Cgs synth

Take the COM line to your 0V connection. Do not connect 0V/COM directly to
the case earth. Instead, place a 1K 5W resistor between the case and your
0V/COM connection. This will help prevent earth-loops.

The +S and -S lines are sense lines. Using ordinary hook-up wire, connect
these to the + and - connections on your distribution board. The purpose of
these is to sense any voltage drop at the distribution board, so the PSU can
compensate. You are effectively cancelling any losses in the power wires by
doing this.

Note- these are "generic" power one guidelines. I haven't seen your specific
unit.

Ken

>
>
>If I may high-jack this thread briefly, it is on the subject of
>Power-One PSUs. I've just built a 6U case, incorporating a dual
>output (HCC-15-3) unit. The case has a single distribution
>board (for now) with power going in centrally (to combat line
>overload) and the + and - lines use two tracks anyway. There are
>9 sockets on this board (of which I'm using 5).
>
>
>I have jumpered pegs 2 and 3 and applied AC (via a switch and
>fuse) to pegs 1 and 4, with 5 being left alone as per the
>instructions. I have wired the + out and - out pegs from the PSU
>(there are several others to choose from i.e. S+ and S-, and in
>the centre, S+, S- and Com) to the + and - lines on the dist
>board, respectively. The 0V line I have attached to the frame, and
>from there to the Earth point of the power cable.
>
> I appear to be having trouble with the earth. The case powers
>up, but it doesn't run the modules properly. I've checked the
>outputs, and I'm getting 24V across the + and - terminals, but
>when I check +12V to Earth or -12V to Earth I get a reading of 0
>and -0 respectively.
>
> I've checked the continuity from the IDC sockets through to the
>earth pin of the plug and there is good continuity. Similarly, there
>is good comtimuity for each of the power rails back to the PSU.
>The IDC sockets are sound with no shorts, and the board is
>correctly isolated from the case. All the mains wiring and the
>wiring from PSU to dist board is from mains flex rated at well
>above the 3.4A maximum.
>
> I suspect I've misunderstood something rather than there being
>a physical problem with the wiring.
>
>Your assistance would be greatly appreciated.
>
>
>--- In cgs_synth@yahoogroups.com, sasami@h... wrote:
>>
>> >BTW, If you're outside of the US NEVER buy from Allied. I
>thought
>> >this shipping charge was large because of the weight of the
>Power
>> >One PSU's, so last month I foolishly ordered some Vactrols
>and 20 of
>> >8 pin IC's that would fit into a jiffy bag and Mouser would
>charge
>> >$12 by USPS small packet. They came in a big box (!) and
>Allied
>> >charged me $89 shipping, despite me requesting that items
>be shipped
>> >by USPS small packet service. I'm now the proud owner of
>some of the
>> >most expensive Vactrols in the Universe :-(
>>
>> I've heard this story before, so you aren't the first person they've
>done it
>> to. Bad news.
>>
>> Ken
>>
>__________________________________________________
>_____________________
>> Ken Stone sasami@h... or sasami@c...
>> Modular Synth PCBs for sale
><http://www.blaze.net.au/~sasami/synth/>
>> Australian Miniature Horses & Ponies
><http://www.blaze.net.au/~sasami/>
>
>
>
>
>
>
>See the following URLS for the CGS Modular Synth home page:
>Main: http://www.cgs.synth.net/
>Secondary: http://otherunicorn.0catch.com/synth/
>Yahoo! Groups Links
>
>
>
>
>
>
>
>

_______________________________________________________________________
Ken Stone sasami@... or sasami@...
Modular Synth PCBs for sale <http://www.blaze.net.au/~sasami/synth/>
Australian Miniature Horses & Ponies <http://www.blaze.net.au/~sasami/>