3904/3906 tranny specs

[<<marjan>>]

perienced another nasty thing about trannies as a switch.
> The transistor was used in a voltage-shifter circuit and I had to connect a
> square-generator (about 1Hz) to it.
> I started the generator and left it alone for about half an hour.
> When I came back the tranny was broken.
> When I compared load-line and transistor-curve (ofcourse after the usual
> cursing and wishing all trannies to hell :-))it seems to be that the
> Vbe-capacitor (specific to every tranny) was the cause.
> The transistor has switched to slow (the cap slowed it down) between on and
> off-state, became hot and broke down...

if square goes negative more than 5 or 6 v directly to Vbe it can break
down
BE junction because of great inverse voltage
or you had too large collector current that fried(overheated) tranny


marjan