Re: [Leica] M6 electronics

[Ken Wilcox <wilcox@umcc.umich.edu>]

Don:

My very elementary electronics knowledge says that a diode has only two
(di) electrical connections. This thing has 28 of them. Am I really that
far off on my understanding of electronics?

With LOTS of respect for those who know this stuff!

kw

>Ken,
>
>I believe what you are describing is a simple
>voltage regulation circuit.  The "ram chip" is
>probably just a simple diode.
>
>This is necessary because the battery voltage
>changes as the battery gets old.  The cameras
>from the 60's that used mercury batteries
>did not have voltage regulation.  That was possible
>because mercury batteries have an almost
>constant voltage output, up to the time they
>die completely.  Later batteries (alkaline, etc),
>have a more gradual drop-off in voltage.  This gives
>the operator more warning that the battery is getting
>old, but of course it changes the reading of the
>light meter.
>
>The voltage regulation circuit corrects for this problem.
>The simple printed circuit you saw is just another form
>of wires to connect the pieces.
>
>I don't have the exact dates handy, but I believe
>printed circuits were invented in the 50's, and
>solid state diodes were from the very early 60's.
>
>Therefore, you can rest easy - your M6 does NOT have
>a computer chip inside.
>
>don ferrario
>
>-----Original Message-----
>From: Ken Wilcox <wilcox@umcc.umich.edu>
>To: leica-users@mejac.palo-alto.ca.us <leica-users@mejac.palo-alto.ca.us>
>Date: Sunday, June 28, 1998 5:30 PM
>Subject: [Leica] M6 electronics (was Leica and 15 year...)
>
>
>>I have a complete meter circuit in front of me. I'm not an electronics
>>expert but I'll describe what I see and perhaps the experts can identify
>>the parts.
>>


- ----
Ken Wilcox                             Carolyn's Personal Touch Portraits
LHSA, MEA, LAW                      preferred---> <wilcox@umcc.umich.edu>
                                                     <kwilcox@gfn.org>