E**************************************
* *
* How to build a BLACK BOX *
* *
***************************************
To all who dare --
What is a BLACK BOX? A BLACK BOX
is a device that is hooked up to your
fone that fixes your fone so that when
you get a call, the caller doesn't get
charged for the call. This is good for
calls up to 1/2 hour, after 1/2 hour
the Fone Co. gets suspicious, and then
you can guess what happens.
What this little beauty does is
keep the line voltage from dropping to
10v when you answer your fone. The
line is insted kept at 36v and it will
make the fone think that it is still
ringing while your talking. The reason
for the 1/2 hour time limit is that the
Fone CO. thinks that something is wrong
after 1/2 an hour of ringing.
All parts are available Radio
Shack. Using the least possible parts
and arangement, the cost is $0.98 !!!!
And that is parts for two of them!
Talk about a deal! If you want to
splurge then you can get a small PC
board, and a switch. There are two
schematics for this box, one is for
most normal fones. The second one is
for fones that don't work with the
first. It was made for use with a Bell
Trimline touch tone fone.
** Schematic 1 for most fones **
** LED ON: BOX ON **
FROM >--------------------GREEN-> TO
LINE >--! 1.8k LED !---RED--> FONE
!--/\/\/\--!>--!
! !
------>/<-------
SPST
Parts: 1 1.8k 1/2 watt resistor
1 1.5v LED
1 SPST switch
You may just have two wires which you
connect together for the switch.
** Schematic 2 for all fones **
** LED ON: BOX OFF **
FROM >---------------GREEN-> TO
LINE >------- ---RED--> FONE
! LED !
-->/<--!>--
! !
---/\/\/---
1.8k
ŠParts: 1 2 watt resistor
1 1.5v LED
1 DPST switch
Here is the PC board layout that I
recommend using. It is neat and is
very easy to hook up.
Schematic #1 Schematic #2
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* * * ------- *
* --
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