One/two last question/s before I start my first build.

[Guybrush]

Hi.
I'm gearing up for my first build and have pretty much everything in place. The only thing that is still throwing me is transisotr pinouts.  There are hundreds of threads dedicated to this but that makes it even more confusing as there's lots of contradicting advice.
On the madbean Krankosaurus layout, 2 of the transistors legs are labelled S and D.  What is this refering to? Where ever else I look the legs are labelled E, B, C.

On other madbean layouts (Deadringer) the transisors aren't labelled at all (other than Q1, Q2 etc).  How are you able to know how to orientate them in this case? 

Thanks.

[sam_c]

I have also found this confusing, but I think I understand now (Im still very much a noob too)

E,C,B are emitter, base, collector found on bipolar transistors

D,S,G are drain, source, gate found on Field effect transistors

that is the limit of my research on this so far 

[metfreak]

Simply look at the picture provided in the layout, where the Q's cut-off is located. Simple as that

E (emitter), B (base) & C (collector)

2N5008 => http://www.datasheetcatalog.org/datasheet2/8/0upxrqy5ox3qaerhx602gy1iszky.pdf

D (drain), G (gate), S (source)

2N7000 => http://www.fairchildsemi.com/ds/2N/2N7000.pdf

For technical explanation, we'll need an expert since we're all "diode destroyers" Guess we can call ourselves now "transistor destroyers".

[gtr2]

Always check the datasheet to double check your pinouts.  A quick google search will give you datasheets for your part.

Josh

[Guybrush]

Thanks that's made it much clearer.

Please forgive my photoshop skills but is there ever a situation where the legs need to be crossed?

Like this for instance.




Thanks again!

[jkokura]

Very rarely.

Usually, if you are using the specifies transistor, you will not need to twist the legs like that. If you substitute and use the wrong transistors younger need to turn it backwards, or very, very rarely need to do that to the legs.

Jacob

[Haberdasher]

btw you may find it's a nice time saver to include the filetype in your google search terms.

example:  fairchild BS170 filetype: pdf

[Guybrush]

All great advice.  Thanks guys!

And Haberdasher, I've checked with my old workplace and they are cool to post my PCBs to my new address so no worries. 

[gtr2]

I've had to swap legs before like your picture, but only for some germanium transistors.

Josh

[TNblueshawk]

Also, if you were to say use some MosFet's when the build calls from some bipolars for example, you would not cross the legs but insert backwards from the pin orientation on the build docs.