Why do people use MOSFETs?

Well, since you're here I assume you are particularly interested in MOSFET issue or you may have some competition to win ;) No matter which option applies to you I hope you'll find that post useful. Professional knowledge may not only provide you competitive advantage over other AIRSOFT players but also give you authority of an expert within your local community so I think it’s worth it. Let’s stop empty words then and start a factual content of that entry.

At first goes the theory. MOSFET is a transistor that is used for amplifying (or switching) electronic signals. The metal–oxide–semiconductor field-effect transistor (because that is an abbreviation's meaning) does not apply only to AIRSOFT replicas. In fact it is widely used in the electronic world. You can find various types of MOSFETs in your TV sets, laptops, smartphones and many others. The device itself consists of gate, body, source and drain. As you can see in the picture below (g = gate, b = body and so on) it is not unbelievably complex. But remember that it’s just an example of the easiest product: the best engineers specialized in MOSFET’s manufacturing are true wizards who are able to create the most compound projects that may add innovative features to various types of devices. Between gate and body you can see a white rectangle – it’s an insulating layer, often made from silicon oxynitride responsible for blocking gate from the current’s flow.

Source: Wikimedia Commons

How does it work in AIRSOFT though? Authors of the idea at first were thinking about safety of the trigger contacts. If you tune up you’re replica it is highly probable that you'll have to use the more powerful battery. The main issue connected with that fact is electrical arcing: that phenomenon occurs just before trigger contacts touch each other. It is very dangerous for the gun because it implies a very high temperature that may destroy fragile parts and make your replica unusable. That problem is typical for the batteries with voltage bigger than 7.4v. What does the MOSFET do? It transfers some of the voltage directly to the motor what gives a relief to the trigger contacts and makes the mechanism as a whole more reliable and persistent. Are players using weaker type of batteries completely safe? Unfortunately no. Electronic arcing is always taking place in replicas with no MOSFETs so it’s just a matter of time when the contacts will burn. That is why MOSFETs are applicable and beneficial for all kind of AIRSOFT guns.

But when the primary goal was achieved someone wise gave a thought: why won't we develop MOSFETs even further? If the device can influence dependability of the replica why can't it add any new features? One may point out that some players don't care about technical innovations, all they are interested in is realism. But actually, using MOSFET may provide you not only technological innovations taken from a science-fiction movie but also a feeling of reality.

If you are looking for the latest technologies you should focus on functions like ROF control, Smart Trigger or Burst Mode. The first one enables you to reduce the rifle’s rate of fire what will make you more precise. Smart trigger gives you an opportunity to react faster for threats during the battle: faster reaction of a trigger may save valuable fraction of seconds. The last one, Burst enables you to make shot series. Because of that your gun will gain another mode of fire that you'll be able to use in even the toughest situations.

If you are a fan of the realism on the other hand, you will definitely enjoy Active Brake function. While the brake won’t allow for compressing the piston after a shot you'll be sure that just after you release a trigger the rifle will immediately stop shooting.

The early AIRSOFT MOSFETs faced two main issues: dimensions and problems connected with installation. First one was specifically irritating for the owners of smaller guns. Fortunately the progressing process of a miniaturization gave an answer for this serious issue: the newest MOSFETs fit in practically all replicas. Of course it all depends on the particular model of device: not everyone will be suitable but I'm sure that after doing some basic research you'll find something for yourself. Installation was a bigger issue: players who hadn’t been very into technical stuff often found fitting of the device pretty difficult and gave up with it, afraid of the high service’s costs. But it is also changing: the most innovative manufacturers had started to produce MOSFETs in the Plug&Play system that does not need any modifications in your replica – you just plug a device in and benefit from its features.

MERF 3.2: Plug&Play MOSFET

PicoAB: 4x9x19 mm MOSFET with Active Brake

It’s not easy to be a fortuneteller and predict the future. But really, if something gives an advantage in such competitive sport as AIRSOFT, guarantees longer life of fragile, expensive constructions and is affordable for the vast majority of players can we assume that it'll be a market failure? I don’t think so. Be sure therefore to keep in touch with the technological development of your hobby. I don't think you wish to be the last one on the battlefield with no MOSFET in your gun!