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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17 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.
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2answers
47 views

Replacing glass fuse with reset button fuse?

Several months ago i made a 10Amper power supply with 5 outputs, each output has a fuse holder for crystal 10A Fuses, they work as intended but its a chore to replace them every time i short them, i ...
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0answers
12 views

how to hardwire a car.(dashcam) [migrated]

video where i check all my fuses: https://www.youtube.com/watch?v=74YimFvXEsQ fuses that lighted up without key: 11 Moonroof (20a) 12 accessory power socket (with idk why it did since it doesnt ...
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3answers
124 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 ...
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2answers
116 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. ...
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1answer
41 views

Appropriate fuse for 12V battery - solar power controller connection

I'm a biologist tracking migratory bats and need to build a bunch of antenna towers to listen for pulses from tagged bats flying nearby. These are off-grid, so we'll have 55W solar panels charging ...
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1answer
43 views

How to detect if a high voltage fuse is blown

I have a 150A fuse on a 100A @ 400V nominal battery pack. There are 5 service relays and 2 isolation relays (one on each pole) in this battery pack. I'd like to make sure that none of these relays can ...
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1answer
38 views

Fuse and AWG choice for immersion heater circuit

I am planning to operate a 1500 W resistance immersion heater with an SSR and I'm trying to determine which fuse and AWG wire to use. The 1500 W heater on 115 VAC should operate at a current of around ...
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0answers
66 views

Resettable fuses in parallel to limit output current

What are your experiences with this? it is reliable do use PTC smd to limit 15A? the datasheet has a hold value and a trip value. How I choose the values?
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1answer
52 views

Multimeter reports voltage but no power?

I have an Insteon FilterLinc, which is an electrical line filter. It doesn't work. When I connect a lamp to the "filtered" outlet, I get no power. So I stuck multimeter probes into the filtered outlet ...
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3answers
86 views

Do fuses affect a PC PSU's amperage output?

I have a PC PSU powering a load that should pull 20 Amps. I put a 10 Amp fuse in series with the load and the PSU. However, the fuse simply will not burn, and the PSU continues to supply the load, ...
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1answer
117 views

What are the correct zener diode and PTC fuse size?

Noob here. I need to add overvoltage protection to a small, portable solar power system I'm putting together. The solar PV array has a loaded voltage in the 23-26v range and an open circuit voltage ...
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0answers
13 views

SKM15C-05 which fuse for input and output?

I'm very new to this, but I've ordered an SKM15C-05 documented here: http://www.meanwell.com/search/SKM15/SKM15-SPEC.PDF My plan is to use it to power a small SOC unit via power over Ethernet (POE). ...
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1answer
92 views

Fuse blown indicator circuits compilation

I have been working in a compilation of circuits to use that basically show to the user that a fuse has blown up, this is particulary useful in the bench, needless to say I haven’t tested all of them ...
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2answers
39 views

Fuse for AWG 8 wiring

Assuming I put a 60amp fuse to an AWG 8 wire, whats the worst case scenario when a short circuit happens? Therory about short circuits says the current goes to "infinity" however, shouldnt the fuse ...
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6answers
2k views

How To Know If a Fuse Will Work Properly?

I want to know what kind of periodic test we use to test if a current-limiting fuse will normaly open and protect an electronic circuit (a battery charger) if a failure occur (short circuit or over ...
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0answers
65 views

Time-graded overcurrent protection setting

Source: "Protection of industrial power systems" by T Davies. I am the typical calculation for fuses section, page 92, from chapter 5. There is a calculation were the max overload current of the ...
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2answers
96 views

Transistor fuse problem

I can't find out how this transistor fuse works. I know that the R1 is there because of voltage drop 0,7 V when the voltage on output is at its highest possible value. But I don't understand why there ...
1
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2answers
149 views

DC Motor drawing too many Amps

I have a treadmill incline motor that is blowing its circuits fuse every time it starts to run. This is the motor that lifts the treadmill up and down. The motor is labeled: Output: 65W Input 36VDC ...
3
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2answers
248 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
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1answer
328 views

avrdude: initialization failed, rc=-1

when trying to program the fuses I get this known error message: $ sudo avrdude -c usbtiny -p m328p -U hfuse:w:0x05:m avrdude: initialization failed, rc=-1 ...
2
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3answers
168 views

What is the function of fuse here

The datasheet states that TPS2400 protects the load from an over-voltage, by disconnecting the load from the power supply (Q1 goes off), without blowing the fuse. Why is the fuse F2 here, if there ...
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3answers
110 views

Short Circuit Indicator circuit

This circuit was designed to save electronic components in the assembled board from damage. It gives warning beep if there is a short circuit in the assembled board. Thus it helps to switch off the ...
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4answers
186 views

Turning on a led with negative voltage

I have been using this fuse blown indicator circuit for a bit, it basically works perfectly fine with positive voltages no matter if there is or nor a load connected The problem starts when I feed ...
0
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1answer
46 views

Can't read/write to/from the atmega328p

I cant communicate with the Atmega328p. I've flashed fuses low: 0x59, high: 0xD9 and changed wiring. Now I've connected 16Mhz crystal to the XTAL1, XTAL2 pins, and 2x22pF to the crystal. But I can't ...
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2answers
125 views

How can I work out if a cable can take a momentary current spike?

In this video here, almost 1000A is being run through a 10mm steel bar, and after a minute or so, it melts. https://www.youtube.com/watch?v=YzZ3aJqmT-M So in terms of charge, 60,000C applied for 1 ...
3
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3answers
132 views

Is this the proper way to fuse a DC/DC Converter?

I am designing a solar power system for camping. I'll use a couple different DC/DC converters to provide DC voltages for the specific items I want to power. I want to properly fuse the various ...
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1answer
82 views

Can i replace a 0.75A 76V SMD fuse with a 1.25A 250V one? [closed]

It's for an LCD TV inverter. The seller said I could even use a thin wire. I'm not sure about that that's why I still bought it but I want to make sure before putting it in. It seems that it's for ...
0
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1answer
110 views

4 iPad Air charging circuit indicator led not working

I developed this circuit in order for it to be connected to 4 ipads at the same time the current they use to charge when they are on low battery goes around 1.8Amps, That its working as intended, ...
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2answers
95 views

Bitbang ATMega-328PU with CT210x using avrdude

I have made a breadboard-arduino with an ATMega-328PU and the standard components taking help from http://arduino.cc/en/Main/Standalone I interfaced the CT2102 Breakout Board with this assembly: DTR ...
6
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2answers
665 views

Short circuit protection for high current wearable: fuse, polyswitch, TBU, circuit breaker, something else?

I am thinking about design elements for a rather high current, battery powered, wearable application. Maximum current of 40A at 5V, but typically around a third to a half of that. Power would come ...
1
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0answers
170 views

Can I determine a formula for fuse disconnection times?

This is the first time I have used this stack site so am not 100% sure this question is on topic (based on the tags I couldn't find) but thought someone may still be able to help me. For those not ...
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4answers
401 views

Why does a 10A fuse blow at 10A and 5V or 10A and 500V?

Something that's always puzzled me: Wire and fuses can handle a given max current, pretty much regardless of voltage. A 10A fuse will blow if you exceed 10A, if the voltage is 5V or 500V. Why is ...
1
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1answer
84 views

Battery power in the home: Fire Safety

I would like to use 12v LED tape powered by an 8 x AA battery holder and switched with a motion sensor. This will be connected in my home 24/7, so I would like to know what precautions (if any) I ...
0
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2answers
238 views

Turn on an LED when power is lost with a relay

A friend of mine has just finished his race car but is having fan issues. What I want to help him do is setup an LED that turns on when the fans have lost power. Often the fuse blows. I would assume ...
1
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0answers
304 views

Atmega32 can't verify after setting correct fuses for external crystal. HELP

I am having trouble with some Atmega32A's purchased off from eBay. The MCU's does not seem to be fake as they are functioning properly. I am experiencig the following problem: I want to use external ...
3
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2answers
179 views

AC Short-circuit Protection

I have a bunch of electro-mechanical relays on a board intended to switch 220VAC for CFLs. The maximum load on the relays will be 100W with inrush currents of upto 2A (lasting for less than a second). ...
0
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3answers
130 views

What are the big plugs for that you find on high demand devices in North America (120V-Areas)?

Talking about AMEA socket system and 120V. High power demand devices like A/Cs do have bigger plugs with some switches on them. What exactly is their purpose? Seems like a fuse but isn't the socket ...
0
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1answer
148 views

Does any thermal fuse with the same cut off temperature work?

Would any thermal fuse cutoff for 216°C work as a replacement for the fuse in the picture below?
0
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4answers
382 views

Is it reasonable to use a current limiting diode in place of a fuse?

I'm trying to source some fast-blow 5mA or 10mA fuses but Littelfuse has discontinued the only reasonably affordable ones I have found. My circuit when operating properly will not output more than ...
0
votes
1answer
168 views

1:1 isolation transformer fuse on secondary side - an option?

We sometimes use an old self build 1:1 isolation transformer (150VA) in our company to isolate devices under test. It is equipped with a primary 500mA fuse (slow) in series with a on/off switch. ...
0
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3answers
164 views

preventing blown fuses in simple circuit

I am trying to prevent blowing fuses in a simple circuit: that consists of a battery(12V), fuse, and 2 lights(50W). There are no switches; the lights are connected and disconnected from the live ...
0
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1answer
60 views

Downsides of using 5mm fuses in 6.3mm sockets

For my multimeter I need to replace a fuse. It is 6.3mm in diameter, 25mm long, rated 500mA/250V AC and 1500A interrupt rating. I have a couple of such fuses, but they are 5mm in diameter, and ...
1
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1answer
113 views

Use a relay as a resettable fuse?

I was thinking; If a relay is used to power a circuit AND itself, if the circuit is shorted - the relay should lose its own power and turn off - almost like a resettable fuse. To power it up, I would ...
25
votes
3answers
3k views

Why did my fuse not blow?

I purchased a few fuses to get familiar with their workings, and I was surprised to see that the 100mA fast-blowing fuses I bought happily conducted up to 215mA (6V power supply, 10\$\Omega\$ ...
5
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3answers
190 views

Given metal dimensions and material, is it possible to determine the maximum current that the structure can handle? [semiconductor processing]

I have a linewidth structure that has very low resistance. I want to know the maximum current that this structure can handle. Since the resistance of the metal is so low, it's hard to measure the ...
1
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3answers
314 views

AVRDUDE with buring settings of AVR Studio

I make my own electronic boards often with an Atmel ATmega328P. I used AVR Studio for programming. Now I tried to make the same settings with avrdude and it looks, that they are not really ...
1
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3answers
219 views

What do the abbreviations “SPF” and “SPH” mean with respect to fuses? (Single line drawing for 480 V system.)

There are two lines connected between the transformer low voltage side and the 480 V bus, one with a fuse labeled "SPF" that connects to a GE power quality meter, another with a fuse labeled "SPH" ...
1
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1answer
105 views

How can I protect against shorts in low voltage AC ~16V

I'm looking for a method of protecting a circuit against shorting. I would rather not use a regular fuse as I expect I will short the circuit (unintentionally) fairly often (probably once or twice ...
0
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1answer
69 views

Rating for this circuit breaker at 120 voltsAC

Here is a circuit breaker rated 2 amps at 32 volts DC and 2 amps at 250 volts AC What is the amperage it will break at when I apply 120 volts AC