The wrong Mosfets / Not really Mosfets !?!

[Zarrin]

So I've been making my own mosfets for about a year now, I used YT and this guide http://unconventional-airsoft.com/2009/08/26/how-to-make-a-basic-mosfet-switch/

My knowledge of circuitry or electrics is not that great, however I understand some basic concepts including what mosfets do, what all the components do.. the resistors, diodes, the chips etc, and my soldering has improved over the years to the point that I can fairly confidently follow a diagram and set of instructions and have a working unit at the end of it all.

So I've been using IRF2804 and IRLB3034 chips, because they are pretty much what everyone seems to recommend, especially the 3034 - pretty standard stuff.

So i ordered a set of 10 IRLB3034 chips from China to replenish my stocks, but instead the damned commies sent me 25 of... something else ( 24 units of LD1117AL and 1 LD1117)

From what I can tell from the spec sheet... these are not even Mosfets, they are 'low drop voltage regulators' - https://www.sparkfun.com/datasheets/Components/LD1117V33.pdf

The specs are not even the same referenced specs to say the 3034, so I cant even start to figure out if they would actually be a usable replacement chip in an airsoft circuit.

This is a datasheet for the 3034 for reference: https://www.infineon.com/dgdl/irlb3034pbf.pdf?fileId=5546d462533600a40153566027b22585

My gut feeling, (and the fact that none of the specs seem to be equivalent to those of the 3034) tells me I would just be wasting a couple of resistors, a diode and some wire by trying to build a mosfet with these.

So my question is, does anyone know enough about this stuff to say whether I could actually use these LD1117 chips in a mosfet setup?

I've already been refunded for them, you know, cos they sent the wrong freakin item - they were cheap as chips (heh ?) - i think under 5 quid for the 10 I ordered, so they didn't even bother asking for a return.

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[Adolf Hamster]

i think you need to consult an electrical engineer  dark wizard for this sort of thing.

funny i need to get me some basic mosfets, the gate nano in my aksu is causing jams on semi and i'm starting to wonder if the same thing has been fucking up the f2000 all these years.

 

[Zarrin]

i think you need to consult an electrical engineer  dark wizard for this sort of thing.

funny i need to get me some basic mosfets, the gate nano in my aksu is causing jams on semi and i'm starting to wonder if the same thing has been fucking up the f2000 all these years.

Yeah, i mean it's like anything really... if you don't have the basic foundation knowledge about something technical it may as well be voodoo.

I run standard mosfets on almost all my AEGs, if you're looking for decent no fuss options definitely check out Jefftron: https://www.jefftron.net/

They pretty much have every kind you could want, standard, standard mini, v2/v3 switch assembly, AB or non AB, with or without wiring, and they even have their own micro-switch/computer sets, similar to the Titans.

I've only used their standard and standard mini types.. both work really well.

 

[Sitting Duck]

I buy these...

https://uk.rs-online.com/mobile/p/mosfets/6887204/

Thing is buying cheap is always a gamble...

3034's are highly regarded by DIY Airsoft & Capers

(Unregulated mods used in vaping)

If you get stuck also check what MOSFETs vapers are using at a push

Nowt to lose building a couple to use in mild builds

You can always push it to limits dropping one in a stressful build and spamming like fuck on semi

The real stress is say spamming on semi one shot a sec for say 30 secs or so, if the MOSFET hasn't fried itself to death it should be good for a while

TVS diode is a must but you know that

Other thing is s Schottky Diode across motor perhaps, but only for fully insulated motors like cheapo China motors with tabs. Not for G&G or SHS motors as they affix with a potential risk of short with a SB160 Diode.

You shouldn't need a Schottky Diode with a TVS diode, but on a stock gun a Schottky will reduce spikes and "some" arcing at motor. (Still arcs a bit but lessens the arcing at brushes and reduces the flyback spikes etc...)

Thing is, give a go on a mild build, but buy from RS

China stuff can be anything, often clones, sometimes rejects or end of line

Sometimes you win, often there are some failures in a batch, usually they are not the real deal on AliExpress etc...but something similar or fuck all like it playing the Chinese lottery

(Yeah many things are, but IC's especially at times)

TBH you don't need anything like the full spec of a 3034

If the gun is built right it will often draw under 20a on auto

With say an initial 80a surge briefly from still or something for a few milliseconds

(Or something like that I saw)

If your shimming is shit, or locked up with no fuse continuing to fire it will blow any stuff

So unless the fet's are made of Dairy Lea I reckon they might be ok for a mild/stock gun

But buy proper ones next time from RS

 

[Adolf Hamster]

Yeah, i mean it's like anything really... if you don't have the basic foundation knowledge about something technical it may as well be voodoo.

I run standard mosfets on almost all my AEGs, if you're looking for decent no fuss options definitely check out Jefftron: https://www.jefftron.net/

They pretty much have every kind you could want, standard, standard mini, v2/v3 switch assembly, AB or non AB, with or without wiring, and they even have their own micro-switch/computer sets, similar to the Titans.

I've only used their standard and standard mini types.. both work really well.

yeah, i think it's the ab on the titan's is what's screwing up semi, they're not fast builds so possibly stopping too quickly

 

[EDcase]

I was going to post these questions about MOSFETs but since we're here...

I'm thinking of getting the Gate Nano AAB (or now, a JeffTron)  to put in an AGM Sten.

1.  As far as I understand, 'active braking' will put a bit of power to the motor in reverse polarity to make it stop instantly.

I presume this can degrade a standard motor over time?

2. Since the AGM Sten only has full auto mode, will the active braking actually help get single shots?

 

[Sitting Duck]

I was going to post these questions about MOSFETs but since we're here...

I'm thinking of getting the Gate Nano AAB (or now, a JeffTron)  to put in an AGM Sten.

1.  As far as I understand, 'active braking' will put a bit of power to the motor in reverse polarity to make it stop instantly.

I presume this can degrade a standard motor over time?

2. Since the AGM Sten only has full auto mode, will the active braking actually help get single shots?

Try something that has a programmable burst mode

Sounds similar to the Firehawk Dsg  HC05 no semi

YES it kinda works but a pita to set up

Though once done you should get a limited duration to make 1 shot/cycle

And if you hold trigger down for a bit longer it then proceeds to full auto

What was it burst Wizard or maybe something not quite mosfety like the ye olde avacado burst bollox might work

 

[EDcase]

Thanks for that SittingDuck.

I duno if I'm ready to try that but will see how I get on and may be asking more questions in future

LOVE 'Airplane' btw ? 

 

[Zarrin]

Thanks @Sitting Duck - some food for thought for sure.

Funnily enough my first bundle of components all came from RS, but I just thought I'd see if I could get lucky with some chinezium stuff at a small fraction of the price - I mean i've been both punished and rewarded with that attitude many times so, it is what it is i guess!

I mean i have the chips and the other bits and bobs literally all cost less than a quid each so I could go ahead and test them out as you say, my issues with these things are psychological as much as anything.. I know i'll feel crest fallen putting in the work for a big X result - but maybe I should just go at it with a 'i will do this for science' kinda attitude ?.

I've never used a Schottky Diode, will have a read into them...

I had an early model Burst Wizard for my M16A2, it lasted a few years but eventually died. If I remember correctly I used to clock at 10-15% lower ROF with the burst wizard attached on a 9.6v. The tech may have improved since then, i dunno.

 

[Sitting Duck]

Thanks @Sitting Duck - some food for thought for sure.

Funnily enough my first bundle of components all came from RS, but I just thought I'd see if I could get lucky with some chinezium stuff at a small fraction of the price - I mean i've been both punished and rewarded with that attitude many times so, it is what it is i guess!

I mean i have the chips and the other bits and bobs literally all cost less than a quid each so I could go ahead and test them out as you say, my issues with these things are psychological as much as anything.. I know i'll feel crest fallen putting in the work for a big X result - but maybe I should just go at it with a 'i will do this for science' kinda attitude ?.

I've never used a Schottky Diode, will have a read into them...

I had an early model Burst Wizard for my M16A2, it lasted a few years but eventually died. If I remember correctly I used to clock at 10-15% lower ROF with the burst wizard attached on a 9.6v. The tech may have improved since then, i dunno.

ICS spoke about them....

this bloke also is dabbling in schottky stuff

only wish I could understand what the fuck he is saying

but he seems to know a bit and quite fluent in this teching stuff

sadly though he is very fluent, alas in different languages

if I could speak say Mandarin I would tell him his shimming sounds a bit rough on some vids

but he gets right into it with loads of info - just wish i could fucking understand what he is saying

(but at this point I dare say I may not full understand the electrical science crap - even in English)

But fill ya boots if you understand Chinese....

 

[Zarrin]

@Sitting Duck   jeez, just when I thought i had started to get to grips with this stuff, i'm feeling well out of my depth again!

When I was running a G&G ETU (piece of crap) I observed an internal spark/arc seemingly coming from inside the motor on semi auto, I took this to the the AB polarity reversal - would that arcing be classified as an inductive spike, and would the schottky 'soak that up' so to speak?

The installation seems simple enough, but i need to fully realize the difference in the plate gap distance from motor to motor you mention.. I have an SHS and an ICS3000 kicking about some where so will compare them side to side.

Also, what were the alternate models of mosfet chips you were going to list? I'd like to know whatever the case as it'll just broaden my pallet regarding what is usable.. from what I've researched, they all can have slightly different properties...  ability to use lower voltage batteries, ROF and responsiveness. In fact the reason I bought a batch of IRF2804 was because apparently their ROF and trigger response performance is better than the newer and more reliable 3034.

*Edit...

Very good video about the schottky, and I think I understand it's function... at least I was asking the right questions at the right time; 'well why wouldn't you use them all the time?' which he addresses a second later. ?

Subscribed to that guy, gonna watch through all his basics stuff and see if I can a bit of a better foundation.

 

[Sitting Duck]

@Sitting Duck   jeez, just when I thought i had started to get to grips with this stuff, i'm feeling well out of my depth again!

When I was running a G&G ETU (piece of crap) I observed an internal spark/arc seemingly coming from inside the motor on semi auto, I took this to the the AB polarity reversal - would that arcing be classified as an inductive spike, and would the schottky 'soak that up' so to speak?

The installation seems simple enough, but i need to fully realize the difference in the plate gap distance from motor to motor you mention.. I have an SHS and an ICS3000 kicking about some where so will compare them side to side.

Also, what were the alternate models of mosfet chips you were going to list? I'd like to know whatever the case as it'll just broaden my pallet regarding what is usable.. from what I've researched, they all can have slightly different properties...  ability to use lower voltage batteries, ROF and responsiveness. In fact the reason I bought a batch of IRF2804 was because apparently their ROF and trigger response performance is better than the newer and more reliable 3034.

*Edit...

Very good video about the schottky, and I think I understand it's function... at least I was asking the right questions at the right time; 'well why wouldn't you use them all the time?' which he addresses a second later. ?

Subscribed to that guy, gonna watch through all his basics stuff and see if I can a bit of a better foundation.

The other mosfet that came up as a suggestion & seemed to match nigh with 3034 was...

https://uk.rs-online.com/web/p/mosfets/8967349/

this was about £1:10, but has shot up in last month to same price

it is called a few variations to 40s212 but looked like a half price 3034 to me

there are 2 main types of motor cans...

the cheap std - inc ICS - even 3000, use two tabs that pinched hold the end bell onto motor can

The SHS, G&G, ASG & other higher end ones with two bolts that go into a lock ring underneath

(this is where a short can occur if insulation fails)

there was also another type that CORE & higher end neo SRC used

where the plastic end bell pushed on and held there with 4 (2 on each side) tiny screws

(really easy to open and well insulated) - doddle to open & work on but seems to be a thing of past now

shame coz they were easy to open like I said...

anyway... seems to be just the two types of motor now...

cheapo tabs that are well insulated like in ICS vid - bit of a pain to open in a vice bending back tabs

and the SHS/G&G types that are easy to open but must ensure the insulation washers in good condition

wrapping a diode on the SHS type is not so easy like the ICS as you risk creating a short unlike cheapo type

a bit of info on insulation and the flaw in expensive old Systema motors...











there was some old posts about Systema's insulation failing, but must be on another laptop

anyway if/when the insulation failed the hand wound, hand balanced motor precision motor

simply just fried the arm/windings etc...

So on those types like G&G SHS etc... you must ensure the plastic washers are intact and effective

so introducing a schottky on these types, fitted like the ICS is a very risky matter it seems

though you could fit it by soldering to motor plate - bit messy or not so simple

or fit it across the motor tab connections - but where motor is fitted & adjusted you don't really have the room

then others say if you have TVS you don't need it - but the two are slightly different still in use

(and cost)

Look I'm no expert - don't really understand it all if I'm honest

just passing on crap I've seen

one side of it is like the electrical engineering side of how motors are assembled

(yeah kinda get my thick skull around this bit - well just about)

but the electrical or electronic circuit in depth shit is way way over my head

yes I feel there is a bit more that could be done to protect the motor/mosfet circuit

but as I said feel manufacturers aren't too bothered about it from business point of view

besides AEG's are just very crude slung together toy sewing machine guns

with virtually little after thought most of the time to in depth electronics

(take the basic AEG, no mosfet just a friggin' crude switch arcing away & fuck all else)

Instead if/when companies make improvements they add fancy bells/whistles not always needed

I say that coz over half of fancy features added few actually use

plus braking is needed more on ferrite motors than on neodym motors that slow quicker from stronger magnets

you still get overspin but much more on ferrite imho and think ferrite motors will store more inductive crap I feel

anyway - just more info to confuse you, I don't know what is actual gospel

and what is perhaps important or what is just potential hearsay or not that important

but do feel there could still be merit in schottky's for some aeg's though manufacturers don't give a crap much

have fun & lmk any findings if possible - ATB

 

[Zarrin]

I'm gonna do some more reading into it all before enacting anything on an actual motor - I've done very little motor work tbh... swapped out the carbon brushes on a few that were worn down and that's about it.

As for the Mosfets / LDVR units, I will endeavour to sling one together and report back on my findings... unfortunately i'm currently working up in north London, only back home at the weekends at this point and honestly wont have too much time for any projects for the next couple months.. or for airsoft for that matter ?

I do actually have one of those motors with the 2 screws in the side, it's red with a ported casing (so a window looking onto the coils on the side) - not sure what the make is... pretty scratched up; I think i got it with a job-lot - pretty average motor. As you mention they are easy to get into, I may use it as my guinea pig!

 

[Sitting Duck]

reckon if it is red, with screws & with window cut out it was:

X HIGH-TECH written on it as I got one of those with a tiny small window on both sides

well old but easy to work on

View attachment 54917

 

[Zarrin]

@Sitting Duck Yep that's the one, mine is so scratched up i can hardly make out the wording , but i can see it's the same one.

 

[Luke26]

Thanks guys I have just done a load of upgrades it gas a gate titan in it just wondering if it was a good motor that's all 

 

[Sitting Duck]

I'm gonna do some more reading into it all before enacting anything on an actual motor - I've done very little motor work tbh... swapped out the carbon brushes on a few that were worn down and that's about it.

As for the Mosfets / LDVR units, I will endeavour to sling one together and report back on my findings... unfortunately i'm currently working up in north London, only back home at the weekends at this point and honestly wont have too much time for any projects for the next couple months.. or for airsoft for that matter ?

I do actually have one of those motors with the 2 screws in the side, it's red with a ported casing (so a window looking onto the coils on the side) - not sure what the make is... pretty scratched up; I think i got it with a job-lot - pretty average motor. As you mention they are easy to get into, I may use it as my guinea pig!

TBH - if they are voltage regulators then....

DON'T BOTHER using them

I was out & about last night having a drink & some grub etc...

so didn't pay ultra close attention - thought they were oem cheapo 'fets

A voltage regulator is ergh a voltage regulator - totally different to a mosfet

ye classic 7805 is a VR that takes say 12v+ to 30v and outputs 5v

so totally different to a switching power mosfet

BIN THE THINGS - I wouldn't bother chucking one together if it is a regulator

otherwise you will end up like this electrical genius using the wrong stuff incorrectly

so NO - DON'T BOTHER trying to use them - get some proper mosfets than blow shit up

apologies for not paying closer attention and suggestion nowt to lose

(but I like seeing things go bang when I've had a drink)

 

[Zarrin]

@Sitting Duck   mate the reality is, had you not been ever so slightly melted, I wouldn't have had nearly as much useful info out of you. It would have been... 'no don't use those', and that would have been the end of that ?

 

[Sitting Duck]

still would have got a classic Duck "War & Peace" novel response

there is some bizarre reason why I am restricted from responding in AF-UK's:

Quick Questions & Answers thread, as I fail to adhere to the concept when answering

ho hum