Archived posting to the Leica Users Group, 2000/11/10

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Subject: Re: [Leica] mechanical shutters
From: "A.H.SCHMIDT" <horsts@primus.com.au>
Date: Fri, 10 Nov 2000 21:32:49 +1100
References: <B62F599A.90FF%howard.390@osu.edu> <3A0A9FB3.1462B8C8@primus.com.au> <3A0BA5C4.4F7E45F9@yahoo.com>

Javier Perez wrote:
Snip

> . I think the
> Industrial engineers invented the MTBF concept just for this sort of thing.
>
> Javier

Javier, This reminds me, of the time I worked for ITT in Germany. At this time, we
developed the first microprocessor operated telemetry system used in Germany (I believe
in the world, but are not 100% sure)

It used an 8080 Processor, 4Kb of Rom and 16Kb of Ram together wit some other Small
scale IC's, relays and resistors and Capacitors. The time was about 1978.
The statistics department was asked to work out the MTBF figure for the whole setup.
Using data supplied by the individual component manufacturers.
This setup  consisted of about 16 of the above mentioned boards, some power supplies
and a big 19" rack. The outcome was:

                                          2.5Hrs (Two point five)

We received somewhat of a shock. However the system was build, and as I understand, It
still works to day (running 24 Hrs a day)  without failure. Roughly 3 Million 197
thousand 4 hundred  years later.

So much for MTBF.

Regards, Horst Schmidt

Replies: Reply from Javier Perez <summarex@yahoo.com> (Re: [Leica] mechanical shutters)
In reply to: Message from Martin Howard <howard.390@osu.edu> (Re: [Leica] mechanical shutters)
Message from "A.H.SCHMIDT" <horsts@primus.com.au> (Re: [Leica] mechanical shutters)
Message from Javier Perez <summarex@yahoo.com> (Re: [Leica] mechanical shutters)