Slow Blow Fuses

[millsy]

Have to fit all fuses to a 63 Sweethearts as they are missing,schematics list all normal fuses except for the fuse near the power transformer, it shows a Slow Blow Fuse- do these fuses take longer to blow ?  Thought, what happens if a coil or something starts smoking wouldnt be better for the fuse to blow quicker ?
Explanation please all you sparkys out there.

[dj10555]

Some circuits have an initial surge of high current but then the current drops back down to a steady flow. You use a slow blow fuse so it does not blow with the initial high current. These will only blow if the high current such as a fault continues. If you use a fast blow where a slow blow was specified it will blow the fuse every time. If you use a slow blow where a fast blow was specified the fuse will not blow fast enough and could cause further damage. Only use the correct type of fuse as originally specified. I also come across alot of boards where 10A fuses are used for 1A fuses or pieces of wire have been soldered across fuse holders. Of course, rather the blow the fuse the circuit stays on and frys the boards or the coils.

[millsy]

  Thank you,well explained.

[Strangeways]

Good Explanation, Derek 

I've always understood a SB necessary as the fuse can take a higher current rating for a period of time longer than a standard fast blo fuse.

[Marty Machine]

Replacing the fuse with a nail or alfoil is considered "extra-slo-blo", and will always smoke your components instead.

As the other guys said, use the EXACT fuses specified.
MM.