Questions tagged [fuses]

Questions regarding physical fuses. Fuses are a safety device consisting of a strip of wire that melts and breaks an electric circuit if the current exceeds a safe level. PPTC, PTC, and Polyfuse questions should use the Polyfuse Tag. Please keep in mind that repair questions are typically closed if not within the scope of the Site and FAQ.

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0answers
57 views

Electric bicycle circuit diagram

I'm a first time poster and a beginner so be gentle if possible. I am working on building an electric bicycle. So here is the plan I have so far: Primary Power Source 52V 20Ah DIY battery made from ...
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1answer
60 views

Can I melt the plug fuse metal strip using heat?

Since I do not have a lot of equipment right now, I am trying to find an alternative to strip a plug fuse using fire or heat. I tried to put it on heat for about 2 minutes, but when I tried it again, ...
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49 views

How to fix a Christmas light which i accidentally connected to over voltage? [closed]

Accidentally connected 120V bulbs to 240V. I have three such strings, each one having 50 bulbs. Connected using male and female sockets. All worked well for a day and then strings at both ends stopped ...
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1answer
48 views

What gauge size and fuse should I use?

I've purchased a Thlevel Car USB Charger Socket to install in my 12v system campervan and I'm confused regarding the fuse and wire I need to use to wire things together. By my calculations, given that ...
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1answer
46 views

Removing unnecessary fuses from 12V DC car plugs

I have a 12V DC car socket is connected to a car battery and cable with 12V car plugs on each end. The socket and each of the plugs has its own fuse, which seems unnecessary. If I were to blow a ...
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1answer
84 views

Allow current draw only when it is over a certain value

Is there a way to passively allow the current to flow over a certain amount? i.e., if it is a small parasitic drain, ignore it, but if it is something larger like starting an engine, allow it. Almost ...
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1answer
924 views

Auto Fuse Tap Parallel or Series

Am looking to use a fuse tap to run a dash cam. These are instructions https://www.lumision.com/wp-content/uploads/2015/09/Micro2-Fuse-Tap-Instructions-e1441486778366.jpg for a fuse tap and consistent ...
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1answer
2k views

How do I use the I2T rating of a fuse?

I've read on a Littelfuse page that I2T of a fuse is a measure of the let-through energy. The units of amps^2*resistance is power. Multiply that by time and you have energy. But in a I^2*T rating of a ...
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1answer
43 views

Do thermal cutoff fuses wear out if used below rated temperature?

I tend to keep my electrical applicances alive for decades and have had several thermal fuses (the non-resettable axial kind) repeatedly wear out for no apparent reason, some of them in expensive ...
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0answers
17 views

I2t fuse rating for input capacitor

Can anyone confirm to me if my calculations are right? I need to choose a fuse for a circuit which has a 220uF capacitor on the input, after the fuse. The proposed which I intend to use has 0.17 Ohm ...
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1answer
33 views

Choosing fuse for 2S li-po

I Have 2S 8000 mAh li-po battery I want to use as an external power source for my DSLR camera (Canon 7D Mark II). Previously, I failed to power it with power bank and DC-DC converter, most probably ...
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1answer
52 views

How to identify the polyfuse used in this RS-485 module

This is the popular RS-485 module found in the market, how can I identify the polyfuse/heat recovery fuse in it? Also its manufacturer or electrical ratings?
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0answers
40 views

Is it ok to connect the output of a solar controller to a fused outlet on a fuse panel?

The fuse panel is breakered to a battery and is used to power other low amp equipment. The model is the 6 gang blue sea panel with blade type fuses. Since the fuse panel is just a couple pieces of ...
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1answer
77 views

Are there any “smart” fuse boxes? [closed]

I'm not sure I know the proper term or how it is in other parts of the world, so I'll just explain in detail: In my country every house has a "fuse box" - the electrical entry point to the ...
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1answer
107 views

De-rating / Re-rating criteria/theory for frequency in circuit breakers

I'm trying to spec a circuit breaker for a system that will be performing in the 3kHz range, and am not finding much info on how to calculate a new rating based on frequencies in this range (where ...
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5answers
14k views

Does it matter if a fuse is connected to the negative or positive terminal of a battery?

I am currently going through the conundrum of where to place a fuse in my DC battery-powered circuit to protect the circuit components and the DC battery. I've been googling for a definitive answer, ...
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1answer
118 views

Fuse detection in a lithium Battery Parallel connection

I really need your help in order to figure out a solution to detect a blow fuse in a 16S parallel connection. The issue is: Despite a fuse has been blow the voltage at the other side of the fuse is ...
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1answer
193 views

Fuse on Primary Side of Transformer keeps blowing

I have a HVAC which is having a 24V 40VAC transformer. I might have shorted the output of the transformer while working on the wires. I noticed that the fuses on the input side of transformer blew ...
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10answers
9k views

What causes a fuse to blow, the current or the power?

Fuses and circuit breakers are often specified at a certain current they will 'blow'. Increasing the current will also increase the power. So if a fuse is rated for 12V DC and 20 A, this would be ...
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3answers
78 views

Simple and compact Over-Voltage protection with fuse and resistor

I know there are many techniques to protect over-voltage on the power supply. However, it does not apply to my case as it only provides single polarity voltage protection. Additionally, I want to ...
2
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1answer
66 views

What models and brands can I find for logic fuses?

I'm trying to find logic fuses like the ones found here. As I'm new user, I couldn't comment there, so I created this new question. That fuse, in my case, is on a Clevo P170EM battery. This battery ...
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1answer
51 views

Do eFuses work with AC current?

I was wondering if integrated eFuse solutions exist that are designed to protect a low voltage AC bus. In my application I would like to replace a 2A PTC that protects a 24VAC bus but I cannot find an ...
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1answer
53 views

How does a fuse resistance vary with temperature change?

In datasheets usually a cold resistance is given, which represents fuse resistance at low load, according to Littelfuse guide https://m.littelfuse.com/~/media/electronics/product_catalogs/...
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1answer
93 views

How can I prevent my multi-meter fuse from blowing with a brief 120VAC surge?

I wanted to test how much power a GFCI outlet uses while idle, so I hooked up my multi-meter to test the current flow. I put my test lead in the amp socket, and confirmed the current was on the order ...
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1answer
90 views

Guitar amplifier repair: burnt fuse, capacitor, what else?

A friend has asked me to take a look at his guitar amp: Peavey Valve King VK212. Problem: suddenly the amp stopped working during operation and the status lamp went off. First reaction: fuse ...
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2answers
125 views

Symmetrical power supply: Rail fuses useful or dangerous?

I'm designing/testing power amp stuff with symmetrical power supplies (43V-0-43V). In the next future I'm planning to control all safety/healthy stuff (like over current / over voltage / temperature ...
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3answers
13k 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 ...
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1answer
307 views

Meter fuse availability/substitution conundrum

I own a Brymen BM235 multimeter, among other test instruments. While it's a nice multimeter, I have one problem with it: the fuse for the mA jack is a Siba 7017240.0,4, and nobody even bothers with ...
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1answer
711 views

atmega32u4 reset, bootloader and fuses

I have a atmega32u4 from factory with dfu inside. The HWB is pull down, and RESET pin is pull up. The first USB plug, dfu programmer appears on my Linux box. I upload the firmware without problem. ...
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1answer
53 views

When to use different types of fuses

Fuses come in all sorts of shapes and sizes, assuming that i have a specification for its current and how fast i need it, what are the other considerations for choosing a fuse type? Fuse types that i ...
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2answers
75 views

Is it safe to replace a ceramic fuse with a radial one? [closed]

I have to repair a led tv with a blown fuse. On the power board the fuse required is a T4.0AH/250V fuse, but I couldn't find it at the shop. They gave me instead a radial fuse, claiming that it's the ...
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3answers
91 views

Why does fuse rating not coincide with max power of device?

I am reviewing the electrical specs for a few different devices, and I am just confused why some devices have a fuse rating that allows for a higher power input than what is listed as the "max ...
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1answer
70 views

Unexpected increase of resistor's resistance after overload

I was trying to make a so-called bridgewire (an electric fuse to initiate fireworks remotely). I took a low-power 1206 SMD resistor (1.8 Ohm, 0.25W) and applied high current to it (a pack of three ...
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2answers
219 views

Fuse Protection inline with DC Brush Motor

I have run into a number of instances where my 12A DC brush motor (linear actuator) is being overloaded. I have tried fusing it with a 10A Blade Fuse as well as a 15A Blade Fuse. In both instances, ...
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1answer
112 views

How to choose the correct fuse in a double paralled battery supply system?

Suppose I have the following system: simulate this circuit – Schematic created using CircuitLab As you can see we have: Two 500V battery with an estimated 500mohm average internal resistance. ...
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6answers
73k views

How does a fuse blow at its current rating, regardless of voltage?

I know from reading elsewhere that it's safe to use a fuse with a higher voltage rating when replacing one, so long as the current rating and reaction speed is the same. For example, if a fuse is ...
1
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1answer
165 views

Selecting true crystal settings for 328P [7.3728 MHz]

I want to make a new board working with 115200 (gsm modem) UART. so I want minimum baud error rate. I look at https://cache.amobbs.com/bbs_upload782111/files_22/ourdev_508497.html table and decide ...
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3answers
56 views

How to Put a Fuse on the DT-9205M Multimeter?

I got a DT-9205M multimeter, it has 20A unfused and 0.2A fused after I saw the PCB, surprisingly there is no fuse on the 0.2A and instead of that they put 000 resistors on it I wonder if I could put a ...
0
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1answer
35 views

What is the voltage and amperage rating for “Q” labeled SMD fuse?

I am looking for the specification for the "Q" rated SMD fuse. Since this was found on a 12V rail on a 150W graphics card I can deduce a 12A fuse should work but I wanted to be sure that is ...
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1answer
133 views

IEC connector with both Line and Neutral Fused

I require an IEC connector mains entry with both the Line and Neutral fused. The double fuse is required in order to be compatible with reverse polarity of the mains connector on the other side of the ...
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0answers
30 views

Appropriate fuses for inverters?

I have a 2000w inverter in the camper-van I just bought and I am getting my hear around the whole electrical set-up in general. There is a 30A fuse in-line between the 12v leisure battery which the ...
0
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1answer
56 views

Is using a wire rated the same as its circuit's fuse OK?

I want to add a kill switch on the fuel pump relay in my car, which includes extending a line connected to a 15A fuse. I bought some 15A auto wire, but on reflection I'm not 100% sure if that's right. ...
0
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1answer
97 views

How unsafe is it to use a 10 amp fuse with a trace designed for 4 amps?

Obviously I am a hobbyist and yes I am messing with mains. I do understand the danger which is why I'm asking this question. I originally wanted to make a PCB that can handle 10 amps but I couldn't ...
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4answers
2k views

Fuse keeps blowing on AC/DC Adapter

Recently I have noticed high freq. screeching noise coming out from my laptop's adaptor. I opened it up and found that it came from somewhere around a diode named egp10a. I checked it (unplugged) with ...
0
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1answer
29 views

What is the best way of connecting electricity fuse/cut-out

I am talking about home/industrial electrical fuse fitting or correct mointing . Should the fuse be mounted on L(live) wire or N(neutral) wire?.
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1answer
44 views

Jump starting a motorcycle behind a fuse? (slow blow atc fuse?)

I have a motorcycle with an SAE 12v 10ga lead for charging that I'd also like to occasionally jump-start the motorcycle with, I need about 90amps for about 1 second, which is fine for the 10ga wire, ...
3
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2answers
146 views

combine two identical fuses in parallel

I'm thinking: If I have two fuses of same type and rating in parallel, the current would split approx 50/50. If one fuse have a lower resistance, then more current will flow in that, it will get ...
0
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1answer
101 views

Trying to identify SMD component from a Ps2 Slimline

(English isn't my first language) I'm trying to fix an old Playstation 2 Slim my cousin had that was turning off by itself after 5 minutes playing. After some search on the internet, I found that it ...
0
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2answers
515 views

Placement of varistor with respect to fuse

My design includes a pretty standard AC/DC converter powered by mains for intended use at home. For overvoltage and overcurrent protection, I am planning to use a combination of varistor and fuse ...
6
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1answer
120 views

Hair dryer fuse too low for spec power?

So I'm tearing down this hair dryer for a school project where I need to make it have variable heat and variable motor speed which can be controlled through an Arduino. I'm currently looking at where ...

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