bluemoondriver
Fuses are tiny pieces of low value resistors which when heated to the correct temperature by excess current passing thru them, melt and avoid damage & a possible fire.
They contribute ABSOLUTELY NOTHING to the sound.
I just measured the resistance of 2 ’normal’ fuses:
a 500 mA fuse had a resistance of 0.7 ohms. Meaning, that the power dissipation on it will be I^2 x R = 0.5 x 0.5 x 0.7 = 0.175 watts as it is about to blow. It means that the fuse will melt at such a very low power dissipation, when its limit current is reached. And the voltage drop across it at that current will be 0.5 x 0.7 = 0.35 volts. Absolutely negligible. This fuse is obviously for a very low current circuit.
A second fuse I measured was for 8 Amps, more typical of a 2 x 200/250 watt 120 VAC typical amplifier. Its resistance was 0.3 ohms. This means it would dissipate about 8 x 8 x 0.3 = 19 watts. And the voltage drop across it at that current would be 2.5 volts just as it is blowing. Again totally negligible voltage drop.
What makes them different is the melting point of the material used in them. Note that the one that passes 8 amps must withstand a dissipation of about 20 watts before it blows whereas the 500mA fuse is required to blow at only 0.175 watts.
Note that I did not mention temperature. When a fuse is working at less than its maximum limit, it is obviously still dissipating power and is likely to get warmer/hotter. This typically will increase their resistance, meaning the power dissipation on them is likely to increase FASTER than I^2xR with increasing current, meaning they start actually dissipating more heat as they get closer to their blowing current.
Here is a link which explains that relationship, towards the bottom of the page, which headlines "PTC characteristics", if you really want to understand them deeper:
https://www.littelfuse.com/~/media/electronics/application_guides/littelfuse_fuseology_application_g...
Basically, fuses HARDLY affect the currents passing thru them. They are almost ’transparent’ as they should be, not to affect any operating parameters in the rest of the circuit.
Fuse believers are just hearing things which are not there. They need urgent help.
Fuses are tiny pieces of low value resistors which when heated to the correct temperature by excess current passing thru them, melt and avoid damage & a possible fire.
They contribute ABSOLUTELY NOTHING to the sound.
I just measured the resistance of 2 ’normal’ fuses:
a 500 mA fuse had a resistance of 0.7 ohms. Meaning, that the power dissipation on it will be I^2 x R = 0.5 x 0.5 x 0.7 = 0.175 watts as it is about to blow. It means that the fuse will melt at such a very low power dissipation, when its limit current is reached. And the voltage drop across it at that current will be 0.5 x 0.7 = 0.35 volts. Absolutely negligible. This fuse is obviously for a very low current circuit.
A second fuse I measured was for 8 Amps, more typical of a 2 x 200/250 watt 120 VAC typical amplifier. Its resistance was 0.3 ohms. This means it would dissipate about 8 x 8 x 0.3 = 19 watts. And the voltage drop across it at that current would be 2.5 volts just as it is blowing. Again totally negligible voltage drop.
What makes them different is the melting point of the material used in them. Note that the one that passes 8 amps must withstand a dissipation of about 20 watts before it blows whereas the 500mA fuse is required to blow at only 0.175 watts.
Note that I did not mention temperature. When a fuse is working at less than its maximum limit, it is obviously still dissipating power and is likely to get warmer/hotter. This typically will increase their resistance, meaning the power dissipation on them is likely to increase FASTER than I^2xR with increasing current, meaning they start actually dissipating more heat as they get closer to their blowing current.
Here is a link which explains that relationship, towards the bottom of the page, which headlines "PTC characteristics", if you really want to understand them deeper:
https://www.littelfuse.com/~/media/electronics/application_guides/littelfuse_fuseology_application_g...
Basically, fuses HARDLY affect the currents passing thru them. They are almost ’transparent’ as they should be, not to affect any operating parameters in the rest of the circuit.
Fuse believers are just hearing things which are not there. They need urgent help.