245 lines
5.7 KiB
Plaintext
245 lines
5.7 KiB
Plaintext
Written by: Mavicon M.D.
|
|
|
|
Design: The Ear and Mavicon M.D.
|
|
|
|
|
|
|
|
Diverter Plans
|
|
|
|
|
|
|
|
Parts List:
|
|
|
|
Everything can be obtained at your local Radio-Shack. As much as
|
|
|
|
i hate that store, they are convenient...
|
|
|
|
|
|
|
|
RLY1 DPDT relay
|
|
|
|
T1 1:1 audio transformer
|
|
|
|
D1 1N914 or similar diode
|
|
|
|
D2 large LED
|
|
|
|
LMP1 neon lamp
|
|
|
|
R1 10 k
|
|
|
|
R2 photocell
|
|
|
|
R3 22 k
|
|
|
|
R4 47 k
|
|
|
|
Q1 2N2222, 2N3904, 2N4401, most any other NPN switching
|
|
|
|
transistor
|
|
|
|
1 nine volt battery. The negative terminal goes to ground on the
|
|
|
|
schematic. Positive terminal to +9 volts.
|
|
|
|
Black electrical tape
|
|
|
|
|
|
|
|
Assembly:
|
|
|
|
|
|
|
|
The best way to assemble the design is to grab one of those small
|
|
|
|
copper lined perfboards from Radio-Shack. They are nice to work
|
|
|
|
on, and can easily be trimmed down to a minimum size once
|
|
|
|
everything is soldered in. The process is the same as any other,
|
|
|
|
solder all the parts in per the schematic. The photocell must be
|
|
|
|
in a position so that the light from the neon lamp(LMP1) and the
|
|
|
|
LED(D2) both shine on it. No other light must get in, so use
|
|
|
|
some black electrical tape to seal it all up. All the polarity
|
|
|
|
must be observed. Whichever direction you put the LED in, you
|
|
|
|
must remember (color code your wires, green is positive, red is
|
|
|
|
negative, yellow is positive, black is negative) the negative
|
|
|
|
side of the line must go to its negative side. The same goes for
|
|
|
|
the transformer. The positive side of each line has to be
|
|
|
|
connected to the correct pair on the transformer. On the Radio-
|
|
|
|
Shack transformers, put positive of both lines on the Red and
|
|
|
|
Black pairs, The negative on Yellow and White. Our prototypes
|
|
|
|
have reached less that 1" x 1" in size.
|
|
|
|
|
|
|
|
Theory of Operation:
|
|
|
|
|
|
|
|
The diverter works on some basic electronic principals.
|
|
|
|
Step by step:
|
|
|
|
The phone rings. The neon lamp is activated by the high
|
|
|
|
voltage(88 p-p) ac and flashes. This light shines on the
|
|
|
|
photocell, decreasing its resistance. When this happens, the
|
|
|
|
positive voltage flowing through the photocell and the 10k
|
|
|
|
resistor exceed the breakdown voltage of the base of the
|
|
|
|
transistor and switches that transistor on. Once the transistor
|
|
|
|
is on, current flows freely from emitter to collector, energizing
|
|
|
|
the relay. The relay's two sets of switches connect both lines
|
|
|
|
to the 1:1 audio transformer, effectively taking both lines off
|
|
|
|
the hook and coupling any audio signals from either line to the
|
|
|
|
other one. Once this happens, current is now flowing through the
|
|
|
|
transformer, relay, and LED loop. This current lights the LED
|
|
|
|
and that light shines on the photocell. This is what keeps the
|
|
|
|
device latched. The light from the LED keeps the photocell
|
|
|
|
resistance low enough to keep the transistor on. Now, you make
|
|
|
|
your call and get on with your business. You hang up. Now, the
|
|
|
|
local CO keeps current flowing through the indial line for about
|
|
|
|
5 seconds, at which point it drops down for a second or so and
|
|
|
|
then goes back up. This is the signal the device uses to
|
|
|
|
determine when you've hung up. When the current drops down,
|
|
|
|
there is no light from the LED, and the photocell resistance
|
|
|
|
raises enough to turn the transistor off and delatch the entire
|
|
|
|
system.
|
|
|
|
|
|
|
|
Applications:
|
|
|
|
|
|
|
|
The applications are relatively obvious. Hook it up to two
|
|
|
|
unused lines and make free calls. Hook it up to two payphones,
|
|
|
|
and red box calls. The only thing to watch out for is ringing.
|
|
|
|
If you hook it up to a residential line for the indial a small
|
|
|
|
(maybe 1/8) of a ring occurs when you call, tipping off people
|
|
|
|
inside the house.
|
|
|
|
|
|
|
|
|
|
|
|
|-------------------------------------
|
|
|
|
| | o +9V
|
|
|
|
| L1+ T1 | |
|
|
|
|
| o-------wwwww----------| | |
|
|
|
|
| | | |
|
|
|
|
| L1- | | |
|
|
|
|
| o-------------| | | o--------|
|
|
|
|
| | | | | |
|
|
|
|
| | | | | |
|
|
|
|
| | | | | |
|
|
|
|
| L2- | |---l----------l---------l--| _____
|
|
|
|
o-------\ LMP1 | | | \| | | w | /^\ D1
|
|
|
|
R4 47k * | | | | |\ | w | /---\
|
|
|
|
--\/\/--/ | | | | | | | w | |
|
|
|
|
| | |-l----------l-----------l--| |
|
|
|
|
| | | RY1 | | |
|
|
|
|
o L2+ |------| | | |
|
|
|
|
| | o---------
|
|
|
|
| | |
|
|
|
|
| | ----|
|
|
|
|
| D2 | /
|
|
|
|
| |\ | T1 | /
|
|
|
|
|----------| >|-----wwwwww---------- /
|
|
|
|
|/ | 000
|
|
|
|
|--------- 000 Q1
|
|
|
|
| 000
|
|
|
|
oooo | \
|
|
|
|
o o 10k | \
|
|
|
|
o-------o-/\/\/o------------/\/\/---| \
|
|
|
|
+9V o o R2 \ R1 |
|
|
|
|
oooo / 22k -----
|
|
|
|
\ R3 ---
|
|
|
|
| -
|
|
|
|
|
|
|
|
|
-----
|
|
|
|
---
|
|
|
|
-
|
|
|
|
|
|
_/_/_/ _/ _/
|
|
_/ _/ _/_/_/ _/ _/_/ _/_/ _/_/_/ _/ _/
|
|
_/_/_/ _/ _/ _/_/ _/_/_/_/ _/ _/ _/_/
|
|
_/ _/ _/ _/ _/ _/ _/ _/ _/ in
|
|
_/ _/ _/ _/ _/_/_/ _/_/_/ _/ _/ peace...
|