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RE: [N8VEM-S100:1005] S-100 backplane request for help
The reason for this is that you have to do it for every single board, every time Jack. If you have a simple system with just a few boards then that's fine. If you have many and/or exchange them in different boxes to debug, test etc. it becomes a pain reconnecting etc. BTW, if doing this watch, out for some boards that use Zeniers. One second in a 8V system without regulators and the whole board is toast!
John
John Monahan Ph.D
e-mail: mon...@vitasoft.org
Text: mon...@txt.att.net
-----Original Message-----
From: n8vem...@googlegroups.com [mailto:n8vem...@googlegroups.com] On Behalf Of Jack Rubin
Sent: Monday, July 23, 2012 7:11 AM
To: n8vem...@googlegroups.com
Subject: Re: [N8VEM-S100:1005] S-100 backplane request for help
Sorry - I haven't been following this thread, but especially when building new boards, why not scrap on-board regulation and just run +5 and +12 volts on the power rails? Cuts cost and heat rejection. Modern switching supplies are well-enough regulated not to need the margin of the old linears. Godbout (and
others?) went to this strategy on their later systems.
Jack
----- Original Message ----
> From: Terry Sare <ts...@sareusa.com>
> To: n8vem...@googlegroups.com
> Sent: Mon, July 23, 2012 8:09:34 AM
> Subject: Re: [N8VEM-S100:1004] S-100 backplane request for help
>
> Paul,
>
> I got two of these -- $13.29 each plus ~$14 shipping, adjust up to
> 16.5 volts.
>
> http://www.powergatellc.com/mean-well-rs-25-15-power-supply.html
> Output(s) 15.0V @ 1.70A
> Power 25 Watts
> Dimensions 3.08 x 2.00 x 1.10"
> Operational Efficiency 83.50%
> Operating Temperature -20~+70°C
>
> The old transformer and p/s in my 22 slot chassis weighs around 20 lb
> -- the 3 switchers together weight about 4lbs. Nice.
>
> terry
>
>
> On 7/23/2012 12:03 AM, Paul Birkel wrote:
> > Terry: Excellent pointer, and more cost-effective supplier :->.
> > What did you do about the 16V rails?
> >
> > John: I haven't seen any 16-or-more-bit boards yet and failed to
> > consider their impact; thanks for reminding me about the near
> > future (coming soon to a backplane near you ...).
> >
> > On Sun, Jul 22, 2012 at 4:47 PM, Terry Sare <ts...@sareusa.com> wrote:
> >> And for those of us that want overkill I found this
> >> 1 x 350 Watt, Single Output, SE-350-7.5 from Mean Well
> >> (SE-350-7.5) =
>$48.29
> >> http://www.powergatellc.com/mean-well-se-350-75-power-supply.html
> >>
> >> Output(s) 7.5V @ 46.00A
> >> Power 350 Watts
> >> Dimensions 8.46 x 4.53 x 1.97"
> >> Operational Efficiency 80.00%
> >> Operating Temperature -20-60°C
> >>
> >> Total with shipping was around $62 so not bad.
> >>
> >> Terry
> >>
> >> -----Original Message-----
> >> From: n8vem...@googlegroups.com
> >> [mailto:n8vem...@googlegroups.com] On Behalf Of John Monahan
> >> Sent: Sunday, July 22, 2012 3:29 PM
> >> To: n8vem...@googlegroups.com
> >> Subject: RE: [N8VEM-S100:1001] S-100 backplane request for help
> >>
> >> Paul, 12A on the 7.5V may be a little on the low side unless you
> >> are just sticking to 8 bits. The 16 bit CPU boards have 3A
> >> regulators and if you have a dual (or more) CPU master slave setup, things could get tight.
Agree
> >> 20A's is probably best. The 16 V lines are really only used for RS232 etc.
> >> these days and even there, there are converter chips. So 1-2 A is fine.
> >>
> >> John
> >>
> >>
> >>
> >> John Monahan Ph.D
> >> e-mail: mon...@vitasoft.org
> >> Text: mon...@txt.att.net
> >>
> >>
> >> -----Original Message-----
> >> From: n8vem...@googlegroups.com
> >> [mailto:n8vem...@googlegroups.com] On Behalf Of Paul Birkel
> >> Sent: Sunday, July 22, 2012 11:37 AM
> >> To: n8vem...@googlegroups.com
> >> Subject: Re: [N8VEM-S100:1000] S-100 backplane request for help
> >>
> >> While John has some great information on his backplane/ps page
> >>
>(http://s100computers.com/My%20System%20Pages/The%20Box/The%20Box.htm#T
>he_Po
> >> wer_Supply),
> >> one point that is missing is the proper power supply sizing for an
> >> 8-slot system.
> >>
> >> The IEEE 696:1983 spec is silent on the allowed/anticipated
> >> ps-loading per slot, but it seems reasonable to assume 1 A to
> >> maybe 1.5 A average per
>slot
> >> on the 8V rail, max (most cards hosting a single 1A +5V regulator,
> >> with
the
> >> occasional dual-regulator configuration like the dual-IDE card)?
> >> That suggests maybe 12A on the 8V rail, and we might guess 1-2A
> >> max on the +16 and -16V rails (since these aren't used much at all on modern cards)?
> >>
> >> Am I way off-base here?
> >>
> >> FWIW, here are what appear to be the most relevant Meanwell
> >> supplies (via Power Factor, as pointed out by John) -- all of
> >> which can have their
output
> >> voltages adjusted upwards a bit to fit the 8 and 16 volt
> >> bus-targets:
> >>
> >> http://www.power-factor-1st.com/g2-series/s-100f.html 7.5V, 0~13.5A
>$49.45
> >> http://www.power-factor-1st.com/g2-series/s-150.html 7.5V, 0~20A $55.45
> >> http://www.power-factor-1st.com/g2-series/s-210.html 7.5V, 0~27A $70.95
> >> http://www.power-factor-1st.com/g2-series/s-40.html 15V, 0~2.8A $37.90
> >>
> >> The 20A (second line) seems to be the cost-effective sweet-spot
> >> "with headroom".
> >>
> >> Happy hunting :->.
> >>
> >> On Sun, Jul 22, 2012 at 1:55 PM, Andrew Lynch <LYN...@yahoo.com> wrote:
> >>> Hi! I’ve gotten a request for some help with the S-100 backplane PCB.
> >>> Since it will probably require a PCB respin to fix I would like
> >>> to gather up all the feedback and incorporate them as best I can.
> >>> Thanks to Don Caprio there are some excellent builder instructions here:
> >>>
> >>> http://n8vem-sbc.pbworks.com/w/page/35158565/Build%20Instructions
> >>>
> >>> Please post photos of your completed working S-100 backplane
> >>> systems on the wiki in the S-100 backplane folder. Actual builder
> >>> photos are
> >>> *very* helpful for new builders.
> >>>
> >>> http://n8vem-sbc.pbworks.com/w/browse/#view=ViewFolder¶m=S-100%20b
> >>> ackplane
> >>>
> >>> There is a new file for S-100 backplane fixes and improvements here:
> >>>
> >>> http://n8vem-sbc.pbworks.com/w/page/55620344/S-100%20backplane%20i
> >>> mpro
> >>> vements%20and%20fixes
> >>>
> >>> Please edit with any issues you’ve encountered on how to fix
> >>> and/or improve the S-100 backplane.
> >>>
> >>> The photos that are in the folder at the moment are getting
> >>> rather dated so they should be retired to the archive as to not
> >>> confuse any new
> >> builders.
> >>> Thanks and have a nice day!
> >>>
> >>> Andrew Lynch
> >>
> >> -----
> >> No virus found in this message.
> >> Checked by AVG - www.avg.com
> >> Version: 2012.0.2179 / Virus Database: 2437/5147 - Release Date:
> >> 07/22/12
> >>
> >> -----
> >> No virus found in this message.
> >> Checked by AVG - www.avg.com
> >> Version: 2012.0.2179 / Virus Database: 2437/5147 - Release Date:
> >> 07/22/12
> >>
> >
>
>