DC answering machine [RE-wrenches]

[Steve Willey, Backwoods Solar]

FAX/ANSWER  POWER TIMER:
Thanks the diagram, looks great, but I think I can add something.  I did
start out something like that but having found people hesitated to supply it
with AC as well as DC and all the assorted wiring, I worked to simplify it.
The present design eliminated all phantom ,load as well as eliminated the
need to provide DC power. The ring of the phone primes it and it goes AC
self powered from there. But it did put the cost up there. I offer the
details for wrenches to copy for themselves or custom use fro their
customers, but hopefully not as a competing product. Sorry I can't make a
drawing on email yet:

I used an SSAC timer #HRDB424.  This is a 120 VAC powered timer with
adjustable delay 1 to 100 minutes. It has a 15 amp isolated relay output and
is the only timer they have that can work with a parallel load on the
trigger circuit. The phone ring trips a Radio Shack ring detector which
closes its relay only during the interval of the ring, putting a 20 - 40
watt bulb and the trigger of the timer across the inverter. this starts the
inverter and triggers the timer to latch up and start timing out. The timer
relay is then feeding the already started inverter to the fax (or answer
machine or both) AND also, if necessary, to a second bulb to assure holding
the inverter active. The timer fits inside a deep 4 plex outdoor box with
metal cover, one duplex outlet and one switch/outlet combo.  This gives 3
outlets, one is permanently taken to plug in the radio shack ring detector
which is like a little wall cube, all contained there. The remaining duplex
outlets give one for the inverter-start bulb load, and the other for the
timed fax & holding bulb. So everything is contained and just plugs in. No
DC required and no phantom load.

Now note that with fax units you must have a fax machine that can be plugged
in to power at first ring, go through its song and dance and wake up to
answer the call before too much time passes.  Of course simple curly thermal
faxes do this. Canon bubblejet plain paper fax will do that too after about
4 rings.  Not sure about laser type plain paper units.  One warning, if you
don't get the holding load correct and the inverter starts cycling, you can
dump a whole $40 ink cartridge in one hour of head cleaning cycles.

(By the way, Sharkey's address below DOES work if you change the comma after
www to a period)

Steve Willey   www.backwoodssolar.com
Backwoods Solar Electric Systems
----- Original Message -----
From: R. Sparks Scott <sharkey at mrsharkey.com>
To: <RE-wrenches at topica.com>
Sent: Monday, September 11, 2000 1:04 PM
Subject: Re: DC answering machine [RE-wrenches]>
> Interested List Members;
> Finally, I got some time and put the telephone wake up circuit together so
> you can view it. Go to <http://www,mrsharkey.com/wrenches/widget.pdf>. If
> anyone wants to use their CAD program to make the schematic more
> presentable, let me know, I'll update the Acrobat file with the new
diagram.
>
> -S


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