Choosing a suitable fuse to protect PWM circuit

[riccardo]

Hi,

Can someone please help me to choose a suitable fuse for an adjustable PWM circuit. The circuit has a continuous / average current rating of 14A (limited by temperature rise) and the transistor is rated for 32A of continuous current (at 25C).

What fuse would I need to use to protect it from short circuits, or anything above 32A perhaps? (I just want to make sure I don't accidently blow the transistor)

I'm a little confused by the ratings given in the manufacturers datasheets for the fuses. Should I use a 32A quick blow type?

Thanks

 

[Gary B]

Here is everything you need to know to select the correct fuse for any application.

 

[crutschow]

The transistor is usually faster then the fuse. Thus, the transistor is likely to blow before the fuse, the result being the transistor protects the fuse instead of vice versa.

To protect a transistor from overload, you will need to add an electronic current limiter circuit of some sort that only takes microseconds to operate, not the milliseconds that a standard fuse requires.

 

[carmusic]

fuse is just there to protect from fire, it will blow once the transistor has shorted. there is some semiconductor fuses that exist but they are expensive