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-
- -----------------
- -/SWITCHBOX PLANS/-
- -----------------
-
- This tutorial is notable in that it is totally and absolutely within legal
- bounds. It's only object is to guide you in building a device with which you
- can control, on many different levels, your home phone lines. It is designed
- primarily for two phone numbers, although I suspect that provisions for more
- than two can be easily added. With it, you can put one or both phone lines on
- hold with visible indicators of each lines status; conference call with two
- people; change a phone from line #1 to line #2; and lastly, make one phone line
- physically dead to outside world. This is good, for instance, if you don't want
- to recieve any calls, or if you want to stop someone from talking on that line
- really quickly.
-
- The circuit is relatively simple to build and I believe it is much more
- economical than buying something like Radio Shack's line controller. It will
- require some knowledge of electronics and the phone line in general, but I don't
- think that should be a problem. I have personally found many uses for the
- controller, and have put in into a pleasant "project box" so it is not an
- eyesore.
-
- OK, now, let's start with the parts list --------
-
- ============================================================
-
- *** Parts List ***
-
- 1. Two pushbutton (on-off) switches for hold
- 2. Two LED's for line status indication
- 3. One DPDT switch for conferencing
- 4. One SPST switch for line shut off
- 5. Another DPDT switch for phone line switching
- 6. Get some wire, you'll need it!
- 7. 2 modular phone plugs with at least 10 feet of wire each
- 8. Two 1.7K ohm resistors
- 9. *OPTIONAL* - Project Box
-
- =============================================================
-
- *** Construction ***
-
- We will take the construction of the switchbox-controller in parts. First,
- the hold switches and status indicators. The following is a diagram of the
- essential circut:
-
-
- Pushbutton #1 LED
- --------------------------!x!-----0---
- Phone Line #1 1.7K Resistor !
- -----------------/!/!/!/!/------------
-
- Some word of explanation is in order. First of all, the second phone line
- hold is constructed the same as the first. Basically, there are two wires come
- out of your phone line, the red and the green. You have to experiment to find
- out which one is connected to the pushbutton switch and which one to the
- Resistor. To do this, just connect it in any way and then turn the switch on.
- If the LED lights up, you connected it right, otherwise reverse the connections.
- Got it? Good, now do the same for line #2, following exactly the same
- procedure.
-
- Now, let's do an easy one. This will be the line black- out switch. First,
- decide which line you wish to black out. Actually, you can do it to both lines
- if you wish, just get an extra SPST switch. Now, connect the switch across the
- line as follows:
-
- --------------------------------!!!!!!!!
- x ! Hold !
- !x! <---Switch !Circut!
- x ! !
- --------------------------------!!!!!!!!
-
- Don't worry that your line can't handle both circuts, it can. To test out,
- pick up a phone on the line you have connected the switch to and flip it on.
- There should be dead silence. Now, turn it off. You should hear a dial tone.
- You have to be an absolute idiot if this doesn't work.
-
- OK, let's see what we have so far. If everything is working you should now
- have two hold circuts and a black- out switch connected. Now it really gets
- tough!
-
- Next on the agenda is the conference switch. I have a few precautions for you
- on this one. First, you have to know what you're doing, and second, it doesn't
- work that well. The reason it doesn't is because I am naturally very lazy and
- didn't feel like adding the needed phone transformer. But, it is still good for
- many uses, limited only by your imagination (to use a cliche').
-
- First, take the double pole double throw switch into your hand. It should
- look like this on the back:
-
- ---------
- - 1 2 -
- - 3 4 -
- - 5 6 -
- ---------
-
- * Note - Numbers correspond to actual pins. Now connect two wires to pins 3 &
- 4 and two wires to pins 1 & 2. The wires going to pins one and two are
- connected across the first phone line and the wires from three and four go
- across the second phone line. Test it out: Pick up your phone (either line)
- and wait for dial tone. Then throw on the conference switch. You should get a
- second dial tone. Now dial 555-1212. You should now have two D.A.'s on the
- line, asking each other "What City?". If not, then reverse the connections to
- phone line #1 or #2, it doesn't matter. Now it should work. If not, then
- recheck EVERYTHING! You messed up!
-
- Now for the last section - the phone line switcher. With this, you can
- connect a phone directly to the switchbox and have it operate from line #1 or
- line #2, depending on the position of the last DPDT switch. Let me emphasize
- that this is optional. Actually, all the circuts are - they are in- dependent
- of each other and each can be built separatly or together.
-
- Now, refering to the diagram of the DPDT switch above: Connect two wires to
- pins 1 & 2. Then connect these to phone line #1. Now connect two wires to 5 &
- 6 and connect these to phone line # 2. Lastly, connect two wires to 3 & 4 and
- con- nect the ends of these to a phone. That's it! Now, pick up the phone and
- you should hear a dial tone. Throw the switch and you should hear another dial
- tone. In some areas you may dial '958' to hear exactly what number you are
- currently connected to, but that should be a problem. If you really can't
- figure it out, then either trace the circut back or call one of the numbers and
- see if you get a busy signal or if it rings.
-
- Finally - Put the whole mess inside a project case, unless you like the site
- of wires all over the place. This also shouldn't be a problem if you know even
- the basics of hardware construction.
-
-