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 ...

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4answers
102 views

Benchtop circuit breaker

I repair electric appliances and tools. Every once in a while, the main circuit breaker trips when I plug in a device. I don't want to prevent a circuit breaker from doing its job, but I would prefer ...
1
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2answers
50 views

Cannot enter programming mode ATMega328p

I'm using an ATMega328p Xplained Mini development board. I was able to program it using Atmel Studio 7, being new to AVR programming I accidentally set the RSTDISBL fuse to 0 (has a default value of ...
6
votes
8answers
1k views

Can I use a 10A light switch with an appliance with a 13A fuse?

I have a vacuum cleaner, which I wish to add a switch to, so that I can leave it plugged in all the time and use the switch to turn it on and off. The vacuum cleaner has a fuse rated 13 Amps. I ...
3
votes
1answer
56 views

What fuses can I use for branch circuit protection above 600 amps?

My present understanding is that not just any fuse meets the paperwork qualifications of "branch circuit protection". In particular, I want to protect a variable frequency drive, so J-type fuses are ...
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1answer
66 views

what fuse for an electric circuit tester

Cannot seem to get a clear answer on the web. I have a mains tester with a blown 100mA fuse (glass) do I replace it with a quick blow fuse or a time delay fuse. Common sense would say a quick blow ...
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5answers
112 views

Preventing breaking of fuse wire very frequently [closed]

we have two geysers 3kWh each. When we turn on both the geysers, the fuse wire breaks. This happen s quite often and in the same scenario. How to prevent this from happening keeping both the geysers ...
3
votes
5answers
311 views

Why don't DC PSUs need a fuse?

This feels like a silly question, but after taking apart some of our 6W 12V DC power supplies I've noticed that none of them are fused. Out of curiosity more than anything else, I'm wondering why a ...
0
votes
1answer
51 views

Can you identify this fuse?

Sorry, dumb one really. I just had the heating out for a couple of days and eventually found a fuse blown in a controller for the (LK) underfloor heating. I can't tell what rating it has (amps). It ...
16
votes
4answers
4k views

Why did my fuse blow after 3+ years of no problems?

For several years, I have had a solenoid wired to the 24VDC output of a PLC (Rockewell Automation 1769-OB16). To protect the PLC output card, a fast-acting 500mA fuse was installed between the PLC ...
0
votes
2answers
258 views

Where to put the Fuse in a circuit

I have circuit where the input can be 12-48V AC or DC. This is fed to a bridge rectifier. I plan to put a fuse and got a bit confused, what is the best place to put a fuse? before the bridge ...
1
vote
1answer
851 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 ...
0
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1answer
44 views

Glass fuse identification - Siran No. F 13 4A

We have a glass fuse for a 12v lighting circuit that has "Siran No. F 13 4A" written on paper inside it. The circuit takes 5.5A at the moment with all the lights switched on without the fuse blowing. ...
2
votes
2answers
253 views

Fuse: why does it connect in parrallel with resistor?

I have a wire in normal condition runs 4A. The device I am using is auto-transformer, and its data sheet recommend to use fuse of 10A. So I went to buy the 10A fuse, and mount it onto a fuse holder. ...
5
votes
1answer
206 views

Why can't I blow a fuse?

In the book I am reading, there is an experiment that consists of connecting an automotive style fuse and a 1.5V battery to observe blowing of a fuse. However my fuse does not blow. I have repeated ...
8
votes
5answers
50k 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 ...
13
votes
6answers
84k 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 ...
0
votes
4answers
917 views

Why is this switched power inlet fused on both load and neutral sides?

I've purchased a Schurter 4304.6090 power inlet for a project and am a bit confused by the fuse configuration. The inlet requires two fuses: one on the load side and another on the neutral side of the ...
0
votes
1answer
44 views

Using AC fuse for DC & DC fuse for AC…!

Recently I visited a site where I saw that in an inverter AC fuse are use for DC..it is quit odd for me..!!! Is it ok to use the same? What are the factors to be considered when we use AC fuse in DC ...
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0answers
45 views

How to set oscillator fuse settings for PIC32

I have PIC32MX795F512L MCU and I am doing a I2C program in it. I am using MplabIDEv8.92. During debugging, PicKit3 gives an error: ...
0
votes
1answer
80 views

Electronic fuse

I teach electrochemistry to students in chemistry. During each class, there is at least one student that manages to burn the 200mA fuse of our $15 multimeters. It's quite annoying. I am thinking of ...
1
vote
3answers
115 views

Where/How should I fuse this transformer?

Background: I have a step-down transformer P241-5-36, which is a single mains primary coil to 36V Center Tapped (18-0-18) secondary. I would like to use this transformer to build a linear regulated ...
2
votes
2answers
63 views

spec of a fuse holder

While searching for fuse holders in the web, I found an infinity of pages like this, where the rating of the fuse holder is e.g.: "10A/250V AC, 15A/125V AC" (it is an example, values do not matter). ...
1
vote
1answer
51 views

How to verify fuse ampere rating

Is there any method to verify the fuse ampere rating without destructing it .I know the fuses works on the principle of resistive heating .If there is any method to verify the ampere rating without ...
1
vote
2answers
129 views

How can I make a Fuse Blown Indication LED circuit with variable voltage input?

I'm creating a power supply with an input fuse and and output fuse, and I'd like to have blown fuse indicators. However, the circuits I have found typically have set voltages and thus set resistors, ...
25
votes
4answers
2k views

Can thin sections of copper traces be used as fuses?

Is it safe to use thin sections of copper traces as one-shot fuses when cost is important, but when it is also vital to protect the rest of the circuitry? Should the solder mask be removed at that ...
1
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0answers
57 views

Is a Zener and a fuse enough protection?

We have a power chain that runs from an alternator, to a 24->12 dc regulator, to a battery charging circuit, to a 12 v battery. We were thinking of using this circuit minus the ac-dc converter part ...
0
votes
1answer
107 views

Directional audiophile fuses

There are some "audiophile fuses" in the market, and the manufacturers claim that they are directional. Here are some examples: HiFi-Tuning Isoclean Here is a quote from a fuse review (yep...): ...
3
votes
2answers
398 views

Current Determination - 12V to 5V (USB Output)

I am attempting to determine the current in an automotive installation of a 12V to 5V converter that will supply a USB output. Max output on the 5V side will be 3 Amps. ...
2
votes
5answers
736 views

How to blow a 0.6 ampere fuse

I am trying to do a simple project in which I am trying to show that when a high voltage battery is connected in a circuit then the fuse will blow and protect other appliances. In detail, I have four ...
0
votes
3answers
134 views

3.15A and 4A fuses - can I swap?

I have an old oscilloscope which doesn't work. I tried swapping the 3.15A/250VAC fuse with a 4A/250VAC fuse. The fuse immediately blew. My questions are: Did the fuse blow because it was the wrong ...
2
votes
1answer
56 views

Fuse resistor type

I want to build a flyback SMPS based on "TNY274". About the fuse before bridge, I don't know what kind of resistor should I use for correct operation! Metal oxide film or Metal film or Thick and thin ...
1
vote
2answers
203 views

need advice with LM317T current limiting circuit ,new alternative

i am using an LM317 as a Current Regulator for series LED similar to protecting LEDs From over current ( in time of short circuiting) for my LEDs and Mosfets, similar to this picture: the problem ...
0
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1answer
71 views
4
votes
4answers
981 views

How can I detect fuse failure?

I have two components in parallel on a DC circuit driven by a single momentary switch. Each component is individually fused. I need to detect failure of either fuse and in that event power on a ...
8
votes
4answers
3k 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 ...
7
votes
2answers
1k views

What are the dangers of a DIY fuse in a multimeter?

For the past few years I have been running my Fluke 79III without a fuse in its F44.100A 1kV fuse holder. This has meant that I've been unable to use the 40mA circuit. When I blew the old fuse, I ...
4
votes
2answers
622 views

Did I choose the correct fuse for my USB powered circuit?

I need to drive a circuit (operational current 150mA) with a USB port. I would like to protect the port with a fuse and from this question I concluded, that what I want is a PTC fuse. Is that the ...
0
votes
2answers
84 views

can I place 250ma fuse instead of 200ma fuse in multimeter, affacts meter calibration? [closed]

Well I know that it fuse will pass more 50ma in my multimeter but I want to know that will it make some change in my calibration of multimeter? can more 50ma current can damage my meter?
0
votes
1answer
39 views

Can a fast blow fuse with higher current rating affect motor's performance? [closed]

I have an old blender that I wanted to use after a couple of years. When I turned it on, it was functional for about half a minute and then stopped working. When I took it apart, I found that the ...
0
votes
1answer
57 views

Which type of fuse should I use with a coil heater?

Fast blow or time delay (anti surge) type? I have read motors require anti surge fuses to permit higher than rated current for short periods during start up.
2
votes
2answers
87 views

What's the real inrush current in my AC/DC rectifier?

I'm working with rectifiers and power supplies at the moment and I'm trying to reconcile simulations with real world observations about my circuit. It's a full-bridge diode rectifier (4x 1N5821's) ...
3
votes
2answers
509 views

Are regular fuses temperature sensitive?

Are common fuses, like AT car fuses, temperature sensitive? Say a 12v 5A fast blow fuse, would it have any significant change in its reaction at 0ºF than it would at 100ºF? In either time to blow or ...
1
vote
1answer
85 views

PCB/SCH Design: Fuse w/ Holder

How would one go about creating a library component for a through-hole fuse that sits in a holder? The part in question is this: Fuse: ...
1
vote
2answers
364 views

Determining voltage of fuse

My car battery is dead, and the fuse in my car battery charger is missing....(don't ask me why) I have a 20A fuse lying around and a 7.5A fuse that I took out of the car. The car battery charger ...
0
votes
1answer
61 views

Fuse position in relation to load and switch

Where should fuse be in relation to the power, switch and load? Any suggestions on a better approach or tips on the matter would also be helpful. POWER > [FUSE] > SWITCH > LOAD POWER > SWITCH ...
1
vote
1answer
49 views

AC resettable fuse

I am designing a circuit that plugs into a 12VAC source and I'd like to add a resettable fuse/PPTC for over-current protection. There's plenty of info on using such fuses for DC but I can't confirm if ...
2
votes
1answer
216 views

Overvoltage protection for RS485 inputs

I am using an Analog Devices ADM483E RS485-chip to build a device with RS485-capability. Datasheet here: http://www.analog.com/media/en/technical-documentation/data-sheets/ADM483E.pdf . The finished ...
0
votes
1answer
52 views

How long does it take (in seconds) to burn a fuse with high surge current?

Like the title says, how long does it take in seconds to burn a fuse? Of course it will depend on what type of fuse and the one I'm using is 61NM 250V/8A but looking at datasheets I could find on ...
0
votes
1answer
119 views

Is an older APC backup UPS likely to be the source of blown fuses in new lab equipment? [closed]

I have new laboratory equipment plugged into an older APC Back-UPS XS 1000. It derives all of its power from this backup system, which in turn is plugged into a regular power outlet. The lab equipment ...
2
votes
3answers
132 views

Phone travel charger for powering circuits dangers

I am thinking of using a phone travel charger to power a circuit.Ratings: input:110-240VAC(my outlet has 220volts) 50/60Hz 0,3A output:DC 5,2volts at 400mA The problem is that 220 V are of course ...