Hi, a friend of a friend was talking with me and he said that his shielded garage lamp is having some problems (I don't remember what it was, but it's not the topic). This is the first time I've heard such thing. Apparently these are some examples, and checking a little bit the prices, they are freaking crazy, like between $200-400 for a lamp:



I copy the info:

Spoiler: Details

• LF shielded work lamp with clamp base
• 48W bulb luminaire included

The solid lamp for the writing and working place is handcrafted and laboriously manufactured. A friction joint with a wing nut on the lower and middle joint reliably holds the lamp arm in the selected position. A reliable working light for long-term use!

The Lamp is equipped with an E27 socket and a suitable adaptor for G9 lamps.
These G9 (230V) halogen lamps have higher lumen values for more light while at the same time lower watts for lower power consumption.

Technical data:
Metal pipes, metal joints: robust construction, reliable positioning
Aluminium reflector, diameter approx. 19cm: 2-coloured lacquered, outside in lamp colour, inside matt white
Arm length: approx. 100cm
Toggle switch: 2-pole, at the reflector
Shielding cage against electrical AC field of the luminaire E27 candle type: patented stainless steel spring coil
Shield (electrical alternating field, 50Hz mains voltage): metal housing, shielded power cable (aluminium strip, supplementary earth wire)
Tested according to the screen monitor standards TCO#99 (MPR II, DIN EN 50279): Limits for all measurement procedures with a factor of 20 or more were undercut.
Reduction of the magnetic alternating field by twisted power cable onto the luminaire: Cable strike 10 (single wires twisted ten times per metre).
Mains connection cable, shielded: Angled protection contact (Schuko) plug DIN 49441, 2m long, black
Connection voltage: 230V/50Hz
Protection class: 1 (with protective conductor) to DIN/VDE
Test: individually to 100% according to EN 60 320/2.2
Warranty: 3 years
Scope of delivery: Shielded lamp with 2m black connection cable, metal reflector, E27 socket, max. 60 watts.


Usable in the following countries: CEE-7/4 (German system) and CEE-7/7 (French system): Afghanistan, Algeria, Andorra, Austria, Bosnia-Herzegovina, Belgium, Bulgaria, Croatia, Czech Republic, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Indonesia, Italy, Korea, Latvia, Lithuania, Luxembourg, Macedonia, Moldova, Monaco, Montenegro, Morocco, Netherlands, Norway, Poland, Portugal, Romania, Russia, Serbia, Slovakia, Slovenia, South Korea, Spain, Sweden, Syria, Tunisia, Turkey, Ukraine.

I know that electric charges moving (through a wire in this case) create a magnetic field, it's Ampere's Law, coils principle basically. I understand that lamp cable is carrying 230V AC at 50Hz, creating a circular magnetic field with maximum value when the current is at its peak. Basically, 50 times in one direction (loop) and 50 times in the other direction each every single second. So very fast. So, to start with, any magnet or ferromagnetic material would not react to such a low intensity magnetic field, that is so neutral due to the 50 times it changes direction each second. If it was DC that would be another thing, although still so very low (we are talking about a lamp with what, 60W maximum if you use incandescent bulbs). So I don't understand why a lamp with twisted pair cables to lower MF, shielded and all, is sold to "the public". I mean, it sounds like something that's only useful in labs that work with very sensible sensors to magnetic fields. I don't know what's that twisted wire around the bulb either.

What's the deal with these lamps and why are them so crazy expensive?

 

They are to keep from interfering with their low oxygen speaker cables.

 

"Here we offer shielded luminaires for electro-sensitive people and for those who do not want to become electro-sensitive."

Snake-oil is always expensive.

 

Apart from crazy people, there can be issues with RFI from switching drivers interfering with the RF remotes used by garage door openers.

 

Nsaspook nailed it. It is to capitalize on the delusion of certain people that they are being harmed by EM fields.

Bob

 

What they are offering is a nice lamp with a several hundred dollar lamp spring coil 'EM shield' plated with

Spoiler

Most 'crazy' people are smarter than that.

 

I know it's funny to make jokes, but I was dead serious, hahaha. Is there any reason one would want that?
May be as bassbindevil said there could be a solid reason to use these kind of lamps in a garage so you don't interfere with remote controlled doors and that stuff?

 

I know it's funny to make jokes, but I was dead serious, hahaha. Is there any reason one would want that?
May be as bassbindevil said there could be a solid reason to use these kind of lamps in a garage so you don't interfere with remote controlled doors and that stuff?

No, No, No. Actual EMI shieding is a serious subject, this type of 'shielding' is magical thinking.

 

No, No, No. Actual EMI shieding is a serious subject, this type of 'shielding' is magical thinking.

So lamps like these (or your regular garage illumination/light set up) don't need any kind of EMI shielding or shielding at all because they don't interfere with anything?

 

So lamps like these (or your regular garage illumination/light set up) don't need any kind of EMI shielding or shielding at all because they don't interfere with anything?

These types of standard modern incandescent lighting lamp (non-led) powered devices should already have an agency emissions approval (FCC Part 15 rules) for any electronic power supplies and dimming control systems. The actual lamp is a hot glowing wire inside a bulb with some type of gas that's very unlikely to have RF detectable emissions with modern lamps. There are a few strange types that might cause problems but they are unlikely to be used on any lamp outside of an old Russian prison.

https://www.radiomuseum.org/forum/rustika_lightbulb_fm_measurements.html