Brent Brown wrote:

> http://www.phys.ualberta.ca/~gingrich/phys395/notes/node97.html
>
> And now I know what a Sziklai circuit is. Looks to me like VCE(sat)
> would be at best 0.7V, which is this application is better than a
> darlington but not as good as a MOSFET.


Hi Brent, yep it's not that good, not as good as
a fet or even a high-side pnp driving a low-side
npn, especially for the solenoid circuit where the
high-side pnp can be driven from the 5v rail.
Some good NPN power transistors have very low sat
voltages, a circuit I built recently the NPN had
a Vce sat of only 19mV, that's like a relay! :o)
-Roman

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