[SOC] Big Time Technical Question

Wed, 6 Mar 2002 21:13:05 -0600

No, actually (to show how weird things - topics and such can become really,
really weird) my question was "what's a Schottky diode".  Why'd I want to
know?

My treadmill broke and I've already spent a lot of money on replacement of
certain items which needed replacement, but the replacement of which did not
resolve the problem.  That being a mysterious little circuit board which
drives the DC motor using SCR circuits.  Do I hear bored yawns already?
Anyhow some devices on the board are TO-220 case items mounted to a heat
sink.  Two are SCR's and three are what appear to be PNP transistors mounted
as diodes.  Base/Collector, emitters cut off.  They labeling on these things
cross reference to nothing I can find.  Probably proprietary labeling.
Anyhow, two of the things are shorted Collector to base.  One is not.
Though there is no holmic reading between either of the other leads and the
third one which I'd think to be the emitter.  Assuming normal element
layout.

So, I figure diode.  Looking at the foil pattern and other components, sure
looks like a power circuit.  Of course, I don't have a schematic!  Stamping
on the board says "D507" etc.  Looks like that means diode to me.

So what does that have to do with Schottky diodes?  In my junk box of
diodes, I find some pretty hefty ones and I read the number and cross
reference it in my ECG reference.  Calls it a Schottky Barrier Diode.  So I
wondered what that was as compared to a "normal" silicon type.  But my
'silicon' ended up as 'silicone' and the whole thing went down the toilet
from there.

I put in some (ok, I'll finish the saga) regular silicon diodes and the
machine runs again.  Still got a problem with it surging and vibrating under
load.  The load being me trying to walk on it.  So, I got a motor problem or
something else on the DC board is kaput.  Empty out my wallet in any event.

Dan W. Dooley  WB5TKA  Bedford, Texas
   e-mail to: [email protected]
   Web site: http://www.qsl.net/wb9tka
May Goddes love blest ye alle
"Ancient Pistol, I do partly understand your meaning."

----- Original Message -----
From: "Claude TERRIER - F5PBL" <[email protected]>
To: <[email protected]>
Sent: Wednesday, March 06, 2002 2:39 PM
Subject: Re: [SOC] Big Time Technical Question

> John, don't go QRT so quickly  !!
> The funniest part of the story now is to read the latest emails of this
thread
> and then read again the TITLE of the thread :o))))
>
> So I think we can discuss of this Technical Question / Procedure to use
tubes of
> silicon to make silicone boobs :op
>
> If you remember, the original question was abt diods made by Mr Schottky
in
> order to detect some VHF signal to be injected I do not remember where but
I
> hope not in some silicone balloon ;o))
>
> 73!
> Claude, F5PBL
>
> http://www.qsl.net/f5pbl
>
> DIG #4451 - FISTS #7722 - FP #383 - SOC #503 - 10-X #71724
>
> ----- Original Message -----
> From: "W2AGN" <[email protected]>
> To: <[email protected]>; "Dan W. Dooley" <[email protected]>
> Sent: Wednesday, March 06, 2002 2:41 PM
> Subject: Re: [SOC] Big Time Technical Question
>
>
>
> >Better quit before I catch Hell for being "off-topic" on THIS list, too.
>
>
>
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