Microwave direct energy beam and its effect on electronics? - Page 1
Forum section: electronics / rf-microwave

author: ocset
author_rank: Super Contributor
timestamp: December 13, 2017, 05:16:06 pm
content: 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 beneath the lamp, on the ground?…..we are wondering because we are getting unexplained failures, whereas many of our other installations report no problems whatsoever.

author: Monkeh
author_rank: Super Contributor
timestamp: December 13, 2017, 05:17:53 pm
content: Seriously?

author: retrolefty
author_rank: Super Contributor
timestamp: December 13, 2017, 05:43:09 pm
content: Quote from: Monkeh on December 13, 2017, 05:17:53 pmI certainly hope not. Hint for OP...Heat Management

author: Kire Pûdsje
author_rank: Regular Contributor
timestamp: December 13, 2017, 05:47:11 pm
content: I can at least confirm that the housing is destroyed by high energy very high microwave signals.Your light are being irradiated by electric fields of up to 600 V/m.Edit:S u n l i g h t, 1 k W / s q m

author: ocset
author_rank: Super Contributor
timestamp: December 13, 2017, 05:50:06 pm
content: seriously, i reckon with a microwave power source, a bit of flexible waveguide, a cheap horn antenna, and our streetlights are toast. (maybe a stepladder to get a bit nearer the lamp so as to increase beam strenth at the electronics "target")

author: SeanB
author_rank: Super Contributor
timestamp: December 13, 2017, 05:50:46 pm
content: Kreosan on Youtube has a series of videos on this, however I would more likely assume your lights are being killed by high supply voltage or by poor supply connections, that either add way too much in the way of voltage as the line rises, or puts in massive voltage spikes that exceed the input protection devices. Long supply lines, with a lot of residential loads dropping the voltage randomly, and the long lines ringing with supply fluctuations, are a much more likely thing than them being hit with microwaves, though if your lines are near a high power RF source like a radio station transmitter ( within around 5km if the orientation of the wires is right and the length right to resonate) you can get high RF on the supply lines. If Rf from a radio transmitter then simplest is to add inductance or a trap to damp the voltage on the line, or add another transformer mid way and split the line to damp the system.For reference the street lights by me have been out for the last 2 months, because of cable faults ( mostly caused by the piss poor work the subbies do in this case) and aggravated by the poles all being occupied with bee hives that need removal. Saw the one failure as the cable blew out in the fitting, caused by them not using a cable gland to run it in, and using ordinary insulation tape to hold the cables to the caternary wires as well, instead of using a stainless steel tie and a sleeve. Then make a joint with minimal tape, and have it flapping against the stainless steel caternary as well, causing a regular arc to ground that blows the 80A main fuse for the section.

author: stj
author_rank: Super Contributor
timestamp: December 13, 2017, 07:53:33 pm
content: i looked into a "deathray" some years ago,it's unlikely - the concept is very dangerous.rember that microwaves are directional and can be reflected - potentially at the operator!!

author: AndyC_772
author_rank: Super Contributor
timestamp: December 13, 2017, 08:37:43 pm
content: Hanlon's Razor applies here. Which do you really think is more likely?a) Someone in possession of a hugely dangerous directed energy weapon is targeting street lights, of all things, orb) Your lights have a design flaw.When you say the failures are "unexplained", who has tried to explain them? With what expertise and resources?

author: Gyro
author_rank: Super Contributor
timestamp: December 13, 2017, 09:14:57 pm
content: How many threads are you going to start on your faulty light design - I count three now!https://www.eevblog.com/forum/beginners/mains-in-uk-can-go-up-to-292vac-for-periods-of-several-minutes/https://www.eevblog.com/forum/beginners/mains-transients-caused-by-air-conditioning-units-on-the-mains/and this one.... and that's just in the last 24 hours. This one smacks of paranoia!EDIT: Correction,four...https://www.eevblog.com/forum/beginners/long-mains-cable-leading-to-product-filters-noise-out-or-brings-more-noise-in/

author: stj
author_rank: Super Contributor
timestamp: December 14, 2017, 09:35:02 am
content: maybe posting photo's and schems of the product and it's housing would be more usefull.btw, electrolytic capacitors are a good starting point.i know outdoor led lights with thermally uninsulated circuits dont like nordic winters.

author: ocset
author_rank: Super Contributor
timestamp: December 15, 2017, 08:19:20 pm
content: Thanks, well our products do use big electrolytics, but we provide them in abundance so that the ripple current in each is very low.

author: jonovid
author_rank: Super Contributor
timestamp: December 15, 2017, 08:42:12 pm
content: Quote from: stj on December 13, 2017, 07:53:33 pmlooked into a deathray ...and ........... You survived............microwave ovens are dangerous

author: floobydust
author_rank: Super Contributor
timestamp: December 15, 2017, 10:36:49 pm
content: This post is on other forums, such asEDA board.

author: Neomys Sapiens
author_rank: Super Contributor
timestamp: December 15, 2017, 11:02:09 pm
content: IT'S A TRAP! The OP wants to seek out people with knowledge about destructive electrical techniques!Maybe he only wants to sabotage the LED steetlights of the competitors (phew!)but I rather think, that something far worse is planned!

author: stj
author_rank: Super Contributor
timestamp: December 16, 2017, 12:41:00 am
content: lolwell you need a long combining waveguide,with multiple magnetrons pulsed in sequence to reduce duty cycle and a shroud over it with forced airflow.now go kill yourselves!

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: December 16, 2017, 03:01:17 am
content: Paraffin lenses, folks.

author: floobydust
author_rank: Super Contributor
timestamp: December 16, 2017, 03:36:38 am
content: My friend was trying a SETI experiment, with a high-power (several kW) microwave transmitter in his basement, beamed up the (open) stairs to a waveguide and then to a massive dish antenna. I did not walk through the beam.To see if it was working, he would put his hand in the beam, and if it got warm, it was transmitting. This was a common way to test microwave transmitters, even on the DEW line. I have no idea what tweets he sent into outer space.Years later, I see he is very active in SETI:"Alien Extraterrestrial visitors who are also Extradimensional were with you guys in the dish control room as you were sending those messages! I operated the Canadian Project TARGET SETI Program for 29 years. Last April 2012, my search succeeded and I received a highly complex graphical message. I received pages and pages of data in unrecognizable alien writing, engineering and mathematical symbols for over a week before the transmission went dark. For the dummies like us at the receiving end the pages were liberally sprinkled with recognizable faces as a clever ‘this way up’ clue. What is a very significant new discovery I’ve made is that the advanced aliens do not use slow, light speed limited radio waves to communicate between the stars, they broadcast in another dimension where linear time doesn’t exist, the messages just pop out of hyperspace at the receiver with no time delay. Until my discovery we based our searches on what little we understood. My signal reception blows this wide open. There is no SETI reporting category for such an advanced discovery as mine, so the dummies of the scientific community who don’t wanna know, frankly haven’t been told. Some knowledge is far too advanced for many feeble minds. I know ‘they’ are there with you because ‘they’ are observing me closely at my facility. They have been frequent guests in my home. I have video. That is the only way I would have known.I can tell you that any further efforts in microwave, EM based SETI is a total waste of time!I am now exploring hyperspace with a Quantum Field Receiver. You cannot buy one of these, you have to make them yourself. My program is upgraded to Project Quantum-TARGET. Regards Rob Stephens, Ontario, Canada. The first to succeed in the SETI search."

author: radar_macgyver
author_rank: Frequent Contributor
timestamp: December 16, 2017, 06:58:43 am
content: Highly unlikely to be the result of directed energy weapons. Like others said, it's more likely either transients on the power line, or poor thermal management. If streetlights were so susceptible to this, the 1 MW transmitter of one of our bigger radars, coupled to a 45 dBi antenna would fry all the nearby streetlights (which are just under beam height) all around the site.

author: German_EE
author_rank: Super Contributor
timestamp: December 16, 2017, 08:43:05 am
content: Given the height of the average street pole wouldn't the Inverse Square Law be a problem here? That and the eyesight of the person operating the death ray.

author: stj
author_rank: Super Contributor
timestamp: December 16, 2017, 10:54:15 am
content: inverse-square?a microwave beam can travel hundreds of miles and still be pretty focussed - that's why they are used as point2point linksreflection is another issue.

author: chris_leyson
author_rank: Super Contributor
timestamp: December 16, 2017, 11:02:29 am
content: The good news is that you can't use multiple magnetrons coupled to the same cavity because they will all work at slightly different frequencies so I think we're all safe for now. Back to the topic, protection diodes in chips will act as wideband RF detectors and that will have an effect.

author: ocset
author_rank: Super Contributor
timestamp: December 16, 2017, 01:37:32 pm
content: QuoteThanks, you mean they will be damaged?Also, tazers i think woudl do damage to electronics?We have 1000's of units in installations that have no problem, but then some that have these weird issues.If i am honest, after reading the above, 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.Which company?....i couldnt possibly tell.....i wouldnt even give you a cryptic clue.......by the way , do you like Heavy Metal music?

author: Kalvin
author_rank: Super Contributor
timestamp: December 16, 2017, 01:44:37 pm
content: Quote from: stj on December 16, 2017, 10:54:15 amInverse square law is still valid with directional antennas:https://en.wikipedia.org/wiki/Inverse-square_lawThe antenna's beam needs to be very narrow.

author: fourtytwo42
author_rank: Super Contributor
timestamp: December 16, 2017, 01:53:06 pm
content: Quote from: treez on December 13, 2017, 05:16:06 pmHad you thought of sunspot cycles or perhaps an unusualy high concentration of householders cooking ready meals in microwave ovens in the vicinity of your streetlamps or maybe to many kids running netflix on there phones clustering under them, also actually there have been an increasing number of reports of UFO activity recently perhaps they are concentrating on your product as it contains technoligy unknown to them (or anybody else) ?

author: ahbushnell
author_rank: Frequent Contributor
timestamp: December 16, 2017, 10:21:42 pm
content: Quote from: stj on December 16, 2017, 10:54:15 amBut the inverse square law still applies.See:https://en.wikipedia.org/wiki/Friis_transmission_equation

author: SMdude
author_rank: Frequent Contributor
timestamp: December 16, 2017, 10:32:18 pm
content: So, do these failures always happen to the same location/installation, or just in a small area?Have you thought about installing some dataloggers to record abnormal voltage events on the mains power inputs? Temperature, humidity?How about some hidden cameras?I think if you did that, you would at least prove if it is sabotage or not, which I highly doubt it is, but you just never know!!

author: chris_leyson
author_rank: Super Contributor
timestamp: December 16, 2017, 11:11:07 pm
content: QuoteQuoteHi Treez, no I don't think the protection diodes would be damaged but I think I need to think a little bit a more about my blunt statement about protection diodes and RF immunity. It all depends on the silicon, is it bipolar or mos, how are the protection diodes implemented in the silicon but more importantly what is "down stream" after the protection diodes and how does that handle RF pickup. It's not something that is documented, well not in datasheets anyway, but the field strengths would have to quite high to have any effect and that's quite likely at microwave frequencies. Maybe some RF immunity testing is in order just to prove or disprove the possibility.

author: radar_macgyver
author_rank: Frequent Contributor
timestamp: December 17, 2017, 06:46:11 am
content: Quote from: chris_leyson on December 16, 2017, 11:02:29 amWell whichever magnetron fires first will back-feed energy to the rest of them, which will injection-lock to the first. This effect was exploited in the crossed-field amplifier, which is really just a magnetron with an extra port.

author: SeanB
author_rank: Super Contributor
timestamp: December 17, 2017, 11:16:43 am
content: Multiple magnetron microwave oven do exist, and are common in industrial use as driers for things like laminates, where they have a number of them in a broad antenna box and feed the laminate through, with a stub filter cavity on the inlet and outlet side to reduce radiation.

author: stj
author_rank: Super Contributor
timestamp: December 17, 2017, 11:59:19 am
content: also i said you pulse-drive them in sequence to reduce the duty cycle - you never have more that one emmitting at the same time.

author: floobydust
author_rank: Super Contributor
timestamp: December 17, 2017, 09:31:55 pm
content: Inducing a forward-current or reverse-voltage enough to damage a several watt LED, through air... need several kW of microwave power long duration, enough for the thermal effects?It would be difficult to generate in a mobile rig. Granny would notice a sinister truck driving around her front street and surely call the authorities.My city uses one dusk sensor to turn on an entire string, several blocks worth. These are crap CdS sensor and thermal-relay units that oscillate (blink on and off) at dusk.The only way to take out a string of streetlights, as an evil overlordwould be applying an overvoltage at the branch feed.But really, probably a design/manufacturing/site weakness causing failures. Wonder what the warranty period is.

author: eelearn123
author_rank: Newbie
timestamp: December 18, 2017, 01:09:20 am
content: You seem to be in a somewhat tricky situation here. Speaking from experience in other areas and dimensions of life I would say that the truth often is less nefarious that one may think.Anyway, maybe a solution here would be to build some units with additional logging regarding supply voltages and so on and installing in these troublesome locations. Maybe you could gather additional info this way.Also, maybe having some external consultant look over your designs for weaknesses.Good luck!EDIT: also maybe check out some of the failed units. In what manner have they actually failed?

author: stj
author_rank: Super Contributor
timestamp: December 18, 2017, 12:09:58 pm
content: you need to try to eliminate or reduce useage of electrolytic capacitors,and remember that these things are stuck in the sun all day and exposed to the wind all night.they need to handle exreme high and low temperatures without (for example) losing control of the current limiting.i would at the very least, try to test a few by putting them in the freezer for a few days before powering on,also heating them with a fan heater or hot-air gun for a while till they are too hot to touch before running.better yet, send them to someplace with a real enviromental testing chamber.

author: CopperCone
author_rank: Super Contributor
timestamp: December 24, 2017, 10:28:44 pm
content: ET does not want to be seen, clearly.

author: vk6zgo
author_rank: Super Contributor
timestamp: December 24, 2017, 11:10:20 pm
content: Quote from: stj on December 16, 2017, 10:54:15 amNope!The signal from a dish antenna as used in point to point links is not really "focused".It starts out as a point source, is reflected by the dish and ends up a wavefront which appears to come from all parts of the dish.It is easiest to describe this using the tools of Classical Optics, showing the signal path inside the dish and beyond as individual rays.The rays are initially radiated in all directions by the antenna feedpoint, then are converted by the dish curvature so they are all effectively travelling in the same direction, parallel to each other.The wavefront does diverge over distance, so the "rays" are no longer truly parallel at the receiving end, but there are a sufficient number which are "near enough" for practical purposes.At this point, the dish antenna intercepts some of the "rays" & focuses them back to a point at the antenna feed point.(this is the only time any "focusing" takes place)OK, the "rays" are just a convenient way early Optical researchers invented to allow them to draw those nice diagrams in your High School Physics books, but they make visualisation easier.Point to point microwave services usually top out at about 30miles or so.100 miles is really stretching things.