Also known as a fusible link, a circuit element that is designed to fail when the fuse rating is met or exceeded. It works on the principal of heating a precisely thinned piece of metal as the current flows through it. The higher the current the faster it "blows". Fuses typically are low ...
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3answers
260 views
Can a fuse be placed after a load?
Considering that the regular treatment of a fuse is to place it on the positive side, "before" a load, is this just common practice, or is it backed by an actual reason?
Can a fuse be placed on the ...
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3answers
55 views
DC Fuse Placement?
Imagine the following world's simplest diagram:
12V Battery -> 5V/3A Voltage Regulator -> Load
My question is, would a 3A fuse best protect the circuit if ...
0
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0answers
28 views
Trying to replace a Sun 1/2 amp mini fuse
I am trying to replace a fuse on a board and I'm a novice. The fuse itself is labeled "Sun 1/2 amp" and looks similar to ceramic, although I am not certain of this. It is held to the board by 2 leads. ...
0
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1answer
80 views
Choosing Fuses or MCB in 24VDC vehicle circuit
I am currently designing a 24VDC circuit for a small vehicle. I personally prefer using MCB's since they are simple to reset and easy to detect faults in the system, although i do find it rather hard ...
8
votes
3answers
204 views
Why might a multimeter ask for “wrong” fuse sizes?
Why might a multimeter ask for the "wrong" sizes of fuses?
On the front of my Fluke 87 multimeter, the two probe ports for amperage are labeled as fused at 10A (max) and 400mA (max). When opening the ...
1
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1answer
100 views
Grounding in a DC circuit on a vehicle
I am working on a vehicle with batteries, but i am not quite sure if my grounding solution/design is correct. It is supplied with two 12VDC batteries in series, connected to a DC-DC (24VDC-24VDC) ...
-2
votes
1answer
47 views
Cheap switch 125V 5A fuse blew [closed]
Cheap switch glass fuse blew, 125V 5A. Found a 125V 8A fuse in a string of Christmas lights. Can I use it to replace 125V 5A?
1
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1answer
77 views
Live-Neutral transformer fault
In this critique of an ELV PSU design, it is suggested that a "Live-Neutral" fault could result in a fault current of thousands of amps. I'm sceptical. Please could someone explain how this could be? ...
6
votes
2answers
285 views
ATTiny85 not working after burning bootloader
I am having a problem with my ATTiny85. I should mention I use Arduino as an ISP to program it.
My ATTiny worked fine until I decided that I need to step up the clock speed from 1MHz to 20MHz so I ...
1
vote
5answers
383 views
Why do 0.02A fuses not protect a person? Why no protection from shocks?
I understand the user here so that fuses do not protect people from shocks. I am planning to put put fuses such as fast-blown fuses and PPTC fuses around all kind of positions such as ...
2
votes
1answer
96 views
Fuse settings in ATmega128 Micro controller
I am working with ATmega128 board. The datasheet states
ATmega128 is by default shipped in ATmega103 compatibility mode
In ATmega103 mode, the MCU both serial communications cannot be used and ...
3
votes
3answers
173 views
Building a power supply, want to stay alive
I am building a power supply for a very old laptop. The circuit uses a transformer (220 V primary to 15 V secondary, 33 VA) and that worries me a little. (Please note that I an enthusiast and so far I ...
9
votes
1answer
163 views
Understanding fuse specs
Can somebody please help me in understanding the fuse specifications. Actually i went through many fuse parameters. I am getting cofused between the hold current and the cut-off current since there is ...
2
votes
1answer
159 views
What does 3AG mean in “Fuse Block 3AG”?
I have read from a vendor website. It mentions 3AG fuse block. What does 3AG mean?
2
votes
1answer
856 views
How to check if my multimeter's fuse is damaged?
I recently bought a cheap multimeter. I played around measuring stuff on simple circuits and I think I managed to damage it as I don't seem to be able to measure current anymore (always get zero ...
3
votes
1answer
86 views
Question regarding fuses
What is the difference between thermal fuse and MOV and polyfuse.Which is faster and also which companies produce polyfuse, especially in Asia.
I have to search for a component that can save my ...
2
votes
2answers
164 views
Should a fuse with the correct amps, but is physically too small, still power my stereo unit?
I'm not sure if I'm asking the right kind of question for this site. But if someone could help me, I'd be grateful:
I blew a 125V 2.5A fuse in my home stereo head unit. I couldn't find that fuse at ...
2
votes
1answer
127 views
Will an opening fuse cause an inductive kick, or not?
I'm looking at designing a high-current crowbar circuit. We need to blow a 1400A fuse on demand. One question that has arisen is, what about inductive kick? If you short a large capacitor through a ...
9
votes
2answers
222 views
How to ensure my device is safe for every day use?
I have put together a simple wake up light. It has an external powersupply, at the moment rated 7V and 600mA. Inside it has Arduino and bunch of LEDs controlled by a MOSFET.
It works fine at the ...
1
vote
1answer
237 views
How do I choose the right replacement fuse for my multimeter?
I have a BK Precision 2709B Multimeter. I managed to blow the uA fuse (500mA/500V fast blow ceramic) on it. Is it an ok to replace this fuse with a 500mA/1kV fast blow ceramic fuse? What impact would ...
5
votes
1answer
341 views
'Voltage Fuse' or better
I have a power supply with multiple outputs (5v, 12, 24v)
According to the manufacture (and after testing) there must be a minimum load on the PSU for it to supply the stated voltages. Without a ...
2
votes
2answers
142 views
Negative Voltage Breakers?
I've been reading a bit on negative voltage, but I have a question that will probably reveal some ignorance, so I apologize ahead of time. If someone tells me that they want a (2) 5A breakers, (1) ...
8
votes
3answers
388 views
Blowing a Fuse to Permanently Disable Functionality
Certain electrical designs require permanently disabling hardware functionality on the fly. Sending an overcurrent to a weak fuse may be a method for accomplishing this, breaking the circuit in a ...
2
votes
1answer
150 views
Are those some kind of timed-resetting fuses in DMMs?
Yesterday, I did something dumb, in a hurry. I wanted to check the AC voltage at the terminals of a hair-dryer, to determine the voltage being applied to the terminals of the AC fan behind it. ...
1
vote
2answers
551 views
Where should I put the fuse in this circuit ? Critic the design
I've the following circuit , that used to measure the current through shunt resistance ,
The circuit have analog & digital ground ,
the terminals 1 ,2 ,3 are for AC source .
I need to protect ...
1
vote
1answer
269 views
Not sure how to replace a blown fuse in a building's fuse box
One of our fuses in our secondary fuse box just blew. Luckily, there there is a backup. I am not an electrical professional but I know a little 101.
I just want to ask about the correct fuse / amps ...
12
votes
4answers
2k views
What not to do with a Multimeter
So I just bought and installed a new fuse for an analog multimeter I scored for free and now it works like a charm. The new fuse is the same rating as the blown one I found inside, which is 0.5A ...
3
votes
2answers
733 views
Why do PTC fuses have different voltage ratings depending on package size / hold current?
I've been trying to figure out the PTC fuse I want to use in a little automotive power supply circuit and I'm a little disconcerted by the max Vdc ratings most of these things have.
For instance, ...
10
votes
5answers
4k views
Fuses: What are the practical differences between Ceramic and Glass cartridge fuses
What are the practical differences between ceramic and glass tube cartridge fuses?
I am trying to find new fuses for a piece of consumer electronics. The original fuses are going out of production.
...
2
votes
2answers
405 views
Low value manually resettable adjustable electronic fuse
I might be asking for too much with this one, but I hope it is out there. I would like a fuse that can be reset, but not automatically. I need to be able to know that the fuse is blowing and with a ...
5
votes
5answers
6k views
Why does fuse blow up sometimes?
Sometimes once in a year, either one of main fuses or a fuse in room blow up due to something. What is the cause of this? Why do we even use fuses? Is it because the voltage doesn't stay at 220V all ...
1
vote
1answer
541 views
Are thermal fuses polarized?
I have a device with a thermal fuse in it. The fuse has failed, and I would like to replace it.
Does thermal fuse have a polarity, similar to an electrolytic capacitor, or is it the same with normal ...
4
votes
3answers
2k views
Should I use slow fuse or fast fuse?
When I design something or going to add a fuse to place where fuse isn't used now, should I prefer slow or fast fuse? I understand that this depends on situation, but I'd like to hear what do you ...
3
votes
4answers
9k views
Slow Blow vs Fast Acting Fuse
Is there any way to tell the difference between a slow blow and a fast acting Fuse? I had one blow in my amp and I know its 125v 5a, but i'm not sure if it is a slow blow or fast acting fuse.
Is ...
1
vote
1answer
456 views
Do fuse blow on ampere or effect?
I have a faulty car (bad central locking engines) and a fuse is blowing every time I open/lock the it. I'm looking to do a quick fix, and just replace it with an automatic fuse. The car runs on ~12V, ...
7
votes
4answers
2k views
Fuse blowing in 12 multimeters rated for 200mA, only measuring 12.5mA. Why?
I'm a high school electronics teacher and while doing a lab on Ohm's Law we just blew the fuses in 12 out of 18 brand new digital multimeters while measuring current, and no the meters were not hooked ...
4
votes
4answers
3k views
How do I choose a fuse?
I realise this is an extremely broad subject area but I need to know how to choose a fuse to protect a circuit.
Recently, a cheap PSU of a friend's blew up quite spectacularly (the two primary ...
3
votes
3answers
244 views
Are PTC fuses called some other way?
I recently learnt about the existence of PTC fuses, and I'd like to use one for an USB power supply I'm building. I guess there are PTC fuses on the PC side, but you never know.
I went happily to buy ...
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vote
2answers
196 views
My power supply tripped the RCD
I also posted this at All About Circuits but I thought I would get some more opinions as I'm quite worried.
I was using my power supply to power an electronics project (Super OSD.) The power supply ...
