Loading 2200µF with 30V

[Exo]

I've made a circuit here and i'm trying to test it ... It's unloaded so for safety purposes i use a 1A fast fuse.
The fuse blows immediately, but i can't find anything wrong with the circuit. everything measures out fine.

Could it be that the initial loading current of the 2200µF capacitor is so high it makes the fuse blow ?

2200µF at 30V would that draw a currentspike enough to blow a 1AF fuse ?

 

[Nigel Goodwin]

I've made a circuit here and i'm trying to test it ... It's unloaded so for safety purposes i use a 1A fast fuse.
The fuse blows immediately, but i can't find anything wrong with the circuit. everything measures out fine.

Could it be that the initial loading current of the 2200µF capacitor is so high it makes the fuse blow ?

2200µF at 30V would that draw a currentspike enough to blow a 1AF fuse ?

Quite probably - you shouldn't use a fast blow fuse for something like that.

Personally I only ever use anti-surge fuses, in fact they are all we stock at work!.

 

[Styx]

If you want to keep such a fuse rating for normal operation you can do one of two things.

you can put the fuse after the capacitor, thus initial in-rush will go into cap and thus the main cct will not see the rush of current - IF there is a prob with the cap no protection.

OR (a better option) is use a pre-charge resistor. This resistor limits the charging current to the DC-link capacitor, when it reaches a preset threshold short out the resistor with either a Thyristor or another switching device.

or as Nigel said up-rate the fuse, just some ideas