The Mosfet Thread

[Tommygunn]

This is the Mosfet I use, an IRL2203N: Link to specs

 

This is the guy I bought it off: http://www.ebay.co.uk/itm/380179760580?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2649

 

Plus the usual two resistors.

 

Tom.

[Bluestripe93]

Thanks I'll get a couple of them

[Bluestripe93]

Got 3 of the IRL2203N Mosfets today, Still need to get the resistors though,

 

Couple of questions though

Whats the best way to wire it?  Some guides say to cut off the Drain pin and use a bolt through the hole others say to solder to the Drain pin? 

Whats the best size to use for the big resistor? Some guides say to use 22K, some say 30K and one says 2.2K?

[hawaiianjuggernaut]

22 and 30k is too much from my limited knowledge. I think they mean 2.2k-3k

 

If you use a diode, then i think you have to bolt it. If you dont use one, soldering should be fine. 

 

-Hawaiian

[Tommygunn]

Soldering all the way. The bolt method is both bulky and a bad electrical connection.

Here's my effort before putting on some heat shrink to encapsulate the whole thing:

http://www.arniesairsoft.co.uk/forums/index.php?/topic/161764-the-mosfet-thread/page-28&do=findComment&comment=2490788

 

I used 30kOhm and 100Ohm, ¼Watt resistors for my setup, works a treat.

 

Tom

[Bluestripe93]

Got the mosfet built and put into my G36c, I used the IRL2203N mosfet and a 22K for the big resistor,

with all the other upgrades its firing at 19 rps and the trigger response has increased

 

Here are a couple of pics

http://i710.photobucket.com/albums/ww107/bluestripe93/DSCF3075_zps572ad3ea.jpg

 

http://i710.photobucket.com/albums/ww107/bluestripe93/DSCF3082_zps42939a69.jpg

[Tommygunn]

Well done on completing the project, however, I have to criticise your work.

The soldering is very poor and should not be patchy with gaps, peaks and troughs. It should be a slim, all enveloping capsule of solder completely covering all components.

You can cut the legs right back to save space. The contact point between the leg of the Mosfet and the resistor, at minimum, needs to be no less than the cross section of the resistor wire. That's small.

Heat shrink is meant to be an electrical insulator. You have it covering the resistor body but not the important bit, the legs. Use some heatsink all over the resistor right up to the solder joints.

Heatshirink all possible electrical conductors.

 

Tom.

[Bluestripe93]

I agree the soldering isn't great but I think it turned out ok for the first one, I'll make a few more to put in my other guns, but I found the 16 AWG to be too thick to go inside the grip of the G36c, so I'd go with the next size down wire next time

[richwuk]

The 1st one is always rough, the 2nd one is better! I should try and get some pics of what I did with my G36. I soldered the motor wires coming directly down (so I could fit heat shrink) and then bent it in the shape of a sock to run it back up one side and looped the other around the base and so they both rang up the same side of the hand grip.

 

Alpha Eco wire has a thinner casing than silicone (2.06 mm vs 3+ mm) and still quite flexible - airlab appear to have it if you wish to try some out.

[outblaze]

hi all,

 

I have been looking into this thread with allot of info about mosfett i really want to make my own but there are some really big diffrences in used parts. Are there people that actually tried some of those self made mosfett's and actually work? If so which one did you try and succeed. Sorry for the question but i like to ry things myself before spending big money ..

 

 

cheers

[Tommygunn]

Right here:

http://www.arniesairsoft.co.uk/forums/index.php?/topic/161764-the-mosfet-thread/page-28&do=findComment&comment=2490788

 

Using an IRL 2203N, a 30K? and a 100?. Absolutely ideal for a 1 Joule spring on either 7.4V or 11.1V.

 

Tom.

 

[Tom Andrews]

I use exactly those components for making mosfets for our lipo equiped hire guns. They work a treat. 

Only ever fail when numpties fill the barrel with mud and try to clear it buy continually pulling the trigger............

[Tommygunn]

The question marks were meant to be the Ohm symbol but Arnie's doesn't like it.

 

Tom.

[eatthis]

theres a modified version of this with 2.2k ohm resistor instead of 22k and an irlb3404pbf and a diode 5pk18a between the souirce and drain pin (cathode goes to drain) this is to protect the fet from voltage spikes

[outblaze]

Right here:

http://www.arniesairsoft.co.uk/forums/index.php?/topic/161764-the-mosfet-thread/page-28&do=findComment&comment=2490788

 

Using an IRL 2203N, a 30K? and a 100?. Absolutely ideal for a 1 Joule spring on either 7.4V or 11.1V.

 

Tom.

is there a guide on how to make it with a parts list? 

 

thanks allot!

[Tommygunn]

International Rectifier IRL 2203N x1

30K Ohm resistor x1

100 Ohm resistor x1

 

I use 18Awg for the main wires and 22awg for the trigger wires.

 

Here's the circuit diagram.

 

Tom.

 

 

[outblaze]

http://www.conrad-electronic.co.uk/ce/en/product/418137/1x-06-W-100-1-Metal-film-resistor-0207

http://www.conrad-electronic.co.uk/ce/en/product/420913/1x-06-W-30-k-1-Metal-film-resistor-0207

 

 

just to show are this the right resistors? 

[tiff_lee]

Hi all, been out of airsoft for quite some time and was hoping someone may be able to recommend a suitable off the shelf mosfet for what I need.  

 

I have a prowin V2 gearbox and it always overruns slightly after every shot, now the last time I messed around with it was well over a 18 months ago but I remember trying all sorts with the cutover lever and trigger assembly but failed to sort the issue and came to the conclusion I needed a more advanced mosfet setup.

 

Any recommendations? just needs something that is functional.

[LordElpus]

Fireworks Beta from Fireworks Airsoft are a good bet for around £25 and they are UK based. Otherwise, been very impressed with Gate Electronic's NanoAB, PicoSSR and PicoAB fets. Gate's fets can be got from Firesupport, ebay or direct.

[mamba17]

I am old school and still using Infected mosfet since there inception.
 

All my AEG's, which my son is using now have this mosfet.

I still have the original Extreme Fire Panther and Cheetah and only use them for my Semi Locked AEG based DMR.

 

My son used my AEG last Sunday and the Infected Mosfet didn't turn him down.

We primed if first in the AM game with 7.4V 20C lipoly, and used 11.1V 20C Lipo in the afternoon.

 

And they still works. 

[GroundZeroUK]

Hi guys I have had someone fit an airfet braked system inside a v2 gearbox with shs motor and gearset. Also a speed trigger with short trigger pull now if I pull the trigger too fast on semi after 10 shots or so the gearbox locks up and I have to switch to full auto to unjam. Is this something that can be fixed?

[LordElpus]

no. it's a common issue with V2 gearboxes however it should be lessened by the fet. Typically it's because power is lost before the cycle has been completed. ie the piston is almost all the way back before power is lost but there isn't enough ampage from the battery/motor doesnt have enough torque to pull the piston that little bit more to release it.

It could be a fet issue, a motor issue or you not pulling the trigger all the way to the "bite" point (again, the mosfet unit should prevent this last one assuming that the fet is the standard type not the naff plug n play type)

[RedRob]

Recently built an active-braking mosfet for my L119A1 following DoubleTap's excellent guide. It works really well - ran through a whole day of mainly semi-auto and never missed a beat or locked up. Now need to order the parts for another 2 and get soldering!

[GroundZeroUK]

no. it's a common issue with V2 gearboxes however it should be lessened by the fet. Typically it's because power is lost before the cycle has been completed. ie the piston is almost all the way back before power is lost but there isn't enough ampage from the battery/motor doesnt have enough torque to pull the piston that little bit more to release it.

 

It could be a fet issue, a motor issue or you not pulling the trigger all the way to the "bite" point (again, the mosfet unit should prevent this last one assuming that the fet is the standard type not the naff plug n play type)

 

The mosfet is an airfet with braking. I dont know if this is related but now on full auto it seems to fire at different speeds when I do bursts of fire I dont think something is jelling quite right in the gearbox?

[LordElpus]

more likely the fet itself. Having no experiance of the airfet I have no idea if it's based on the standard DIY setup as shared by several others on this board, or if it's based on the many control unit designs that are about.

Do you have the issue with different batteries?