What is an airsoft MOSFET?
An airsoft MOSFET is a smart piece of electronics. Please don’t bail on us, we’ll keep it simple. Promise! The only thing you need to know (and you’re allowed to forget it after this), is that MOSFET is short for Metal Oxide Semiconductor Field Effect Transistor and that it’s quite a fancy name for an electronic switch. That’s all. See, it wasn’t that hard.
When used in an airsoft replica, the MOSFET is soldered onto a circuit board, together with some other electronic bits and bobs. Often they offer lots of extra functions, besides just switching on and off. To keep things simple though, the whole lot is just called an airsoft MOSFET.
What can an airsoft MOSFET do?
An airsoft MOSFET in its most basic form, will protect your airsoft replica from current overload. One of the first things airsoft MOSFET’s are used for, is protecting the contacts of your trigger against pitting as the result of arcing. But the wiring and connectors are also protected against overload. Why you might need that, is something we’ll explain below.
Sometimes, airsofters will ditch their 7.4 V battery in favour of an 11.1 V one. This will give more power, making the motor spin faster, resulting in a higher rate of fire and a faster trigger response. We don’t really recommend it, as the internals of your airsoft replica will wear harder. But for some this is an acceptable thing and we can respect that. As long as you know and accept you’re putting more stress on the internals, it’s fine. Just don’t say we didn’t tell you. Next to the mechanical internals experiencing a harder life, the trigger contacts also get more abuse, as does the rest of the electrical system that has to cope with a higher current. Luckily, the electronics can be protected. The answer: an airsoft MOSFET.
Mechanical contacts will always have a bit of arcing, a tiny arc of electricity jumping, just before closing or just after opening. This arcing will cause pitting (also called spark erosion) and creates carbon deposits, all resulting in a lower or even failing conduction. A small amount of arcing is normal and the pitting and carbon deposits are just normal wear for a switch. But by using an airsoft MOSFET, the actual switching is done electronically by de MOSFET. This means no contacts and no arcing. The current will flow from the battery through the airsoft MOSFET directly to the motor, bypassing the trigger contacts completely. The only thing those contacts need to do, is sending a signal to the airsoft MOSFET and for this, just a very tiny current is all it takes. When you’re using an 11.1 V battery instead of a 7.4 V one, the trigger contacts will burn much faster, making an airsoft MOSFET not only a smart upgrade, but also a necessity. The bigger spark not only will quickly cause too much resistance, it can actually make the contacts weld themselves to each other, resulting in a replica that keeps on firing all on its own.
Please note, that if you want to protect the trigger contacts with an airsoft MOSFET, you need one with a wire to the trigger. Some (plug & play) airsoft MOSFET’s are just placed between battery and electrics to protect the battery in case de wiring gets damaged and a short circuit occurs. airsoft MOSFET’s that do just that, won’t protect the trigger contacts.
Another basic use for an airsoft MOSFET is to protect the wiring itself. A current overload can melt the insulation around the wiring and an airsoft MOSFET can regulate the amount of current flowing. It can also deal with peak loads.
An airsoft MOSFET can also do this!
Depending which airsoft MOSFET you buy, it can offer you a lot of extra functions. So, take care reading the product texts from the airsoft MOSFET’s in our webshop, where we explain exactly which functions they offer. Often, there’s an overlap and we’ll take you through the most common functions an airsoft MOSFET can have.
Too much of a discharge will have a negative effect on battery life, especially when it’s a Li-Po battery. A deep discharge can be caused by the wiring shorting, but most often it’s simply caused by draining the battery too much. This happens when you just keep on playing until the battery has drained itself completely. Or by putting an airsoft replica away for a long time with a nearly empty battery. Some airsoft MOSFET’s will give a signal when the battery reaches a critically low level, others will shut down the current flow completely to prevent a deep discharge.
Very often, an airsoft MOSFET is used to alter the fire modes. You can, for instance, turn a semi-auto into a full-auto, et cetera. Simply said: you can adjust the functions of the fire selector and within many levels too. You might want to adjust burst to continue a bit longer. Or convert your single shot mode to semi-auto, just because you can? The possibilities are often endless.
Sometimes an airsoft MOSFET can be programmed by using clicks of the trigger when in programming mode. Others can be programmed with an external programming module or by attaching them to a computer. There are even airsoft MOSFET’s that can be programmed using Bluetooth.
Pre-cocking (what’s in a name) is another function some airsoft MOSFET’s offer. This means that after a shot, the piston is pushed halfway back against the spring load, ready for the next shot. As soon as you pull the trigger again, the piston just needs to travel a short bit and overcome a small amount of resistance before it’s ready to fire. The result is an exceptionally fast trigger response.
Working in the same manner, but with a different result, is the cycle completion function. It’s quite a useful one too, albeit not one that directly enhances performance. What it does, is using sensors to recognise the position of the sector gear, ensuring the gearbox makes a full revolution. It will stop exactly with the piston resting in top of the cylinder, relieving the teeth of the gearbox and piston of spring tension. This will prolong the lifespan of the parts, including that of the spring.
The function can give you the possibility of setting your burst for a certain number of shots, instead of for a set amount of time. It also can allow pre-cocking to be automatically switched on in certain firing modes. And you’ll never have to experience a semi-lockup ever again. That’s when the cut-off lever has stopped exactly where it prevents the trigger from working.
So, you’ve put a high voltage battery inside your replica and also changed the motor and gearbox to get an otherworldly high rate of fire. Everything is tuned to spread a maximum amount of BB’s. With all internals spinning as fast as they can, mass inertia can mean they will won’t come to an immediate standstill when you’ve released the trigger, causing one or two shots to inadvertently follow. To prevent this, an airsoft MOSFET can offer you active braking. It’s simply done by switching the polarity, making the motor want to reverse. This’ll make it stop immediately.
An airsoft MOSFET can also help you to slow down the rate of fire. Some airsoft fields have a maximum rate of fire, but slowing the rate of fire down is also done by airsofters who want a more realistic feel from their replica. And speaking about realistic: an airsoft MOSFET can also have a function called sniper delay. It lets you choose a certain amount of time before the next shot can be fired, comparable with the time it takes for a real sniper to reload.
Trigger sensitivity is another nice function that can be had. Using sensors, the airsoft MOSFET detects where the trigger is moving, meaning you can adjust the travel. With that, you can make the trigger fire by just touching it or allow a nice and long travel. It’s whatever you want.
Another handy feature can be the empty magazine indicator. It does happen quite a lot that airsofters don’t immediately realise their magazine is empty, while their replica happily keeps firing. An airsoft MOSFET with empty magazine indicator will stop the replica from firing.
Airsoft MOSFET in an ETU
An ETU is an Electronic Trigger Unit, simply said: an electronic trigger. Conventional airsoft triggers feature a sliding contact where a brass lip slides in between two brass contacts. An ETU on the other hand, has a microswitch that’ll give a click with nice feedback. Some ETU’s don’t even have a switch at all, using light sensors that’ll give a signal. It’s a very refined system that usually has lots of adjustment possibilities. And very often, an airsoft MOSFET is incorporated in the system, offering many more options and functions.
Buying an airsoft MOSFET
You now know there are many airsoft MOSFET’s to choose from. Some just offer you protection of the electronics inside your replica, such as protecting the trigger contacts, the wiring and the battery. But even in its most basic form, an airsoft MOSFET is one of the best upgrades you really should consider for your airsoft replica. It helps boosting the durability and also offers protection if a short circuit might occur for any reason.
The most advanced airsoft MOSFET’s will do a lot more and will provide you with lots of extra adjustment options and many extra functions. When you see what an airsoft MOSFET can do for your airsoft replica, it definitely is the upgrade that’ll give you the most value for money. It’s absolutely worth the investment, improving your replica in many ways.
All airsoft MOSFET’s on our website have clear descriptions of what they can do and for which replica’s they’re suitable. If, however, you have any questions. please feel free to contact our customer service. Or ask the experts in our shop for advice if you’re visiting our shop in Staphorst.