Benbox Laser Machines/CO2 Lasers/3D Printers

Laser Machine Service & Repair => Repair & Testing Services => Topic started by: Alvis on September 09, 2017, 04:24:46 PM

Title: Replacing mosfet
Post by: Alvis on September 09, 2017, 04:24:46 PM
Ok. Not an expert but shall i try.

Got FU024 Mofset on my Arduino Nano(clone I believe) and have decided to replace it, but, there's a problematic situation, is this mofset been installed by manufacturer  to get cost down, or, is this a quality mofset. Hard to tell.  If it's quality made, I'll replace it by the same(and put heatsink on it), but if it's been put in so it works "just on edge" why shouldn't i try put different in?! Better?!

Got an idea to replace it with Logic Level mofset RFP12N10L as it opens fully and closes fully when needed, but it's turn on voltage starts at 2 with max 4v compare to FU24N which opens at 1 and turns off at 2v.
 Been told by one smart guy that i will be unable to install Logic Level without modification.







Title: Re: Replacing mosfet
Post by: Zax on September 09, 2017, 04:35:03 PM
Eleks use the LR7843 IR538P which is rated at 6W. I haven't had any problems with them, even without a heat sink but then my non-TTL lasers are only 2.5W.
Title: Re: Replacing mosfet
Post by: ggallant571 on September 09, 2017, 05:27:03 PM
I posted reverse engineered schematics for a couple of controller boards elsewhere on this site. They might be helpful in analyzing your MOSFET driver circuit. From my limited knowledge, the goal is to get a fast transition from OFF to ON and vice versa.
Title: Re: Replacing mosfet
Post by: Alvis on September 27, 2017, 01:06:56 PM
Ok. I have run my laser with new mofset for some time now without any problems which shows that you don't have to buy new control board if your mofset goes out, just replace it!! I know, i know new control board doesn't cost  much but hey, mofset cost 3 which is nothing(cheapest option first right?!)
The new mofset is about three times of size of old one but that's not bothering me, just soldered on other side of control board and now it stick out on top, but again, that's not a problem, you could cut its pins shorter if wanted. Winner! 😀  Not sure if this is useful information to someone.   Thought I'll share my experience. Hahaha
Title: Re: Replacing mosfet
Post by: mrehmus on September 27, 2017, 05:34:14 PM
I always feel guilty when I have an active component with a tab and don't put a heat sink on it for insurance.

It would be good if you would post the ID of the replacement MOSFET.
Title: Re: Replacing mosfet
Post by: ThothLoki on September 27, 2017, 07:18:06 PM
I always feel guilty when I have an active component with a tab and don't put a heat sink on it for insurance.

It would be good if you would post the ID of the replacement MOSFET.

I looked up the FET that was in the picture
https://people.ece.cornell.edu/land/courses/ece4760/FinalProjects/s2012/tcj26_ecs227/tcj26_ecs227/F12N10L.pdf
Title: Re: Replacing mosfet
Post by: mrehmus on September 27, 2017, 08:53:06 PM
Thank you 8)