Re: [N8VEM-S100:1002] S-100 backplane request for help

[Paul Birkel <pbi...@gmail.com>]

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#The_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&param=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%20impro
>> 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
>
>
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