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From: DaveC on 9 Dec 2008 02:22
This is a partial wiring diagram for an early 80's (West) German guillotine
paper cutter:

<http://freefilehosting.net/show/42l0i>

The goal of this circuit is to energize an electromagnetic clutch coil (m27)
that takes rotational energy from a flywheel to do a task (bring down the
knife blade). This circuit is currently not working.

This machine has no ICs. There are some monolithic rectifier bridges and
discrete transistors (the common symbol for which I cannot find *one* in the
diagram), and plenty of passives.

The transformer (m) primary center tap is connected to 24vdc. Do I interpret
this correctly that the primary is run by a switched dc voltage? (This on a
machine that runs on 3-phase 245vac.) Why?

I can say from experience that other machines of this same manufacturer use a
voltage derived directly from the 3-phase input to drive the electromagnetic
clutch. Why use a switched voltage, I cannot understand.

Is the triangle within a square symbol some sort of odd representation of a
transistor? And the "arrow thing" that feeds them? Ideas?

Help!

Thanks,
--
DaveC
me(a)bogusdomain.net
This is an invalid return address
Please reply in the news group

From: Ross Herbert on 9 Dec 2008 04:19
On Mon, 8 Dec 2008 23:22:17 -0800, DaveC <me(a)bogusdomain.net> wrote:

:This is a partial wiring diagram for an early 80's (West) German guillotine
:paper cutter:
:
:<http://freefilehosting.net/show/42l0i>
:
:The goal of this circuit is to energize an electromagnetic clutch coil (m27)
:that takes rotational energy from a flywheel to do a task (bring down the
:knife blade). This circuit is currently not working.
:
:This machine has no ICs. There are some monolithic rectifier bridges and
:discrete transistors (the common symbol for which I cannot find *one* in the
:diagram), and plenty of passives.
:
:The transformer (m) primary center tap is connected to 24vdc. Do I interpret
:this correctly that the primary is run by a switched dc voltage? (This on a
:machine that runs on 3-phase 245vac.) Why?
:
:I can say from experience that other machines of this same manufacturer use a
:voltage derived directly from the 3-phase input to drive the electromagnetic
:clutch. Why use a switched voltage, I cannot understand.
:
:Is the triangle within a square symbol some sort of odd representation of a
:transistor? And the "arrow thing" that feeds them? Ideas?
:
:Help!
:
:Thanks,

Not even LM Ericsson x-bar schematics use such nondescript symbols, and their
symbols took some getting used to back in the 60's.

I'm afraid you are going to have to trace out the wiring while comparing it with
the schematic and that way you should be able to work out what each of the
nondescript items with the triangle symbols are. My guess is that they indicate
some sort of active semiconductor function block. There may be additional
schematics detailing what is in each block but if that were so then one would
expect to see some identifier number written inside each block but I don't see
this information either.

Good luck!
From: N_Cook on 9 Dec 2008 05:22
DaveC <me(a)bogusdomain.net> wrote in message
news:0001HW.C5635CA9009BC01BB01AD9AF(a)news.sf.sbcglobal.net...
> This is a partial wiring diagram for an early 80's (West) German
guillotine
> paper cutter:
>
> <http://freefilehosting.net/show/42l0i>
>
> The goal of this circuit is to energize an electromagnetic clutch coil
(m27)
> that takes rotational energy from a flywheel to do a task (bring down the
> knife blade). This circuit is currently not working.
>
> This machine has no ICs. There are some monolithic rectifier bridges and
> discrete transistors (the common symbol for which I cannot find *one* in
the
> diagram), and plenty of passives.
>
> The transformer (m) primary center tap is connected to 24vdc. Do I
interpret
> this correctly that the primary is run by a switched dc voltage? (This on
a
> machine that runs on 3-phase 245vac.) Why?
>
> I can say from experience that other machines of this same manufacturer
use a
> voltage derived directly from the 3-phase input to drive the
electromagnetic
> clutch. Why use a switched voltage, I cannot understand.
>
> Is the triangle within a square symbol some sort of odd representation of
a
> transistor? And the "arrow thing" that feeds them? Ideas?
>
> Help!
>
> Thanks,
> --
> DaveC
> me(a)bogusdomain.net
> This is an invalid return address
> Please reply in the news group
>


repost to
de.sci.electronics
perhaps


--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/



From: Jeff Layman on 9 Dec 2008 05:33
DaveC wrote:
> This is a partial wiring diagram for an early 80's (West) German
> guillotine paper cutter:
>
> <http://freefilehosting.net/show/42l0i>
>
> The goal of this circuit is to energize an electromagnetic clutch
> coil (m27) that takes rotational energy from a flywheel to do a task
> (bring down the knife blade). This circuit is currently not working.
>
> This machine has no ICs. There are some monolithic rectifier bridges
> and discrete transistors (the common symbol for which I cannot find
> *one* in the diagram), and plenty of passives.
>
> The transformer (m) primary center tap is connected to 24vdc. Do I
> interpret this correctly that the primary is run by a switched dc
> voltage? (This on a machine that runs on 3-phase 245vac.) Why?
>
> I can say from experience that other machines of this same
> manufacturer use a voltage derived directly from the 3-phase input to
> drive the electromagnetic clutch. Why use a switched voltage, I
> cannot understand.
>
> Is the triangle within a square symbol some sort of odd
> representation of a transistor? And the "arrow thing" that feeds
> them? Ideas?
>
> Help!
>
> Thanks,

Try de.sci.ing.elektrotechnik perhaps

--
Jeff



From: Frithiof Jensen on 9 Dec 2008 06:18

"DaveC" <me(a)bogusdomain.net> skrev i meddelelsen
news:0001HW.C5635CA9009BC01BB01AD9AF(a)news.sf.sbcglobal.net...

> This machine has no ICs. There are some monolithic rectifier bridges and
> discrete transistors (the common symbol for which I cannot find *one* in
> the
> diagram), and plenty of passives.

Hmm. The box-with-a-triangle symbol looks like a logic gate to me.

>
> The transformer (m) primary center tap is connected to 24vdc. Do I
> interpret
> this correctly that the primary is run by a switched dc voltage? (This on
> a
> machine that runs on 3-phase 245vac.) Why?
>
> I can say from experience that other machines of this same manufacturer
> use a
> voltage derived directly from the 3-phase input to drive the
> electromagnetic
> clutch. Why use a switched voltage, I cannot understand.

Probably some safety loop required/mandatory wherever the machine was first
sold; the cutter will not operate when certain hatches wired with door
swithces are open e.t.c. Machines are often customised - even the same
machine from the same manufacturer can be somewhat different. If they are
picked up used or at bancrupcy auctions - as I like to do - it will show.

>
> Is the triangle within a square symbol some sort of odd representation of
> a
> transistor? And the "arrow thing" that feeds them? Ideas?

I really think they are logic gates, it looks a bit like the way Siemens
would draw them. The box-with-triangle-at-top looks like some kind of limit
switch, probably pneumatic.

The individual gates may well be implemented with a bunch of discrete
components, including transistors!

Guess you have to dig out the ole meter and walk the wiring in the terminal
blocks* - ohh those were the times ;-)



*Often the wiring is wrong too - yet the unit still worked thousands of
hours with the fault. This should not worry you unduly. Muahahahaha ;-)

>
> Help!
>
> Thanks,
> --
> DaveC
> me(a)bogusdomain.net
> This is an invalid return address
> Please reply in the news group
>

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