For a 100% test: You measure the resistance of your first fuse using the 4-wire method. Then you do the test. If the fuse is ok, you can measure the resistance of all your other fuses and compare it without blowing them. The good ones should have a similar resistance.

@jamesmichener7526

Ай бұрын

You would think that all fuses of a given rating and size should have a specific nominal resistance. We want more! (sorry to steal your line) How about measuring the resistance of the Bosch fuses, along with the standard deviation... to provide a reference. Then compare that to the Chinese twins

@AndreasSpiess

Ай бұрын

@@jamesmichener7526 They were very similar (I mentioned it briefly). The bad ones seem to have much lower resistances, a sign that they used high-value fuses and repackaged them.

@InssiAjaton

Ай бұрын

My concern is a bit different. I never use the automotive style fuses anywhere in my designs and also have not met them in any of my measuring instruments. But the 5 millimeters (or the 1/4 inch American) cylindrical ones are something I deal with. As well as some BIG powere electronics types. There I pay attention to their rated Interrupt Capability. I see a related number as the specified maximum Circuit Voltage. Even a reputable manufacturer of American fuses specifies their 15 to 30 A 1/4 inch fuses for use no more than 32 V, while their lower current fuses in the same housing is rated 125 V. That is based on their Interrupt Capability, which the lay people have minimal or no concept. I have chosen to avoid the “empty”, glass tube type fuses in general, at least for more than 1 or 2 A nominal rating. Instead I want to have the ceramic, sand filled ones, as they can interrupt much higher prospective short circuit currents, >200 A, rather than a few tens of amperes. Simply put, the internal sand quenches the arc when the fuse has to interrupt currents and VOLTAGES that could cause a continued arc and explosion of a plain fuse in a fault situation. The safety codes talk about fuse co-ordination and backup fuses even for breaker units. But enough said!

@Sylvan_dB

Ай бұрын

@@InssiAjaton FWIW, this american uses two standard sizes of tubular glass fuses: 5mm X 20mm and 6.4mm X 25.4mm. The latter is a 1/4inch fuse. I've never seen a 5mm in higher than 32VDC while the 1/4in (6.4mm) are available up to 250VAC (in at least some amp ratings, as you noted). The D.C. vs. A.C. is important.

@Willy_Tepes

Ай бұрын

What are your thoughts on Linear Array Solid State LiDAR Sensors? Does it bring anything useful in comparison to single beam?

I tested all my fuses and they blew according to spec, so I know they are good, put them back in the box for future use 😂

@AndreasSpiess

Ай бұрын

:-))

@tonysheerness2427

Ай бұрын

This is the problem you know the ones you tested worked, the untested ones are still dubious as the quality control shown by other you tubers can very.

@colinstamp9053

Ай бұрын

Funnily enough, it is possible to test a fuse without blowing it. e.g. kzread.info/dash/bejne/hJWH0sGliZarYrg.html

@ecospider5

Ай бұрын

@colinstamp9053 Fantastic video. I learned a lot watching it. Really though my intuition of how things react was greatly increased. It was really cool to see the resistance being so linear to the current. Until it wasn’t 🤓

@ecospider5

Ай бұрын

@colinstamp9053 To be more precise he was measuring the voltage drop across the fuse. So the voltage drop increased linearly to the current. Until it didn’t.

There is an Electronic Engineering joke about testing fuses! Yep that worked…. Yes that worked…. Yes that worked! Ah no more fuses :-)

@AndreasSpiess

Ай бұрын

:-)) Indeed, without ordering a few more, I would have had exactly this problem...

@uiopuiop3472

Ай бұрын

i will mayb buy 300 and test 250 and mean it out

@gg-gn3re

Ай бұрын

@@uiopuiop3472 It's probably best if you buy a pack and test 1 or 2 of each rating and if they're good, that batch is probably good. The brand will change every few months so just know your specific batch is good when bought

@TomasNovotny-ep5br

Ай бұрын

But what if the next one will be the bad one?😂

@uiopuiop3472

Ай бұрын

@@TomasNovotny-ep5br that what the mean values protect from

I caught Louis' video the day he published it. As I'm a US citizen, I immediately reported the video to the US Consumer Product Safety Commission. Turns out, especially for a government agency, they are fairly responsive. In a couple business days I got an acknowledgement thanking me for the tip, and noted their Internet team is looking into claims like this. Good to hear my tax dollars are at work. Hopefully they are eventually able to put a dent in the supply of bad fuses like Louis found. That's a serious fire hazard.

@AndreasSpiess

Ай бұрын

I agree that it is a danger. That is why I made the video… good to know they will disappear.

@realedna

Ай бұрын

They're already at work to take down the video! ;-)

@michaelgleason4791

Ай бұрын

Oh my sweet summer child.

@JaredConnell

Ай бұрын

​@@michaelgleason4791it's kinda cute actually, he thinks something will happen lol it must be nice to be so naive about the world

@urnoob5528

Ай бұрын

there are so many dangerous and dubious products from china that aint stopping shit

We used to blow a lot of fuses as part of our FSAE team. To save money I ended up going to the junk yard and pulling good fuses from old cars. Lots of cars still have the OEM fuses in them so it’s a great source of high quality fuses for cheap.

@AndreasSpiess

Ай бұрын

Good idea!

@gorak9000

Ай бұрын

Or learn to use heat shrink, and you won't blow as many fuses in the first place

@dominik4205

Ай бұрын

​@@gorak9000 What does heat shrink have to do with circuit breakers?

@mekkertroniker2002

Ай бұрын

Fuses also wear out, every part that carries current wear out.

@J-Eagan

Ай бұрын

@@mekkertroniker2002 That could make for an interesting video. Testing old fuses to see how closely they match the original specs. I do agree it’s probably a bit easier to blow, but I’d rather have that over the cheap fuses that don’t blow.

Just knowing the lack of quality that can come from Aliexpress, EBAY, and even Amazon, I stopped buying fuses from those sellers and started only getting brand name ones from digikey, mouser, or local stores that had a reputation. I also found AGC fuses from China to not be the same diameter and length as spec fuses, being slightly smaller on each dimension, which had me also concerned about quality. This is a great video for those who want to be safe.. thank you!

@AndreasSpiess

Ай бұрын

As adults, we have to decide and carry the risk. But to do so, we need information. When I bought my assortments, I did not know about those problems (as many of the thousands of other buyers, I assume). Now at least a few people know...

@SnakebitSTI

Ай бұрын

These days Amazon is selling the same products as you find on AliExpress and eBay. Don't buy anything important which might be counterfeit from Amazon.

@JuulCPH

Ай бұрын

Yeah me too but I actually couldn't find an affordable brand name fuse kit for 5x20mm fuses that had a decent assortment of values and the two no-name kits I bought were completely unsafe.

@paulsengupta971

Ай бұрын

I buy the AliExpress ones. I find they're a lot more resilient than the others...

Andreas, thanks for the video. Tell your wife how IMPORTANT your lab is to the rest of us!!!! Keep on going, my friend. 73!!

@AndreasSpiess

Ай бұрын

Wilco!

During my internship my mentor decided to showcase how the fuses blow, saving the system. However later we were astonished to see that the 10 amp fuse didn't blow at 25 amps! At that point, all the engineers came around and all started placing bets on when it would blow! 35 amps did the trick 😂

@AndreasSpiess

Ай бұрын

Different fuses seem to have different curves, particularly if motors are involved. 3.5 times more current would not be acceptable for a car fuse.

@tiagoferreira086

Ай бұрын

That sounds dangerously funny lol

@kevinwalters5160

Ай бұрын

There are different types of fuse, Stack Exchange has a discussion on slow blow vs fast acting.

@NinoJoel

Ай бұрын

A regular fuse for home use that is rated at 16A often only blows below 80 amps. Everything below that needs time to heat it up enough.

Fuses from reputable vendors have full sets of specifications within which they have to fall (e.g. time to blow at 110% rating, 150% etc.), and also voltage rating. The voltage rating is important, especially now vehicles with 48V+ are getting more common, as above this voltage the fuse is not gauranteed to provide full insulation once it has blown. Even the reputable brands start at 32V rating, and I wouldnt trust the no-name fuses without a spec sheet and the certification of their performance. The companies pushing these uncertified safety components should be held to account, as the saying goes "Safety standards are written in blood".

@AndreasSpiess

Ай бұрын

I agree.

@125brat

Ай бұрын

@@AndreasSpiess It is quite an eye-opener when you start to look into the technology behind fuses, as most people dismiss them as a simple piece of thin wire which burns out usually at an inconvenient time. I worked in technical support for one of the largest electrical distributors in the UK some years ago and learnt a hell of a lot about fuse types and rating etc from the older and wiser engineers about such an innocuous component. Specifications such as voltage rating (a.c. and d.c. rating) , breaking capacity, I^2t characteristics, temperature derating etc. are vitally important when specifying the correct fuse for a specific job and if you can't use a reliable fuse you're wasting your time and risking fire, explosion or worse. This problem of out-of-spec and even counterfeit fuses doesn't end with automotive fuses. I was involved with some counterfeit BS1362 fuses that were being sold by the UK's largest DIY sheds which were extremely dangerous. Samples of the fuses were tested at ERA Technology (One of the 2 UK certified test houses for BS1362 fuses who put the ASTA mark on them) with shocking results and a video showing one of the tests is here on KZread: kzread.info/dash/bejne/fYp-uNWwfMXXkaQ.html By the way, fuses don't "Blow", they "operate" 😁

@ArielNMz

Ай бұрын

>The companies pushing these uncertified safety components I'm pretty sure it's not "the companies" but people cheaping out on components

6:33 - you might want to check the specs on your IR thermometer. That red laser is just an aiming aid. The actual measurement is being taken over an area considerably larger. The size depends on the model of thermometer and the distance. To get pinpoint accuracy, you probably need to upgrade to a IR camera so you can see what is getting hot.

@AndreasSpiess

Ай бұрын

You are right. But I used my skin as a second „thermometer“. And it indicated no danger.

@bazzaar1869

Ай бұрын

@@AndreasSpiess ah, the thermal imaging finger :) I've be using it for years!

@125brat

Ай бұрын

@@bazzaar1869 In conjunction with the Mk1 Eyeball, most testing jobs are covered 😁

Using alligator clips for your test are not ideal. (unless that is what you use in the application) You should use good quality fuse clips soldered as normal. The fuse clips act as a heatsink for the fuse, cooling it and modifying the trip current. Now retired, I used to design equipment for an electronic manufacture. Some of our products included fuses. The fuse clips, and the pcb it was soldered to, were factors in the continuous current capability of the fuse. Of course ambient temperature mattered. For some products we had to use beryllium copper fuse clips because regular fuse clips would fail under high current (20 amp) long term load.

@AndreasSpiess

Ай бұрын

I agree. However, my expectation was that the fuse blows below one second @10A. So I did not expect too much heat transfer in this test.

can't believe i only found your channel this week. this fuse video was eye opening, and i've been playing with circuits for 30 years (i'm no expert, however). excellent work for all skill levels. cheers from Alaska!

@AndreasSpiess

25 күн бұрын

Thank you for your kind words!

Fuses are quite a huge topic with 48V DC Solar Battery setups (DIY setups). You have to look at the KA (kilo ampere) rating because lifepo4 batteries can cause huge short-circuit currents, which may sustain an arc (will result in a fire for sure).

@jeffschroeder4805

Ай бұрын

fuses for extremely high amperage situations are in an entirely different class from those Andreas was testing. He seemed to be testing those we were likely to be using in our electronics or automotive projects. Channels that deal with solar power projects would be more likely to provide you the information you are searching for.

@AndreasSpiess

Ай бұрын

Indeed, jeffschroeder is right. I use entirely different fuses for that purpose. And I am not equipped for testing them.

If you repair her stuff, she will stop questioning your expense’s;)

@AndreasSpiess

Ай бұрын

Good advice!

@musiqtee

Ай бұрын

Yep! That’s why her things always work - and mine always need repairs… (18 years and counting…🙏🪛💡🪫)

Ай бұрын

And then she will say to your daughter: Never marry an engineer, you will never have anything new, he will fix everything..

Not surprised about AliExpress products quality. Everyone who encounters bad sellers or products should report that and give negative feedback. That will help everyone.

@AndreasSpiess

Ай бұрын

That is what I do. And dispute also small amounts. Only if it hurts it will change ;-)

@FlnSkr

Ай бұрын

the problem is that lately, we are getting worst products on Amazon than on Aliexpress.

Fuses in engine compartments ought to be de-rated as they are preheated by about 50°C. They will blow sooner, if they don't fail due to mechanical vibration. The latter being a diagnostic nightmare if the break is intermittent.

@AndreasSpiess

Ай бұрын

Indeed, the environment. In a car is hard. Particularly in hot or humid countries. This is why I always have a spare fuse with me…

Great video, glad your fuses from AliExpress worked ok, as I've recently purchased a similar power distribution board from there. Will be looking at the fuses received to double check 👏👏👍

@AndreasSpiess

Ай бұрын

I hope they are ok!

This is very approachable test method! Thank you for the guidance

@AndreasSpiess

Ай бұрын

You're welcome!

I'm glad Andreas didn't get too angry and... blow a fuse. ;)

@AndreasSpiess

Ай бұрын

:-))

Thanks Andreas, great as usual. One could use a car battery as power source - plenty of juice in there, and saves your 'precious ' 18650 gear from abuse.

@AndreasSpiess

Ай бұрын

I agree. Just change the resistor.

Great knowledge. I had no clue I should be worried about fuses being crap quality. For testing automotive fuses car batteries are probably the simplest choice because you will definitely own one if you need fuses for a car. You need to adjust the amount of resistors/resistance you put in, though. Car batteries are easily capable of multiple hundred amps output.

@AndreasSpiess

Ай бұрын

Also a good idea. My car is parked far from my lab, so I went this way.

Fuses also have other important aspects of specifications. This includes ensuring that they do not explode, that they are able to extinguish the arc, etc. These are not elements that are replaced every day. I also believe that it is definitely not worth saving on them - because they usually protect much more expensive elements, and sometimes it is for safety reasons.

@ecospider5

Ай бұрын

I have built some 60v battery packs. I decided using these spade fuses are a bad idea since they might arc for a long time after blowing.

@TheEmbeddedHobbyist

Ай бұрын

@@ecospider5 High current current can be a real pain in the ass for fuses, as if the arc gap is not big enough they just arc over and the current stays flowing until something burns out. May be a magnet can be placed next to the fuse to drag the arc away from the contacts to increase the arc gap and extinguish the flame. in the same way they do with high power DC relays.

@danga55gan

Ай бұрын

true In Zimbabwe, there is no smorgasbord of variety, only cheap ones

@mrfrenzy.

Ай бұрын

@ecospider5 that's because these fuses are rated for 32V (24V nominal). 6.3mm and especially 10mm ceramic fuses are a very good and cheap option for higher DC voltages.

@ecospider5

Ай бұрын

@@mrfrenzy. Thanks for the search terms. I really don’t like the fuse holder options for those. But when I just searched for them I found some with leads soldered to both ends. That’s kind of perfect for the type of projects I do. So thanks for that.

Andreas, if you think those are dodgy, you should test the resetable version of those fuses!

@AndreasSpiess

Ай бұрын

Another viewer suggested also resettable fuses. But they seem to be quite expensive (>10$ each)

@tsbrownie

Ай бұрын

@@AndreasSpiess If you google "resetable blade fuse for car" you can find them from less than $2 USD up. I did some rough tests and they are slow and not very accurate. I know you're busy, but you might do a lot of people a favor by reviewing them.

I appreciate the information. I plan to test a few when I get a chance.

@AndreasSpiess

Ай бұрын

Good luck!

as always - informative, educational and well presented.

@AndreasSpiess

Ай бұрын

Glad you think so!

I just did some quick tests on my cheap generic assortment from ali. Most were at least in the 'okay-ish' range like Andreas' (breaking in a couple of seconds at 2x the rated current) but I got one 3A fuse (out of a total of 9 3A fuses tested) that withstood at least 3 minutes at 6A. I'm definitely gonna get myself some more reputable ones.

@AndreasSpiess

Ай бұрын

Thank you for sharing your results. Good decision!

@marcusone1

Ай бұрын

Why I wouldn't rely on Andreas method. If one blows on spec, doesn't mean the all will. I was like you and tested a number of them in a pack I had from Amazon. Some blew regular, some slow, some went for minutes before i gave up/ran out of amps. So I just tossed all Alliexpress/Amamzon fuse and order a whole bunch from Digikey.

Years ago, I was working as a dispatcher at the police station, a bad storm blew in and then lightning hit the building. There was a loud bang, then everything was dead, including the lights. It blew the fuses (all black) in all the radios and scanners and blasted the connector on the rear of the Motorola radio into pieces (just the cord left). I replaced all the fuses and was amazed that they all still worked, including the Motorola transceiver just needing some resoldered wires. It took out two breakers in the main panel on the wall, but we just doubled up some wiring temporarily and everything was back. I've had a new respect for name brand fuses since then in my own stuff.

@AndreasSpiess

15 күн бұрын

Cool story! You were very lucky, I think.These days, I am not sure if your damage would be so small because high voltages usually kill the delicate ICs, not the current. I assume you had a very high voltage inside your building back then.

@robert574

12 күн бұрын

@@AndreasSpiessA couple of ham radio guys showed up right after, brought some equipment and tested the transceiver and the antenna (and brought a soldering iron). They were the real heroes of the story, but the main radio fired right up after a power cord repair. I was amazed.

thanks Andreas, very helpful video. time to test my fuses too.

@AndreasSpiess

Ай бұрын

Good idea!

All fuses have a time current curve (and so do circuit breakers). Circuit breakers will trip EVENTUALLY at rated current - which is why they provide superior protection. Blade fuse replacement circuit breakers are available if protection rating is critical. Circuit breaker’s typically drop 1V at the rated current (which can be important at low voltages).

@AndreasSpiess

Ай бұрын

Thank you for the additional info!

Thank you so mu h for the test really answers my questions!

@AndreasSpiess

Ай бұрын

Glad the video was helpful!

Good video and very informative! I will check my fuses also. But good to see that there is al lot of panic about bad fuses what is not correct. I also have a assortment glass fuses. :) So you advise is to use a resistor of 3-Ohm and at least 10 watt?

@AndreasSpiess

Ай бұрын

The resistor value and its wattage has to be calculated with the voltage you use (Ohms law).

Thanks for the excellent work!

@AndreasSpiess

Ай бұрын

My pleasure!

Next time wife tells you to get rid of your stuff, tell her you'd do it as soon as she gets rid of her shoes! 🤣

@AndreasSpiess

Ай бұрын

:-))

Thank you Andreas for the PSA.

@AndreasSpiess

Ай бұрын

My pleasure!

Thank you, Andreas. Keep up the good videos.

@AndreasSpiess

Ай бұрын

You are welcome!

Great video as always Andreas! Some dubious QA going on at these Chinese suppliers. It’s a race to the bottom, who can make the fuses for the lowest cost.

@AndreasSpiess

Ай бұрын

It seems so. And it is dangerous if you do not know.

@daveys

Ай бұрын

@@AndreasSpiess - What worries me is that the whole supply chain has been corrupted. These bad products mean that trust in all the products drops. I’d maybe say “OK, well just choose the Bosch branded ones” but there are instances of fake branded fuses in the supply chain too. Your suggestion of testing just one 5A fuse upon receipt of the pack and rejecting if not performing to spec is a good one. Luckily I have all the kit to do the testing without needing to short out a Li battery…although having shorted the mains a few times, maybe shorting the battery is safer! (I’ve also been in the room when a pack of Lithium cells blew up and still remember the smell 20yrs on!)

I believe there is another very important specification that should be tested for high current lithium battery systems. I note that the fuse spec shown in video has a short circuit breaking current of 1000 amps at 32v max. Some fuses (particularly in DC circuits) can create an arcing situation even after the fuse burn out that keeps the current flowing. To test this, one needs to short the full voltage of the battery system through the fuse with high current operational wiring. This is a dangerous test and one should have standby cable cutters. I used only the current stunt resistor in this test which will also be in the operational system (and also can be connected to an oscilloscope for current measurements). With a 29 volt battery the different fuse types would typically blow between 1000 and 2000 amps. For higher voltage battery systems the fuses tested in the video should not be used. Special fuses filled with sand for arc suppression are needed. Thanks for your great videos.

@AndreasSpiess

Ай бұрын

As a builder of a 7kW Lifepo4 battery, I agree. They are very strong and you have to pay attention. However, I use different fuses there, not 5A car fuses…

Great idea using the electronic load - it surprised me I was only thinking in terms of the power _supply_, not the drain. It’s funny how sometimes you need to flip your thinking, it was one of those facepalm moments for me when you mentioned the electronic load 🤦‍♂️ Great video as always! 👍

@AndreasSpiess

27 күн бұрын

Indeed, out of the box is sometimes easy…

in my e-scooter (german brand) once a fuse burned (25A). It has burned because they didn’t installed it probably. one leg was displaced. the fuse and holder were isolated with kapton tape. i replaced the holder with one of the “water proof” black once you showed in your video. I may install a temp. measurement circuit with a buzzer :) Thanks for your effort the idea to measure the time with your scope is intelligent. Danke Peter

@AndreasSpiess

Ай бұрын

Check if these "waterproof" holders have thick wires for 25A (mine do not have it).

@so4706

Ай бұрын

Thanks, yes they are from Hella and rated for 30A fuses - i measured around 3.5mm2. the wires to the batteries seems to have slidly less then 4mm2.

Thanks for your educational vidéos. ❤

@AndreasSpiess

Ай бұрын

My pleasure!

I discovered a blown 5A tail light fuse in my vehicle and all I had as a replacement was a Chinese fuse. Great point, I'll be testing these fuses.

@AndreasSpiess

Ай бұрын

Good idea!

This is a good reason to use breakers. More expensive but SUPER easy to test

@AndreasSpiess

Ай бұрын

Agreed if you have the space.

Great video!!

@AndreasSpiess

Ай бұрын

Glad you enjoyed it!

I was gonna say that LiFePO4 is not pronounced 'life eppo 4' but honestly i love your mini mispronunciations

Wonderful information

@AndreasSpiess

Ай бұрын

:-)

Good video, as always! Bosch fuse cost vs amazon, 2x? 5x? 10x more expensive? Also, without quality control there way to be sure each fuse will perform to any spec. For low amp protection untested fuses like this are probably ok. Like you I use the cheap fuses and my only defensive strategy is to overspec the wires to help mitigate the unknown fuse quality for low amp protection. For high amp, is the cost difference really worth the piece of mind using a reputable brand?

@AndreasSpiess

Ай бұрын

Bosch: 11 Fuses for 5$ on Amazon No Brand: 80 fuses for 8$

I guess the future will be active fuses like tesla does in cars! It´s just a FET instead of a fuse and a current measurement shunt and a comperator which kills the gate voltage to the FET.. + an PWM from an IC + a small capacitor to generate the voltage to compare to! You can implement "intelligent" fuses that way, which for example have different current limits and trigger characteristics depending on operating state of the connected circuit, you can switch on/off circuits from your IC that way, thereby integrating "fuse" functionality and control (on/off) in one function.

@AndreasSpiess

Ай бұрын

Well possible. Most relay are also replaced by transistors and SSRs.

the graph tells "average melt"! any additional info in the spec about the scatter? I would want such info from such an expensive piece of "paper". It reminds me how we are made to be scared when there is any temperature anomaly wrt the "norm".

@AndreasSpiess

Ай бұрын

I did not check. But the datasheets are public ( not the norm papers)

Andreas excellent video, this was not expected, like you mentioned about TRUST, well global manufacturing does not have any type of regulation, unless the product made in another country perform the test under the regulations provided by the company to meet their requirements. I typically by may electronics these days on Amazon, I went back to test the 1A, 5A, and 10A fuses. I was wondering why my old car was frying some electronics in dash and never thought it as the fuses. When I saw this video I took the fuse that I replaced it was a 1A found that it did not blow at the expected amperage. Therefore, caused me to buy the electronics for the dash board that supports the dash instruments. I had an auto start system put in which allowed me to start my vehicle using a key fob, the tech added this to a circuit tapped from that fuse element, well from your test now we know what and why. I wonder if the glass tube fuse fall under the same demise?

@AndreasSpiess

Ай бұрын

I mainly use glass fuses in my multimeter. So far, they have blown before the instrument was damaged, but I have not tested it.

Andreas, thanks for the video! Can you do another one comparing the "normal fuse" with the "PTC" fuse? @Greatscott has done one fast video about that, but you are more technical. I'd like to implement PTC in my projects but the Trip current and Trip time for greater currents make me nervous to use it, if we compare it with a normal fuse. Example: PTC with 7A holding current will trip only with 14A and the trip time is 2s... Can I use this PTC rated for 7A (Littelfuse 2920L700/24SLER) with 8 or 9A? Thank you for your videos!!!

@AndreasSpiess

Ай бұрын

PTC resistors are not fuses, they are resistors that change its value with heating. They have a different purpose.

I bought a whole bunch of fuses for my UPS battery cells, only to discover that the max voltage is only 32V and they are low interrupt current. Now I am in the market for a Class T / high interrupt rating 60V fuse.

@AndreasSpiess

Ай бұрын

Indeed, the voltage rating is also essential for some applications. For car batteries, it is usually 24V only.

When do fuses get warm? At or near spec? I am asking because of paralleling solar modules. To prevent backflow of current thru a bad module which can lead to fire you can either use diodes (which get warm because of the voltage drop ) or fuses. If a solar panel is rated to 12A and i fuse it by 15A, does the fuse get warm during 12 hours of 12A load? Or do they keep cool even at 15A for hours?

@AndreasSpiess

Ай бұрын

AFAIK all current panels have built-in diodes to protect the cells from overheating. They take the current if a part is covered. BTW: These are not fuses for solar panels because most panels I know have an output voltage of more than 40V. As I showed. mine did not get very warm at the rated amperage.

@thiloreichelt4199

Ай бұрын

Current panels generally come with diodes to prevent the one panel in the chain being in the shade for 15 minutes being driven "backwards" (and signaling its indignation by smoke).

@kain0m

Ай бұрын

Getting warm is their method for blowing. You sinply can't overheat a fuse, it will just blow and break the current flow. Voltage rating is another consideration, though...

What devices are you making in which another component would not blow up without the fuse. I normally install them to protect the PCB only. All Plugs in U.K. must have fuses that meet the standards and there is also a fuse box backup. I guess this is mostly about battery powered stuff? Although I haven’t yet thought of a PCB that wouldn’t die. I guess the thinking is of voltage regulators blowing and in doing so short circuiting, but then wouldn’t the battery wires and PCB traces blow?

@AndreasSpiess

Ай бұрын

These car fuses are for low voltage only. This is where I use them (for example on my Harley)

At 7:50, the fuse you showed was brown, that, according to the color codes mean that it was rated to 7.5A and according to the chart you showed a bit later, seems to be totally in specs (I see that the time at when the fuse blow is below the curve). Am I wrong? Correct me please. Interresting topic, I never doubted a fuse, now makes me think about them.

@AndreasSpiess

Ай бұрын

I later discovered that the Bosch 5A did not comply with the color schema of the others. It was a 5A fuse (and you are a very good watcher!)

@sebastian19745

Ай бұрын

@@AndreasSpiess Thanks. I have seen fuses that colors are off, enough that one have to read the value to be sure.

Oh, so they exist. Interesting. I had one of those 300pcs assorti kits and like you had been giving them away as well, but after seeing the video by the ham radio guy I tested them using a 5A car battery charger. I could not get any of the 5A, 3A or even 2A fuses to blow. So... I had to try and retrieve the fuses I gave away, and I put them all in a bag for further experiments. Unfortunately I cant test the large current fuses. But I will never trust unknown fuses again unless I know exactly where they came from. (And probably test 1 or 2 of the lower range types using a charger).

@AndreasSpiess

Ай бұрын

Your "call back" was a good idea!

Perhaps ICs like TPS2553D could serve as better overcurrent protection as they also do a lot of other things, handle typical amperage ranges, and you could even just make a little breakout board with a pot to set the range.

@mrfrenzy.

Ай бұрын

If you really know what you are doing or are making a commercial device this is a really good solution, however it's easy to make a mistake in construction. Regular fuses are foolproof.

@AndreasSpiess

Ай бұрын

Good idea for low current devices (

@BeefIngot

Ай бұрын

@@mrfrenzy. Im not sure its all that complicated. The datasheet has a full schematic, and its a simple calculation to set the fuse current via resistors. You can also test it just as easily as fuses and still use it after.

@inotoff

Ай бұрын

And what happens the day your IC fails and shorts the power line ? That's why we use fuses. They are passive and can not create shorts.

@BeefIngot

Ай бұрын

@@inotoff What happens when it fails? A meteor hits and magic pixies escape from the rocks we stored them in. That is to say, with what evidence do you so proudly claim fuses to have higher reliability than this ic in countless products without any recalls or failiures noted? Anecdotes and uncle jimbobs rules of thumb? You think your smartphone uses big car fuses instead of efficient multi purpose ics? why stay in the past? Dont let a lack of knowledge and discomfort limit capability.

Fuses are a total minefield. We used to have to carry US, UK, CE rated fuse as they all had different spec. for example the 'slow blow' US fuses could not be replaced with a UK slow Blow of the same rating as they were specc'd differently. So we would need to put a far higher UK rated fuse in to stop it blowing with the surge. To the point the cct board could go up in flames with constant current! A total pain. Also in the UK the fuse in the plug is NOT there to protect the device but only to protect the cable (flex). yet people still often just leave a 13A fuse in the plug when it is connected to a 5A flex (they make 1,2,3,5,7,10 and 13A fuses) Also if I remember correctly (going back too many years since I did the course) For a fuse to be in spec (13A plug fuses) if you had 1.5 times overload then the fuse must blow within 4HOURS!! (they are designed for shorts). So if you had a10A fuse then you could pull 15A through it for 3 hours 59 mins and then it blew the fuse was in spec. You were long dead mind lol.

@AndreasSpiess

Ай бұрын

Thank you for sharing your experience. I am no expert at all. But I found that it is good to know that there are issues and how to at least check if you are in big danger.

@salan3

Ай бұрын

@@AndreasSpiess The reason for the plug fuse in the UK is because the mains sockets are on a 'ring main' with 32A MCB's. EU generally has individual feed to sockets.

@TheEmbeddedHobbyist

Ай бұрын

the point about protecting the wiring is spot on. No fuse will be fast enough to protect the electronic equipment. Normally you pick the wiring to cope with the power demand and then pick the fuse to protect the wiring.

Thank you, Andreas.

@AndreasSpiess

Ай бұрын

My pleasure!

Dear Andreas Can you find a way to use bricked Gigaset elements products with another DECT bridge, like Fritzbox? AVM sensors seem identical to the old elements. Thanks and BR

@AndreasSpiess

Ай бұрын

I do not know anything about the products you mention :-(

@davideyres955

Ай бұрын

@@AndreasSpiessgigaset are phones and the Fritzbox is an adsl router with a dect gateway, so it should be able to connect the handsets to the router as it has a POTS interface in it. Thanks for your video’s Andreas. Edit: tell a lie Gigaset elements is an alarm system so the talk of sensors makes more sense. It may work over dect.

i find some blown fuses when try to charge a lifepo4 pack ... and it seemed that precharging something was the reasson.. i still use that specific amps fuse for the cables and hope i forgot the dc converter at low rate of amps.......!!!

@AndreasSpiess

Ай бұрын

LiFepO4 batteries are very strong and easily blow fuses...

Strange, this never occurred to me even though i had never trusted cheap products, Thanks Andreas for the video

@AndreasSpiess

Ай бұрын

Increasing the price (as many resellers do) does not make a product better ;-)

Thank u for this heads up, will be testing my selection boxes, 👍👏

@AndreasSpiess

Ай бұрын

Hope they will be ok...

@nargalda773

Ай бұрын

test all fuses, just to be sure

I had one of these cheap unbranded fuses in my car. One day I found the inside of my car full of smoke. There had been a short circuit due to me installing a radio too far back which shorted the wiring loom behind it. When the fuse blew it kind of melted into a blob which shorted out both sides of the fuse and turned into a great conductor. I have never used a cheap fuse ever since.

@AndreasSpiess

Ай бұрын

That was really bad luck!

Did you consider using a large supercapacitor as an energy source rather than a lithium battery? If you used a 3V 350F 3 mohm capacitor, the voltage droop calculated from I = C dv/dt should be reasonably small, but the lower energy density of the capacitor is less likely to start a fire...

@AndreasSpiess

Ай бұрын

Unfortunately, I do not have such a super cap handy (as most of my viewers). Also pay attention: Super caps have an exponential voltage curve that results in a variable current. Maybe not what you want for this test (unless you use a really big cap).

I lucked out, only bought 1 pack years ago, tested the samples that I had the ability to test: they blew around their rating (which was twice what I needed in that circuit)

@AndreasSpiess

Ай бұрын

Thank you for sharing your results!

When im Honest, i always was under the impression thst those fuses can't be fucked up while making them because they're just stamped parts that have a known/ calculated size. Expected the accuracy to be higher than on other cheao products. I started to use ABB S200 Breakers for projects where the size is not important a while ago due to the convenience when there is already a DIN rail. But all my small projects use 5x20mm fuses from random sources. Wonder if they have similar quality issues. Since the Fuses Blow from "overheating" of the small section, i wonder how much the results are affected by the temperature of the room they're in.

@AndreasSpiess

Ай бұрын

They look nice! As you write: If you have enough space, a good solution. The car fuses also have a temperature curve and you are right, they blow at different currents at higher temperatures.

@bastiannenke9613

Ай бұрын

@@AndreasSpiess took me a eternity to find Din Rail mountable Breakers that are approved for 12/24V DC. I like Din Rails because of the modularity. Also looks more professional and you usually don't have conductive parts that are exposed. Upgrades and Maintenance are neat with those. Since they can turn off 6000A (or more), I'd expect them to last a long time. (Which is a reason why I bought some used from renovation projects)

@AndreasSpiess

Ай бұрын

@@bastiannenke9613 I use such a DIN rail for my solar plant at our remote radio station. But there, we have to handle higher currents (the highest is the coffee machine at 60A/24V)

@bastiannenke9613

Ай бұрын

@@AndreasSpiess I'd probably use a lower power coffeemaker at 24V. True, din rail stuff is great for high currents. Depending on how remote that station is, it's also great that a lot of the Breaker manufacturers have remote control options. Or as a really expensive bistable Relais ;)

@AndreasSpiess

Ай бұрын

@@bastiannenke9613 The coffeemaker is standard 220V ( on an inverter). It consumes around 1.3kW... I do the monitoring of the entire battery with an ESP8266 and MQTT.

But should we take the risk at all with a part that is really just small fractions of the device it is protecting? Especially considering the fire hazard, shipping time, etc?

@AndreasSpiess

Ай бұрын

This video is for people like me who already purchased and use these fuses. All others can decide which risk they want to take.

It's possible your batch that's taking a few seconds are "slow blow" types (while the others are standard or fast-blow) that are designed to tolerate brief overcurrent spikes. These are a perfectly normal/reasonable fuse design depending on the application, but of course you don't know what kind you get when you buy unbranded or badly labeled stuff from Amazon or Aliexpress.

@AndreasSpiess

Ай бұрын

Maybe you are right. However, I did not find specifications for "slow" car fuses, only the ones I showed.

I had a customer have a wire melt in a correctly fused automotive harness years ago. The fuse was unbranded junk from Amazon. He had more, so I tested a couple. They were way outside spec. You can't go wring with Littelfuse, MTA, or other OEM brand fuses if you care about the application.

@AndreasSpiess

Ай бұрын

Thank you for sharing your experience. I agree with the brands you mentioned. For the rest, you have to be careful.

Tested a couple of chines 5 amp fuses. 1 brand dit not blow at 15 amp even after a minute or so! Thx

@AndreasSpiess

Ай бұрын

Thank you for sharing your results. Definitively time for a change…

Thank you for the tests and your effort publishing it. You had good luck. Of course, we know Slovenia. It's inhabitant have a higher median wealth per adult than Germany (en wikipedia "List of countries by wealth per adult")

@AndreasSpiess

Ай бұрын

Good info (I did not know that fact). The remark was more for the guys that sometimes mix Switzerland with Sweden ;-)

@john-r-edge

Ай бұрын

@@AndreasSpiess Famous Slovenians (a mixture here): Philosopher Slavoz Zizek, Pro cyclists Tadej Podacar and Primos Roglic, and also Melania, wife of Trump - cannot expect all of them to be good guys and girls.

@shanent5793

Ай бұрын

​@@john-r-edge Žižek is an idiot but that doesn't make him a malefactor

Nice experimental setup for these 5A and 10A fuses. My question is about larger fuses from ebay/aliexpress etc. how to test a 100A or 150A ANL fuses for example?

@AndreasSpiess

Ай бұрын

I have no clue because I am a low voltage/low current guy ;-)

@EgonSorensen

Ай бұрын

I've never done it, but I would use a new car battery (12V, 400-600-800 ColdCrankingAmps) recharged a day or 2 ago, left to settle. Then I would take some thick copper wire, of which I know the diameter and length - and calculate Ohm/meter. Now I have a power source, a current limiting wire/resistor - which I adjust to the number of amps I need to flow in the circuit. A scope across to verify various parameters :ø) I would also test on some resettable fuses first, and likely incorporate some kind of mechanical/electrical switching to be as safe as possible

@GuidoAmbar

Ай бұрын

Probably with a good inverter welder. They reach over 100 Amps and I think they should be at least 10% accurate. They have short circuit protection, so you would have to be performing the welding arc. It is also quite safe (no high voltage).

@BenMitro

Ай бұрын

@@GuidoAmbar Nice idea, thanks Guido.

@BenMitro

Ай бұрын

@@AndreasSpiess You mean a low power guy :)

The sound at 8:52 got me to frantically search for a short circuit in my surroundings 😊

@AndreasSpiess

Ай бұрын

:-))

Do you know if the slow blow fuses were sold as actual slow blow? There is such a thing as a slow blow fuse when circuits are prone to initial startup surges.

@AndreasSpiess

Ай бұрын

I did not find datasheets for slow car fuses. It seems that one size fits all.

@kain0m

Ай бұрын

No slow / fast blow for this style of fuse - they have one defined target characteristic.

Also if you have access to a datasheet there are 2 important numbers. Theres a must blow curve and a must not blow curve. Just because your results differ from the value on the label doesn't necessarily make it out of spec or illegal unless they provide a standard (like ISO 18894 or whatever it was) or a datasheet.

@AndreasSpiess

Ай бұрын

I thought that these values are included in the curves (forever to blow=must not blow)

I've been using a lot of eFuses in my designs recently and while this wasn't among the reasons why I'll add it to the list. :D

@AndreasSpiess

Ай бұрын

They do not suffer from these problems, I assume...

@oliverer3

Ай бұрын

@@AndreasSpiess Being digital you basically have perfect control of their characteristics, they of course have other draw backs such as price and maximum voltage capabilities but they're great when you want a high level of control and something resettable.

This is why professionally sourced parts cost more. Also if you working as a professional in the electrical industry in Europe every part you use has to be traceable. So Amazon and AliExpress parts do not comply with this requirement. Like it or not it is the reason behind approved standards. For myself when I worked in the UK as a registered electrician BS 7671 Wiring Regulations is the standard I used as guidance, and every part I used had its own relevant standard that it had to comply with. In the end you get what you pay for.

@AndreasSpiess

Ай бұрын

I agree.

I found this with some fuses I purchased from Aliexpress about a year ago, they were all exaclty the same fuse/ the internal wires were all the same thickness ( which is why i did the test in the first place ). I could not actually blow one (safely). To conduct my tests I used a 12v car battery and a 12v dc to 240v ac inverter, with the fuse placed in the 12v circuit. I then placed increasing loads on the inverter whilst monitoring the current with a clamp meter. From memorty a 5a fuse refued to blow at around 30a.

@AndreasSpiess

Ай бұрын

So you definitively bought off the bad ones! Good that you know now.

I was dealing with this very problem this morning! BTW, your wife is just like my wife, but my workshop is even smaller than yours. We live on a boat!

@uranoxyd

Ай бұрын

That could be a good excuse to have every device twice ... for "load balancing" :)

@AndreasSpiess

Ай бұрын

Which problem? Wife or fuses ;-)

@Poult100

Ай бұрын

@@AndreasSpiess Haha! Both, I suppose, but I was referring to each in equal quantities. 😆

Someone who's more motivated that I am could come up with an inexpensive fuse qualifier. You won't be able to test all the parameters, but as far as current and time you could. Use an ESP32, OLED display, a high current FET, and the other miscellaneous bits. Program it with a set of nominal fuse curves, user interface to specify the amperage and any other interesting parameters, then start the test. If the fuse doesn't blow after some point, the processor can kill power to it. It'd be a pretty good basic entry level project for someone.

@AndreasSpiess

Ай бұрын

Go for it!

Schönes Video Andreas. Müsste man nicht auch mit einem Motorregler von einem RC Auto oder Flugzeug diese Ströme rel genau regeln können? Ich meine dass meine Regler am Akku bis 40 oder 60A gehen. VG

@AndreasSpiess

Ай бұрын

Ja, du kannst jede Stromquelle dafür nehmen. Ich habe etwas vorgeschlagen was in vielen Haushalten rumliegt. Einfach den Widerstand neu berechnen.

You can blow a fuse in two ways, one is overload, the other is a dead short, some may claim that it is the same, but not in my textbook. My experience with these kind of fuses is that they in real life most often blows at a dead short, I know that other peoples mileage may vary. So the way I see it is, that a fuse that may be slow is better than smart Joe's universal fuse replacement like nails, a small piece of wire, and the list goes on, the fuse is there to protect the wire not the gear connected to the wire.

@AndreasSpiess

27 күн бұрын

During a "dead short", the capabilities of the source is important. For "potent" batteries, I agree what you describe.

These have been around for a very long time lol I remember when I first came across them in a melted the fuse box. I prefer glass fuses for home projects

@AndreasSpiess

Ай бұрын

I also often use glas fuses. But for cars and motorcycles, I use these.

My spare time is too precious to test each batch of fuses I buy from junk marketplaces. I just buy my fuses from reputable sources.

@AndreasSpiess

Ай бұрын

Good point!

This in theory is what we do for breaker testing. How ever i would really recommend testing your instantaneous (short circuit) trip curve since a short is where you'll have the highest amp draw and if it doesn't open fast enough the current exponentially rises

@AndreasSpiess

Ай бұрын

Also a goo thing. I just wanted to sort the bad ones out.

That’s a relief I was worried for you.

@AndreasSpiess

Ай бұрын

Indeed, I was happy to see the results, too.

Blade fuses use the same colors for the same amperages only from Micro to Midi sizes, for Maxi sizes they reuse some colors for much higher amperages but that's not a problem because a Maxi fuse won't fit on any smaller fuse holder. *Warning: Many manufacturers use the same color or a very closer one for two or more amperages* 5A "amber" fuses can actually be brown, amber or orange. 7.5A "brown" fuses can actually be brown or dark red. 10A "red" fuses can be any shade of red. 40A "orange" fuses can actually be brown, amber or orange. Maxi 35A "brown" fuses can actually be brown or dark red. Maxi 70A "amber" fuses can actually be brown, amber or orange. Continental/Torpedo fuses *use another color code* that is almost the opposite, colors that are for lower amperages on blade fuses are for higher amperages on continental fuses.

@AndreasSpiess

Ай бұрын

Good info. I did not know that. Thank you!

Very useful video Andreas. Was it not necessary to also test for shorts, how fast they would blow or was testing over current sufficient to establish quality level?

@AndreasSpiess

Ай бұрын

For me this was ok because I only wanted to test if they are of teh bad bunch. 1 second is fast enough for me.

But I read that some auto fuses are intentionally "slow blow" to account for inrush current from motors such as power windows and wipers so that muddies the water a bit.

@AndreasSpiess

Ай бұрын

Maybe. I just did not find specifications for slow blow car fuses.

@Enigma758

Ай бұрын

@@AndreasSpiess Well it could just be that they size the fuse accordingly in that case so that the inrush is within 2x of the fuse rating. A quick search indicates 15A for a wiper motor which seems sufficient.

Thanks!

@AndreasSpiess

Ай бұрын

My pleasure!

Are there any resettable car fuse’s?

@AndreasSpiess

Ай бұрын

Yes. Another commenter mentioned them. However, they are not cheap (>10$)

For a while there was an epidemic of practical jokes involving fuses at work. People became hesitant to turn things on for fear of the flash. Some fuses made very spectacular flashes.

@AndreasSpiess

Ай бұрын

Mine unfortunately not. Not enough energy involved...

@RS-ls7mm

Ай бұрын

@@AndreasSpiess You might be amazed what happens when you put 120V or 240V AC across a normal fuse. Will light up the room.

I've just looked up the British Standard (BS1362) for the default "13 amp" fuse found in UK plugs. A compliant fuse must be able to pass 20.8 A indefinitely. At 40 A, the fuse must blow within a time window of 0.5 s to 100 s to be compliant with the standard. The 13 A rating comes from its power dissipation at that current, which must not exceed one watt. Fuse specs are surprising!

@AndreasSpiess

Ай бұрын

I learned that the fuses in your connectors (a UK-speciality!) are more like the ones we have in our distribution boxes. They have to protect the cables where the plug is mounted. Your home wires support a very high amperage. Very different to how we cable our homes.

Already did such tests on my chinese assortment. I can produce 8A with my Power Supply and neither the 2A nor the 5A fuses blew.

@AndreasSpiess

Ай бұрын

Thank you for sharing your results!

While I get the idea of this video, I disagree on the topic of buying such important parts from no name manufacturers.Fuses are kind of life saving devices. They protect our houses, equipment and even ourselves from damage. Nobody would buy lifesavers from dodgy sources. Why do we different for fuses? Don't go cheap on security. The reputable brands are only a single click away from the dodgy ones.

@AndreasSpiess

Ай бұрын

I agree. I made this video for the guys like me who did not think too much when we ordered an assortment. I would see it as a "call for action": Either test yours or throw them away without testing...

@BeefIngot

Ай бұрын

I say dont buy fuses at all (for most projects) Use ICs like TPS2553D instead.

@r_firefly4292

Ай бұрын

@@BeefIngot For your personal projects, sure you can modify your design to accommodate a current limit IC. But in most cases, a simple and robust fuse from reliable suppliers can fulfill this role just fine. Furthermore, you can also get counterfeit ICs from shady sources, just like how you can get counterfeit fuses.

@BeefIngot

Ай бұрын

​@@r_firefly4292 I don't see why this would be limited to personal projects when power management IC like this are literally created for mass adoption in commercial products. This is the most professional solution and certainly better than bodging in a fuse which wont also do things like reverse current flow prevention and over voltage protection. Furthermore, there isnt any reason you cant order from LCSC, Mouser, Digikey etc. These chips arent exactly expensive. Compared to a pack of fuses, a reusable, tunable IC seems the expedient option to me. I mean, consider this: The IC I mentioned, is quite literally the same price per unit as an assortment kit of Bosch blade fuses on Amazon, sure a little bit more if mounted onto a breakout board, but nothing crazy. Actually, if you buy the same number of these IC bulk discounting gets you down to 2/3rds the cost of a fuse. To me thats crazy. A more efficient solution for less money, from a reliable manufacturer.

@BeefIngot

Ай бұрын

​@@r_firefly4292 For personal projects? I dont get the distinction. The IC I mentioned is made by a reliable manufacturer, sold from valid distributors like LCSC, Digikey, Mouser, and is cheaper per unit than buying a bulk pack of bosch fuses from Amazon. Cheaper, more precisely set, and with a bunch of other features like overvoltage protection, reverse current protection and more makes this a great option in my mind. Adding a breakout board you still might come out ahead on price per unit and if you are putting this onto a pcb, it completely destroys fuses on cost.

The max breaking current should also be tested to see if the cheap fuses explode in flames rather than just blow. A shorted automotive battery can push several thousand amps through a fuse.

@AndreasSpiess

Ай бұрын

Unfortunately, I do not have the means to do that. But for these small value fuses they have a far too high resistance even when working to allow such high currents.

Voltage may be important in terms of dynamic processes during blowing

@AndreasSpiess

Ай бұрын

For fuses in general, you are right. To sort out the fakes, probably not. Keep also in mind that these fuses are used at 12 and 24V.

I have tested mine and have the same box, they’re fine. I do however have a smart fire alarm that does not alert even if held over a burning material. How many fire alarms from China are potentially deadly like this?

@AndreasSpiess

Ай бұрын

Indeed, a scary thing, too!

you should be able to see that they're probably halfway ok... if the fusible link is different sizes between the ratings, lower rated, thinner wire. testing one per batch would be a good idea. when i watched rossmann's vid, it looked like they were all the same size.

@AndreasSpiess

Ай бұрын

I also thought that they re-packaged some high ampere fuses and marked them with other ratings...

Does anyone know where in the U.S. you can buy a brand name 5x20mm fuse kit with a decent assortment of values? Especially something that includes smaller values like 200 to 800 mA

@AndreasSpiess

Ай бұрын

I obviously do not know :-(