Sys7 sound board - c27?
Chad
yet in case the mistake is mine. The kit has a 12000uF cap for C27
but the schematic I have lists a 4700uF cap and the board had the
original 4700uF cap in it.
One more bit of oddness... the components map in the manual shows a
really big cap in that spot, much bigger than 4700uF would be, and
connected to a different thru-hole than the 4700uF cap is - BUT it's
on the same trace. That implies to me this is another of those
Williams configure-by-changing components issues. There has clearly
never been a cap in the wider thru-hole would be used by the 12000uF.
Help?
John Wart, jr
I've had sound boards with both, and I replace with the one in the GPE kit
and it works just fine :) Probably revised by WMS at some point for some
reason.
I'd rather have the bigger one and not need it than have the smaller one and
need the bigger one :) In this case, the bigger cap won't hurt anything.
"Chad" <chad....@gmail.com> wrote in message
news:2e431ba0-5c4d-4ac1...@f19g2000yqh.googlegroups.com...
BarryMinnesota13
The bill of materials for this board, item 40 for C27, lists the
capacitor at 12,000 uf, 16V. And indeed some schematics indicate a
4,700 uf cap. I have found one type 2 board from the factory using
the 12,000 uf cap most seem to be equipped with the cheaper 4,700 uf
cap. The early type 1 board uses the 12,000 uf cap exclusively. The
circuit differences are in the amplifier circuit between the type 1
and type 2 board. If you look on your board you will see an optional
through hole next to a diode for mounting the large 12,000 uf cap.
There is confusion between the bill of materials and some schematics.
Note that the sound board schematic from the BK system 7 manual lists
12,000 uf for C27. I would put in the 12,000 uf for C27 using the
optional through hole next to the diode.
Barry
Chad
Cool, thanks guys. I'll use the 12000mfd cap. Just wanted to be sure
here. :)
Chad
> You're not the first to notice this..
>
I searched for an answer and didn't find that thread... which is
doubly ironic here because *I POSTED IN THAT THREAD*.
Please excuse me a minute while I slam my head a few dozen times.
GPE
>
> Cool, thanks guys. I'll use the 12000mfd cap. Just wanted to be sure
> here. :)
I really gotta add a note to my website to clear up this issue someday...
The 12KuF caps will work fine. There is such a small load on this supply
that the extra capacitance won't affect the bridge rectifier.
The boards were originally designed with 12KuF caps. Wms saved money with
smaller caps... and these supplies worked fine with the smaller caps as
well. But, rather than offer variations of ktis with smaller and larger
main filter caps, I just offer the one kit. I barely have enough time
making the kits that I sell ... not sure where I will find the time for more
kits (as planned).
Ed
GPE
"GPE" <GPE_N...@Cox.net> wrote in message
news:3PDYl.11252$Dr4....@newsfe24.iad...
Aw heck... maybe I should just offer two versions of the kit....
Ed
Chad
Nah, Ed, a note on the desc would do just fine.
Unless, you're a *total* idiot like me... and in your haste to get it
in and the board tested you put that 12000uF cap in backwards... and
blow the only two 4A fuses you have on hand... and possibly the cap
itself.
I'm going to give up for the night now. kthxbai