TI Silent 700 power supplies

From: Tothwolf <tothwolf_at_concentric.net>
Date: Wed Dec 15 23:34:37 2004

On Wed, 15 Dec 2004, Vintage Computer Festival wrote:
> On Wed, 15 Dec 2004, Dwight K. Elvey wrote:
> > Do all the pins show low ohms to each other? It might be a center tap
> > or even just a ground lead that doesn't carry current. Since you have
> > the box open, you should be able to see where all the wires go.
> Well, I would have had the wires not broken off on the last whack that
> got the casing opened :( As it is I cannot tell what each one was
> connected to.

I decided to pull my Silent 700 out of storage tonight, however it turns
out the power supply seems to be MIA. I guess it got separated from the
terminal the last time I moved things around when I was bringing in the
batch of Alpha and VAX systems I got this year. I'll take a multimeter to
my terminal later, but if the power supply has a ground pin on the line
plug, the center pin of the 3 pin molex connector would very likely be a
ground. Since the terminals were usually connected to telephone equipment,
it would make sense that TI provided a ground back then. Its also possible
that the center pin is a center tap for the transformer, but since I can't
find my power supply, I really can't say for sure without looking at the
internals of the terminal.

On the topic of battery packs, the cells that make up the batteries used
in these terminals are still available. Each of the two battery packs is
made up of 4 series wired EnerSys (formerly Hawker Energy (formerly
Gates)) Cyclon "D" 2V cells. As of now, the part number for these is
0810-0004. The battery packs each have an in-line fuse, but I'm not sure
what the rating is or where it is wired in. The positive lead of the packs
terminates to the keyed/pointed end of the molex connector.

The cells that make up genuine TI battery packs do not have any markings
on them but they are a very distinctive type of cell and only one company
makes them. They are a sealed lead acid cell with a spiral wound grid type
plate. Due to their unique design, it is not uncommon to get 15-20 years
of service life out of them if they are properly charged and maintained
(I've replaced a number of 15+ year old cells that finally quit holding a
full charge). I've used these type of cells extensively in data collection
and remote monitoring / standby applications. For detailed information on
the individual cells see:

Received on Wed Dec 15 2004 - 23:34:37 GMT

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