Type Of Fuse

[NoTransistors]

I need to get a package of fuses for the 299D. It calls for a slow-blow. It is impossible to find USA-made fuses, so the simplest alternative is radio shack. So, should I get the ones with the coil-spring surge absorber or the new-fangled ceramic-type?

 

[cademan]

I'd use the recommended slo blo. You can't see anything with those ceramic type fuses unless testing with a meter.

 

[for_p1]

Fuses with coil spring are FAST ACTING. You need slow blowing either glass or ceramic. Good fuse will cost you few dollars.

 

[gadget73]

My usual slow-blow is the Littlefuse 313 series. Its a glass fuse with what looks like a glass rod inside with the fuse wire wound around it. I get them from Mouser or wherever the order is going in to.

 

[ggizzy]

Another place I've found with a good selection of various fuses is Truevalue or Ace Hardware. I'm sure it differs by location, however. Might save you cash on shipping.

 

[whoaru99]

The ones with coil element plus straight element are a dual blow type fuse. They have some characteristics of both slow blow and fast blow.

If it calls for a slow blow I'd probably just stick with a plain old MDL-style glass cartridge fuse. MDL (Bussman designation) is of the style gadget73 describes, the thin rod with wire coiled around it.

If you don't mind waiting DigiKey and others have good selection of fuses in stock. DigiKey has no minimum order and will ship by USPS First Class so you can get quite a few small parts with just a few dollars in shipping cost.

 

[Hyperion]

new-fangled ceramic-type?

Ceramic bodied fuses are not new, and they aren't normally used/needed in the kind of equipment we like. As I understand it, the reason for the ceramic body rather than glass is to withstand the 'blast' when the fuse wire ruptures in these usually higher (amperage) rated fuses.

 

[NoTransistors]

Lots of good information here,


Thank You

 

[Kahoona]

My usual slow-blow is the Littlefuse 313 series. Its a glass fuse with what looks like a glass rod inside with the fuse wire wound around it. I get them from Mouser or wherever the order is going in to.

++ That is what I do also. Not cheap but convenient.

An inexpensive and easy source would be any auto parts or hardware store. They usually have Buss fuses at a low price.

 

[gadget73]

Just make sure its a 125v or 250v fuse. Some auto parts stores only have 32vdc fuses, which might not break a higher voltage circuit properly. I think my local hardware store does have them tho.

I tend to buy fuses in 10 packs. Slight price break usually, but I have a bunch of gear running the same fuses it seems, and whenever I buy something new I get extra fuses for it. Seems to be cheap insurance against ever needing the things. I only ever blow fuses I don't have on hand.

 

[for_p1]

Ceramic bodied fuses are not new, and they aren't normally used/needed in the kind of equipment we like. As I understand it, the reason for the ceramic body rather than glass is to withstand the 'blast' when the fuse wire ruptures in these usually higher (amperage) rated fuses.

Not only that. Most ceramic fuses are filled with fine sand. That allows to suppress arc that happens when high current flow is interrupted.

 

[gadget73]

also useful for high voltage applications. Fuse ratings get sort of involved. That 2 or 3 amps is not the only rating. There is a fault current level too that it must be able to break. The 313 for example can do 100 amps of fault current at 250v, but 10,000 amps at 125v. Beyond those points, the fuse might blow but you might be able to sustain an arc across the inside of that glass body. The ceramic ones are typically able to break higher voltages and/or currents.

 

[Pio1980]

MDL are slow blow, MDA are the ceramic delayed action. MDL are good for the line in end of the power supply, MDA for DC supply rails and for speaker protection.