Fuse Ratting
I need to fuse a loudspeaker to prevent overpowering it. Can anyone help me relate the correct fuse current and voltage value to the loudspeaker watt value?
I need to fuse a loudspeaker to prevent overpowering it. Can anyone help me relate the correct fuse current and voltage value to the loudspeaker watt value?
This should give a workable minimum value for a fast-blow fuse:
Fuse (amps) = 1.414 X sqrt (Power rms / Impedance)
A good trick for protecting a speaker from over-cooking is to connect it in series with a filament bulb.
Fuse (amps) = 1.414 X sqrt (Power rms / Impedance)
A good trick for protecting a speaker from over-cooking is to connect it in series with a filament bulb.
Fuses don't always protect well. You don't say if you are protecting a single driver (what size) or a whole system.
Best is to start with a low current rating (voltage doesn't matter as long as it is more than your amp can put out) and increase it a bit if it blows too often.
I have a 250Watt, 4 ohm speaker that came with a 2 amp slow-blow fuse on the input. 250 watts into 4 ohms is sqrt(250/4)=7.9 amps. I have blown a tweeter before the fuse blew....
Also look at polyswitches and other types of protection devices. I think Parts Express sells something like this.
http://www.partsexpress.com/webpage.cfm?webpage_id=3&SO=2&&DID=7&CATID=41&ObjectGroup_ID=568
http://www.partsexpress.com/webpage.cfm?webpage_id=3&SO=2&&DID=7&CATID=41&ObjectGroup_ID=237
Best is to start with a low current rating (voltage doesn't matter as long as it is more than your amp can put out) and increase it a bit if it blows too often.
I have a 250Watt, 4 ohm speaker that came with a 2 amp slow-blow fuse on the input. 250 watts into 4 ohms is sqrt(250/4)=7.9 amps. I have blown a tweeter before the fuse blew....
Also look at polyswitches and other types of protection devices. I think Parts Express sells something like this.
http://www.partsexpress.com/webpage.cfm?webpage_id=3&SO=2&&DID=7&CATID=41&ObjectGroup_ID=568
http://www.partsexpress.com/webpage.cfm?webpage_id=3&SO=2&&DID=7&CATID=41&ObjectGroup_ID=237
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