Boneyard
Of Mosfets and things!

Well the article on the ICS MX5-Pro got me around to thinking of Mosfets and how easy (or difficult) to source these and crucially to fit to an AEG.

So like a lot of people new to these I had a few burning questions that I needed answers to before I could make up my mind on the benefits to adding one to my setup. After a little searching around I found a relatively local guy who was willing to answer some questions from this noob to the subject.

Ralph Gault from Larne in County Antrim runs a little operation building and supplying Mosfets for AEG's around the world called Fireworks Airsoft . A maintenance fitter by trade, electronics is a hobby for Ralph, he found the mosfet design on the internet and decided to give it a go. That then lead to the creation of Fireworks Airsoft in Feburary 2010. (checkout the website for latest prices and Mosfet info).

The mosfet designs used are by Terry Fritz of Extreme-Fire.com in the States. The designs are all open source which means you are free to use and develop them provided they remain open. All the information regarding the different circuits is on the download section of Fireworks Airsoft.

The advantages of a mosfet are well documented, essentially the high current load caused by the motor spinning up is directed through the mosfet instead of across the copper trigger contacts. This eliminates arcing and premature wear of the contacts (carbon deposits making poor contacts). The Beta and Ares models feature a second mosfet to short circuit the motor and provide active braking when you release the trigger.

If you can confidently strip down your AEG and 'fiddle' with the gear box and do a bit of soldering then fitting one of these puppies should be a doddle. A wiring diagram is provided with instructions when you order one of these from Fireworks Airsoft . Some advice from the maker of these mosfets is "Take care to plan the wiring layout so as you can disassemble the gun again in the future without having to snip the wires, use small crimp connectors instead."

'Alpha'

'Beta'

'Ares'






The design of these mosfets are well tried and tested the failure rate is extremely low. Each unit is bench tested before despatch. The materials used are professionally manufactured pcb’s with high quality components. If you’ve got a problem with one Fireworks Airsoft will replace it free of charge.

When ordering a mosfet from Fireworks Airsoft remember it's a small operation. Although they try their best to always have one ready for dispatch sometimes orders do get a little behind. Please be patient if you have to wait, especially when some custom builders order a lot at once. Keep checking the website for regular news and updates.

So while a mosfet won't dramatically increase performance what the Ares unit will do is give a great 3 round burst, protect the tigger mechanism from arcing, and provide active breaking and spring release, also on the Ares model active battery monitoring for Lipo's ensuring you don't run the battery all the way down (this removes the need for a seperate battery monitoring pcb). All mosfets are wrapped in clear heat shrink to protect the PCB and have wires and spade terminals attached.

All Fireworks supplied mosfets come with the original 'Extreme Fire' programming however by request these can be flashed with Unconventional-Airsoft's 'Trigger Master' software. This features 2 extra modes:

• semi - 3 rnd burst - followed by NO full auto and

Yosser Says:
A big thanks to Ralph for taking the time to explain to us about mosfets, I'm sure myself and a few others will benefit from it. I'll let the readers of this blog know when I've got one fitted to my AEG (probably an Ares model as the benefits for running my Lipo's are obvious).