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Thank you so much! If you liked that, you might enjoy my wavelength of light video where I laser print a diffraction grating to do it: ruclips.net/video/WwQXQrm33JM/видео.html

Yes! By no means accurate to retest without letting it cool down. A better (longer) test would be to try at 20A, 25A, 30A etc, measure the trip time for each, and between tests let the temperature of the breaker go back to ambient. Not sure how long it would take. - probably a few hours. Probably should also test at various ambient temperatures, and also multiple breakers to see how consistent they are.

Yes! Military subs do : ruclips.net/video/cPxYYwFiK0k/видео.htmlsi=Zn_JEbXGwHXq-hhb&t=852

Ebay - its a vintage piece of equipment. Unfortunatluy they dont make them any more. You could make your own by winding a coil on a suitable frame of some kind (doesn't have to circular - could be rectangular).

Thanks! And welcome aboard!

If you look for the subsequent videos I did, the 14-2 cable was placed in the middle of 2x4 walls surrounded by typical household insulation. The safety margin which was you point out was large for the 14-2 cable in air almost disappears in those situations. The 15Amp spec for 14-2 is to ensure that its safe in virtually all situations it would ever normally be found in, and also when operated with a breaker that may allow up to 2x the rated current to flow for something like 30 minutes before tripping. Hope that helps!

Thanks! Yes - I was particularity interested in how old devices would behave - had they slowed or become less sensitive over time. Like you said - nice to know that even the old ones I tested seem to work well and should save lives.

Exactly!

Not quite sure what you mean. Reluctance circuits are a pretty standard way of approximately calculating magnetic fields in this sort of situation. Here is a link a that describes it in a bit more detail: eepower.com/technical-articles/magnetic-circuit-properties-understanding-reluctance/#

Your comment made me look a a broken GFCI receptacle I had disassembled to confirm it was the spring that was used to open it when tripped and it was - a solenoid is used to release the spring. Some regular breakers use the AC through a coil to help speed up the opening sequence. I'm so intrigued I will have to open some GFCI breakers and see how they trip. The spring powered trip - as you point out, there is speed limit based on the spring force and its own mass, but add to the the mass of the contacts being moved. I guess the conclusion is springs do hold enough energy in proportion to their mass to be able to accelerate and move really fast. You expensive GFCI experience. I probably would have made the same mistake. You right about how gfci's sense the current so that cant be the issue.My guess is it is the tripping electronics and solenoid used trip it. The trip solenoid would be powered from the normal line side of the breaker. With the generator attached, its now on the load side. If a ground fault was detected, it would try and trip, possibly begin to open the breaker, and loose power to the solenoid and sense electronics before the it can finish opening. It would close again, let more power in and essentially become a high power buzzer circuit, probably generating all sorts of spikes and passing current through a solenoid that was only intend to be activated for a few ms. So with spikes and solenoid heat, destroy the breaker. Thinking a bit about generators, many have ground and neutral tied together, and so would the power service to you outbuilding (if not directly, via you house's main panel). So not surprising that there would be ground currents tripping the GFCI under normal operation of the generator. Fascinating! Thanks for sharing that - good thing to know!

@@ElectromagneticVideos Reading your analysis, I flashed back to the event (pun intended), and I do recall the breaker destruction was accompanied by a brief loud scary buzzing noise. So I think you nailed it. Thanks for that, I consider that one less unsolved mystery in my life. I recall pondering long and hard about whether to disconnect neutral and earth at the generator, but I don't remember what I decided. In hindsight, they should definitely be disconnected, or the return current would split in some proportion between earth and neutral according to their relative impedances, and you never want current purposely flowing through protective earth (green wire) except in a fault situation. The feed cable from the generator was pretty long, and the large metal frame of the generator is connected to the green wire, so I suspect there was enough stray capacitance to cause enough earth current to trip the GFCI breaker even if not connected to neutral at the generator.

@@miltonthecat2240 To add to that, being outside, there could easily also be in various things also leading to leakage. I do have a few of those GFCI breakers I used in the video - I may try and re-create what happened to you. Of course a different brand of breaker ma behave differently. Do you recall what type of breaker that was?

@@ElectromagneticVideos It was a Square D HOM250GFICP (4884006004)

Interesting! Great way to save power! Is there any issue with nuisance tripping with a so many devices on a single RCD? I gather the trip fault current is 10 to 30 mA for most home RCDs in Europe which probably alleviate the problem. Regarding the the 32A 240V circuits - I'm always amazed to see how small your circuit breakers panels are compared to ours. I;m sure you find ours to be gigantic! The crazy thing over here is there is enough space to put a fuse in our Canadian/US power plugs - some Christmas light string do that. We should have that at least on extension cord plugs.

@@ElectromagneticVideos When RCDs were first introduced they were often implemented as a "whole house" RCDs - with the RCD placed inline before the distribution board. That certainly did have nuisance tripping issues. One of the main problems that brought was the total lack of discrimination - any fault caused a loss of power to the whole installation. It made electrocution less likely, but breaking your neck falling down the stairs in the dark more likely! So that quickly evolved to "split load" consumer units, with only the more risky socket circuits on the RCD side of it. More recently multiple RCDs with circuits split between them has become normal, and the trend is towards "all RCBO" installations (a RCBO is a "Residual current Circuit Breaker with Overcurrent protection" - basically combined miniature circuit breakers and RCDs, so every circuit gets its own RCD). For shock protection, 30mA trip threshold devices are normal, and sometimes 10mA devices are used in particularly risky situations. 30mA keeps you out of the danger zones in the time vs shock current curves. Most domestic installs don't have nuisance tripping issues unless there is actually a latent fault somewhere, but some loads can me more problematic. Lots of IT / electronic kit on a circuit can cause problems with the combined effects of multiple mains input filters, each with a small leakage current adding up. Kitchens / utility rooms can also be another with lots of mineral insulated heating elements that can become leaky if they get any moisture in them.

@@johnrumm4786 Interesting - I can see the unintended consequences of a whole house RCD plunging the place in to darkness. The combination of many RF filters causing nuisance tripping - I actually had videoed the leakage current from some power input connector filters and was going to point out how multiple ones can be an nuisance trip issue but didn't include it due to the video getting too long. Thanks for mentioning it! I didn't know heating elements get leaky due to moisture. Over here we dont have things like that on GFCIs - just ground for protection. I suspect its because we feed them with 240V from our split phase system (two opposing phase 120V wires = 240V) which requires essentially two GFCI breakers connectd together ($$$).

@@ElectromagneticVideos The mineral insulated elements found in ovens are a common culprit. With age and repeated heating and cooling, the metal case can develop cracks. That can allow moisture into the element where it combines with the magnesium oxide insulation, creating magnesium hydroxide which is electrically more conductive. In regular use it does not matter - the heating will drive out enough moisture to stop the situation getting worse. Infrequently used elements though can get to the point they cause a nuisance trip. Historically we did not have things like cooker circuits RCD protected, but the current wiring regulations require RCD protection for any cable that is not buried more than 50mm deep, or not fully enclosed in an earthed metal sheath - so that has lead most new installs to have RCD protected everything. The basic install would be two RCDs with circuits distributed between them (mixing lighting and sockets on each storey so that you don't lose both together in one location). However the price of RCBOs has fallen quite a bit (~ £15 each), so having one for each circuit is not unreasonable. That means the effects of a RCD trip are limited just to the circuit in question.

@@johnrumm4786 Your RCBOs are cheap compared to ours - often i the $50 to $100 range! So with RCDs on everything, do you have arc-fault or combined arc-fault rcd breakers as well? AFCI breakers are being required almost everywhere over here these days - may not be an issue for UK/Europe since you houses are usually brick and concrete and dont go up in flames like our wood framed houses. (correct me if I'm wrong!)

Actually I have an AFCI receptacle to do a video like that - assuming I can get it to trip. I think all I can hope for is series arc since would be hard to make parallel one without tripping a breaker via simple over-current. Funny you mention nuisance tripping - I replaced my 20 year old table saw for that very reason. The basement has AFCI breakers, and they began to trip when the saw was turned on - I think the brushes are getting old and sparking a lot. The new saw solved the probolem, and the old saw in is the garage which was wired before AFCI was a thing. I gather the newer ones are better at reducing nuisance trips. You wonder how many AFCI breakers have been replaced by for situation like that?

As always your comments are so interesting! The first hand GFCI experience is something - interesting that you felt a jolt but not much more - so glad the device worked! I never thought about it before, but many small appliances like blenders a double insulated without a ground. Find for normal use but in your scenario, not much protection. At least with a ground to (internal) metal parts there would be some chance of it intercepting the current before it get to the sink full of water. Great example why kitchens and bathrooms should all have GFCIs. My kitchen doesn't - has 15A split phase non-GFCI - should replace the outlets near the sink with GFCi ones even if one looses the split phase advantage. Your history of the two 120V plugs before standards - there must have been some confusion in the early post war years as two horizontal prongs were phased out. I guess the one good thing is that 240V 2-15 outlets were probably rare so little chance of 240V getting into a 240V device. Probably the biggest issue might have been having to change plugs when moving into a house with modern receptacle. Reminds me when I was a kid and we lived in various countries that had inherited the British power plug standards and often different houses - or rooms in a house - needed different plugs (rectangular or round prongs,and big or small). It seems to have taken them longer to standardize.

@@ElectromagneticVideos well, the good news for your kitchen circuit dilemma is that the 240V GFCI circuit breakers, are made in 15 amps and have 3 load terminals, L1, L2 & neutral, designed for split outlet, technically known as a multiwire branch circuit in the National Electrical Code, in the US anyway, other countries may have different names for this circuit, which has the advantage of using 3 wires (plus your safety ground of course) to run 2 circuits, thereby saving money in labor and material, this is why you typically see this in homes built in the 1990s and older. Since two pole GFCI breakers run between $120-$160 per breaker, and dual function AFCI/GFCI breakers are not yet manufactured and would be SUPER expensive if and when they are, we don't use split outlets in kitchens today, we run two separate 20 amp circuits for the kitchen small appliance circuits instead. For a 240V circuit that doesn't use a neutral and needs GFCI protection, such as for a 240V 20A outlet in the garage for a 4000 watt portable electric heater for example, you would hook up the black and white to L1 & L2 terminals on the breaker, the neutral terminal would be unused. The white wire in this case should be marked with black or red tape or similar method since it is being used as a hot.

​@@Sparky-ww5re Unfortunately, I think both the outlets near the sink are on the pony panel that can bring in power from the generator, and its all tandem breakers. But on loads on those are the radio and can opener, so loosing the extra power isnt that bad.

Did he try to zap himself though a GFCI? I sure wouldn't try that - no matter how many views it might get :)

@@ElectromagneticVideos Electroboom has two sides, which he himself complains about. When he pretends to be naughty and hurts himself, his video gets millions of views. When he is serious and tells correct things he gets thousands of views….

@@emilalmberg1096 Doesn't surprise me! My most popular video is when I test to see how much current can go though some standard house wiring and the wiring burns up in the end. I get that he playing up to the RUclips audience - and is certainly good at it!

I remember you mentioning the garage project a while ago - glad its progressing! That fiberglass insulation is horrible stuff! One bit of advice - make sure there are no gaps that mice could get into it and be cure to cover the vapour barrier with plywood, osb or drwall - I have had cases where they chew though the plastic vapour barrier and make a mess inside the insulation. Anti-rodent spray foam is a good way to seal any entry points. A GFCI protecting all outlets is great protection - did the same for my basement workshop. But keep any ceiling lights on a different circuit so your arnt in the dark when the GFCI trips. By the way - I got a bunch of florescent lights free from a local business that was upgrading. Have the a large number of them all over the ceiling like in an office building. The extra light is fantastic - particularly as our eyes get older! How big a cable do you have providing power for the garage? Big enough to put in an outlet for a construction heater (240V 30A). Would make it much more comfortable on cold days.

@@ElectromagneticVideos I am required to have a light switch at entrance, running through a GFCI . Guess it could just turn on one light and rest run off other circuits. There is zero electrical in there yet but I bought a 200 amp breaker box. My son offered to let me have an house trailer heater he has. Said it worked fine when removed. Is fairly small but should be plenty and it is electric so 240 volt circuit would be needed. You spoke of the extra light. Yes, that is what I wanted. A lot of light, like in an office. My 69 year old eyes would be more relaxed I think. led shop lights is what I was going to put in. But, I want lights that dont buzz when a photocell or photresistor sees it. Slow motion video would also suffer with the wrong lights. But that is a later problem to deal with. BTW , thanks for the advice about mice. First time ever messing with fiberglass and I bought $50 worth of googles, gloves and mask plus wore a long sleeve in a hot garage. Really sucked but it is done. Ok, I said enough. Will let you get back to makeing more great videos/// 😃

@@55Ramius Maybe one gfci to the light circuit, and another to the workshop outlets? By the way - outlets above where the workbench will be are so helpful. 200A panel and 240V - excellent! Use 12-2 for the outlets if you can! Lights the electronic ballasts in standard T8 fixtures with either old fluorescent bulbs or LED-replacement bulbs are flickerless. I use both in my workshop and for "movie lights" aimed at me in front of my electronics bench where I do the intro to the videos. Way cheaper than new LED fixtures if you get them used/free. I really like 4100K color temp - half way between sunlight and incandescent. I have about 20 two bulb fixtures in workshop - area about twice yours so if you can do 10, it will be wonderfully bright. "googles, gloves and mask plus wore a long sleeve in a hot garage" - been there - done that - not fun!!!!!!!

No worries - I will keep my eye open for it so it doesnt get lost in the junk folder!

Your welcome! Finding out how good (or bad) GFCIs actually are, particularly older ones that have aged, is something I have wanted to for a while! I feel much more reassured about the 24 year old ones that were installed in my house when it was built. Tested some of them too - all seems to be operating similar to the ones in the video.

@@ElectromagneticVideos I have a couple that nuisance-trip, either that or I have a genuine hazard ... I might test the devices with this technique.

@@jeremiahbullfrog9288 The variable resistors I used were Digikey CT2160-ND. But a simple 30K to ground would create a 4mA current (hopefully no trip) and a 20K one, 6mA (hopefully trip) which would be a good simple way to do it (even wire the resistor right into a 3 prong plug.

Ha - most people hate the math :(

That is interesting - I had read in 230V places its usually between 10 and 30mA. Sounds like you have a whole or half house one - also explains why such a "large" trip current - would be easy to get nuisance trips from all the electronics we that have RF filtering with capacitors to ground creating trickle ground currents. I'm guessing they are designed to trip very fast if the current is exceeded to stay within the green safe zone. I was actually going to mention the higher tip currents in to 230V places - unfortunately the video as getting too long :(

@@ElectromagneticVideos It's certainly a deep and broad subject. Even with the limited amount I know about the things I could write pages about it. In places that implement TT earthing you will often find a 100mA to 300mA master RCD (RCCB) that can cut off power to the entire installation to protect the wiring against earth faults, but there will also be 30mA devices to provide personal protection on all the final circuits too. In Australia where most installations have a neutral/earth link RCDs are almost exclusively 30mA, even ones built into sockets but they aren't all that common. Different ratings are available such as 10mA but you'll only find them in specific circumstances such as medical etc. The IEC standards that a lot of countries use as some sort of basis for their electrical standard says RCDs may act between 50% and 100% of the rating (30mA would be 15 to 30mA) but must act at 100% or higher. Time to act can be up to 300ms but typically far far less. With electronic (EC) types (has circuitry in the device) trip time is fairly divorced from the level of imbalance directly but can have a response time change built in while magnetic (EM) types are directly influenced by the level since the trip is run directly off and solely by the CT. There are standalone RCD testers used by electricians to see if a device is performing acceptably, as well as multi-function testers that are a magic box of tricks that does anything and everything - voltage, low ohms resistance, insulation resistance including PI and DAR, fault currents and of course RCD testing. EC is cheaper to make but vulnerable to loss of neutral and due to the difficulty of manufacture 10mA devices are 99.9% likely to be EC rather than EM. Where the risk of loss of neutral (not a PEN fault) is considered to be a problem a functional earth wire to the RCD provides a backup 0 volt reference for EC. EM devices don't need neutral and phase intact to operate, put sufficient current through either L or N of the device and it will trip without the other wire being attached. These are different from the magnetic latching type of GFCI you have over there, those types exist in 'IEC' countries too for circumstances where you don't want equipment springing to life randomly after a power failure. GFCIs at 6mA would be classed as electronic (EC) type RCDs. The spec sheets for GFCIs, including 240V ones, that I've read talk about requiring a neutral for the device to produce it's internal power supply. No neutral = no function. A magnetically latched device will release but not because of an earth fault, just that the device's supply went away. Whoops, almost started writing pages ...

@@ElectromagneticVideos 40ms max at the nominal trip current. (In my experience, most manage 20ms or better (2 cycles at 50Hz))

@@johnrumm4786 So really like the "fast" ones I tested.

@@ElectromagneticVideos The standards in the UK used to require all sorts of tests be done on RCDs to verify their operation but recently they relaxed it quite a bit and now follow the IEC standard more closely. RCDs are now considered to be working correctly so long as they trip at no worse than 300ms at the rated trip current for a non-time delayed device. As current rises above the rated value the trip time decreases, same as with GFCIs over there. BTW I made a fairly long comment to this thread 2 weeks ago and only just noticed that youtube shadow banned it. It can only be seen by sorting by Newest First. Nice.

I think that an unfortunate thing is the human body as a load is quite variable. If skin is dry, the resistance can be in the 10s or 100s of k Ohm range. Much less if damp or wet. If the skin gets broken, resistance drops dramatically - after all inside we are mostly salt water. Old time electricians used to test for power by touching wires. One told of of a friend who wasnt thinking and did that with a 600V circuit and blew the end of his finger off- higher than a few hundred volts the field is strong enough to puncture dry skin and make good connection with the salty flesh. Your point about complex frequency and time dependence is a really good one - in a crude sense we probably look like salt water from a skin depth perspective - so higher frequency electricity - even a lighting spike which has a lot of higher harmonics will tend to stay close to the surface - which I suspect is why you often see surface burns from things like that but the person survives. Being wet from rain also probably helps lighting victims. Same thing with Tesla coil currents - they tend to stay on the surface. One thing I edited out of the video due to it getting too long - harm can also depend on where current flows. If its in one toe and out another toe on the same foot, you could probably get get a massive shock without it being lethal. However, in one finger and out the feet, while passing though the heart/lungs and its life threatening. I'm guessing the accuracy of the chart isnt as well verified as we would hope, other than 5mA or less is probably ok for mot people in most situations.

@@ElectromagneticVideos Thank you for the extensive reply. Yes, as always, things can become really complicated once you dig deeper.

@@Potti314 Your welcome! The added complication is what always makes this stuff so interesting - at least to me :)

@@ElectromagneticVideos Quite often we see 10mA trip limit RCD being specified for use on farms where there might be underground cables run near livestock. Animals can be far more susceptible to fatal shocks from any voltage gradient on the ground - the wider foot spacing exposes them to greater potential difference, and any most electrical paths will be past the heart.

@@johnrumm4786 I have also heard even it it doesn't injure them, it can do thing like reduce milk production, presumably because they arnt as comfortable (some farmers around here have installed blow up mattresses for the cows and have had milk production go up from happier cows!). I going to have to ask one of my electrician friends if they do anything special for cow barns etc in terms of keeping ground currents low.

Absolutely! I dont know visible it is in the video , but there is a stub of wire on the other side of the splice that is the remnants of the wire that continued on in that direction. Unfortunately, that wire was cut close to the splice. Not only would the current have been distributed along the splice as you describe, but also the additional wire have conducted some heat away from the splice, increasing its ability to deal with high currents and the associated heat. So yes, not a perfect test. But it was done with what I had available!

I would certainly suggest arc fault breakers for knob and tube even if they are not required. How much additional safety that might add to a knob and tube installation that may have been subjected to renovations over the years is perhaps up for debate, but if replacing knob and tube is not an option, its at least somewhat better than nothing :)

It sure would - I didnt do exactly that but did some videos with modern 14-2 embedded in insulation. The resulting safety margin was concerning!

Plating was apparently also to keep the Sulfur in the rubber insulation from corroding the copper.

Your asking how I matched the 50 Ohm signal generator to the 75 ohm cable, right? I cant find my notes as to what I used, but, a "T" shaped resistor network should work: Three resistor, connected together, one to ground, one to the 75 cable and one to the signal generator. The ground resistor and the signal generator one are 27 Ohms, and the one to the 75 ohm cable is 56 Ohms assuming the signal generator has a good 50 Ohm internal source impedance. If the signal generator does not have a good 50 Ohm internal source impedance, a simpler two resistor voltage divider can be used: 82 Ohm resistor to ground, connected to a 1k resistor to the signal generator. The resistors are connected together and that point is connected to the cable.The cable will see about 75 Ohms but the signal generator will see a bit more than 1K

@@ElectromagneticVideos Thanks for the reply. I mean the resistor here 2:26

@@dayworkhard Oh - OK! So that resistor is the idealized version of the resistor network I described to you: the signal source is a perfect zero ohm voltage source, and the resistor matches that to the cable impedance - in this case it is 75 Ohms. The real signal generator I have is close to that - but the (built in) resistor is equivalent to 50 Ohms because it is meant for 50 Ohm systems. The simple voltage divider I described mimics this well - the 1K resistor is so large compared to the impedance of the source, the voltage on the signal generator side of it is almost unaffected by whatever is attached to the cable side and is a perfect reference point for measurements. And the 82 Ohm resistors combined with the 1K makes the cable "see" the circuit I drew even if it it isnt quite identical!

That's a great question an a topic for a future video! Amazingly the characteristic impedance (a pure resistance in a perfect cable) comes out of an equation from the inductance per meter and capacitance per meter of the cable, both of which are purely imaginary impedance. The imaginary parts cancel - and the restive impedance represents the ability of the cable to carry signal - or power - away from the source end. So - since inductance per meter and capacitance per meter is what determined the characteristic impedance, thats what we change to change the impedance. The two main factors are the geometry of the cable and permittivity of the insulator between the conductors. So by changing the diameter of the inner conductor or shield, or even the shape (2 parallel wires for example rather than coax) or the insulator(air, plastic etc) we can obtain different impedances - and thats how its done. Hope that helps!

@@ElectromagneticVideos thank you

@@tonymon875 Your most welcome!

So the stand-alone inverter output (to power things off grid) has 120V L (Line) and N (Neutral) terminals. The transformer you use should should be a center tapped 120/240 transformer with terminals L1 and L2 and N being the center tap terminal. note: it may not be labelled that way). You hook the N transformer terminal to the inverter N terminal, and the transformer L1 terminal to the inverter L terminal. So that way the output of the transformer is 120V to N for each of its L1 and L2 terminals and the voltage between L1 to L2 being 240V. Note that you need to be sure that under no circumstances can the transformer ever be connected to the grid or other external AC power source or the grid power may damage the inverter or the inverter power may energize a the grid and injure anyone working on repairing the grip during a power failure.

Thanks!

Thats interesting! So you are indicating that the Great Stuff Fireblock is not much different from regular Great Stuff, and the DAP FireBreak is much better? "This video suggests that the quest for better home insulation could very well result in trapping overheating wires and risk of fire." Yes - exactly! No its a worst case for every thing scenario - but I sure would be careful with a cable expected to be used for extended period of time close to its rated amapcity in the middle of modern insulation in an already hot environment - ie running though an attic powering an air-conditioner in the summer. I would certainly increase the wire size a gauge or two from that required by code in that type of situation.

Thank you so much! I really appreciate that!

Its low voltage - only concern is burning my fingers if it gets too hot.

Oops! I guess I should have never mentioned math :)

Interesting you put you it that way. For year I have thought Apples must lucrative "innovation" was turning technology into fashion - and it has so paid off for them. I shake my head at that, but shows how successful marketing can be. There is an element of that in Tesla, but not nearly as effective. Regarding planned "advancements" Year ago I read an article how shaver manufacturers were doing that in some developing countries but with technology they had developed year ago in the west: essentially marketing more and more advanced shaft razers to them one after the other, followed by electric plug in shaves and then battery ones etc. Probbaly had to do that today with the internet spread of information, but sire shows how providing am upgrade path is intensely lucrative.

Thanks so much Kevin! Thats what I was trying to do - so glad it came across that way! Really applicable to this area with all the hi-tech companies and startups around here!

There isn't really an easy way to measure the impedance without some form of RF equipment.or scope/signal generator. I assume there are no identifying numbers on the outside of the cable? Any idea what it was originally used for? Bottom line, if it is for audio, or a short distance standard definition video application, almost any cable will be OK. If its for RF, the most common impedance values are 50 Ohm and 75 Ohm. Assuming your cable is one of these, and you need one of these impedance's, you will get some refection if its the wrong type. Unless you are dealing with a very low power, marginal signal, most receive applications will be OK. Transmit situations are different - some power amps can be damaged by reflected signals, but if you are dealing with transmitters, you probably would have the equipment to test the cable.

Thank you very much! Your answer helped me a lot, i will try if it works then, it was 4g antenna coax but i wanted to use it for tv signal

@@Boz1211111 Your welcome! Usually for wireless stuff 50 Ohms is the impedance so expect a mismatch with TV which is typically 75 Ohms. If you have weak signal issues, 50 <-> 75 Ohm transformers are available (google Minicircuits as a typical but not cheap supplier) to prevent the mismatch. A cheap LNA going into the cable may be a cheaper solution.

@@ElectromagneticVideosThank you! signal is probably strong as its working without issues for now but i learned so much so i know what to take into account

@@Boz1211111 Excellent!

Thanks!

You mean in living areas?

I just stated the equation - neat that you had a real go at it. This is where I wish one could post images in the comments - as good a job as you did expressing math in text only form, its always so much easier to appreciate if one has the luxury of seeing it as one might write it with pen an paper or with an equation editor. Thanks for posting!

vibration & shock tests - I an always amazed at how little vibration or an extended period of time will eat though wires if they aren't secured and rub against anything. The people who ruggedize things for vehicles must do close to the impossible - I did aircraft shock and vibe and that seems to be nothing compared to what a car on a bumpy road experiences - or the thermal cycles from a car left in the sun in summer and outside in wonder. I have some "poor man's" shock and vibe and temperature testing setups at home that I made for initial testing of product before paying for formal testing - will have to make a video about them . Sounds like you have done a lot of product stuff too - few people really understand what goes into taking prototype and making it into a real product.

@@ElectromagneticVideos yes a varied lot..in total..but spread in time over 25 years working in a company.. I was with the R&D div. in the Power Electronics group...besides 3 years in another production unit of our Industrial Electronics div... Being in R&D was a real plus point we were involved in all aspects of the products..from concept ,design , mtl.proc., prototypes, batch, mods ,production , comissioning , cust. support...etc. ... ...the whole gamut...so there was interaction mixing with all strata vertical & horizontal..and all were treated equal & respected

@@ElectromagneticVideos Very true about vibration & the" G" tests...one of our products wasso large..that only one facility in the country supported that size...& it was a 3 days journey by road transport for the product U.T. to reach there.... & after the setup in the 2nd axis "G" test one of the door hinges failed.... Yes we were on hot bricks...during these tests... incidentally this product was an inverter for railway coaches (govt. org.)..& their specs are stringent like you mentioned..as for aircraft.

@@analoghardwaretops3976 How cool! You have a very similar background to mine, other than I tend to deal with signals stuff rather than power. All those things you mentioned are so critical to productization - I will have to do a video on that sometime!

@@analoghardwaretops3976 Wow - you dealt with bid stuff. I never gave a thought to railway stuff - not surprised its a lot like for planes. Did you ever do stuff for the navy? There was one test where you mounted the item at the end of a sea-saw type structure and an a weight was dropped from a set height on the other end of the sea-saw, all while the device was operating. As I recall the device had to survive three drops in a row. Was to simulate the shock from a torpedo. The issue we had was the (small) circuit board flexing and shorting to the chassis. The solution was supports under the PCB. Hadn't thought about it in years - your having to take the product to a distant location for the test reminded me - same thing - only facility in Canada that could do the drop test was in Halifax.

You not the first one who has said that :) Funnily enough, I have never actually seen that show. I'll have to find it and look since apparently I am starring in it :)

Apparently in many manufacturing facilities, floppy drives and 8088 PCs are not uncommon even today. I once had to interface to something to a DOS PC in an air traffic control application!

@@ElectromagneticVideos That reminded me of a telco site I had to do some work at in the very late 90s. There was an early serial number genuine IBM PC (not XT) in a rack acting as a gateway for some dial-ins. It booted off a single floppy that loaded the bridge program directly, no DOS.

@@retrozmachine1189 No DOS! Wow - that itself is amazing! Those were the hardcore computer days!

Yeah - it really shows how simple, seemingly inconsequential small design changes can really have a huge impact on the life of a product - and how likely it is to sell. I tend to avoid electrolytic capacitors whenever possible. I have also had commercial network switches fail due to electrolytics in the power supply (one that failed at the beginning of a weekend and I had to fix by swapping capacitor because there was way to get a replacement till the first few days of the next week). So as hypothetical as it is, there are some parts based on reality :)

I sure hope you dont :) Look at some more realistic video I did with the 14-2 in a walls filled with different types of insulation. Its scary how little current can produce a significant temperature rise!

Thanks! Really appreciate that!

Thanks again! I really liked creating that video!

Wise move! I cant say I have never used it - but rarely too. I actually use slow wireless charging overnight most of the time - mainly to minimize wear and tear on the connector.

If I had a choice, I would buy only appliances with simple mechanical controls - fridges, washer, dryer, stove all worked just as well as they do now, but didnt seem to fail. Sadly you cant get appliances like that any more, at least= in the developed world. Like your experience, we bought a used 1950s fridge around 1970 when I was kid. It lasted for years and was working when it was replaced only because it didn't have automatic defrost. I do have on remnant of the non-digital days - a mechanical timer controlled microwave. Still works perfectly after about 30 years, and has the added advantage of not wasting power when it is not running. Funny - I do remember the avocado coloured appliances! In many ways way better than modern stainless steel that shows every fingerprint!

@@ElectromagneticVideos *cough*SpeedQueen*cough* 😉

@@TheOtherBill Long lasting? or not? As I recall Maytag was supposed to be well built back then.

Thanks you so much Phillip! It was great working together on this and hope we get to do another collaboration sometime. Yes - quite wild hoe modern technology makes collaboration across half a continent possible and getting to know someone without ever meeting in person. It was great to see some of your real examples and observations - plain theory is nothing without real things to back it up. People so often forget the skill need to make or repair things - I was looking at some of your surface mount soldering with envy - I struggle to do decent surface mount work!

Good points for sure! And to add to that, the biggest issue I find is it is impractical to use them for anything other than quite small power supplies due to the relatively small capacitance values. If you need 1000uf, its hard to beat electrolytics.

Certainly agree we need to build things that can repaired for sustainability! I think part of the issue is that large scale manufacturing has made things so cheap, that the cost of labour to repair if often hard to just even when an item is repairable. I try and do "repair rather than replace" for the exact express purpose of sustainability. Less practical if you have to pay to repair rather than doing it yourself. I did read somewhere that one of the Scandinavian countries did something like repair expenses deductible on your income tax. The added bonus of that is the money paid to repair stays local.

@@ElectromagneticVideos agreed. but stuff is being made specifically to not be repaired like smart phones and apple laptops. When it comes to repair costs, I think people need to learn practical skills and to repair their own stuff. Farmers are great with that because they need their equipment running right away and don't have time to waste taking to repair shop. People should be able to sew, do basic mechanical/electrical repairs of appliances, repair their homes doing plumbing-electrical/drywall. It's crazy how these basic skills have been out-sourced to paid professions. I in part blame education system that doesn't teach practical skills.

@@Jon-hx7pe "People should be able to sew, do basic mechanical/electrical repairs of appliances, repair their homes doing plumbing-electrical/drywall." YES!!! It can be both a huge time saver to not have to wait for a tradesman to show up as well as huge money saver. While I am all for things like the right to repair and ability to repair, I dont think its a practical for most people to be able to do that. The miniaturization needed to make a smartphone also makes it hard to repair, but at least an independent local shop should be able to do it. Laptops should be easy to open an repair. A great example is the old Dell Latitude E series laptops - so easy to open and change parts (and also a great keyboard which is why I still use one!). Education system - I wonder if they still have shop classes? Even way back when I was in school shop classes were discouraged for anyone going to university. Luckily I took electrical shop which was a great lesson house wiring. Wish I had taken auto shop and machine shop.

@@ElectromagneticVideos there were no shop classes when i was in school in the 90s, but it may vary but school. I really liked the old lenovo-thinkpads for durability and repair. its been downhill since 2011 or so with the new designs.

@@Jon-hx7pe The Lenovos/Thinkpads were actually my other option when I went for the old Dell Latitudes. Similar design approach. What bugs me most of all with the new ones is the lousy keyboards - flat keys are terrible for touch typing. Style over function :( You know, they should have some basic combined shop class - change a receptacle, change the oil on your car, basic carpentry etc. Would be way more valuable over the coarse of a lifetime compare t. o many other courses in high school!