Luca wrote:

> There is a little strangeness: the wave clipper darlington transistor Q1 is
> marked as 1854-0611, equivalent to the standard darlington 2N6055. But why
> there is a simple 2N3055 in the picture? Some sort of version update fail?

One other reader (Ian) pointed out this same discrepancy, and there clearly is 
a part number error somewhere.    I remember using the Darlington device on 
purpose, because with its higher gain, it took a less base current to 
accomplish the wave clipper job I used it for.

As you can see, getting these details right in documentation is challenging.  I 
remember working on it pretty hard, and this one got past me.   Who knows, for 
the photo shoot of the PCA, I may have just stuck the wrong part in there 
because I didn’t have the right one on had that day.  “Hey, no one will notice 
that the stamping on the transistor doesn’t match the parts list.   I’ll bet no 
one will look at this schematic carefully anyway.   Take the picture.”    Never 
knowing that 30 years later, some “time-nut” would scrutinize the photo vs. the 
schematic, and point out to me “those numbers don’t match!”

Putting things in writing and disclosing it to the public is a risky 
undertaking!   😊

Best wishes,
Hugh




From: time-nuts <time-nuts-boun...@lists.febo.com> On Behalf Of Luca
Sent: Sunday, February 10, 2019 8:55 PM
To: Discussion of precise time and frequency measurement 
<time-nuts@lists.febo.com>
Subject: [time-nuts] HP Stories: Battery Chargers, and a fading idolization of 
HP

Thanks Hugh for the story, and thanks for the schematic!
Quite interesting.
There is a little strangeness: the wave clipper darlington transistor Q1 is
marked as 1854-0611, equivalent to the standard darlington 2N6055. But why
there is a simple 2N3055 in the picture? Some sort of version update fail?
Thanks
Cheers
Luca
iw2lje

Il giorno sabato 9 febbraio 2019, Rice, Hugh (IPH Writing Systems) <
hugh.r...@hp.com<mailto:hugh.r...@hp.com>> ha scritto:


_______________________________________________
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

Reply via email to