Normal for FET to heat up?

[Schlyder]

I was wondering if it is normal for a FET to heat up?

[mcguyver]

Yes.

[Schlyder]

Thanks MacGuyver, I figured it was normal, can it it overheat if something is wrong? what can cause one to fry out?

[Tankdude]

Water for one thing.

[ujiro]

Overheating to the point of melting is bad.. Other than that it will be fine. Caused by too much current/voltage

[mcguyver]

Originally Posted by IronOverlord

Thanks MacGuyver, I figured it was normal, can it it overheat if something is wrong? what can cause one to fry out?

It can overheat if the load is too great, or the load is applied for a longer time than designed (like holding down the trigger in full auto for a minute for eaxmple).

There are a thousand ways to kill a FET. They are actually quite delicate, and can be killed by heat, over/under voltage, stray static discharge, etc.

[Death March]

If it's a Mosfet it will have a thermal shut down so it does no pop,but you I guess it depends on what it's in and whats it doing? Is it a Drive transistor? They usally run on the warm side.Fans are your friend,keeping them cool helps them live longer

[mcguyver]

Most mosfets don't have a thermal protection system. They just pop. I've replaced one or 2 that could have benefitted by that.

[Tankdude]

since we are on the subject. Can you hook up mosfets in paralle?

[mcguyver]

Originally Posted by Tankdude

since we are on the subject. Can you hook up mosfets in paralle?

Yes, but there are different requirements for AC and DC.

[Schlyder]

Water , hahaha yeah don't it get wet. hahaha Thanks for the input guys. Just doing some studying on FETs.

[Kos-Mos]

The Trigger Master has thermal shutdown, but it is controlled by the microcontroller, not the FET itself.

Usually, all the limits/rating of any electronic part is listed in the datasheet.

The FETs I am installing as a trigger switch replacement are rated for 110A continuous current and 350A pulsed. They can run from -40 to 175 degC. And they have a built-in diode to prevent EM spikes from burning the FET. Still, I saw some burn by missuse, moisture/water, phisical shock etc.

They are sensitive parts, and they are supposed to heat a little bit. Nothing electric is 100% efficient (yet), so there HAS to been heat generated somewhere.