So I just ordered the parts for the new Sunking II board except for the BS250 transistor. I bought parts from Mammoth and mklec.com this time around and neither one carries that one in particular. Are there any others that can be subbed in that are easier to acquire or that I might even have on hand? Will any MOSFET do as long as the pinouts match up? I know I have some BS170's and 2N7000's on hand.
Any help is appreciated.
It's a P-channel device. The others you listed are N-channel. You can't substitute them in the same way you can't sub a PNP transistor for an NPN.
BS250 is pretty much the cheapest P-channel MOSFET you can get. I'm surprised Mammoth doesn't even carry a single P-channel device. Smallbear has them for 50c. Tayda has a couple power MOSFETs that might work, but they are a larger form factor with a heatsink.
You can skip the BS250 if you have to. But, you should at least put a 1N4001 or even better a 1N5817 between the drain and source of the transistor. The banded end should be soldered to the source pad.
you can always go to ebay and get those or mouser
http://www.mouser.com/ProductDetail/Diodes-Incorporated/BS250P/?qs=sGAEpiMZZMsG1k5vdNM%2fc52GX1Nllsba (http://www.mouser.com/ProductDetail/Diodes-Incorporated/BS250P/?qs=sGAEpiMZZMsG1k5vdNM%2fc52GX1Nllsba)
What is the purpose of that tranny, buffering the V+?
Didn't really want to start a new thread, so Ill post in this one. Would this be a good substitute:
VP0808L
Datasheet: http://www.supertex.com/pdf/datasheets/VP0808.pdf
I just searched for a P channel Mosfet, from my local supplier