A third generation MOSFET with 10 different features, newest of them an adjustable burst fire. In addition, the system makes it possible to adjust the rate of fire, without compromising efficiency. The unit has protection for modern batteries: Li-Ion, Li-Po and LiFePO4 (as well as NiCd). Other features include i.a. an active braking and the standard MOSFET benefits in protecting the trigger switch. Thanks to the smart trigger you get the quickest possible trigger response regardless of the set rate of fire.
The MERF 3.2 can be installed in two ways:
Directly into the gun's old wires, which enables only some of the features.
A more advanced installation requires installing the signal wire into the trigger switch. The MERF 3.2 is compatible with most electric guns, including the most powerful upgrades. The unit’s operating voltage range from the battery is 7.2 V – 12.8 V (absolute min and max 3.2 V – 15 V)
3rd generation MOSFET
micro-switch compatible (digital signal control)
rate of fire adjustment
adjustable burst fire
two ways to install:
simple – changes to the gun are not necessary
advanced – requires installing the signal wire to the trigger switch
voltage range for the batteries 7.2 V – 12.8 V (absolute min and max 3.2 V – 15 V)
compatibility is excellent with highly upgraded airsoft guns (i.a. DSG guns)
easy to install – you need only to install the signal wire and change the old connections with conductor surfaces
comprehensive protection for the electrical system
very low power consumption in standby mode (0.15mA)
very low resistance (2.4 mΩ)
four LED display
The package includes:
GATE MERF 3.2 unit
extra pair of Deans connectors
signal wire (60 cm)
double signal wire (60 cm)
MOSFET (Metal Oxide Semiconductor Field Effect Transistor)
The unit reduces power loss due to normal mechanical contact in the trigger switch. When using MOSFET only the signal current flows through the trigger switch and the actual running current goes directly from the battery to the motor. This prevents the burning of the trigger contacts, which is going to happen sooner or later, especially when using powerful batteries – the average lifetime for contact surfaces in an actively used gun is around one year. At the same time, the MOSFET unit enables the maximum power flow in the circuit without unnecessary resistance due to worn trigger contacts. This also gives you a higher rate of fire and a faster trigger response.
3rd generation MOSFET
The use of modern transistors and microprocessors has enabled the manufacture of small and reliable MOSFET units with microswitch compatibility.
Microswitch compatibility (digital signal processing)
With digital signal processing the MOSFET can filter out the vibrations of the microswitch during firing, which might cause excessive sparks and wear in the switch, lower rate of fire as well as heating of the motor, MOSFET, wires and battery, like with traditional MOSFETs. Since the MOSFET filters out the extra signal oscillation, there are no disadvantages of the vibrations created.
In operation, the motor and the gears accumulate kinetic energy (energy from motion). The magnitude of the energy is mainly determined by the speed of the mechanical parts. The maximum speed is reached approximately after the fourth shot. For this reason, the motor doesn’t stop immediately after releasing the trigger, but continues to rotate for a moment. This is due to the accumulated kinetic energy; the more there is, the longer the motor keeps running “extra”. The active brake is a feature, which stops the running parts with the motor immediately after releasing the trigger.
Benefits of ON/OFF active brake:
1) No more double shots or double feeding. The gearbox performs only one full cycle with semi-auto. The piston always stays in the front position, which extends the lifespan of your gearbox.
2) Realism – You get the exact amount of shots with every pull of the trigger as you meant. The advantage can especially be experienced with semi-auto builds.
The smart fuse protects the MOSFET unit, the gearbox and the whole gun from electronic problems. The smart fuse is essentially an enhanced electronic fuse. The unit actively monitors the voltage, power and temperature, which ensures the fuse’s reliability as well. The fuse protects your gun from both short circuits (SCP – Short Circuit Protection) and overloading (Overload Protection) as well as from overheating (OTP – Over Temperature Protection). Short circuit and overheating protection are important especially with LiPo batteries, because a short circuited LiPo battery might cause severe damage also to the gun.
Under Voltage Protection for different battery types (UVP)
Protects LiPo and Li-Ion batteries from excessive drainage. Adjustable for batteries of 7.4V – 14.8V voltages.
The transparent protective coating protects the MOSFET unit from splashes, debris and minor damages.
Enables the fastest possible trigger response. Works in cooperation with ROF adjustment. After connecting the battery, with the first shot the system sets the ROF adjustment to 100%. With the next shot the rate changes to a preset (e.g. 50%). Thanks to this the first shot always fires as fast as possible and the following shots according to the preset speed. You’ll get the best effect by using batteries, which have a high operating voltage, like 11.1V LiPo batteries. Thus, you can achieve a very fast trigger response, but still maintain a moderate rate of fire.
Rate of fire adjustment
The adjustment is based on the Pulse-Width Modulation, PWM. The level can be adjusted between 30 – 100% (with 10% intervals) and it does not compromise efficiency in other parts of the system
NOTE! The adjustment scale does not mean that you can adjust the rate of fire 30% from the original, in practice it corresponds to about 50% of the actual rate of fire. Which means you can adjust the rate of fire between 50 – 100%.
Adjustable burst fire
First and foremost, the burst fire saves your BBs
If you release the trigger before the last shot, you can also shoot shorter sets.
You can adjust the time of the burst fire on a 4 ms (0.004s) scale from the system settings.
Thanks to the adjustment, the burst fire works on different rates of fire and practically makes it possible to have two, three or four shot bursts.
In the simple installation in addition to the standard SAFE/SEMI/FULL settings you can also choose a SAFE/SEMI/BURST setting.
In the advanced installation you have two options in addition to the standard one:
The MERF 3.2 MOSFET control system has a programmable microprocessor. The settings will remain in the memory even when the MOSFET is disconnected from the battery. Changing the settings on the unit is done with the included programming button or with the gun's own trigger. The unit has a four LED display to help with the programming.
Rate of fire (30-100 %)
Burst fire adjustment
Smart trigger (ON / OFF)
Undervoltage protections for 7.2 V – 12.8 V batteries
The instructions for programming are found in the manual.
Two ways to install
With the simple installation you don't have to make modifications to the gun and the unit is directly connected between the gun and the battery. Note, however, that the unit has Deans connectors. Which means the unit does not conduct the power directly to the motor past the trigger switch and thus does not protect it from sparks and wear. In the simple installation you get the following features:
Rate of fire adjustment
Adjustable burst fire
Advanced installation requires you to solder the trigger switch again and install the signal wire, like other GATE MOSFETs. That's how you get all the available features.
24 month warranty
GATE MOSFETs have an extended two-year warranty. It covers manufacturing defects and problems that come up in normal use. The warranty does not cover any fault that is caused by a faulty installation or misuse, like one caused by too high a voltage. You have to use a separate fuse, which protects the MOSFET from short circuits especially with more powerful LiPo batteries, when using NanoASR, -AAB and PicoAAB MOSFETs or SSR series MOSFETs which do not have an electronic fuse. The use of a separate fuse in other MOSFETs is recommended. You will find installation instructions on GATE's website or in Tradetech.