FW: Can some kind electronics bod help?

["Paul S. Gale" <groups@xxxxxxx>]

I posted this a while back but no one wanted to talk to me :-(



Any thoughts?



Paul.



-----Original Message-----
From: Paul Gale [mailto:groups@xxxxxxx] 
Sent: 25 January 2003 15:27
To: ukha_d@xxxxxxx
Subject: [ukha_d] Can some kind electronics bod help?



I'm trying to wire into my multi-source, multi-zone amp (Kustom
KHS6640). It has wall controllers that pass through IR to the amp. To
be
able to control each zone from a central location (or via HV, pronto
etc), I need to 'tap' into Kustom's IR system. I found someone on the
web saying they'd done it by using a transistor (see below). What I
don't understand is how to add the resistor as mentioned - what value
should I use and where should it be connected? Anyone understand this?

Thanks,

Paul.

++++++++++++++++

So I've finally gotten the Ocelot to control a Kustom whole house audio
system with no keypads.  All the credit goes to my father, the real
EE
in
the family, but hey, I did the soldering.

So, the problem is not modulation.  The problem is that the Ocelot
uses
some
sort of open collector (?) CMOS-based output that, when measured
against
the
Kustom's ground is 15V rather than the 5V the Kustom wants, and not to
mention that the "steady state" voltage is 15V rather than
0.  So
basically
all I did was hook up the IR to the emitter and base of a PNP
transistor,
and wire the collector to pin 3 of the Kustom RJ-45 input.  Done.

I'm putting a resistor in to make sure I don't overpower the Kustom,
but
we're talking about $3 in parts compared to a $99 keypad.  Woohoo!

Anybody wants some Kustom keypads let me know. :)

Thanks to the Ocelot folks for wiring diagrams and assistance. 
They
continue to rock.



++++++++++++++





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