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Guide: MOSFET switch

Posted: Thu Apr 02, 2009 3:31 pm
by Moondog
SWICHING TO MOSFET
by Moondog

MOSFETs (metal–oxide–semiconductor field-effect transistor) are electronic switches that augment the physical switching mechanisms of most AEG's. The advantage to a MOSFET is that it allows 99.9% of the current to bypass the trigger, virtually eliminating the electrical arcing leading to melting of the trigger contacts over time (even with 9.6v batteries.)

Some advanced MOSFETs feature Active Breaking, resettable fuses or are programable, allowing players to select 3-shot burst or semi-fire only. Active breaking precisely stops an AEG motor from over turning and virtually eliminates accidental spring compression from a half-cycled gearbox. Resettable fuses are just as they sound, solid-state circuit breakers that reset themselves after a cool-off period.

MOSFETs are mostly an after-market installed part that requires basic electronics and soldering skill. Some newer AEG's (the newest JG M4 and AUG) have them pre-installed. We hope to see MOSFETs and Active Breaking to become standard in all mid range AEG's in the next few years due to the growing use of LiPoly and LiOn batteries.

DIAGRAM of MOSFET install

VIDEO of MOSFET Install on M4
http://www.youtube.com/watch?v=hhtmB0k_TV4


MOSFETs available from retailers

Extreme Fire is a company started by a hobbyist and he makes custom MOSFETs and fuses that sells directly.
http://extreme-fire.com/

Echo-1 MOSFET and Automotive Fuse unit for M4
http://www.airsoftpost.com/echo-wiring- ... 30538.html

Pro-Arms 3-round burst MOSFET
http://www.airsoftpost.com/proarms-roun ... 30529.html

Re: Guide: MOSFET switch

Posted: Sat Aug 13, 2011 11:41 am
by Shogun Mitsu
I would like to install a mosfet in a Diablo project I've been working on. I have found a few, but my buddy Ghostrider found this & it looks like it may the right choice for me. My question is, if I install this Mosfet will I be able to run a lipo on it? The rifle was a JG m4 S-system I purchased about 2 years ago. I dont know what version gearbox it is, but I am pretty sure its a version 1. Any input would be greatly appreciated. Eventually I will be changing the gearbox completely, but for now I added a few upgrades to it & will be changing the gears to cnc'd alluminum very soon. THANKS GUYS!
http://www.airsoftpost.com/advanced_sea ... mit=Search

Re: Guide: MOSFET switch

Posted: Sun Aug 14, 2011 11:34 am
by Moondog
Mitsukai wrote:I would like to install a mosfet in a Diablo project I've been working on. I have found a few, but my buddy Ghostrider found this & it looks like it may the right choice for me. My question is, if I install this Mosfet will I be able to run a lipo on it? The rifle was a JG m4 S-system I purchased about 2 years ago. I dont know what version gearbox it is, but I am pretty sure its a version 1. Any input would be greatly appreciated. Eventually I will be changing the gearbox completely, but for now I added a few upgrades to it & will be changing the gears to cnc'd alluminum very soon. THANKS GUYS!
http://www.airsoftpost.com/advanced_sea ... mit=Search
Every M4/M16 has a Version 2 gearbox. The only gun with a version 1 gearbox is the Famas. See here: viewtopic.php?f=16&t=128

The Burst Wizerd you link'd to is a 'technically' a type MOSFET switch but it only controls the amount of current flowing to the motor (allowing you to "tune" it to fire bursts) but it does NOT bypass the trigger. So any high voltage current will still surge through your trigger contacts.

Re: Guide: MOSFET switch

Posted: Mon Aug 15, 2011 12:40 pm
by Shogun Mitsu
Ahhhh, I understand now. I thought it was too good to be true. So my best bet would be a Mosfet wired to the trigger to regulate power flow from the battery & to control the burst I would install the wizard? Correct? I'm thinking a lil ahead now, & seeing if a Ver.3 gearbox that is lipo ready would be a better idea for me financially. Hmmmm, to much to consider. Help me make a decision, PLEASE! lol

Re: Guide: MOSFET switch

Posted: Mon Aug 15, 2011 2:07 pm
by Moondog
Mitsukai wrote:Ahhhh, I understand now. I thought it was too good to be true. So my best bet would be a Mosfet wired to the trigger to regulate power flow from the battery & to control the burst I would install the wizard? Correct? I'm thinking a lil ahead now, & seeing if a Ver.3 gearbox that is lipo ready would be a better idea for me financially. Hmmmm, to much to consider. Help me make a decision, PLEASE! lol
Why buy two things? There are programmable MOSFETs that both shunt high-voltage AND offer various modes such as burst, semi-only (for snipers) modes and active breaking (burst of reverse polarity to offer crisper trigger action.) I mention this in the 1st post: http://extreme-fire.com/

Re: Guide: MOSFET switch

Posted: Sat Aug 20, 2011 11:22 am
by Shogun Mitsu
Hey Moondog, Do you know anyone talented in the art of Mosfet installation? I'm looking at a Cheetah, but installation looks a bit intimidating! :cry:

Re: Guide: MOSFET switch

Posted: Wed Aug 24, 2011 12:19 pm
by Moondog
Maybe contact JuiceWizard or Headkill. Unfortunately there isn't any electricity at Zulu24 or else I'd suggest bringing it up. I might try and schedule another gearbox BBQ this September if we can do it at Don Chullo's or on my roof deck.

Re: Guide: MOSFET switch

Posted: Thu Jul 26, 2012 12:24 am
by Rosales
Anybody ever tried or know someone using an ASCU II mosfet? It looks pretty good for a drop in fet, thing is it replaces the traditional trigger assembly with a micro switch. Now Im not too familiar with the micro switch and from what I've read before players hated it (micro switch). Any thoughts before I dump a benjamin on this one?

Re: Guide: MOSFET switch

Posted: Thu Jun 26, 2014 12:02 pm
by Bacon01
can someone tell me how good this burst regulator looks to them?http://www.evike.com/products/42543/thanks!

Re: Guide: MOSFET switch

Posted: Thu Jun 26, 2014 7:44 pm
by Rosales
Bacon01 wrote:can someone tell me how good this burst regulator looks to them?http://www.evike.com/products/42543/thanks!
If you're only looking for the burst feature, it does the job pretty well. As for preventing trigger arcing no. It is not a true mosfet so you are still running the risk of burning your trigger contacts.