MOSFETS

MonkeyGuy

I know what they do but I'd like to know do most people make their own or buy them and if so where?

NakedDex

Part of my day job involves building and repairing avionics systems and I still wouldn't bother my ass making up a MOSFET for an airsoft device when it'd cost me about the same to buy a good one as to make one.

Extreme Fire do some very neat package microprocessor controlled MOSFETS, as well as some equally excellent basic AB versions.

DeBurca

I get mine from Mid West Airsoft in Limerick

Inari

You can build basic ones fairly easily, and fairly cheaply apparently - never touched it myself though.

Eirsoft used to get them made by AirsoftHacks if I remember correctly. You can also find some cheap ones on RSOV. I think we still have a couple left in-store as well.

One that I want to try is something I saw on Redwolf - the Airsoft Systems Smart Control Unit. Haven't had the money to get it yet though. I am exceedingly curious about it though.

NakedDex

If you wanted to make your own, it's rather simple now given you can get diagrams for a basic AB MOSFET online. You'll just need about a tenners worth of parts and a soldering iron.

If it's your first time soldering though, I'd practice on some resistors on a stripboard first...

CpcRc

NakedDex wrote: »

If you wanted to make your own, it's rather simple now given you can get diagrams for a basic AB MOSFET online. You'll just need about a tenners worth of parts and a soldering iron.

If it's your first time soldering though, I'd practice on some resistors on a stripboard first...

+1 on practising. Soldering is easy once you learn how to do it right. But if you get it wrong, if you're lucky it's a bad connection and you start over, and if you're unlucky the component breaks or you burn yourself (It hurts, talking from experience). Don't forget you're holding a tool thats 300+ degrees at the tip.

Make sure you work in a well lit and ventilated area, and use a needle nose pliers or similar as a heat sink. A heat sink is something metal that you clamp onto a component between where you're soldering and the component itself. The heat sink should draw the heat away from going into the component and breaking it. Heat sinks should be explained in the how to solder links too.

A video on how to solder:
http://www.graspr.com/videos/How-To-Solder-PROPERLY-2

And a website:
http://www.rchelisite.com/how_to_solder_properly_tips_and_techniques.php

As for the components, they are cheap and electronic components are pretty easy to find. But in order to make a proper MOSFET with active braking, you'll need very specific components, a certain type of transistor to be specific, not the regular one that you can easily find in shops.

I know this because I tried to find the components for a MOSFET I'd found online. And they weren't easy to find and where also difficult to get, but still cheap enough. It's the components which are the difficult part of making a MOSFET, assembly is straight forward enough.

A link to how to make a MOSFET with Active Braking:
http://www.cerberusairsoft.co.uk/Mosfet/

NakedDex

Good solder makes it easier too, and ensures a better connection. I use Multicore 60/40 fluxed, in work and at home. It has the best flow I've found and is the least susceptible to dry jointing (although if you're not practiced at it, it's still completely possible).

The solder found in places like Maplin is unfluxed and contains no lead, and is more difficult to work with. Especially if you're new to soldering.

JonnyTwoCombs

NakedDex wrote: »

I use Multicore 60/40 fluxed, in work and at home.

Can this be found in a shop here or is it an online purchase

NakedDex

I'll be honest, I don't know. I get my components OEM from RS, often through my job. The solder I mentioned, I sourced from there, but I get it in 500g reels, a quantity you'll never really need unless you're using it professionally. If you're just doing the odd repair, even a 250g reel will last you years.
RS (aka Radionics) have a trade counter in Crumlin - though I've never been there - where you can pick up the parts I'm sure. The only alternatives as regards high street stores that I know of are Peats and Maplin, and Maplin definitely don't have it. The solder they carry is awful, and they don't stock flux at all. Peats might, but the last time I was in there it looked like it turned into a glorified home entertainment store.

Radionics and Farnell are both based in Dublin and can be ordered from onine. Radionics, as I said, have a spot on Crumlin where you might be able to just walk in and get the parts from (again, I've never used it. This is something I've only ever been told). Farnell are based in Santry, I think, and may offer the same service.
Be aware that both companies are primarily commcercial/industrial suppliers, so all of their website prices are excluding VAT.

Radionics
Farnell

JonnyTwoCombs

Cheers! ND

Dread-Lock

Yeah don't waste your time or money in the likes of Maplins or Peats. Like Dex said just head to Radionics. I get all my stuff there, although don't go if your in a hurry as the quickest I've ever been in and out of there was about 15 minutes and thats when I knew exactly what I wanted (thats the only downside). And the smallest amount of solder they sell is a 250g reel (or at least thats all they had when I was out there last.

NakedDex

The 250g reels are about €20, if I remember correctly? Handy to have all the same.
Start some practicing on a stripboard and some resistors. When you're confident in your technique you can try your MOSFET. After that, there's plenty more airsoft and non-airsoft uses for your new-found ability to solder.

MonkeyGuy

But if I wasn't able to travel to Dublin where might I get the parts?

NakedDex

Same place. They deliver. Just go to the website and order them like you would anything else. The delivery is usually within a day or two.