19 Mar
2011
19 Mar
'11
7:30 p.m.
Are there any documents for a DEC 872-A Power Controller floating around?
The 872-A is a 12A, 110V power distribution/control unit that I have in
the bottom of my "corporate rack".
Specifically I'm interested in what the signaling is on the two, 3-pin
Molex jacks labled "DEC Power Control Bus", which presumably is a means
to remotely control the power to the devices in the rack via this PDU.
Chris
--
Chris Elmquist
19 Mar
19 Mar
8:16 p.m.
On 3/19/11 4:30 PM, Chris Elmquist wrote:
Specifically I'm interested in what the signaling
is on the two, 3-pin
Molex jacks labled "DEC Power Control Bus"
http://bitsavers.org/pdf/dec/standards/EL-00123-00_B_DEC_STD_123_Power_Cont…
20 Mar
20 Mar
7:06 a.m.
On Saturday (03/19/2011 at 05:16PM -0700), Al Kossow wrote:
On 3/19/11 4:30 PM, Chris Elmquist wrote:
ah ha! Thank you Al. Exactly what I need.
Chris
--
Chris Elmquist
Specifically I'm interested in what the
signaling is on the two, 3-pin
Molex jacks labled "DEC Power Control Bus"
http://bitsavers.org/pdf/dec/standards/EL-00123-00_B_DEC_STD_123_Power_Cont…
3:44 p.m.
Are there any documents for a DEC 872-A Power Controller floating around?
The 872-A is a 12A, 110V power distribution/control unit that I have in
the bottom of my "corporate rack".
Specifically I'm interested in what the signaling is on the two, 3-pin
Molex jacks labled "DEC Power Control Bus", which presumably is a means
to remotely control the power to the devices in the rack via this PDU.
All power cotnollers after a certain date (early 1970s, IIRC) use the
same 'power control bus', os the manual and/or printset for any of them
would be a good start.
From what I rememebr, the 3 pins are ground,
ground-for-on, and
ground-for off, 'off' taking priority over 'on'
if both are grouded.
There is no lartching in the power controllers.
You interconnect all the power controllrs in the system with
straight-through cables. The power swtich on the CPU box is connected
betweem the ground and ground-fro-on wires, so that turning this on
acrviates all the controllers and powers up everythjing. Over-temperature
swtiches and the like are connected betweem ground and ground-for-off, so
thatr if any device overheats, the whole system shuts down.
Thes signals are not TTL level. They may be up to 24V, nd you may have to
sink enough currnet to operate a reed relay. Just in case you want to
design your own swithcing units...
-tony
21 Mar
21 Mar
11:34 a.m.
On Sunday (03/20/2011 at 07:44PM +0000), Tony Duell wrote:
All power cotnollers after a certain date (early 1970s, IIRC) use the
same 'power control bus', os the manual and/or printset for any of them
would be a good start.
Thanks Tony. I plan to put a rocker switch between ground and
ground-for-on and use that to power up my entire "corporate" rack.
Someone has already cut a square hole in the bottom front kick plate
of this rack and so I was looking for something to fill that hole--
plastic plugs, body putty, and then a nice rocker switch came to mind.
With that I won't have to crawl behind the rack to power it all up...
and so this will connect nicely to one of the Power Control Bus connectors
with just two wires and fill the void (so to speak) that someone put in
this panel.
Chris
--
Chris Elmquist
From what I rememebr, the 3 pins are ground,
ground-for-on, and
ground-for off, 'off' taking priority over 'on'
if both are grouded.
There is no lartching in the power controllers.
You interconnect all the power controllrs in the system with
straight-through cables. The power swtich on the CPU box is connected
betweem the ground and ground-fro-on wires, so that turning this on
acrviates all the controllers and powers up everythjing. Over-temperature
swtiches and the like are connected betweem ground and ground-for-off, so
thatr if any device overheats, the whole system shuts down.
Thes signals are not TTL level. They may be up to 24V, nd you may have to
sink enough currnet to operate a reed relay. Just in case you want to
design your own swithcing units... 
11:44 a.m.
On 3/21/11 11:34 AM, Chris Elmquist wrote:
Thanks Tony. I plan to put a rocker switch between
ground and
ground-for-on and use that to power up my entire "corporate" rack.
Someone has already cut a square hole in the bottom front kick plate
of this rack and so I was looking for something to fill that hole--
plastic plugs, body putty, and then a nice rocker switch came to mind.
With that I won't have to crawl behind the rack to power it all up...
and so this will connect nicely to one of the Power Control Bus connectors
with just two wires and fill the void (so to speak) that someone put in
this panel.
What's in your corporate rack?
-Dave
--
Dave McGuire
Port Charlotte, FL
2:04 p.m.
On Monday (03/21/2011 at 11:44AM -0400), Dave McGuire wrote:
On 3/21/11 11:34 AM, Chris Elmquist wrote:
Two RL02 and 11/34A... which fills it except for one ugly 1U-ish gap
above the CPU and below the top RL02. The CPU can't go up tight to
the top RL02 because of some structure in the rack so it looks like
they always had some other small panel piece to fit there... which I do
not have.
There's a good picture of one here,
http://museum.dyne.org/index.php/Immagine:P5182215.jpg
So, that piece just below the RL02 is on my "to find" list ;-)
Then the very bottom panel piece on mine has a roughly 1" x 3/4"
rectangular hole cut in it near the right side. A white rocker switch
with ( 1 / 0) embossed on it will fit that hole though and serve as my
master on / off for the rack (via that 872-A PDU) I guess.
Chris
--
Chris Elmquist
Thanks Tony. I plan to put a rocker switch
between ground and
ground-for-on and use that to power up my entire "corporate" rack.
Someone has already cut a square hole in the bottom front kick plate
of this rack and so I was looking for something to fill that hole--
plastic plugs, body putty, and then a nice rocker switch came to mind.
With that I won't have to crawl behind the rack to power it all up...
and so this will connect nicely to one of the Power Control Bus connectors
with just two wires and fill the void (so to speak) that someone put in
this panel.
What's in your corporate rack?
3:20 p.m.
On 3/21/11 2:04 PM, Chris Elmquist wrote:
That's really nice-looking packaging for an 11/34.
What's
in your corporate rack?
Two RL02 and 11/34A... which fills it except for one ugly 1U-ish gap
above the CPU and below the top RL02. The CPU can't go up tight to
the top RL02 because of some structure in the rack so it looks like
they always had some other small panel piece to fit there... which I do
not have.
There's a good picture of one here,
http://museum.dyne.org/index.php/Immagine:P5182215.jpg So, that piece just below the RL02 is on my "to
find" list ;-)
Ahh yes, there's one of those (in what looks to be an identical rack)
in my VAX-11/730. There are two metal clips which screw into the rack,
and the white piece snaps onto them.
It's 1U tall, so in the worst case you could get a 1U flat filler
panel and paint it to match the rest of the cabinet.
Then the very bottom panel piece on mine has a roughly
1" x 3/4"
rectangular hole cut in it near the right side. A white rocker switch
with ( 1 / 0) embossed on it will fit that hole though and serve as my
master on / off for the rack (via that 872-A PDU) I guess.
That sounds like an excellent plan.
-Dave
--
Dave McGuire
Port Charlotte, FL
3:26 p.m.
On 3/21/11 10:44 AM, Dave McGuire wrote:
On 3/21/11 11:34 AM, Chris Elmquist wrote:
A cell phone, $60 mad money, and a lipstick.
Doc
Thanks Tony. I plan to put a rocker switch
between ground and
ground-for-on and use that to power up my entire "corporate" rack.
Someone has already cut a square hole in the bottom front kick plate
of this rack and so I was looking for something to fill that hole--
plastic plugs, body putty, and then a nice rocker switch came to mind.
With that I won't have to crawl behind the rack to power it all up...
and so this will connect nicely to one of the Power Control Bus
connectors
with just two wires and fill the void (so to speak) that someone put in
this panel.
What's in your corporate rack? 
5:22 p.m.
Thanks Tony. I plan to put a rocker switch between
ground and
ground-for-on and use that to power up my entire "corporate" rack.
FWIW, that's exactly what DEC did on the RL01 version of the MINC.
There's a power controller (I forget which one) in the bottom of the rack
with the RL01s in it, and a rocker switch on the front lip of the top
panel. This is wired to the power control bus socket on the controller.
Flipping it turns on the drives (and MINC processor box which is also
plugged into the controller).
There will eb a little toggle switch on the controller. In the centre-off
positoon, the controller will never power up, no matter what you do to
the control bus connectors. In the 'local on' position, the ground-for-on
line inside the controller is groudned (so the outlets on that controller
are powered), but the connection on the power bus socket is isolated so
that other controllers are not also turned on. In the 'remote on'
position, the controlelr works as I described. Youwant 'remote on', of
coruse. I think the ground-for-off signal works as an emergency shutdown
even in the 'local on' position, but I would have to check.
Someone has already cut a square hole in the bottom front kick plate
of this rack and so I was looking for something to fill that hole--
plastic plugs, body putty, and then a nice rocker switch came to mind.
With that I won't have to crawl behind the rack to power it all up...
and so this will connect nicely to one of the Power Control Bus connectors
with just two wires and fill the void (so to speak) that someone put in
this panel.
Should be fine. Any rocker switch will handle the votlages and currents
used on the power control bus (it's <<1A at under 24V). And all you need
is an SPST contact.
-tony
4877
days inactive
4879
days old
13 comments
7 participants
participants (7)
-
aek＠bitsavers.org -
ard＠p850ug1.demon.co.uk -
bfranchuk＠jetnet.ab.ca -
chrise＠pobox.com -
cisin＠xenosoft.com -
doc＠vaxen.net -
mcguire＠neurotica.com