2 WIRE TELEPHONE WITH DTMF DECODER

SCOPE :-

This system has the facility of point to point communication between Cabins – ASM & Level Crossing Gates.

It is possible to interface Telephone with Microwave and Optical Fibre System.

The system works for Voice Communications & on omnibus circuit tapped at different places.

FEATURES :-

1. This system is having a DTMF Decoder, Ringer Circuit, Line Interface, Speech Circuit, & Battery Indication.

2. The system works on 3V DC [1.5V x 2 Dry CELL – Type R-20] as per IS:8144. [The batteries are housed in a leak proof compartment.]

3. The Telephone instrument is moulded of ABS [Acrylonitrile Butadiene Stryrene] plastic powder.

4. Glass Epoxy PRINTED CIRCUIT BOARD [P.C.B.] is used for better environmental performance.

5. Ferrite core Transformers are used for miniaturization and better quality performance.

6. The Telephone Unit has Trans & Receive speech circuits.

7. Electro Dynamic Transducers for both Transmitter & Receiver are used.

8. Visual & Audio Indications:

   1. Yellow LED [5mm] for Incoming Ring & Buzzer for audible tone.

   2. Dual LED [5mm] :-

      1. Green LED for power supply indication irrespective of handset is ON Hook or OFF Hook.

      2. Red LED for low battery voltage [10% below normal voltage].

9. Equipment should be protected from:

   1. Surge & transients current from lightning.

   2. Acoustic protections to receiver.

   3. Reverse Polarity.

10. The volume level of the buzzer can be adjustable in two steps (Low & High).

TECHNICAL SPECIFICATIONS:-

SR. NO.	TESTS	RANGE
1	TRANS EFFICIENCY	> 0dBm
2	TRANS DISTORTION	< 3%
3	SIDE TONE	< -18dBm
4	RECEIVE EFFICIENCY	> -18dBm
5	RECEIVE DISTORTION	< 3%
6	IDLE CURRENT	< 20mA
7	TALK CURRENT	< 50mA
8	RING CURRENT	< 200mA
9	INSERTION LOSS (ON HOOK)	< 0.5dB
10	INSERTION LOSS (OFF HOOK)	< 0.8dB

All Technical & Mechanical specifications are subject to change, without prior notice, for better performance & up gradation.

End.