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Mosfetguide

What is a MOSFET and what are its benefits in airsoft?

The MOSFET (metal-oxide-semiconductor field-effect transistor) is an electronic component used to control currents. A MOSFET always has at least 3 terminals:

1. Gate (control electrode)
2. Drain
3. Source

The function is simply explained: at terminal 3 (source) the source current is present, i.e. the connected battery. The MOSFET keeps the current from flowing to terminal 2 (drain) as long as a certain voltage is not applied to terminal 1 (gate). This control voltage is much lower than the source current.

A MOSFET divides the current into two "flows", so to speak

1. Main voltage - goes directly to the motor
2. Secondary voltage - continues to be conducted via the switch unit

Thus, a MOSFET creates the effect that the Switch Unit (trigger unit) is protected by a lower current flow (voltage) and is thus only used as a signal generator when the trigger is pulled, so that the main current flow from the battery to the motor is released and thus a shot can be made. Another advantage is also the improvement of the response behavior, since the internal resistance of a MOSFET is significantly lower than with the contacts of the Switch Unit. In addition, the metal contacts are subjected to far less stress due to the lower current flow, so a potential source of failure (defective contacts due to charring) can be delayed. With a fully automatic AEG, there is also the advantage of a higher rate of fire (ROF) due to the lower resistance of the current flow

MOSFET Types:

Basically, before installing any MOSFET, it should be checked whether the space required for it is available in the gun at all. For AEPs, for example, you should always go for the micro MOSFETs, since these take up the least space and so the accommodation of a battery is still possible. But even with long guns such as AR15/M4 models, you should look carefully at how much space is still available for the battery accommodation, if you want to install a MOSFET. Furthermore, the wiring instructions, which are usually enclosed in paper form, must be observed so that there is no short circuit or the like after installation (unless the MOSFET is not already wired from delivery)

"Regular" MOSFET:

The standard MOSFETs are larger compared to the micro variants, which means on the one hand a higher load capacity with corresponding current flows. Especially when using stronger springs from M140 on, these MOSFETs are more suitable than the Micro MOSFETs, because the load on the components on the board is lower. On the other hand, these MOSFETs are more user-friendly especially for beginners in terms of soldering the cables, because the soldering points on the MOSFET board are larger and thus facilitate the installation. These types of MOSFETs are hardly used nowadays (01/2023) and have been largely displaced by the drop-in MOSFET (EFCS), since these systems do not have programmable additional functions

Micro MOSFETs:

These designs are particularly suitable for models where space is at a premium. These include first and foremost the AEP guns and electrically operated submachine guns. Due to their compact design, these have little to no additional features and are designed for maximum spring strengths of M120-M130. The most common representative of Micro MOSFETs is the JeffTron Micro II

<img src="https://www.begadi.com/media/wysiwyg/CMS_guides/JT_Micro.jpg" alt="" />

Drop-In MOSFETs / EFCS:

Drop-in MOSFETs are installed instead of the switch unit and are ultimately a hybrid, since the MOSFET is incorporated into the switch unit here. As a rule, no soldering knowledge is required here, since these MOSFETs are usually completely pre-wired. A common representative was the JeffTron Basic Internal Mosfet, which was available for both V2 and V3 gearboxes. In the meantime (as of 01/2023), the Drop-In MOSFETs have been almost completely displaced by the EFC systems, since these allow far more setting options

The BEGADI CORE EFCS:

In addition to the classic MOSFETs, the so-called EFC systems (Electronic Fire Control System) have also been available for several years. These are advertised by the various manufacturers with a wide variety of names (EFCS, ETU, EFC, GCU, etc.), but the basic idea of all systems is the same: in addition to the functions of a MOSFET, EFC systems are intended to monitor the firing cycle of an electric airsoft and protect the system from malfunctions, e.g. due to insufficient battery voltage or a short circuit.

<img src="https://www.begadi.com/media/wysiwyg/CMS_guides/CORE_1.jpg" alt="" />

The Begadi Core is a proprietary development of BEGADI and only available through us. It was developed and built especially for the German market and is installed in almost all new BEGADI weapons. We offer a 4 year warranty on the BEGADI CORE, so that our workshop service is available in case of malfunction or defect.

The functions of the BEGADI CORE EFCS include the following:

Shot cycle monitoring
Battery monitoring (LiPo, LiFe, Li-Ion, NiMh)
Battery shutdown (LiPo, LiFe, Li-Ion, NiMh) System shuts down when battery is low and signals this by vibrating the motor twice
Intelligent active brake (accurate "stopping" of the motor to avoid double shots, automatic adjustment to installed spring)
Overcurrent and short-circuit protection (system signals by vibrating twice that there is a fault, no firing possible)

<img src="https://www.begadi.com/media/wysiwyg/CMS_guides/CORE_2.jpg" alt="" />
Other functions are available for other systems:

different firing modes (semi-automatic, freely programmable bursts, fully automatic at less than 0.5 joules)
Ammunition limitation: EFCS counts fired shots, weapon stops firing automatically at 30 shots → magazine change required (especially interesting in MilSim)
simulated magazine change: after magazine change Bolt Catch must be pressed for weapon to fire again
Sniper delay: weapon fires only every 1.5 seconds (especially interesting for DMR setups)
adjustable Pre-Cocking function (spring is preloaded after each shot, so that a fast firing is possible)

We have summarized more information about the Begadi CORE EFCS on a separate page: https://www.begadi.com/core-mosfet/

<img src="https://www.begadi.com/media/wysiwyg/CMS_guides/CORE_3.jpg" alt="" />

<img src="https://www.begadi.com/media/wysiwyg/CMS_guides/CORE_4.jpg" alt="" />

Difference - mechanical and optical EFCS - systems:

Among EFC systems, a distinction is made between two types of construction:

the mechanical systems, such as the BEGADI CORE EFCS
and the optical systems, e.g. the GATE Titan, Perun Hybrid, JeffTron Leviathan

But what is this distinction all about? It is explained quite simply:
in mechanical systems, all movements of the firing cycle are recorded by mechanical components and transmitted to the electronics. Optical systems use light sensors for this purpose, via which the system's functions are read out.
Another important difference is often the way in which the safety is adjusted: with mechanical EFCS, this is usually still done via the factory-installed components (with V2 gearboxes, via the safety lever).
With optical systems, on the other hand, the trigger can be fully pulled even when it is externally secured. Here, the safety is provided by the installed light sensors, which read out the position of the fire selector lever via a sticker on the selector plate.
Furthermore, most mechanical EFC systems usually consist of only one component or circuit board, whereas optical systems usually consist of two circuit boards that are plugged onto each other inside the gearbox. On the one hand, this allows less light influence on the light sensors, and on the other hand, there are additional sensors on the upper circuit board, which are essential for the functionality of the system

<img src="https://www.begadi.com/media/wysiwyg/CMS_guides/Titan_1.jpg" alt="" />

The advantages and disadvantages of the two systems in a direct comparison are marginal and more due to personal preferences, e.g., regarding the implementation of the fuse or the reprogramming of the functions. In the following, we have summarized the important key data of the mechanical and optical EFC systems as a small decision-making aid:

Mechanical systems

Trigger locked in secured state (cannot be pulled)
Trigger via microswitch
System not susceptible to grease/oil
Trigger travel not so short adjustable (compared to optical systems)
Programming via trigger not always clear ("menu navigation")
Control cam for the Sector Gear is wearing part

Optical systems

Trigger travel can be adjusted very sensitively
Trigger travel partly adjustable via app (GATE Titan, Jefftron Leviathan, Perun Hybrid)
Readout of the firing cycle via light sensor (no control cam, which can wear out)
Trigger is not blocked in safe state
Adjustment via app possible (GATE, JeffTron)
Light sensors susceptible to dirt (gearbox must not be too heavily greased)
Sticker on selector plate can come off (in extreme cases: no longer possible to secure the weapon)

Adjustment of the additional functions of an EFCS
The above functions can be set either via so-called trigger commands or, in the case of Gate Titan or JeffTron Leviathan, via an app. When setting via the trigger, a small card is usually included in the scope of delivery, on which the various functions can be found with the corresponding trigger commands. Over a predefined number of triggers, you thus get through a kind of menu in the EFCS, which is confirmed via vibrations of the motor.
Optical systems can be set via an app, which is the more comfortable way for many players, since the settings can be changed here via a few "button presses" and this is designed more clearly. In this case, the weapon is connected to the mobile device (smartphone, tablet) via the battery connector (a data cable is usually included), then the corresponding app is started and the "programming" can begin

<img src="https://www.begadi.com/media/wysiwyg/CMS_guides/GATE_USB_Adapter.jpg" alt="" />

GATE Blu-Link - Reading out data
The Blu-Link from the company GATE is an adapter that can be operated via Bluetooth and is connected to the battery port of the weapon. Through this, numerous system data, the respective installed EFCS, can then be read out, for example, the current required by the motor, temperature of the motor, the firing processes already performed by the system, but also the duration of a firing cycle. For this, in addition to the adapter, the free "Gearbox Control Station" app from GATE is still required on the corresponding mobile device

<img src="https://www.begadi.com/media/wysiwyg/CMS_guides/GATE_BluLink_1.jpg" alt="" />

<img src="https://www.begadi.com/media/wysiwyg/CMS_guides/GATE_BluLink_2.jpg" alt="" />

Additional notes when retrofitting an EFCS:

When retrofitting an EFCS, there are a few things that should be considered before purchasing that are important for a successful self-installation. When selecting an EFCS, in addition to the appropriate version for the corresponding gearbox shell (e.g., whether for V2 or V3 gearbox), attention should be paid to the direction of the wiring. All EFCSs are wired at the factory, so the first thing to consider is whether the battery placement should be in the stock (rear-wired) or in the forend (front-wired). Generally, all M4/M16 models are rear-wired and G36 models are front-wired. Furthermore, the EFCS board should fit in the gearbox shell without tension or adjustments. If this is not the case, malfunctions or similar disturbances may occur. For EFCS with two boards, it is also important to ensure that the upper gearbox shell does not press on the upper board and damage it. In addition, optical systems are susceptible to grease and dirt due to the built-in light sensors, which is why excessive greasing of the gears should be avoided. Special attention should also be paid to the functionality of the fuse. In this case, it is a good idea to glue the sticker on the selector plate with superglue so that it does not fall off.
In the case of mechanical systems, however, additional care must be taken when installing the sector gear to ensure that the control cam on the underside does not rest on the control cam of the EFCS when it is inserted, which could damage it.
Furthermore, the manufacturer's specifications regarding the maximum voltage of the battery (e.g. maximum 11.1V LiPo or 14.8V LiPo), the battery type (LiPo, LiFePo, NiMh) or the maximum spring strength to be installed must be observed

Warranty & Guarantee:

When installing a MOSFET, the gearbox usually has to be opened to re-route the cables. An exception are the V6 and V7 gearboxes, where the EFCS is screwed on from the outside and its disassembly does not require opening the gearbox shell.
It should be noted that opening the gearbox independently will void the warranty. In order not to lose this, our workshop offers an installation service for MOSFETs and EFC systems. We are also happy to help with problems with the installed system and offer the possibility of troubleshooting through our workshop, provided that the airsoft gun and the associated EFCS were purchased from us in the store

Further help: (Video instructions)