HP Forums
Re: HP71Voltages - Printable Version

+- HP Forums (https://archived.hpcalc.org/museumforum)
+-- Forum: HP Museum Forums (https://archived.hpcalc.org/museumforum/forum-1.html)
+--- Forum: Old HP Forum Archives (https://archived.hpcalc.org/museumforum/forum-2.html)
+--- Thread: Re: HP71Voltages (/thread-9634.html)



Re: HP71Voltages - Tony Duell - 06-07-2001

According to the manuals I have (HP71 Hardware IDS, for example), it's not a 3 terminal regulator, it's a simple NPN power transistor.
It's used in the standard zener diode + emitter follower circuit, and it's the zener diode that sets the output voltage. The transistor is not that critical.
Alas the parts list in the manual simply calls it a 'Transistor, NPN' -- no equivalent is given. But I think that just about any small power transistor should work.