More Lidl questions

[Russell Eberhardt]

On Russell Eberhardt Said:

Vast range of tools available in France online.  Many of their power tools, both mains and battery, are made by Grizzly Tools GMBH in Germany and are excellent quality.  They list four different models of welder and a plasma cutter.  My most recent acquisition is a battery operated lawn mower to replace a 30 year old petrol one.  Much easier for this old codger to use!

Shame Lidl won’t deliver to UK.  Perhaps a result of Brexit and requirement of non EU standards?

Russell

I have recently purchased within the last 6 months from Lidl-online.fr

A  20 volt battery rattle gun, 1/2 inch sq drive, mainly for removing mower blades from our tractor mower, and wheels from cars, complete with 4AH battery and charger. €39

 

A 15 mm 20 volt angle battery angle grinder cw with flexible cutting disc, bare with  battery and charger. #

Einhell.de €39

 

A  garden multi tool, a lovely sweet little 28 cc two smoke engine, + hedge cutter+ strimmer + pole pruner+ brushcutter + extension pole

Scheppach .de   €179.

And lastly a replacement compressor €149

Scheppach .de

I haven’t seen “made in PRC” on anything Lidl for the last 2 years or so.

We use a lot of the 20 Volt Lidl garden tools mainly for OH to do strimming and pruning.

They have tonight the 4 ah battery on offer at €19.99.

Compared with the prices of the mainstream tool suppliers it’s good enough kit to do what we want.

 

[Andy StopfordParticipant @andystopford50521]

Perhaps I’m naive, but I find it hard to believe that a large, respectable, EU-based retailer is really selling gear that will blow up your consumer unit, let alone bring down aircraft. Even if (and it’s a big if) their disclaimer protected them from liability, the reputational damage would surely outweigh the relatively small contribution to their profits from selling low-cost welders and plasma cutters.

The bit about Class A would seem to refer to EN 60974-10 which you can download (without paying enormous fees) here:

https://www.china-gauges.com/download/BS-EN-60974-10-2014-A1-2015.html

The relevant bit starts at page 16. I have no idea whether it really has much relevance to such small machines – they mention input currents for testing of 25A for instance. Perhaps someone who understands the technicalities might like to take a look.

[Nigel Graham 2]

On Nigel Graham 2 Said:

…Directly-radiated signal strength from a point source attenuates with radius by an inverse-square law, though I’d still not want to bring down one of the helicopters often flying over my village, albeit probably at some hundreds of feet altitude. Is that a realistic hazard with a low-powered “DIY” welder? What is the range at which they may be a nuisance to anyone, let alone a danger?

Back when I was in short trousers rule of thumb for a communication system was that a watt could be detected a million miles away.   Depends on an efficient antenna, and one of the things that makes EMI tricky is that dodgy gear puts power into the wiring which happens to be just the right length to radiate efficiently.  Radio, TV, satellite, mobile phones, Wifi, pacemakers, emergency services, aircraft, Bluetooth and utility control systems are all vulnerable.

Although not wrong to assume the nuisance extends metres rather than kilometres, whether or not poor gear causes a problem is pure luck.   The perpetrator has no idea he’s a pest unless he has suitable test gear or someone tracks him down.   Here’s an example, in short:

The mystery of why an entire village lost its broadband every morning at 7am was solved when engineers discovered an old television was to blame.

An unnamed householder in Aberhosan, Powys, was unaware the old set would emit a signal which would interfere with the entire village’s broadband.

The owner, who does not want to be identified, was “mortified” to find out their old TV was causing the problem, according to Openreach.

Note the power output of a rogue TV set is tiny compared with a welder!

The noise put into the mains may be a more serious proposition. Are 13A plug-in mains filters readily available?

Yes noise in the mains is also problematic as well, potentially energetic enough to damage nearby equipment; hence Lidl’s stiff disclaimer. They are not responsible if the welder isn’t operated within guidance that’s hard to apply in an ordinary workshop.

Though plug-in mains filters are available they don’t work well.  Effective filters are difficult to engineer and easily bypassed unless designed and installed ‘just so’.   A shielded box and carefully chosen components are needed.  These being rather pricey are often omitted to keep prices down…

Man-made electrical noise is about 18dB above the natural noise floor where I live.  Decibels are logarithmic, so that’s times 63 worse than it should be in real money!   Happened to be running a battery powered receiver when god provided a power cut and I was able to see the difference!    The racket reappeared when the power came back on.  Comes from the myriad of electrical devices we buy on the cheap, a proportion of which are dreadful or faulty.

Broadcasters deliberately beef up their transmitters to overcome high levels of local noise, but people who live in areas of poor reception suffer.   Mobile phone coverage is done with much less power, and interference is one reason the service is somewhat unreliable.  A dodgy welder persistently used in the wrong place is a hissing and an abomination.

Dave

[Maurice TaylorParticipant @mauricetaylor82093]

Hi Dave,

I presume you’ve had every device in your home ,tested for emitting interference.

Maurice

[Robert Atkinson 2Participant @robertatkinson2]

Out of interest I asked Lidl customer service about this yesterday. Today I got a response saying that they comply with all GB nd EU regulations allowing them to sell in the domestic market. When I went to respond with a snip from the welder description saying otherwise I found that the web page had disappeared…..
But I have a copy

I sent them a copy of that and await a response. I won’t hold my breath though.

Robert.

[Maurice Taylor]

On Maurice Taylor Said:

Hi Dave,

I presume you’ve had every device in your home ,tested for emitting interference.

Maurice

Any item sold in the UK since 1994 will have been tested or otherwise assessed as meeting the relevant EMC standards. At least they should have been….

[Robert Atkinson 2Participant @robertatkinson2]

Dave SOD give a good recent example of EMC that had a high profile. Those drop-outs in your streaming movie, or other network issues may well be caused by excessive emissions from electronics.

Another,not so well known interference problem recently was a light bulb interfering with aircraft communications at Glasgow airport
https://www.ofcom.org.uk/spectrum/interference/interference-issue/
When I first heard of this I thought “switch mode supply on an LED light” but I was wrong. These ase basic old fashioned filament lamps. If asked if they needed EMC testing I’d have said “no they are simple devices”. Wrong again 🙁
So what was going on? Well the bulbs had a “antique” coating that was conductive. It appears that this turned the bulb into a Barkhausen-Kurz oscillator operating at VHF.

On emissions from a welder causing a aircraft crash the most susceptable system on the aircraft is likely the Instrument Landing System (ILS) this guides the pilot (or directly controls the autopilot) down to the runway using VHF and UHF radio signals Amplitude Modulated (AM) with 90 and 150 Hz tones.
This system is basically analog and is directly decended from systems designed in the 1940’s
Note that 150Hz is the third harmonic of the UK 50 Hz mains frequency. Not a good choice here but fine in the USA where the system was developed and mains is 60 Hz.
So if the inverter in the welder is running at around 270 kHz then the 399th harmonic will be on the 108.1 MHz ILS frequency. If the inverter input is modulated by the 3rd harmonic of the mains (quite likely with cheap circuitry) you now have a signal that will cause the aircraft to diverge from the correct flight path. There is nothing in the ILS sytem that can detect this interference.
There is a theory that the 1973 crash of Invicta International Airlines Flight 435, a Vickers Vanguard G-AXOP, near Basle was in part caused by RF data links on power lines being modulated by the 3rd harmonic of the mains. Nothing was ever proven though.

Robert

[old martParticipant @oldmart]

One of the museum’s volunteers found 12V batteries complete with charger going for £10, Chippenham area, and today I bought a digital caliper for £7.50 and a laser distance measurer for£12.99. The calipers are not perfect, but better than ones bought a few years ago.

[bernard towersParticipant @bernardtowers37738]

If the ones you bought today are not perfect what on earth were the ones like that you bought before!!!. Buy cheap buy twice at least!!!

[John HaineParticipant @johnhaine32865]

Found this article on “Barkhausen Lamps” which must have been in Wireless World I think.  Written by “Cathode Ray” who was M G Scroggie.

http://www.woodjohn.uk/Barkhausen%20lamps.pdf

 

[Maurice Taylor]

On Maurice Taylor Said:

Hi Dave,

I presume you’ve had every device in your home ,tested for emitting interference.

Maurice

I have the equipment needed to do it myself, in the range 10kHz to 2GHz.  Well enough to detect issues, though not as well as a lab taking accurate measurements/

I live in a village with overhead power lines so interference carries further than normal and is difficult to trace.   Radio Frequency Interference is high enough to disable communications systems, including mobile phones.  A multitude of sources: notably switch mode power supplies, motors, electric fences, lighting, and various domestic appliances.   Despite most sources being low power, a few thousand of them nearby are a considerable nuisance. ADSL signals leaking from telephone wires are a problem, this being due to the wires not being sufficiently balanced.  A few sources are high-power; welders, arc-lamps, fizzing insulators on pylons, and motors. The authorities take no action unless a protected service is affected.

First step in eliminating interference is to test everything in one’s own home, so I have, more than once.

I previously owned a HiFi system that was very noisy, and found 4 or 5 wall-warts that were seriously mucky.    An oscilloscope wipes out a DAB radio on the same table.   By far the worst is my VFD driven lathe.  It is inadequately filtered, and despite various improvements such as screened cable, far from tamed, yet.   I need to fit a proper filter, not cheap.  But apart from the lathe I’ve aggressively scrapped, fixed and mitigated all the detectable RFI sources in my home.

Most of my domestic equipment is midrange, and I found most of it is fairly clean or better.   Open it up, and filters and bypass capacitors are evident.  Not so with ‘too cheap’ stuff – to save a few pence, components are not fitted, or are the wrong spec, or the design simply ignores the need for filtering and screening.  Judging by my limited sample, the situation has improved over the last 15 years, but there’s still a lot of tat about.

Buying too cheap is the main cause of RFI and of course ignorance is bliss; ‘out of sight out of mind’.   In this case though, I ask is it responsible to operate a cheap welder when the supplier warns it’s unsuitable?   Are we in favour of drunken noisy abusive neighbours who scrap cars in their front-garden, burn old tyres when next door’s washing is out, let their kids run wild, and own dangerous dogs that bark all night?  And that’s just the vicar!

🙂

Dave

 

 

 

[old martParticipant @oldmart]

By not perfect, I am guilty of comparing the Lidl digital calipers to my Tesa, Mitotoyo or even the Dasqua. Some edges are a bit sharp, the gibs were not adjusted and attending to these minor matters took a few minutes. A 50mm length bar shows as 49.99mm which is not bad for the price and the main difference between this one and some earlier ones is that the ways are much smoother. If I dropped this one, I would curse, but not be in tears if it had happened to the Tesa.

The VFD that I bought for the Tom Senior Light Vertical has RFD shielding chosen specifically because of where it is used. And I made sure that every cable connected to the VFD and motor was shielded, and the VFD is in a secure metal box with earth wires to the door as well as everywhere else.

[Author]

Posts