I get alot of questions about Mosfets rewiring etc etc. So I decided to put together a guide to help clear up some common issues people might have and to show how to make your own mosfets capacitor banks etc etc.

WIRE SELECTION!

There are many different wire types, all of which have advantages and disadvantages. Here are the main types you should consider using in your AEG.

Solid Wire
Pros - Very thin
- Low resistance
- handles more amperage than comparable gauge stranded wire
- very stiff, easy to route through gearbox and such
Cons
- breaks easily
- very stiff, can be bad in some cases

Hook-up Wire
Pros - pretty flexible
- thinner than silicone wire
- easy and cheap to come by
- tough insulation
Cons
- 16ga wire sometimes too thick for Ver 2 gearbox
- not the top performer in low resistance and amperage rating dept

Teflon coated mil-spec wire
Pros - Standard OEM wire in Systema, Prometheus, and Tokyo Marui
- Very Strong insulation
- Super thin, 16awg teflon wire is thinner than any othe 16awg wire
- typically has silver coated copper conductor
- low resistance
- pretty stiff, routes easily through gearboxes and aeg bodies
Cons
- pretty stiff not as forgiving if you measure out the lengths wrong
- expensive

Silicone wire(deans wet noodle)
Pros - very low resistance
- very flexible
Cons
- very expensive
- silicone insulation tears very easily
- hard to solder
- extremely thick

Speaker wire

don't use it unless you have to.



Wire size
Wire size is typically measured in the American Wire Guage system. In this system the smaller the #, the larger the wire. The Guage is determined by the size of the CONDUCTOR only and not the overall size if the wire.

Most AEG's come with 18 or 16 AWG wire. 16awg wire is best for most AEGs since it handles 75 Amps. If you have room you may try 14awg but the benefit will be minimal.

Connectors

Tamiya(large and small)
These connectors suck . they are worn out after about 50 cycles of being put together and pulled apart.

They are also a huge source of resistance and allow a mere 15amps or so to pass through them

Deans Ultra plugs(T-connectors)

Last a long time and can handle alot of power as they are very low resistance.
Switch to these connectors right away!

typically 10 pairs can be had on ebay for $4!

To add deans plugs is simple.

*Cut off worthless Tamiya Plug (if this is the battery , be sure to only cut one lead at a time to avoid short circuit.)
You can also clamp the deans plug in a vice or clip to hold it while soldering at this time

Typically the battery uses the female end and the male end goes to the AEG harness


* Now pretin each of the deans plug terminals. Do this by adding a bubble of solder to each of the terminal tabs.


*Next put a piece of heatshrink on each wire to be soldered. Then attach the + wire to the vertical tab, and the - wire to the horizontal tab.

Should look like this.


Then heat the shrink tubing to cover the exposed terminals!!

The video shows how to do this as well.

Tools


-soldering iron/irons
-wirestrippers
-heatsink
-voltmeter
-wet cellulose sponge
-sandpaper
-flux
-helping hand tool
-heat gun
-glue gun
-pliers

This post has been edited by GoLgo 13: Mar 20 2008, 06:04 PM

Capacitor BAnks

Capacitor banks Can improve your trigger response and rate of fire.

Electrolytic Capacitors store energy and release it on demand. This will fill in voltage drops seen when you initially pull the trigger, and when the AEG is cycling through some shots.

When the voltage drops, the capacitor releases its stored energy and helps smooth out the current. once the voltage drop is gone, the capacitors fill up once again.

The improvement is nominal though, and to get a noticable difference you need a pretty large bank. Not all AEG's have room for this so keep that in mind.

If you can fit them in though, there really is no disadvantage to using them.


to install a capacitor bank is simple. Just find a suitable location for them, and solder them in paralell into your aeg wire system.

They are polarized so get the +/- correct. The (-) side is shown by having a stripe running down the cap one one side

I usually make my capacitor banks removable so I can switch them from gun to gun.

You can buy capacitors at radio shack or from an online store or in old unused electrical devices such as disposable flash cameras.

here is a schematic


FUSES
Fuses come stock in most AEG's. They heat up and break teh circuit when there is an over load of current. I typically don't run any fuses in my AEG's since I can rewire one on 15 minutes. but if you are concerned about your setup, here are some fuses.

glass or plastic automotive fuses
these are found in most stock AEG's. when they trip, you just pop in a replacement.


polyfuses(resettable)

These fuses gradually expand when heated to the point where they no longer conduct electricity. Once the current is removed, the contract and cool to the point where current can flow again. Once they trip however, they are tripped again very easily unless given sufficient amount of time to cool.

Glass fuse and a Polyfuse


Motor connectors

There are three main options here.

good
standard motor connectors - not the best because of high resistance.

better
gold plated motor connectors - allow more contact between connector
and motor tab which decreases resistance

Best
Solder wire directly to motor tab- best option but must desolder every time motor is removed(sux for ver2 GB owners)

This post has been edited by GoLgo 13: Mar 20 2008, 07:53 PM

Mosfets
A mosfet is a switching transistor that can handle high loads and carries very little internal resistance. There are many benefits to using these and there are really no drawbacks to using them.

-They can do these great things...
- increase ROF
- Allow use of higher voltage batteries
- save your trigger contacts from ever burning up
- increase trigger response
- increase overall efficiency of your electrical system

It is really easy to make one if you have some soldering skills. (watch the video for some soldering tips.)

Here is a good soldering guide that I had nothing to do with making...
http://www.kpsec.freeuk.com/solder.htm

Here is what you need to make the Mosfet unit itself...
100ohm resistor
20-30k ohm resistor
suitable mosfet ( I always use IRL1404z)


You may also want to find plenty of heatshrink tube in various sizes and the wire that you are going to use for the motor and for the gate wires.


The Mosfet has three pins. Gate , Drain , and source.(see first picture)

You need to put the 100 ohm resistor on the gate pin, and the 20-30k ohm resistor(pull down resistor) between the gate and source pins.

I like to cover the mosfets heatsink with heatshink tubing. I do this because the heatsink has the same electrical value as the drain pin, and I don't want anything to short out by touching it.

I also cover the pulldown resistor.


First I attach the pull down resistor...

and then the gate resistor ...


After that you are good to get started. rewiring. First you must desolder the trigger contacts and attach the gate wires. I typically use the small wires found inside of ethernet cable.

Desolder each trigger contact and attach a gate wire to each of the trigger contact tabs. it should look like this.



then you can add new wires that go straight from the battery to the motor.


No all you need to do is find a spot to put the mosfet. When you find it, clip the negative wire in half and take the side that runs to the motor. attach this side to the center pin of the mosfet(drain pin)

then attach the other end of the negative wire, the one that goes to the battery, to the outer "source" pin.

Then finally attach one gate wire to the gate resistor on the mosfet, and the other gate wire needs to be spliced somewhere into the positive wire.

Bam you have a mosfet system!

P.s. quick pictographic diagram



Wait what about active braking?!?!?
Ok that's easy too. All you need to do is add a p-channel mosfet.

The benefit of active braking, is that the motor will "brake" or stop as soon as you let off the trigger.
This helps the piston stay forward and avoid putting stress on the gears and such . It also makes for an amazingly crispy trigger pull.

The guys at www.airsoftmechanics.com pioneered all of this, and made up schematics for us to use! Props to Gandolf(Terry) and PsypherVII.

There are many ways, even some better ways to do this. But here is how I do it, and it works.

Here is a n-channel and P-channel mosfet. I start by glueing them together back to back.

here it is...

Then I bend the P-channel's gate pin to meet up with the N-channels gate pin.



Then I bend both drain pins(center pin) together and solder them as well...



then I add the pull down resistor between the n-channel's gate and source pin as usual.


and finally add the gate resistor(100ohm) to the N-channel mosfet's gate pin.


Now You simply wire this in the same as you would a standard mosfet. The only difference is, you need to take the p-channel mosfet's source pin, and splice it into the positive wire.

Here are some active braking mosfets in various stages of development...


Also here is a video Guide on how to rewire an AEG with a mosfet...!

*** VIDEO ***


WHERE TO GET PARTS!
www.digi-key.com
n-channel mosfet search part # IRL1404ZPBF-ND
p-channel mosfet search part # SPP80P06PIN-ND
polyfuses'
MF-RHT650-ND(use two in paralell)
MF-RHT750-ND(use two in paralell)

Radioshack and Fry's have resistors and capacitors of all kinds as well as digikey

Ebay has all kinds of parts and wire! Use it ! Don't be scared!

references
-www.airsoftmechanics.com
-www.digi-key.com

This post has been edited by GoLgo 13: Mar 20 2008, 11:31 AM

Wow definately pin worthy, now I can make my own. good work! I have a quick question but its in no relation to the guide, what type of grease do you personally use on your gearboxes?

This post has been edited by xsboredom: Mar 20 2008, 08:42 AM

Teflon grease on gears and tappet. Silicone grease on air seal parts. When teflon grease isnt around I use R/c green goop or white lithium.

P.s. quick pictographic diagram



This post has been edited by GoLgo 13: Mar 20 2008, 10:35 AM

CONCUR. Definitely pin meat! Great write up!

ah I see. is teflon grease better? What brand is it or where can I buy it?

Thanks

This post has been edited by xsboredom: Mar 20 2008, 04:19 PM

Your schematic leaves a bit to the imagination *(only to me, I'm not used to seeing them layed out that way).

However, good work. Only 1 comment. Some of your soldering shots, the "close up" is pretty hazy. Overall good info though, and thanks!

This post has been edited by OpSic66: Mar 20 2008, 07:47 PM

I think you are right, I added a better one. Thanks for taking a look. forgive me I finished that thing at like 4 am lol

Good work. Pinned.

Glad to see you didnt take my input negativly. To me the schematic just looked a bit wrong, however placement and wiring was correct. It just didn't "register in my head" correctly.

I also reported this topic, and said it was pin worthy. Good to see that bat21win agrees.

So I pm'ed you and asked you about one of your AB mosfets, but after watching this video, I realized, was it totally worthless to get a Deep fire selector plate for my soon to be CA G36?

I spotted it this morning, and thought about pinning it then, but figured it'd get more traffic today if I didn't.

Your the man GoLgo 13.
Way to put a lot of pertinent information in one well written guide.

Wish I had this 8 months ago when I was finding out this info the hard way.

Wow, how come I managed to miss this for the 5 days it has been up? Very nice guide GoLgo!

I have a couple of questions/suggestions. First, if it isn't too much trouble, could you take a couple more pictures (different angles) of the active breaking MOSFET? I am interested in the design, but it is a little hard to visualize part of it.

Second, on the same active breaking design, is there any reason to not just solder the two heat sinks together on the FET's, and use that instead of the drain pin (just snip it off)? It is a ton easier to attach a wire to that massive hole than to a small (and easily broken) leg on the FET. Then it could be covered with the heat shrink in the same way, and would probably hold together a lot better.

Also, have you ever had over heating problems with the FET's in the shrink wrap? I did two using IRF1303 (bad choice), and they would stop working every 5 shots and have to cool down. My SW-Computer with the 1404 has never had the problem, but it is just wrapped in heat shrink tubing that still allows airflow over it.

I don't have any AB mosfets at the moment , but when I do, I'll snap some pix.

I tried to solder the heatsinks together, but I don't have a powerful enough iron to get it right. and If I did, I may damage the mosfets. I am not the greatest soldering guy. I am a novice at best, and am totally self tought on everything so my skills are weak.

That design is all my own and like I said, there is problably better ways to do it. But that way does in fact work

Thanks for the input. if there is anything else that You guys want to see , let me know and I will try to accomadate you.

If any1 has anything to add, please do.

This post has been edited by GoLgo 13: Mar 25 2008, 10:35 PM

I was thinking about it (might have to order some P-channel FET's and try this).. What about clamping the two chips together, and sticking the wire through both holes. Then fill the rest of the space with a lead solder (low melting point and sticks better). That would effectively join the two heat sink pieces together, and provide a very easy in-line attachment for the negative motor wire to attach to. Then, once the whole thing is wrapped in heat shrink, you have an easy connection for electricity, mechanical, and heat dissipation.

I am not saying your design is bad or anything, I couldn't even understand the connection for AB anyway, much less build my own (I am pretty much self taught like you, and still have a lot to learn). Some of the stuff was easy enough to figure out, but there are not many guides to do this.

Also, from what Gandolf says (I have been talking with him on the Airsoft Mechanics forums), the IRL 1404 is really hard to destroy. So you shouldn't have to worry much when soldering it, but being careful with it never hurts.

I suggest NOT doing that. The heat may possibly damage the mosfet, and they have a screw hole to begin with. There is also a minimal possibilty of the mosfet getting so hot it will re-melt the solder.

I would recommend using a small machine screw, and locking nut. Along with heat transfer paste between the 2 mosfets.

Very nice guide.Excellent work.
I have just one little correction,for you.
When you refer to solid gauge wire you said...,
"handles more amperage than comparable gauge stranded wire"
This is simply not true.Stranded wire handles more amperage than solid,because,
electrons flow on the surface of the wire,not through it's center.Stranded wire has much more surface area than solid,so more current can flow.In fact;you can reduce one gauge down ,with stranded & still support the same amperage flow as one gauge up of solid.
Sorry for the correction,but this is an important fact.
Thanks ,again for your quality posts.

omgomgomgomgomgomgomgomgomgomgomgomgomgomgomgomgomgomgomgomgomgomgomgomgomgomgom
gomgomgomg

VIDEO Update! FULL VERSION!!!!!!!!!!!!!!!
2 videos
http://s7.photobucket.com/albums/y284/mean...MOSFETPART1.flv
http://s7.photobucket.com/albums/y284/mean...mosfetpart2.flv

Anybody know of a guide that show's how to build a three shot burst mosfet or where someone could buy a premade one?

extreme-fire.com

airsoft global
angel makes a 3rnd burst mosfet

Do they make special deans connector chargers, or could you just cut off the tamiya connector on the charger?

I usually insert a WHOLE deans set inbetween the timaya plug and charger. That way I have a deans end for charging mine, and an adapter to charge timaya's.

Hey, great write up here mate. Thanks.

Nice name, too. Whenever I played X-Com I would always name my top two soldiers Gold and Silver from a Golgo movie.

do I have to use both the normal mofset and the active breaking one or is the active breaking one the normal+ the active breaking feaeture

One or the other. If you read carefully, the AB MOSFET has a IR1404Z MOSFET built into it. It just has as p-channel MOSFET "piggybacking" on it.

Here's how to install an AB mosfet:

any guides or videos for p90 and aug?

how much rof will mosfet/rewiring add at the most to a jg mp5 with element speed kit, bank capacitor, 10.8v battery, and eg1000 motor?

This is a great guide! That being said, I don't think I would ever be able to do all the stuff you do, Golgo, but this is great reference.

Thanks for taking the time to post this.

Can I attach the two Drain pins with a 20awg silicone wire instead of bending them I feel like they are to close to the drain.

Yes, or just solder/machine screw the heatsinks together and use it as a drain pin and cut your standard drain pins off.

>>Mike

Made the AB mosfet and it works GREAT thanks so much for this post.

Also can my gun handle a Lipo battery now?

A gun tolerating a Li=Po has more to do with the gearbox, then the electrical system.




For those of you, who are interested in COMPLETELY re-wiring your gearbox, and building a "Dual Gate Wire" mosfet.
A Dual Gate Wire mosfet allows you to completely remove the wiring from the gearbox. Run 1 set of wires (of a much smaller gauge 20-22g is fine) to the trigger contacts. And the battery wires through the mosfet, and directly to the motor!

Here's a Schematic for you:


This post has been edited by OpSic66: Nov 15 2008, 05:16 PM

Ok, I might have missed it but where do you recommend buying deans and mosfet parts?

ok so I have a echo1 m4 and I destroyed the wiring and I was wondering if I could just use speaker wire for my gun. What do you think and how would I get the speaker wire working? How much would the sodering iron cost and what kind of sodering iron would I need?

Deans are usually found at your local hobby shop if you only need a couple of them. If you need a good amount of them, look on ebay. As for Mosfet's www.digikey.com is the best place to source them from.




Bad idea. While speaker wire still meets the ANSI standards for it's gauge and material. I don't recommend it, since its insulation is usually thicker, and not as great as other forms of wire, when it comes to the insulation dealing with heat. Not to mention the flexability of it, is not that great.

What you should be looking for is a good gauge wire (I recommend 16g), and silicone insulation, if you can find it. It'll be more expensive then speaker wire, but it will work better and be safer in the long run.

Please don't flame for the necro. I think my question and OpSic's answer may help more than just me.

Can you do the dual gate wiring with an AB mosfet? If so, any changes from running the three wires off the N channel mosfet?

Thanks.

Yes you CAN do a dual gate wire, with the AB Mosfet.

TAMU John shows how here in this thread. It's post #30

This post has been edited by OpSic66: Jan 15 2009, 11:07 PM

So if I were to install a capacitor bank in my AEG, how much net uF would I need?

(great guide by the way)

This post has been edited by Murph9935: Jan 15 2009, 11:28 PM

Ich bin ein Esel dumm.

I didn't realize that was dual gate. Thanks for not making me feel terribly stupid for not knowing.

Sorgen Sie nicht sich um es

It happens.

Has anyone had luck with buying n-channel or p-channel mosfets? Digi-key has them but wants me to order at least 200 of them meaning a $400+ bill for them.

I really only want to buy like 10 mosfets, so anyone know how to do this through digi-key or are there other places to get them?

BTW, Radioshack and Frys Electronics do not carry them.

I just ordered some P-channels last week. About $3. Minimum order was 1.

http://search.digikey.com/scripts/DkSearch...e=IRF4905PBF-ND

Yeah, those are the p-channels.

I also need n-channels and could only find them orderable in less then 200 on this site HERE

I use the IRL3713s for simple N-channel mosfets. I should have a IRL3713/IRF4905 AB Mosfet together and tested this weekend. I think the 3713 should work...I hope. Anyone have experience with using the 3713 in an AB Mosfet?


3713
Volts: 30
Amps: 260
Power dissip: 330W
Resistance: 4mOhms


1404
Volts: 40
Amps: 180
Power dissip: 200W
Resistance: 2.5 mOhm

This is a wonderful guide! Thank you so much for making it. I now feel so much more comfortable with making and installing my own MOSFET.
Now I just gotta work on those soldering skills and I'll be good to go!
I only have one question.

This may sound noobish, but how do you splice the gate wire with the positive wire? Do you solder them together where they meet at the battery connector and then solder them both onto the Deans battery connector? That seems to me like the most logical choice, but I am not sure.

Thanks for all your help!

EDIT: Don't want to seem like a necro poster. I just figured since someone posted on this about a week ago, I could also post here. So please forgive me if I am wrong in my thinking.

EDIT 2: As I was skimming the rest of the thread, I noticed the second video, which I didn't see before. This answered my question. Sorry for my carelessness.

This post has been edited by XBassDudex: Jan 25 2009, 08:41 PM

I'm looking at taking Golgo's AB Mosfet and sticking it on a piece of circuit board for a cleaner looking install.

I have zero electrical experience. And I don't really know the science behind the function of MOSFETs and circuitry. I don't have any circuit board, and I'm guessing a MOSFET is wider than the three holes shown on the diagram.

Given the above caveats, I made this board layout, hopefully making the same connections Golgo did. Should this setup work? It won't be as wide as the diagram, as you'd be able to run the wire leads more cleanly under or over the board. And it wouldn't be as long as the diagram because a lot of board is shown to show the wire leads. In theory, it should only be as wide as the MOSFETs and one to two holes longer than the 100 ohm resistor to the top of the P-chan mosfet.

[attachment=2480:MOSFET.jpg]

Any input?

my original design employed a perf board quite similar to yours. The only difference was, I bridged the heatsinks together and removed the drain pins.

The perf board thing can work really well, but it is not the route to go if you are trying to save space.

I've got a full stock M16. Space isn't a horrible concern.

Thanks for your input. Off to the Shack to find some perf board.

Hey guys going to build a mosfet with active breaking. Just wanted to check with you guys on if these are the right mosfets for the job. The P-Channel is recommended on the front page. The N Channel is my only concern. Will it do the job?

http://search.digikey.com/scripts/DkSearch...e=497-7529-5-ND

MOSFET N-CHAN 60V 60A TO-220

I just put one of these together, I put 3 35v 1000 uf in parellel and attached them directly to the fet, I wrapped a little etape around them to keep them together and I took a p and n channel fet put them together with the resisters and stuff.

worked great with a 8.4, I was getting really good rof for an 8.4, then I plugged in my 10.8 and it started smoking and got pretty hot

and Ideas on what is wrong?

Here's my homemade mosfet, based on Golgo's design. It's untested and the layout is larger than I wanted because I left extra space for a resettable fuse that I never installed. Why I waste such time on this kind of stuff is beyond me.



Let me know what you think.

Hot damn... Your layout just sparked a VERY interesting design layout in my head.

I'll work one up, and post photo's of it when I get a chance.

I could have moved the FETs three holes closer if I wasn't planning to put the polyfuses between them.

I don't like the way I had to bridge the gate and drain pins either. I don't have the electronic know-how to know if the bridges will alter the functionality since in Golgo's design they are soldered together.

I'll Dean's the heck out of it. Male on the battery end. Female on the gearbox end. Dean's micros for the trigger switch leads.

I hope the danged thing works.

anyone know where I can get some p-channel mosfets... digikey seems to be always out of stock...

I was looking to change my glass fuse to an automotive fuse. I was wondering if any has done this and how did their setup was done.

also, does anyone know where I can get resettable fuses?

This post has been edited by shortys38833: Apr 9 2009, 05:33 PM

I use 30 amp mini blade fuses. Soldered directly inline.

ahh, thats an easy way to do it. Have you tried to do a removable fuse? like a mini fuse box.

Mini-fuse boxes tend to be too big sometimes, I just use two terminals electrical taped together, it's a lot smaller.

Since I run a crane stock, there's not enough room. However, I DID have a removable fuse holder using the same size fuse, in a full stock M16 and that worked well.

Just alittle bit to add about people making their own mosfet. The IRL404z is now "obsolete" according to digikey and other places to buy mosfets. On IR's site the direct replacement, or upgrade from that is the IRL1404ZPBF which I ordered through allied electronics.

I have 5 questions abot "Deaning"

1: Does it matter what kind of solder is used? Recomend any?

2: Does it matter hot hot or cold the heat gun is? Or do you only need it hot enough to melt the solder?

3: Will the deans connecters change the amount of shots a battery can dish out with one charge? Decrease or increase?

4: How much Rof increase if used with an M120-M130?

5: Will it still increase Rof if I only replace 1 of my 2 stock tamayas? (I know its a dumb idea, but its all I can do becuase me and my bro share a smart charger and I cant charge my batteries if they have deans and the charger has tamayas, he wont let me solder his gun in fear I break it, nor will he buy his deans, I'd have to buy em' for him)
So untill I convince him, im going to have to stick w/ only one of my middle connecter being deans.

You need to replace all the connectors or none. A partial deaning doesnt do anything as long as there is a tiamya in the circuit then it's resitance will be felt.

Just make a adapter for the chargers tiamyas to your future deans.

I think this deserves to be pinned,anybody elso think so?

Right here.

http://www.airsoftforum.com/board/Wiring-G...mp-t122174.html

definitely, this post is incredibly helpful for wiring and mosfets.

Well this is just mentioned in a pin,I mean an actaull pin.

It doesn't need to "technically" be pinned twice.

If youre looking for some cheap deans/t-plugs her ya go

What is usually the problem when your gun fires on full auto as soon as a power source is connected? I made the mosfet myself, but I think I may have wired it incorrectly.

Something that was not covered in the thread was the amount of Farads your capacitors should be and how much it matters?

as many farads as possible. TAMU JOHN on here found some 16v 10,000 farad caps that were reasonably sized.

I would personnally skip the caps and go lipo!

I've been reading over this thread (as well various other mosfet articles) for a while and decided to go out and get some parts today.

However, after reviewing the schematics again, the 20-30k ohm resistor between gate and source didn't seem to make much sense to me. The only thing I could think of was to try to negate a little impedance in the mosfet. Then I realized that the original "quick pictographic diagram" didn't even show a gate-source resistor.

So that made me wonder, what's the point of the 20-30k ohm 'crossover' resistor and what would the effect of not using it be?

in that schmatic the cross over resistor is connected from gate to drain but the text above talks about the resistor going from gate to source.

what I am missing?

If you had a resistor from Gate to drain, that resistor would be a short.

This post has been edited by OpSic66: Sep 13 2009, 10:57 PM

just to clarify then, the OP's picture is incorrect where it goes from gate to source?
and should instead be gate > drain?

if it is a short, then howcome the op's seems to work, cheers in advance for clearing it up ( if you do :D )

The problem seems to bee in the diagram 3 posts above. The 1404 Mosfet is marked incorrectly. It should be from left to right Gate/DraiN/Source. The center pin and heatsink are the drain terminals.

So it is supposed to be like this..?

Indeed. Schematic updated!

Ok, Sorry to necro-post here, but I've built the Mosfet with active braking and I only have one problem. I can't get it to work off the single gate wire to trigger unless I take out the 100 ohm resistor between the gate wire and the Gate pin on the mosfet.

What am I doing wrong?

Can I run it without the 100 Ohm resistor?

so on the capacitor bank when attached to deans, do you have a direct wire going from positive to negative :S ?
What I saw in the picture, I can't really make to much sense of how you wire it, advice would be helpful
cheers

A little of a necrobump, but this topic is sticked (sorta), so I guess it's alright. Aaaanyways...

For some reason, DigiKey is making you buy the IRL1404 in packs of 250. I Googled IRL1404, and all I got was datasheets and two or three other sites selling it with outrageous shipping and handling charges. Are there any other good sites that sell this particular MOSFET? If not, what would be a good equivalent?

I just recently started getting them from ebay from china. At $21USD shipped for 10 it isnt bad. They work well. Just search IRL1404

I'm a little terrified of electrical work, so I have a few questions on this fairly epic necro:
1) I can only assume it doesn't matter which trigger contacts get soldered in the diagram by opsic66?
2) I have a 12.8V LFP battery (40C output). Will capacitors do anything for me?
3) Can someone summarize what the various types of mosfets do? 3-shot burst and fast-brake make sense, but I keep seeing walls of acronyms that are confusing me
4) I have something like $700 invested in my primary gun, and I don't have another functioning AEG currently. At about what price range would I start to notice the benefits of capacitors/mosfets?

based on your diagram here is a redrawing for a p90.

This post has been edited by vsr10guy: Mar 10 2010, 05:41 PM

I remember seeing somewhere that Golgo said IRL1404 mosfets were obsolete, and that there was a better one to use in its place. What one was that?

The 1404 can be a bit hard to find. However NTE Electronics, offers a cross referenced one which is the NTE2908

So is the 1404 inferior, or just harder to find? Because I see them on digikey and ebay for pretty cheap, at least compared to most airsoft upgrades.

IIRC, DigiKey was out of them for quite some time. I don't recall hearing about the 1404 being superseded.