Olive Box Plans

This is a relatively new box, and all it basically does is serve as a phone ringer. You have two choices for ringers, a piezoelectric transducer (ringer), or a standard 8 ohm speaker. The speaker has a more pleasant tone to it, but either will do fine. This circuit can also be used in conjunction with a rust box to control an external something or other when the phone rings. Just connect the 8 ohm speaker output to the inputs on the rust box, and control the pot to tune it to light the light (which can be replaced by a relay for external controlling) when the phone rings.

               ______________
              |              |                 NC --|-- 5      4 --|-----/X/X/------->G
              |              |      / R2
  G<----)|----|-- --|---------- - 2 3 6 7 | --|-- --- -- C3 NC U1 -------|--> TO RINGER
              |              |
          ----|-- 8      1 --|--
         |    |______________|  |
         |                       ---/X/X/----|(----- L1
         |                           R1      C1
          ------------------------------------------ L2

                    a. Main ringer TTL circuit



  FROM PIN 2ive:G
                                      P1

            f       b. Peizoelectric transducer


                                                        __  /|
  FROM PIN 2 ||||||||<.--- TRANSDUCER

Parts List

U1 - Texas Instruments TCM1506
T1 - 4000:8 ohm audio transfomer
S1 - 8 ohm speaker
R1 - 2.2k resistor
R2 - External variable resistor; adjusts timing frequency
C1 - .47uF capacitor
C2 - .1uF capacitor
C3 - 10uF capacitor
L1 - Tip
L2 - Ring

L1 and L2 are the phone line.

Shift Rate:

This is the formula for determining the shift rate:

            f        1                   1
      SR = --------------------- = ------------ = 6.25 Hz
           (DSR(1/f1)+DSR(1/f2))    128     128
                                   ----  + ----
                                   1714    1500


                DSR = Shift Devider Rate ratio = 128
                 f1 = High Output Frequency = 1714
                 f2 = Low Output Frequency = 1500