On Fri, 2 Jun 2000, Chuck McManis wrote:
> Ok, I'm cobbling together a PDP-11 and I ran out of slots on my BA11 so I
> put a bus extender into it and plugged that into a BA23. The system works
> fine (thank you micronotes!) but I'd like to figure out how I could set it
> up so that powering up the 11 powered up both the BA11 and the BA23. Now I
> know the little 3 plug do-hickey (I think it is a mate-n-lock) normally
> connects to a power sequencer in the rack, but I don't have one of those.
> Is there any way to make it work otherwise?
Yep... build a power controller. :-)
For info. about power controllers, look through the archives for the
Vmsnet.pdp-11 newsgroup from around November, 1995... not sure if
they're still on deja-news or not, but I found some articles that I
saved from back then containing a thread on power controllers from
when the plug on my 871C melted (BTW, DEC actually sent someone to my
house to check out the burnt plug... they apparently take (or took)
things such as their equipment smouldering rather seriously, even if
it's old and used as a hobby by someone with no service contract).
A word of caution: it's a good idea to check the plugs, that is the
type that are attached to the cable by screws, on power cables every
so often to make sure that the screws are tight and the connection is
good in order to avoid the fragrance of acrid smoke filling your house.
Here's what an 871C looks like, so you have some idea of what one
does; thanks to ARD for corrections and reminding me not to use tabs
in ASCII drawings.
*
purple DPDT switch red
+-----sw1a--+-sw1b-------------------------------------------------+
| | +-----------------------------------------+ |
| orange| c | | |
| D1a | +--------------------------------+ +--C4-+ |
| | c | | | | | |
| - + D2a | | 1 3 1 T1 1| a c | | |
+-C2--------|----+ | R2---? ?--+ +------_at_!!_at_----D4--+ | |
| | | | VR1 | | 2_at_!!_at_2| | | | green
+-----------|------+ +----?----+--+ | J1-3-_at_!!_at_-+------|-----|-|---J2/3-1
| | +-----+6 | a c 2 | | 3_at_!!_at_3 a c | | | black
chasis 1 +-|o |---+--D3-----+ | | J1-4-_at_!!_at_----D5--+ | | |+J2/3-2
gnd. | | | | | (unused) | | | brown
+--C3---R1+--| RY1 |-------+ | +--|------------------------+ +-|-J2/3-3
| +---| |---+ | | | |
| | +-----+ | +-----|----------------------------+
| J1-1 J1-2--+ |
+--------------------------+-----------+
For the diodes, D1 - D5, a=anode, c=cathode
MOV1 - GE V150LA10A
C1 - 0.1 uF, 270VAC, 1KVDC
C2 - 10 uF, 50VDC (electrolytic)
C3 - .022 uF, 270VAC, 1KVDC
C4 - RVX2247, 50V (.0047uF?)
L1 - numbered as 1S00077, appears to be neon light, with built in resistor
R1 - 1K ohms, 5 percent tol.
R2 - 560 ohms, 5 percent tol.
RY1 - reed relay
VR1 - 8V regulator, National Semiconductor 932 736 08A (possibly 7808 type)
DISCLAIMER: Use the above schematic at your own risk; it's intended as
a rough guideline only, for troubleshooting purposes, for those who
haven't peeked inside theirs to trace the schematic out yet; don't use
this as a reliable guide for repairing or building a power controller!
I can't guarantee that no mistakes were made when tracing it out, and
if you rely upon it, there's no gurantee that it won't destroy you or
your equipment.
--
R. D. Davis
rdd_at_perqlogic.com
http://www.perqlogic.com/rdd
410-744-4900
Received on Sat Jun 03 2000 - 10:32:43 BST