Microwave direct energy beam and its effect on electronics?

[treez]

Hello,
This article states that unshielded electronics can be destroyed by directing a high energy microwave beam at it…
https://en.wikipedia.org/wiki/Directed-energy_weapon

…We wonder if some of our competitors are doing this to our streetlights?

In all our lamps, the LEDs are obviously unshielded….also in some of our lamps, the drive electronics is unshielded and just sits next to the LEDs, under the transparent Perspex optic enclosure.
How easy and cheap would it be to make one of these weapons?, good enough to knock out streetlights by someone stood on the ground, beneath the streetlight?…..we are wondering because we are getting unexplained failures, whereas many of our other installations report no problems whatsoever.

 

[volker@muehlhaus]

You decided to leave out filters to save cost, ignore good design practice, question safety standards and interpret DALI levels to your liking.

 

[betwixt]

It's fairly easy to make one but I think it might get noticed:

1. operated by people in chain mail.
2. The 10KW generator they would need to carry with them
3. The large steerable dish/horn and long waveguide.

If you see anyone matching that description I would contact the Police or local mental health authorities. Going to such extremes to damage a competitors products would be highly cost-INeffective and dangerous to the perpetrator. If they really wanted to cause trouble like that, an air rifle would have much longer range and be just as disruptive for a tiny fraction of the cost.

Brian.

 

[biff44]

what are the exact symptoms of the failures? Are they all the same component?
It would be relatively simple to make a perforated metal cage to shield the electronics for your lamp/driver....


it might be more likely that you have an EMI ingress problem, either spikes on the mains line, or magnetic coupling, or even nearby lightning strikes.

 

[KlausST]

Hi,

When I see failures of devices ... then most often it is because of:
* wrongly dimensionated electronic parts
* bad PCB layout
* mechanical or thermal stress
* bad manufacturing, assembling, soldering

Klaus

 

[vfone]

You don't need fancy equipment to make these failures happen.
Look to these $^#@& guys and you understand why:

https://www.youtube.com/watch?v=FIU8WZR9DNA

 

[FvM]

Hem. It's not actually a microwave beam. You have to talk about antenna directivity needed to attack a streetlight.

 

[vfone]

At the minute 2:00 of the film above, the guy use a 2.4GHz Coffee Can antenna (Cantenna), which is a directive antenna with about 10dB of gain.
This provides a microwave beam which can be used for a particular direction.

**broken link removed**

 

[treez]

Thanks, i suspect that the microwave "gun" of the video is indeed real......i reckon it would mess up some LEDs that it was pointed at.
It might even mess up the delicate silicon structures inside an IC or transistor.
I also think a tazer could do some damage to the LEDs too.

 

[Kajunbee]

Google " four reasons led lights fail - remi ".
It states that industry standard failure rate is 3% but that some are seeing failure rates as high as 20%. The point being that your not the only one that's having trouble with high failure rates. I know it's little consolation but unless someone is sabotaging these other companies also I think you can put the ray gun theory to bed.

 

[BradtheRad]

This topic reminds me of stories about ground fighters removing doors on microwave ovens, defeating the safety interlock, then aiming them at the sky so they would act to decoy radar from enemy fighter jets and missiles. Skeptics dismissed the stories as hard to believe. Yet now that I see the Youtube video linked in post #6, it seems plausible to knock out electronics the same way, exposing it to microwaves from a tampered oven. In the case of a streetlamp, by lifting the appliance up close.

 

[betwixt]

The failure mechanism when irradiated with microwaves falls into two classes, the first and obvious one is the parts get fried in the same way as food gets cooked in a domestic microwave oven. Given the difficulties of generating high power and directing microwave radiation in a portable device, this is an unlikely method anyone would use to cause deliberate damage. Consider that even powering a small domestic magnetron would draw around 100A from a 12V battery!

The second and far more likely scenario is the microwave radiation induces voltages in the components and connections that makes the circuit malfunction and go into "self destruct" mode. For example, the LED driver feedback voltage jumps from its normal 0.5V to 0.2V which makes the driver turn hard on and cook the LEDs. The lengths of PCB tracks and probably thousands of semiconductor junctions makes this a relatively easy task. Ask anyone who has operated a HF transmitter and they will have noticed strange things happening nearby such as calculators that enter digits without keys being pressed, digital displays that suddenly get extra segments lighting and of course the very common "funny noises coming from the stereo" complaint!

It is possible to design defensively but it is wise to consider probability too. By far the most likely failure reason is defective components rather that malice from competitors. Don't take the manufacturers specification for granted, especially when dealing with smaller manufacturers, confirm them yourself as part of the "goods inward" QA regime. We have all seen claims like "3mm white hyper bright 50,000 lumens 3V @ 25mA" in adverts, treat them with the respect they deserve.

Brian.

 

[treez]

Thanks, another point is how a tazer would affect electronics in a clear transparent enclosure.

If i am honest, i think our competitors have colluded with some of our customers, to get them to agree to hand over a few of our products, and then they destructively operate them, putting goodness knows what overvoltage to them...and destroying them...i think this because we have a vast number of installations which report utterly no problem with the 1000's of our products.

This also, i dont think is that wide of the mark..., we often receive phone calls from people pretending to be a customer and asking for samples etc, and asking technical questions, and able to support vastly in depth technical conversations about switch mode power supplies, they are obviously not "customers" at all. They tell us they want to install vast numbers of our products, but they dont seem to be from any kind of company at all.....at least, not one that they own up to.....won't give their company website....

Also, some months ago, i was telephoned by a recruitment consultancy about a job in a place which has a premises in the north of uk, its not a British company......they told me the job was to reverse engineer products from companies like LPA Excil, and thus produce products of their own.

 

[betwixt]

A tazer would have zero effect, it relies on direct electrical connection, apart from the remote chance of very short sparking, the technology doesn't allow penetration by any other means. If your LEDs and circuit board are within say 5mm of the reachable outside surface of the enclosure it might have a chance at arcing through but I doubt you or anyone else would produce a product like that.

It is unlikely deliberate collusion is taking place but it wouldn't be unusual for a user, particularly if the financial stakes are high, to obtain products from several companies and evaluate their performance under extreme conditions. That is part of good product selection management. In a previous incarnation I had the responsibility of cycling PCs for days on end at all combinations of mains voltage, humidity and temperature from sub-zero to 70C to see which were most reliable. It was surprising how many would fail diagnostic tests, particularly at minimum voltage and temperature but recover under less extreme conditions.

Reverse engineering is rife and always has been, it's something you have to live with but you can take steps to make life difficult to the pirates. Always make sure programmable devices are copy protected and remove the products ID. If feasible, make software recognize the hardware before it will operate, that makes cloning harder because any slight variance can stop it working altogether. Also make sure serial numbers are recorded and embedded in the product and not just on a label, it won't stop copying but you get the satisfaction of saying telling customers it isn't your product that failed! Hidden check features might also help, for example an unused pin that actually makes something happen if you send a particular sequence of bytes to it. Someone producing a 'work alike' software would almost certainly never discover and duplicate it.

Brian.