x AA but it has a mains adaptor socket as well.


World Business List directory scams

Here’s the latest in a long line of useless Business Directory listings that I've reported on in recent years. They mostly originate in Holland – this latest one purporting to be from ‘World Business List’. Apparently, updates are (still) free!

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PURE Avanti Flow – replacing the OLED display

Updated on Tuesday, March 19, 2019 at 1:16PM by Registered CommenterAlan W

Updated on Wednesday, April 3, 2019 at 2:51PM by Registered CommenterAlan W

I’ve had a few requests asking for advice on replacing the OLED displays in a PURE Avanti Flow. I managed to fix a used, working Avanti Flow which needed a new display but the Avanti Flow is much trickier to repair than an Evoke Flow as it contains a sandwich deck of printed circuit boards inside, each connected by a spaghetti of ribbon cables all located in a restricted space. A full tear-down with photos is here.

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What’s happened to Westfalia.Net?

Updated on Tuesday, September 24, 2019 at 6:05PM by Registered CommenterAlan W

Wo ist es? This online emporium run by Westfalia Werkzeugcompany GmbH was a goldmine of mostly German quality, hard to find tools, equipment and materials for the homeowner, DIY enthusiast, farmer and hobbyist. Not to be confused with Westfalia towbars, this Westfalia worktools company (“Qualität aus Hagen”) boasted 95+ years of service and had a UK mail order outlet at Seems Westfalia have abandoned the UK market and retrenched to Germany.

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Everyday Practical Electronics changes hands

Hobbyist electronics magazine Everyday Practical Electronics (EPE) has new owners. It's been taken over by Matt Pulzer, the current Editor who acquired the title from Mike Kenward and Wimborne Publishing Ltd. on 2nd November 2018. The title will now be published by Matt's new company, Electron Publishing Limited.

New title and magazine style coming in March 2019All the core features in the magazine will stay the same but readers can expect a 'refresh' and restyle and this has already started with some column artwork redesigns. The most important news is that, as from April 2019 issue (published in March), the title will revert to its original one of Practical Electronics.  The 'Everyday' moniker (inherited from Everyday Electronics, a beginner's magazine) was past its sell-by date and no longer needed, so the original Everyday Electronics title will finally be laid to rest.

Stewart Kearn of Wimborne Publishing is helping with the transition over coming months, so it is hoped to be 'business as normal'. Further changes are in the air including the website and shopping cart, the latter never really having been polished off since it was introduced a couple of years ago.

Change is in the air, with the UK's last remaining hobby electronics magazine looking to appeal to the rising trends in the maker and coding sectors. Constructional projects will still be sourced from Australia's Silicon Chip magazine and there are no plans to move away from them. One benefit is that by the time they appear in EPE, the projects have been fully sorted and sometimes updated, so EPE readers benefit from SC's  learning curve.

Interesting and exciting times are ahead, so watch this space for more news.



A tribute to Watford Electronics Ltd.

This article is a tribute to Watford Electronics’ journey from its humble beginnings as a hobby electronics supplier to a major PC system builder and IT supplier in its time.

I retrace their origins and progress, helped by Google Street View, and there's also a download of the Watford 1978 catalogue  available along with some contemporary advertisements from Watford, which became during its heyday. Read more...


Maplin Electronics - the long farewell

Reflecting on the loss of Maplin, one of Britain’s last remaining hobby electronics brands and how hobby electronics has changed dramatically since the 1970s. This article documents Maplin Electronics' rise and fall and offers a snapshot of key events along its timeline along with some interesting links, for anyone interested in the hobby electronics industry. Or just for old times' sake.

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Replacing a PURE Evoke Flow Display

Updated on Monday, February 26, 2018 at 2:48PM by Registered CommenterAlan W

Updated on Sunday, September 30, 2018 at 3:56PM by Registered CommenterAlan W

Updated on Monday, December 10, 2018 at 1:41PM by Registered CommenterAlan W

Updated on Wednesday, December 26, 2018 at 6:04PM by Registered CommenterAlan W

Updated on Thursday, March 7, 2019 at 12:38PM by Registered CommenterAlan W

If you own an old PURE Evoke Flow DAB/ Internet radio then it's likely the yellow OLED display will have failed by now. They have been impossible to find until now - at last I found a source of replacement displays so this article with step-by-step photos describes how to repair the OLED display of a PURE Evoke Flow.

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Marguerite Web Design

Updated on Tuesday, November 27, 2018 at 7:28PM by Registered CommenterAlan W

I am sorry to say that I have been contacted today by Mr. William Mairs, the husband of Margaret Mairs of Marguerite Web Design, who advised that sadly, Margaret passed away on Thursday 27th July 2017 following a stroke.

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