[Diy_efi] A 2N2222A can handle up to 50mA

[Perry Harrington]

An even simpler and cheaper solution is one of the following:

	MPSA27		(TO-92)
	MPSA28		(TO-92)
	NTE 46		(TO-92)

Those are 500ma Darlingtons at about 14 cents a piece in bulk.  They have
a gain of 10,000.  Base current is then unimportant.

Digikey doesn't have any of the above in stock, but they do have the MPSA63,
it's rated for max continuous collector current of 1.2A and has a gain
between 5,000 and 10,000.  It's also 26 cents for 1, 19.8 for 25, and 13.73
at 100.

--Perry

> 11 cents (in bulk) for a TO-92 2N2222A vs. ~$2.50 for a TO-220 FET output
> driver.  Arrange it in a darlington if you want more base gain and stay
> with the cheap stuff.  It's just a switch and either it's off or
> saturated.  There's minimal heat from a saturated transistor -- aka
> class-D.  It's running it linear where you need to concern yourself about
> vce drop equaling heat dissipation (mostly).
> --
> David Gravereaux <davygrvy at pobox.com>

-- 
Perry Harrington			Data Acquisition & Instrumentation, Inc	
perry at dainst dot com					 http://www.dainst.com/

Those who would give up essential liberty to purchase a little temporary safety
deserve neither liberty or safety. Nor, are they likely to end up with either.
                             -- Benjamin Franklin

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