building mosfet help anyone?

[airsoc]

Just hoping someone might be of assistance. Building a mosfet and ive sourced some of the bits but having difficulty getting the rest. so far i have as follows;
irlb 3034 fet
100ohm 250mw resistor
both from an online retailer (i know zeroone dont sell electroinc components but not risking it)

Its the 2.2kohm 250mw resistor and 18v 5kw diode i cant source and im not 100% on what im meant to be buying as im using this*as the guide

[Sitting Duck]

Re: building mosfet help anyone?

RS Online, cheap genuine 3034 fet's

TVS Diode that old 18w thingy has been superseded
Can't remember exact replacement I've used but look at RS or farnell.
Rs have better price breaks on gen 3034

Or just get a firestorm fet if you can't be arsed

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Slightly better guide with nice pics but advise the diode to be used as it protects against spikes
http://ncairsoft.org/forum/showthread.php?7516-Rusty65-s-MOSFET-building-guide

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Resistors fleabay

3034 though RS

ANY FET ON FLEABAY WILL BE FAKE
(it will just fry despite what description says from some Chinese seller selling them real cheap)

[Libris]

Re: building mosfet help anyone?

I've been down that route. Having bought some commercial ones I thought, I could do that; bought the P and N 'fets, the TVSs and the resistors put an AB one together and a standard one with plenty of parts to build more. However, I recently got a hold of some Gate PicoSSRs and have come to the conclusion that while I can built a mosfet that works it's akin to hand machining your own sector gears. Doable but just far, far too much fucking hassle.

[airsoc]

Re: building mosfet help anyone?

Well i have inherited an old ares m4 which has a microswitch and im steering clear of ab fets.

I looked on rs BUT it has £12 shipping (ups i think). farnell i found bits but i dont quite understand the spec im looking for i guess and i dont want to buy the wrong bits.

Any help is appreciated thanks.

[Sitting Duck]

Re: building mosfet help anyone?

uk rswww

irl3034pbf sold in pairs @ £2:50ish
but buy 10 and they drop to £1:50

tvs diode - search up for a 1.5KE18A - again cheap as hell on rs

resistors - just look for 1/4W 0.25W Metal Film Resistor
(i say metal just coz of any heat from fet)

100 Ohm & 2.2k Ohm values can be bought from ebay in small qty's at about £1 for 10 x 2 values
yes you can get cheaper ceramic ones but why bother trying to save pennies when the whole fet can cost about £2:50/£3 in total in bulk

problem is buying the stuff to make just 1 or 2 up, then you may as well just buy an airfet, pico no ab fet, or firestorm one instead
unless you wanna go nutz with loads of guns or get a few of ya at ya site to club together and buy up say 15 to 20 fet kits

hence I suggested getting 1 or 2 off the shelf - or buy gen 3034's from rs

[airsoc]

Re: building mosfet help anyone?

Thanks for the advice super helpful

[Sitting Duck]

Re: building mosfet help anyone?

it is a bit of messing about to build just one fet

best thing is get say 3 fets already - build 'em whilst you doing one,
then put away for another day,

then fit the first one in the gun as iron is all there - all done in one go plus 2 fets ready to go for next build
yup it is a pain to do one - but if you gonna rewire - soldering a fet together isn't that much work really
especially one you built a couple you see how it goes together and others are easy
like MFI or Ikea furniture - 1 takes ages, but the 2nd, 3rd cabinet takes half the time and the 4th you can do in ya sleep
(don't solder with eyes shut, you will burn yourself)

[airsoc]

Re: building mosfet help anyone?

My plan was originally to make a few. I bought a firestorm anyway but i still want to make my own a) for fun cause airsoft isnfun and b) for my other two airsoft guns as well as maybe friends

[Libris]

Re: building mosfet help anyone?

My plan was originally to make a few. I bought a firestorm anyway but i still want to make my own a) for fun cause airsoft isnfun and b) for my other two airsoft guns as well as maybe friends

It's certainly interesting when you do get it all together and it works. It was a bit disingenuous saying that it is too much hassle but the current market for professionally made mosfets has produced some outstanding products that do make my efforts a bit Heath Robinson.

[airsoc]

Re: building mosfet help anyone?

Im not scared of trying it myself or the cost difference. rather thats why i wanted to do it (cause its kinda fun and kinda cheap)