adrian_h:
mjkzz:
I just downloaded datasheet for PN2222A and your 200mV Vce at 100ma Ic seems reasonable. The 1.0V Vce claimed by OP is too high and according to chart, it could only happen at 500mA. At 150mA, Vcesat should be around 0.3V according to datasheet.Sorry, I feign ignorance :). I just got the info from here: http://www.digikey.com/product-detail/en/PN2222ATFR/PN2222AD26ZCT-ND/459004
Looking at the datasheet (which I mostly do not understand) I don't see the info that states 0.3V at 150mA.
I really appreciate all the help you guys and gals are giving me BTW. This is a very difficult but gratifying process (at least on my end), but not without its frustrations.
I got the same datasheet, in about middle of the 2nd page, there are some numbers about Vcesat, please read it carefully.