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This=20is=20a=20simple=20design=20I've=20used=20before.=20=20The=20resisto=
r=20count=20is=20quite=20high=20as=20I=20tend=20to=20play=20safe=20and=20a=
lways=20have=20pullups/pulldowns=20on=20transistor=20bases=20to=20ensure=20=
they=20are=20totally=20switched=20off,=20however=20I=20have=20seen=20this=20=
implemented=20with=20only=20two=20resistors=20in=20total;=20limiting=20cur=
rent=20to=20the=20outer=20NPN=20drivers=20base.

It's=20not=20a=20particularly=20clever=20circuit,=20but=20it=20does=20use=20=
the=20main=20transistor=20in=20a=20common=20emitter=20configuration=20to=20=
ensure=20the=20lowest=20Vce=20drop.

Regards

Mike

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This=20e-mail=20is=20intended=20for=20the=20person=20it=20is=20addressed=20=
to=20only.=20The
information=20contained=20in=20it=20may=20be=20confidential=20and/or=20pro=
tected=20by
law.=20If=20you=20are=20not=20the=20intended=20recipient=20of=20this=20mes=
sage,=20you=20must
not=20make=20any=20use=20of=20this=20information,=20or=20copy=20or=20show=20=
it=20to=20any
person.=20Please=20contact=20us=20immediately=20to=20tell=20us=20that=20yo=
u=20have
received=20this=20e-mail,=20and=20return=20the=20original=20to=20us.=20Any=
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forwarding,=20printing=20or=20copying=20of=20this=20message=20is=20strictl=
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No=20part=20of=20this=20message=20can=20be=20considered=20a=20request=20fo=
r=20goods=20or
services.
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