The Best Protection for your Circuit is NOT a Fuse!…..but a Resettable Fuse? EB#54
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PPTC Fuses from Mouser Electronics: https://mou.sr/resettable-fuses-pptc
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Previous video: https://youtu.be/1dKLF2Ma8nQ
eFuse Video: https://youtu.be/JOhQ3nsR7xo
You can buy the shown resettable fuses here:
https://mou.sr/BournsMFR050
https://mou.sr/BournsMFR090
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In this Electronics Basics episode we will be having a closer look at resettable fuses which I feel like not too many people know about. Traditional glass fuses are super popular and they basically “destroy” themselves when an overcurrent is flowing. Works perfectly fine, but that means you need to replace them and that can be a problem sometimes. Resettable Fuses do not have this problem, but they come with their own unique advantages and challenges. Let’s find out more 😉
Websites which were shown/used during the video:
https://www.mouser.de/datasheet/2/54/mf_r-777680.pdf
https://www.mouser.com/pdfDocs/eaton-ptc-resettable-fuse-application-guidelines-4.pdf
Thanks to Mouser Electronics for sponsoring this video.
0:00 Fuses are Important!
1:30 Intro
2:25 Resettable Fuses & Heat
3:39 How to Select one
5:14 Test Setup & Experiment (Trip)
7:56 Applications
8:23 Leakage Current & Power Losses
10:27 Verdict Resettable Fuse
10:45 Resettable Fuse VS Glass Fuse VS eFuse
never knew about resettable fuses before this! It’s amazing how technology is evolving to make our gadgets safer and more durable. Can’t wait to see this in action in more devices.
TIL there are resettable fuses.
It’s depend. Resettable fuse is not better in all cases
Metal bending from heat, old fashioned thermostat. Cuts power, job done.
They are great but….. the problem with them is that if they fail you will have a hard time i have got a bad batch of them and about 25% were tripping even on lover than a whole current and you will not see that for 20-30min so I shipped about 300 units of my product with them and after a week got to do a recall.
What about fast acting fuse?
In case no has mentioned this so far, ever, to anyone reading:
Fuses do not protect your circuit. Fuses protect the wiring in the wall from faults in your circuit.
In other words: The only thing a fuse protects you from is fire.
খিট খা আমার ঘন্টা কী আমি ডিসটাভ কোরি তবে এখোন কী দরকার
comparing a 0,5A polyfuse to a 1,0A glasfuse is quiet inaccurate :D:D:D… 1,0A on the glasfuse means: 1A will NEVER trip…lol
EDIT: this video is very inaccurate 🙁
@GreatScott! You are wrong about the tripping speed of normal fuses. If you take so called "very fast-acting" fuse, which is designed to trip fast – it trips in time of a few hundreds of milliseconds @ a double current. Used for very current sensitive circuits. So you had to mention the type of the glass fuse you were using. The other reason the world is not completely displaced the melting fuses with PPTCs is that they degrade over the number of times they trip. They are normally used in the environment when the overcurrent situation is rare. The other disadvantage of PPTC is that its resistance before and after it trips differs. It will never be the same again due to the material PPTC is made of. There is another type of fuse you haven’t mentioned: the so called "TBU". This guy trips in about 100 nanoseconds time (the datasheet stated time is 1 uS, to stay on the safe side) and is fully resettable. But as it is the mosfet based device – it’s very sensitive to the voltage.
What a lot of plastic bags send by Mouser. Why not all the component in just one bag with a bill of materials included ?
It is obviously that Mouser doesn’t care about the environment.
Could you use a bimetallic strip as a fuse, almost like a relay to deflects and break contact if enough current passes through and then monitor when the current drops to zero to activate a relay to keep the contact broken
Hi, Im following you from more than two years and then I came across this vide, can you help me with what temperature sensor module you are using for measuring temperature?
Polyswitch fuses were a revelation to me when I encountered them. BUT they are not as fast as fuses, since they need to physically heat up to increase their resistance and break the circuit.
They are great for some applications – like inside a phone which is powered by a battery. But for higher performance power sources they might not protect circuits quickly enough to prevent damage.
I came up with a self resetting fuse once. A big neodymium magnet glued to the back of an 8 gauge cable’s lug, attracted to a plate of iron below it, that would touch the copper lug to a hunk of graphite. Then there was a spring pulling the lug up
When the lug got hotter than about 80C, the magnet lost its magnetism and the spring pulled it back up.
Then when it cooled, it would make contact again
I got it to trip once off of 60 amps at 12 volts on a hot day, but I never made any real use of it.
I am thinking if I could use this to replace one fuse in my car
In many countries, using a resettable fuse in primary side is illegal.
May cause a death, fire. Youtube needs to crack down on these idiots.
I requested components for my brother’s 100 ampere fuse, I will use it in the car
what is that green piece holding the glass fuse? 6:38
Residual current device.
I learned something new! 🙂
I’ve seen these on circuit boards of equipment I’ve worked on or disassembled. I had no idea what the long tubular thing with what looks like heat sink blades was. Now I know. Thanks for the tip !
Resettable fuse: varistor
I often use an incandesent lamp of suitable size.
Great!
A 3D printer blew a fuse, but it wasn’t the fuse’s fault. The fuse connection corroded, causing resistance to heat up the fuse until it blew, partially melting the fuse connection housing. This circuit wouldn’t help with that. Perhaps some WD-40 will preserve it. Or.. maybe it will help if it monitors temperature.
Gamer laptop.
Thanks for the knowledge 👏🏻
The advantage with convention swappable fuses is , the onsafe situation is being lifted and the device needs to be repared and the fuse swapped , but in the case of such an PPTC element the overcurent situation is not lifted if it’s not detected right away, the circuit is broken for a while but when the PPTC cools down the circuit is restored , thus creating a loop , there should be somethin in place with a relay circuit that switches it off other wise the situation is being maintained ?, or am i seeing that wrong?.
Thank you for your good video, I’m almost at the end now, as a noob I had to ask the following question:
Can I use them into a DIY variable power supply from a PC power supply, like in all the videos that are on youtube about it or is it not a good idea and if so why?
Thanks for your help.
Your videos are great! Scott🎉
If current instantly crosses rated Amp, will thermal fuse be blown just like normal glass fuse?
With a suspect mains powered device a good way to prevent blown fuses is to initially power it with a LARGE mains light bulb in series with any input lead … the bulb might glow dimly indicating a working device …. should the bulb glow with full brilliance , the device is VERY faulty , and should be fixed ( but your fuse will be OK ! … tried – n tested ) …. DAVE™🛑
I did not know about them neat.
Resettable fuse… You mean like a breaker 😂
What resettable fuse can i use inside a battery pack , i saw a guy who put one on each cell in his pack to prevent too much current being pulled . is that a good idea ?
+ Thank You for all your vids cheers =)
In ny Opinion, you should use both but using fuse for much higher currents when the pptc might for any reson fail
I’ve never seen a blown glass fuse without a nearby component being blown up too.
Very good video as usual. Where can I get some electronic books on this and transistors and… And…
I was an electronics engineer working in Central Texas.
Mouser has a Dallas TX warehouse, I could order parts in the afternoon and get them the next morning via lowest cost ground shipping. It was great!
Now I am retired and pinching pennies and buy my stuff via AliExpress and wait a week or two.
I use a 10A circuit breaker for my WLED setup, it’s all 12V based and the breaker fits in an automotive blade fuse holder.
I have a UPS for my modem and router and I would like to use a PPTC. The full current of both combined is 4A. What PPTC should I use?
Could this be used with a relay so that after the relay is triggered the pptc goes into a low power state but enough for the relay to stay on ?
eg; I found that a 12v relay will trigger above 8v and stay on until the voltage drops below 4v .
You let the magic smoke out!
I have a Laney Cub series valve/tube guitar amplifier that uses a polyfuse in the heater circuit. They were notorious for tripping under normal use, leaving the amp silent after about a minute of use. I forget whether it was defective components or the wrong rating being used.
What about DC resettable breakers? Ive replaced my trucks fuses with some because changing fuses is cumbersome, especially when you only need 1 and you have to buy a 15 pack 😂
you can find usefull ones in old USBv1 hubs too 5v 1amp max
left handed!
modified batterry bms shoul be as reseteable fast fuse
You have such a thick accent but you enunciate so well.