TLBI Handle Type - Circuits Part 4

TLBI CIRCUITs:

In This lesson we will be learning about TLBI circuits.

1. NORMAL POSITION
2. DISPATCHING TRAIN
3. TRAIN ENTERING INTO BLOCK SECTION- AUTO TRAIN ON LINE CODE TRANSMISSION.
4. TRAIN ARRIVAL
5. NORMALIZING OF BLOCK SECTION
6. NORMAL LC CANCELLATION
7. PUSHBACK LC CANCELLATION
8. TELEPHONE CIRCUIT
9. SPECIAL CIRCUIT ARRANGEMENT

1.NORMAL POSITION

- Normally  Block handle is at Line Closed Position

- SM key - IN

- SH key -IN

- S1(Normal Cancellation) and S2(Push Back Cancellation) - Normal Position

- TOL and Time release indication - White 

- Galvometer- Zero current position.

- All the relay except 1R and 1TPR are in de-energized condition

2. DISPATCHING TRAIN - Part 1

- Bell code transmission to give CALL ATTENTION from station A to Station B

Step 1: PB1 Button is Pressed(At Station A) , Negation On Line , BLR picks up and sounds the bell (At Station B)

Step 2: PB1 Button is Pressed(At Station B) , Negation On Line , BLR picks up and sounds the bell (At Station A)

Step 3: Verbal Communication for grant of Line Clear take place between SM of station A and Station B over Block Telephone.

Step 4: For Sending a train from Station A to Station B

            - TCF code transmission from Station A to Station B

            - PB1 and PB2 Pressed simultaneously (At Station A)

            - PBPR picks up proving 1R up (At station A)

            - Positive On Line (+ve On L1 and -ve on L2)

            - Galvo Deflects, NR picks up and bell sounds(At Station B)

           - With PBPR up power is connected to transmitter.(At Station A)

           - The Modulating frequency F1(85 Hz) is selected as loop between F1 

              and C is completed by Handle 'N' contact is the transmitter.(At STN A)

           - FM Code 'F1' on Line

           - Input Circuit to receiver of same station is isolated by PBPR back 

             contacts. (At STN A)

           - On Getting the Bell and Galvo deflection at STN B, SM Turns the block 

             Handle as far as Y Point. Further rotation is Not Possible as the handle
             is in locked position.(At STN B)

             - At Station B

                - Feed to receiver is connected through DY contact, 

                - CR1 picks up at station B on receipt of modulating current F1 

                  by receiver.

              - Lock Magnet picks up at Y to release the Block handle and Now 

                turned to right position('Train coming From' position)

             - While the Block Handle is being turned from Normal Position to R 

               Position, The circuit controller contact (XY-RD-LB) of the handle in the

               line circuit , in series with the relay NR is opened between the Y and 

               D points.(At STN B)

           - On Opening circuit controller contact in Line circuit, the resistance R3 

             in parallel to 'XY-RD-LB' and in series to line circuit results in reduction

             in the volume of the line current (which is greater than the line drop

             away current of NR).This cause a click on Galvo needle at both stations

             ,from this click SM of button pressing station comes to know that the

             block handle at other station has been turned.(At STN B).

          - Knowing Block Handle has been turned from the click on the Galvo 

             needle , PB1 and PB2 at station A are released.