New Report Training

7/31/2019 New Report Training

1/34

CONTENTS

1. Acknowledgement2. SIGNALLING:

i. Universal Axle Counter(a) Introduction

(b) Flow chart of manufacturing(c) Principle of working

(d) Brief description

(e) Specifications

ii.

Description of various modules of Axle Counter Systemiii. Colour Light Signal (CLS)iv. Relay Sectionv. Block Section

3. TELECOM:i. OFC(splicing)ii. Wireless Sectioniii. Track Feed Battery Charger


2/34

UNIVERSALAXLE COUNTER


3/34

INTRODUCTION

Axle counters were developed as a substitute for track circuiting. Initially axle

counters were imported from Germany to gain experience and to evaluate theirsuitability for adoption on Indian Railways. Having gained acceptability for

introduction on a wide scale on Indian Railways, it was considered to take up

indigenous development of axle counters, which was taken up in collaborationwith IIT, Delhi and DOE. Two models of axle counters known as single

entry/exit axle counter and multi entry/exit axle counters emerged and after

extensive laboratory and field trails under various conditions, the design was

finalized and commercialized through private sector as well as public sector.

Anaxle counteris an electronic device used to detect presence (passage) of atrain on a nominated portion of track, thus ensures safety in train operations.

This can alsobe used for automatic signalling and block working. It is a device

on arailwaythat detects the passing of atrainin lieu of the more commontrack

circuit. A counting head (or 'detection point') is installed at each end of the

section, and as eachaxlepasses the head at the start of the section, counter

increments. A detection point comprises two independent sensors, therefore the

device can detect the direction of a train by the order in which the sensors are

passed. As the train passes a similar counting head at the end of the section, the

counter decrements. If the net count is evaluated as zero, the section ispresumed to be clear for a second train.

This is carried out bysafety criticalcomputers called 'evaluators' which are

centrally located, with the detection points located at the required sites in the

field. The detection points are either connected to the evaluator via dedicatedcopper cable or via a telecommunicationstransmission system. This allows the

detection points to be located significant distances from the evaluator. This is

useful when using centralisedinterlocking equipment but less so when

signalling equipment is distributed at the lineside in equipment cabinets.Axle

Counter detects the presence of a train in any specified track section replacingthe existing DC track circuiting more advantageously for monitoring the

complete track section. The track section can be platform, point zone, yard and

block section. The system is highly reliable, easy to install and fail safe.

Electronic Junction Boxes at track side generate barrier signal of5KHzwhich

are fed to theRail Mounted TX & RX Coilsat Entry and Exit detection points

of section independently. When each wheel of the train passes over the

detection point, the carrier signal is modulated in the RX Coils. The modulatedsignal is sent over a cable to the Axle Counter. These signals are demodulated

and processed in the evaluator of the Axle Counter to generate"InCounts"and"Out Counts. The evaluator compares "In and Out Counts" and


4/34

drives two relays calledEVRandSUPR, in case of count equality at

supervisory levels becoming normal respectively.

The track section is shown as"Clear"when both relays are picked up.

Otherwise track section is shown as"Occupied. The supervisory relay isdriven only when all the functions of supervisory circuits are working normal

for each train movement. This ensures fail safety.

Based on the feedback from field, a new axle counter has been developed byRDSO, known as UNIVERSAL AXLE COUNTER.

NEED FOR AXLE COUNTERS:

The track circuits are considered as the vital components of signaling system toachieve safety of train operations. Various Accident Enquiry Committees have

recommended to bring more and more tracks under track circuiting to safeguard

against reception of trains on occupied lines. The track circuiting could not

achieve desired progress due to virtual scarcity of wooden sleepers, prohibitive

cost and environmental consciousness in the country and the world at large.Availability of concrete sleepers have solved the problem to some extent but

track circuiting on loop lines, points and crossings still suffers for want of

adequate supply and insertion of concrete sleepers.

ADVANTAGES:

The advantages of Axle Counter over a conventional track circuit are:

(i) It does not require wooden sleepers (where concrete sleepers are notavailable) except for short track circuits to suppress the counts due to

movement of insulated trolleys.(ii) An Axle Counter System can cover a very long section of upto 15 km

as compared to 750 mtrs. of maximum length of operation of

conventional track circuit.(iii) It does not get affected either by flooding of track or poor maintenance

of tracks unlike track circuits, which is highly susceptible to these

conditions.

(iv) It does not require insulating joints, thus, rails can be continuouslywelded. This reduces track maintenance cost, lower wear and tear of

tracks and vehicles and to increase traveling comfort.


5/34

APPLICATIONS:

Axle counters are finding more and more uses on modern safety signaling

systems in the railways. These are being used presently for the following

applications:

(i) Monitoring of berthing tracks in station areas and yards.(ii) Monitoring of point zones in station areas and yards.(iii) Automatic signaling systems.(iv) Block section monitoring (between stations) through axle counters

using multiplexers with cable or radio communication (18 GHz).

(v) Level crossing warning system.

Description:

It is an electronic device consisting of:-

1. A set of Track inductors fitted at the entrance of a track which counts inthe number of axle passing over them.

2. Another set of track inductors fitted at the exit of the track which countsout the number of axles passing over them.

3. An evaluator which registers counts in and counts out and clear theline, if two are equal and shows occupied if two counts are different.

4. The principle of counting axles is:a) The magnetic flux generates 5 KHz, current flowing in

transmitting coil induces voltage in the receiver coil. The coils are

fixed opposite to each other on either side of running rail. When a

wheel passes between these 2 coils, the magnetic flux path gets

distributed and the induced voltage in the receiver coil issubstantially reduced. (dip)


6/34

FLOW CHART FOR

MANUFACTURING OF AXLE

COUNTER

Fabrication Electronic Components

Raw MaterialsPCB

Rejected Accepted Rejected Accepted

Mechanical

Components

Rejected Accepted

WAVE SOLDERING

CLEANING

INSPECTION

INSPECTION

SHIPMENT

PAINTING

COMPONENT MOUNTING

INSPECTION

CABINET FABRICATION

MECHANICAL FITTING

INSPECTION

CARD TESTING

SYSTEM TESTING

REWORK

LAC UERING

CABINET WIRING

SYSTEM INTEGRATION


7/34

PRINCIPLE OF OPERATION

Signal aspect for train movement is controlled based on clear or occupied status

of the track section. If a train occupies the track section, signal at the entry pointof the section is made RED and the next train is stopped from entering into the

section. When the track section is clear the signal is made GREEN and the train

is allowed to proceed into the section.

The clear or occupied condition of the track section is decided by Axle Counterby counting the number of axles of train at entry and exit points of the section.

The axle counter compares the IN and OUT counts and in case of count equality

TRACK CLEAR signal is given. In all other conditions TRACK OCCUPIED

signal is given.

Signal Signal

R1 R2 Railway Track R3 R4

T1 T2 T3 T4Entry Point Track Section Exit Point

Signal Control

Relay Output

Cable

Cable

BLOCK DIAGRAM OF AXLE COUNTER INSTALLATION

E B 1 E B 2

EVALUATOR


8/34

BRIEF DESCRIPTION

The Axle Counter is an electronic device and the complete system consists of:

(i) Track mounting and trackside equipment.(ii) Transmission media between trackside equipment and central

evaluator.

(iii) Central evaluator with EV relays and SUP relays as its output.(iv) Reset box.(v) Line verification box.

Track mountings and track side equipments:

The track mounting equipment consists of a pair of transmitter and receiver

coils housed in specially designed housings, which are fixed to flange of a rail

section by means of suitable rail clamps using bolts and nuts. Each detectionpoint has two sets of such tracks devices mounted on same rail with a fixed

stagger between them. The two transmitter coils of a detection point areconnected in series to 5 kHz oscillators housed in electronic junction box which

is installed in a location box by the side of the track. The output of two receiver

coils of a detection point serve as inputs to two receivers amplifiers housed in

the same electronic junction box through cables which are part of the trackmounting equipment. Electronic junction box is powered by 24 V DC supply.

Transmission media between trackside equipment and central evaluator:

The connection between trackside equipment and central evaluator is madeusing balanced twin twisted quad cables of specification IRS: TC/41/90. The

output of electronic junction box and input of central evaluator are matched for

an impedance of about 180 ohms at 5 kHz. There is attenuation of signal from

electronic junction box to central evaluator, which limits the length of the cable.

Other media such as optic fiber and wireless system may also be used in place

of cable by incorporating appropriate interfacing equipment at transmitting and

receiving ends.


9/34

Central evaluator with EV relay and SUP relay as its output:

The signals received from electronic junction boxes are processed in the central

evaluator first by analog circuits and then by digital circuits to produce suitable

output in terms of picking up or dropping of EV and SUP relays. The Dipsgenerated by wheels as they pass over the track devices installed at detection

points, after they get processed, generate count pulses in a fail safe manner.

These pulses are identified as IN COUNTS or OUT COUNTS depending on

the direction of movement of vehicles over the monitored section. The counts

are also displayed through the 7-segment display on the front panel of the

evaluator. The display unit is useful in fault localization and initial and

periodical adjustments.

The evaluator is provided with its own power supply unit known as DC DC

converter mounted in the same rack and requires 24 V DC supply for itsoperation. The output of the EV and SUP relays is used to indicate TRACK

CLEARED or TRACK OCCUPIED conditions.

Reset Box:

This equipment is installed in the station masters room to enable resetting of

central evaluator in case of failure of system after observing prescribed

procedure. The reset unit consists of a RESET key (which gets actuated afterinserting, turning and pressing), the counter and 3 LED indications (Red,

Yellow and Green). This unit requires 24 V DC supply for its operation. This

unit functions in conjunction with the line verification box.

Line Verification Box:

This box is required to be kept near monitored track portion outside StationMasters (SM) office for achieving co-operative feature. This is a box consisting

of a lock with a key fixed inside. The lock gets actuated only when the key isinserted, turned and pressed. Whenever there is a failure of axle counter, SM

will depute his ASM/Switchman to verify whether the track section controlled

by axle counter is clear or not. ASM/Switchman after verification of the track, if

found clear, will report to SM who in turn will handover the key of line

verification box for operation.


10/34


11/34

The design of 4-D system is such that it can be converted into a 2-D system or a

3-D system and viceversa.

SPECIFICATIONS

Universal Axle Counter System mainly comprises of following equipments :

1. Rack, ACS-55/56/57 -- (Common type for all models) 1 No.

2. Evaluator -- EV542 / 543 / 544 1 No.

3. DC-DC converter -- (inside Evaluator only as 10th

Card) 1 No.

4. Electronic Junction -- for 2D system (ACS-55-2D) 2 Nos.box , JB-533 -- for 3D system (ACS-56-3D) 3 Nos.

-- for 4D system (ACS-57-4D) 4 Nos.

5. Reset box -- RB257B 1 No.

6. Track Device -- for a 2D system (ACS-55-2D) 2 Nos.

Assembly -- for a 3D system (ACS-56-3D) 3 Nos.

TR556 -- for a 4D system (ACS-57-4D) 4 Nos.

7. Line verification box -- LV261 1 No.

PARAMETER SPECIFICATIONS

1. No. of Detection PointsACS-55 / 56 / 57 2 / 3 / 4

2. Maximum Train Speed 200 kmph

3. Counting Capacity 1023

4. Max. Line Attenuation (over cable) 20 dB

5. Signal Input (5 KHz) sinusoidal Min. 150 mv.rmsMax. 1500 mv.rms

6. Relay Drive Voltage for 1000 ohmShelf type 4F / 4B relay or Q Style > 10 V

Plug in Relay 1000 ohm, 4F / 4B


12/34

Power Requirement :

Powers required by various units are as follows :

DCDC Converter 1.5 Amp max.24 V (-10% to +20%)

Evaluator 24 V 1.5 Amps

(21.628.8 V DC)

Junction Box 24 V < 250 mA

(21.628.8 V DC)

Reset Box 24 V 500 mA(21.628.8 V DC) (only when reset key is

pressed)

Environmental Conditions :

Relative Humidity 95 % - 98%

Non Condensing

Temperature range :

Universal Evaluator 0 to + 60 C

Junction Box & Track Devices 0 to + 70 C


13/34

PHYSICAL CHARACTERISTICS:

The approximate dimensions and weights of various units of Universal Axle

Counter are given as follows:

Name of UNIT WIDTH

(mm)

DEPTH

(mm)

HEIGHT

(mm)

WEIGHT

(kg)

RACK

SINGLE 570 650 1065 70

DOUBLE 600 650 1460 100

EVALUATOR 482 439 310 21

JUNCTION BOX 208 280 170 5

RESET BOX 255 175 115 2.3

TRACK DEVICE

ASSEMBLY

515 330 170 15

LINE

VERIFICATIONBOX

150 135 80 1.20

Colour:

The rack is painted in a combination of light and dark grey colours. Evaluator,

Junction box and Reset box are also painted in the same colour combination.

The track devices are painted in black colour.


14/34

IDENTIFICATION :

Rack :

The identification label of the rack is put at the left hand top on the front side ofthe rack with inscription.

a) For a 2D system Universal axle Counter, ACS 55 with EV 542Evaluator.

b) For a 3D Universal Axle Counter System, ACS 56 with EV 543Evaluator.

c) For a 4D Universal Axle Counter System, ACS 57 with EV - 544Evaluator.

The serial no. label is mounted on the right hand top side of the rack at the back.

Evaluator :

The label Evaluator, EV - 542, EV - 543 or EV - 544, for a 2D, 3D or a

4D system respectively is marked on the front side of the evaluator. The serial

no. label is on the back side.

Junction Box :

On the top (front) of the Junction Box the label JUNCTION BOX, (JB-533)

given whiles the serial no. label is on the back plate.

Reset Box:

The label RB 257B is given on the front side. The Sr. No. label is on the

back side.


15/34

Line Verification Box:

The label LINE VERIFICATION BOX, LV - 261 is put on the front side and

the Sr. No. label is on the right side cover.

Track Devices:

Labels indicating the Tx and Rx coil of the Track Devices are given on eachtrack transducer.

DCDC Converter:

It is the 10thCard Module inside the Evaluator and it is marked as POWERSUPPLY.


16/34

DESCRIPTION OF VARIOUS

MODULES OF AXLE COUNTER

SYSTEM:

1.EVALUATOR:The Evaluator consists of 10 PCB modules. The interconnections between

the various PCB cards are made with the help of a motherboard. The

polarization arrangement (to avoid wrong insertion of modules) is provided

on the aluminum modular sheets in each. Hence it is important to ensure

correct fitting of modular shield in each card. In the Universal Axle CounterSystem manufactured by Central Electronics Limited, relevant card number

has been number punched for easy identification to ensure correct fitting of

modular shields. A brief description of each P.C. assembly is given below.

(a) Attenuator/Amplifier & Rectifier Card (Card no. 1):This is a double sided PCB (Size: 225mm X 275mm). It contains four

identical channels , each comprising of a 5 kHz high pass filter , a line

matching transformer, attenuator pads, a two stage amplifier and a fullwave rectifier. The output of each channel can be set precisely by means of a

lockable shaft potentiometer mounted at the front end of the PCB module.

Typical output is 300 mv (P-P) or 105-mv rms.

(b) Attenuator/Amplifier & Rectifier Card (Card no. 2):This is a double sided PCB (Size: 225mm X 275mm). It contains four

identical channels , each comprising of a 5 kHz high pass filter , a line

matching transformer, attenuator pads, a two stage amplifier and a full

wave rectifier. The output of each channel can be set precisely by means of a

lockable shaft potentiometer mounted at the front end of the PCB module.

Typical output is 300 mv (P-P) or 105-mv rms.

For 1D and 2D Systems, there will be one such card (Card no. 1) while for

3D and 4D Systems, the evaluator will have two nos. of such cards (Card

nos. 1 & 2).


17/34

(c)Pulse Shaper Card (Card no. 3):This is a double sided PCB (Size: 225mm X 275mm). It contains four

identical channels, each consisting of a low pass filter, a Schmitt trigger, an

impulse time filter and a 10 V to 5 V level converter. The outputs of thesechannels are TTL compatible. In addition to above, each channel comprises

of a Trolley Suppression Circuit.

(d) Pulse Shaper Card (Card no. 4):This is a double sided PCB (Size: 225mm X 275mm). It contains four

identical channels, each consisting of a low pass filter, a Schmitt trigger, an

impulse time filter and a 10 V to 5 V level converter. The outputs of these

channels are TTL compatible. In addition to above, each channel comprisesof a Trolley Suppression Circuit.

For 1D and 2D Systems, there will be one such card (Card no. 3) while for

3D and 4D Systems, the evaluator will have two nos. of such cards (Cardnos. 3 & 4).

(e)LogicI (Card no. 5):This is a double sided PCB (Size: 225mm X 275mm). This card generatesIN COUNTS and OUT COUNTS, depending upon the direction of the

train movement, due to the dips caused form the track transducers E, F, G,

H. In addition to main count pulses, duplicate incount and outcount pulsesare also generated here for supervision purpose. The IN COUNT, OUT

COUNT, Duplicate In count and Duplicate Out count pulses are fed

separately to different combiner gates housed in card 6 (Logic II) and

thereafter fed to the counter card (Card 7) for further processing.

As E, F, G, H channel inputs are used only in case of 3D or 4D Systems,

card 5 will be used only with the 3D and 4D Evaluators.

(f)LogicII (Card no. 6):This is also a double sided PCB (Size: 225mm X 275mm). This card housesthe logic circuitry to generate IN COUNTS, OUT COUNTS,

DUPLICATE IN COUNTS and DUPLICATE OUT COUNTS due to the

dips caused from channel inputs from the track detection points A, B, C andD. It also has combiner gates, which combine the count pulses generated

from all the detection points AB, CD, EF and GH. The outputs of these gatesare fed to the counter card (Card no. 7) for counting and counts supervision.


18/34

Card 6 also has an INTERROGATOR circuit. This generates four clock

pulse trains. All these four pulse trains are staggered in phase, with each of

these pulse trains having a phase difference of 25 secs. As compared to the

subsequent one.

The interrogator ensures that even if more than one incount or more than oneoutcount are fed simultaneously from different detection point, the final

count pulses fed to the counter card get staggered and thus counts are not

missed.

In addition to above, this PCB also houses the IN/OUT supervision circuits,both counter checking each other. In case of any malfunction the system

latches to failure condition. This card also houses the 1st

outcount inhibit

circuit which ensures latching up of the system in the event of 1

st

countgetting registered being an OUT COUNT instead of an IN COUNT.

It consists of following features:

1. Low proving channel circuit: If one channel is kept low and thecomplementary channel is made pulsating, in counts can be registered

and EVR and SUPR will drop. If out counts are made equal to in counts,

EVR will pick up but SUPR will remain in drop condition.

2. Preparatory reset circuitry: After resetting both in counts and out countsreadings become zero. Only EVR will pick up, SUPR will remain in drop

condition. When pilot train will pass and equal in counts and out counts

are registered, SUPR will pick up.

3. One out count proving before reset with hard reset option: The systemwill get reset only when last registered count is an out count. Eleven

leds are also added to display the status of various signals as under:-

a) IOS 2b) IOS 1c) Clock 04d) Clock 03e) Clock 02f) Clock 01g) Duplicate out counth) Duplicate in counti) Out count

j) In count


19/34

(g) Counter Comparator (Card no.7):This is a double sided PCB (Size: 225mm X 275mm). This card houses two

10 stage digital counters. One for counting the IN COUNTS and the other

for OUT COUNTS. It also has count supervision circuits, both for incounts as well as the out counts, to check the integrity of the counters. In

addition, there are two comparators; one being a duplicate of the other, to

compare the counts from the two counters the IN COUNTER and the

OUT COUNTER.

The outputs of the comparators are further compared with EX-OR chain to

ensure integrity of the comparators.

(h)General Supervision Card (Card no. 8) :This is a double sided PCB (Size: 225mm X 275mm). It houses the

following evaluator circuits :

(i) Comparator Supervision.(ii) A series of monoshots forming a chain for static supervision i.e. to

prove the effectiveness of a number of DC levels of the system and

a few ground points.

(iii) Pulse Shaper (Card no. 3 and 4) supervision for all the eightchannels.

(iv) Failure Supervision.

(j)Relay Driver (Card no. 9) :This is a double sided PCB (Size: 225mm X 275mm) and it houses the

following circuits :

(i) Level detector circuits for all the 8 channel inputs to ensure thepresence of proper channel input levels.

(ii) The VOLTAGE MONITOR, which serves as, a WATCHDOG for the +5V power supply to the Evaluator.

(iii) Relay driver outputs for driving the EV relay and the supervisoryrelay.


20/34

(k)Counts Display Card :This is a double sided PCB (Size: 225mm X 275mm) containing four sevensegment LEDs for IN COUNTS and four seven segment LEDs for OUT

COUNTS and it can count upto 1023 counts in both the display. This card ismounted on front panel of evaluator and counts are recorded in decimal

system.

(l)EV & SUP Relay Indication LEDs :The output of the Evaluator is used to drive two 12 Volts DC, 4F/4B shelf

type relays or 12 Volts DC, Q-style 4F/4B plug-in relays which are used to

indicate the track clear or track occupied indications to control signal

aspects. Two 10 mm dia. LEDs (Green and Red) have been provided in the

front side of the Axle Counter Rack in a metallic strip for locally displayingthe position of the above relays. These LEDs have to be suitably wired at the

time of installation as per requirements from the terminal strip connections

provided at the rear side of the Axle Counter Rack.

(m) Mother Board :This is a double sided PCB (Size: 420 mm X 260 mm) mounted at the backof the Evaluator. The PCB is mounted at right angles to the other 10 PC

Cards and serves the purpose of providing various interconnections between

them. The female parts of the Euro Connectors are mounted on this PCB andcorresponding male parts which are mounted on the PCBs (Cards 1 to 10)

mate with them when the card modules are inserted in the unit. The mother

board also provides access, through MS Couplers, to feed various inputs like

channel inputs from the tracks, power supply and trolley protection and to

feed outputs to the EV and the Supervisory Relays kept in the rack.

(n)Reset Relay :This is mounted at the back of the Evaluator on the motherboard. A 67DP-

24-4C3 OEN Relay is mounted on this PCB with a mounting socket. This

Relay resets the System whenever required to do so.


21/34

Wheel dip

When a wheel passes between Tx and Rx coils, the magnetic flux path gets

distributed and induced voltage in the Rx coil reduces substantially. The drop in

the Rx coil output under the influence of wheel, rail profile, type of sleepers and

orientation of wheel in relation to transmitter and receiver coils.

Inadequate wheel dip:

In this type the signal does not fall fully, the axle counter system may miss

some counts. Hence it is undesirable.

Predominant double dip:

Where the signal falls to min. but as the wheels move further toward the centre

line of the track devices, the signal level rises again falls to min. second time

and then rises as the wheel moves further away from the track device. This typeof dip may cause extra counts.

Sharp single dip:

In this, the signal level falls to min. only when the wheel is over the centre lineof the track devices. In this position the system will count correctly.


22/34

ELECTRONIC JUNCTION BOX (EJB):

The Electronic Junction Box houses PCB modules which are inter-

connected through motherboard. All the incoming / outgoing signals areterminated on the MS Couplers (7 pin) mounted at the back of the junction

box. Two types of outputs are available from the EJB. The output of the EJBis sent to the Evaluator either through a 4 wire or a 2-wire system.

(a)4-Wire System :

In a 4-Wire System, two pairs of under ground cable are required to send

transition signal to evaluator for counting the dips. In this system there are

three PCBs consisting of common oscillator feeding to two transmitter coilsin series and two number of receiver amplifiers, one for each receiver coil.

The sequence of cards is, regulator and oscillator in first position, first

amplifier in 2nd

position and second amplifier in the 3rd

position from left to

right.

Detail of individual cards :

CARD No. 1 :

Regulator / Oscillator Card. (Size : 200 mm X 110 mm)

This is a single sided PCB (size : 200mm X 110 mm), which generates 5

KHz 20 Hz sinusoidal signal which is fed to the transmitter coils in series.

The output voltage is 60 V 10% (rms) and current supplied is 420 mA

10% in the coils in series.

CARD No. 2 :

Receiver Amplifier-1. (Size : 200 mm X 110 mm)

This is a single sided PCB of size same as that of card 1 and it rejects any

noise over riding in the signal by means of a two stage tuned amplifier. The

output of the receiver coil (1) is fed to the input of the amplifier. The output

of the amplifier is connected to the Evaluator and voltage is more than 1.2 V

(rms).


23/34

CARD No. 3 :

Receiver Amplifier-2. (Size : 200 mm X 110 mm)

This card is exactly similar to card no. 2 and is used for receiver coil(2).

(b) 2-Wire System :In 2-wire system, a 4

thcard is inserted in the EJB, which converts the

frequency of the second receiver amplifier signal to 3.5 KHz with the use of

converters. Thus, 2-wire system is having output on 2-wire and consists of 4

cards, namely the regulator / oscillator card, the receiver amplifier card-1,

the receiver amplifier card-2 and 4W / 2W card. This is used in block

working at Advance starters only.

The sequence of cards is :

(i) Regulator / Oscillator Card.(ii) Receiver Amplifier Card-1.(iii) Receiver Amplifier Card-2.(iv) 4W / 2W Converter Card.

Test setup:

Install a test setup consisting of two sets of standard transmitter and receiver

coils fixed on 90P/52kg/60kg rails and terminates the transmitter and receiver

coil cables to the terminal board. Connect EJB to be tested to the terminal boardthrough MS couplers, connect variable DC power supply to the EJB supply

point and test the cards as given below

Regulator DC output voltage:

Connect both the transmitter coils in series and feed 24V DC to the EJB. Check

the output on the test terminal provided on the card. It should be between 17.8V18.2V varying the DC input supply from 21.6V 28.8V, the output voltage

should remain constant.

Oscillator:

Measure the oscillator frequency, oscillator output voltage and circulating

current in the transmitter coils connected in series at the output of oscillator on

terminal board.


24/34

Tripping voltage:

Record the input DC level at which the oscillator output trips when the DC

voltage is applied at test points on the oscillator card directly to oscillator card

Install a test setup consisting of two sets of standard Transmitter and Receiver

coils fixed on 52kg or 60kg rails and terminate the transmitter and receiver coils

cables to the terminal board. Connect EJB to be tested to the terminal board

through M.S. couplers

Testing of card 2 and 3 (Receiver Amplifier) Tuned Frequency

test

Disconnect the receiver amplifier cards connection on terminal board. Feedsignal from function generator with sine wave at input of card 2 (amplifier 1)

with 180 ohms resistance connected to output terminal of amplifier card. Vary

the frequency and note the frequency at which the output is maximum. This is

the tuned frequency. Adjust the frequency on either side of tuned frequency at

which output falls to 0.707 of the value at tuned frequency (3dB value).

Test for saturation value

Vary the input signal through function generator at input of receiver amplitudeand measure the input (5 KHz) signal at which the maximum output is achieved

with no saturation at the matter of the second stage amplifier supply at 21.6VDC.

Gain test

Feed the input of 3V (p p), 5 KHz to the amplifier cards and measure the

output of receiver amplifiers

Current drain

Check and record the DC current drain of the junction box at 28.8V DC supply

voltage

The output of EJB acts as input to the Evaluator Box.


25/34

EJB Working Test:

Serial

No.

DC input to card

(V)

Regulated DC output

(17.8V to 18.2V)

1 21.6 17.96

2 24 17.95

3 28.8 17.94

Serial

No.

Current Drain at DC

28.8V DC

Limits Actual Measured

Value

1 Junction Box with 3 cards


26/34

2.RESET BOX :This box houses one 12 way PIRI terminal strip for terminating IN / OUT

signals. The indication LEDs of the reset box are fitted in LED holders and

projected to the front for indication. Green and Red indications are given fortrack clear and track occupied conditions. The Yellow LED indicates co-

operative permission for resetting the Axle Counter.

3.TRACK DEVICE ASSEMBLY :The Single Rail Track Device Assembly consists of two transmitter and two

receiver coils assembly, which are fitted with suitable mounting

arrangements on the rail camp, which in turn is fitted to the rails. The twotransmitter coils at each of the detection point are fed in series by a 5 KHz

sinusoidal signal from the junction box, which forms an electromagneticfield across the receiver coils. The receiver coil in turn generates induced

voltage. The induced voltage drops to a minimum whenever there is an axle

between the transmitter and the receiver coils.

(a) Track Device Transmitter :The transmitter coil is placed in a FRP housing and it is potted in place

by m-seal compound. It is fixed on the rail clamp on the outer side of

the rail. Each transmitter coil will be provided with a 10 meter, 24 / 0.2

PVC cable.

(b) Track Device Receiver:The receiver coil is housed in a composite aluminium fiber glasshousing and is potted in place by the means of an m-seal compound.

The receiver housing is fixed on the base clamp on the inner side of the

rail. Each receiver coil will be powered with a 10 meter, 24 / 0.2 PVC

cable.

4.POWER SUPPLY:The Power Supply, to the Evaluator is fed by a DCDC Convertor. Thevarious output voltage of the DCDC Convertor are as follows :


27/34


28/34

SPECIAL FEATURES

The Universal Axle Counter has the following special features :

PCB LAYOUT :

Better PCB layouts to have supply feeding and decoupling for better noise

immunity.

MOTHER BOARD:

The use of mother board gives extra noise immunity as compared to back panelwiring.

RACK:

The Evaluator is housed in a rack fabricated out of M.S. sheet. This gives goodnoise immunity against electromagnetic interference.

SHIELDING:

The Rack is well shielded for better noise immunity. All the metallic frames ofthe rack are interconnected to the main frame by means of 34 / 0.3 wire.

Shielded cables will be used in system, shield of which is connected to the back

panel of the Evaluator.

CARD INSERTION:

Each Card along with a module is guided separately.

CARD MODULES:

Each Card is provided with a module along with the identification label.


29/34

CARD POLARISATION:

Polarizing holes on the card modules and guiding pins from the Mother Board

side are used to provide card polarization to ensure correct card slotting.

MODULE TIGHTENING SCREWS AND CARD HANDLES :

Module tightening screws are provided to fix the cards along with the module in

the unit smoothly. By loosening, the cards can be removed from the unit. Two

card handles are provided on each module. The modules can be taken out with

the help of these handles.

COUNTS DISPLAY :

The Counts display is given on a PCB and mounted on the front panel inside

and is viewed through display viewing plate at the front panel of the Evaluator.

EVALUATOR MARKINGS :

In each unit input /output labels, the supply, channel markings and trolley

protection A / B, C / D are marked.


30/34

Colour Light Signal

The introduction of electric light bulbs made it possible to produce colour lightsignals which were bright enough to be seen during daylight, starting in 1904.

These at first were "short range" signals, used in low speed applications.

Improvements in signal glassware by Dr. Churchill ofCornell University in

conjunction with Corning Glass Works (Corning, New York) increased the

daylight viewing range to that of "medium range" signals. These were quickly

adopted by many U.S. rapid transit and trolley (street, light) railway systems.Ultimately, by 1913, Dr. Churchill developed the "doublet lens" combination

wherein an outer clear Fresnel lens was sealed with inwards facing ribs to an

inner glass of the desired colour with ribs facing the outer lens. Both inner andouter exposed surfaces were therefore smooth, avoiding dirt accumulation. The

inner lens convexity permitted a 35 watt, 10 volt lamp filament to be almost

surrounded by this system, gathering much more of the light produced than with

previous systems. This yielded the first true "Long Range" daylight signal witha range of over 2,500 feet (760 m) under bright sun conditions. The first

application was by the Chicago, Milwaukee, St. Paul and Pacific Railroad's use

of the US&S "Style L" colour light signal on their line through the Pacific

Northwest in 1914. These were intentionally fitted from the start with two

lamps one ahead of the other, the circuitry so arranged that failure of the mainlamp caused the lighting the back-up lamp to assure the most restrictive

indication always being illuminated. The final improvement came in the early

1920s with Corning's "High Transmission" glass colours increasing this range to

3,500 feet (1,100 m) under bright sun conditions. The results were that in the

U.S., all semaphore manufacturing had ceased by 1944, having been completelyreplaced with light signals of one type or another.

The signal head is the portion of a colour light signal which displays the

aspects. To display a larger number of indications, a single signal might have

multiple signal heads. Some systems used a single head coupled with auxiliarylights to modify the basic aspect.

Colour light signals come in two forms; both were developed in the first quarter

of the 20th century in the U.S. The most prevalent form is the multi-unittype,

with separate lights and lenses for each colour, in the manner of a traffic light.

Hoods and shields are generally provided to shade the lights from sunlight

which could cause false indications; coloured Fresnel lenses are used to focus

the beam, though reflectors are often not used, to prevent false indications fromreflected sunlight. The lights may be mounted vertically or in a triangle; usually

green is on top and red at the bottom. Signals with more than three aspects todisplay generally have multiple heads to display combinations of colours.
http://en.wikipedia.org/wiki/Light_bulbhttp://en.wikipedia.org/wiki/Cornell_Universityhttp://en.wikipedia.org/wiki/Corning_Glass_Workshttp://en.wikipedia.org/wiki/Rapid_transithttp://en.wikipedia.org/wiki/Fresnel_lenshttp://en.wikipedia.org/wiki/Incandescent_light_bulb#Filamenthttp://en.wikipedia.org/wiki/Chicago,_Milwaukee,_St._Paul_and_Pacific_Railroadhttp://en.wikipedia.org/wiki/Traffic_lighthttp://en.wikipedia.org/wiki/Traffic_lighthttp://en.wikipedia.org/wiki/Chicago,_Milwaukee,_St._Paul_and_Pacific_Railroadhttp://en.wikipedia.org/wiki/Incandescent_light_bulb#Filamenthttp://en.wikipedia.org/wiki/Fresnel_lenshttp://en.wikipedia.org/wiki/Rapid_transithttp://en.wikipedia.org/wiki/Corning_Glass_Workshttp://en.wikipedia.org/wiki/Cornell_Universityhttp://en.wikipedia.org/wiki/Light_bulb


31/34


32/34

searchlight mechanism, nor is it necessary. The marginal medium range aspect

of this signal is often somewhat compensated by the use of the illumination of

two red lamps simultaneously lit to improve visual range. Current consumption

of this arrangement would have been prohibitive during the 20th century, when

most signals were battery powered.

More recently, clusters ofLEDs have started to be used in place of the

incandescent lamps, reflectors and lenses. These use less power and have a

purported working life of ten years, but this may not in reality be the case.These are often arranged so that the same aperture is used for whichever colour

light is required, but again only for medium or short range use as the number

per colour of discrete LEDs is much less than found on high signals intended for

long range application.

Operating rules generally dictate that a dark signal be interpreted as giving the

most restrictive indication it can display (generally "stop" or "stop and

proceed"). Obviously this greatly impedes traffic until repairs are made.

Therefore many colour light systems have circuitry to detect failures in lamps or

mechanism, allowing the signal to compensate for the failure by displaying anaspect which, while more restrictive than that set by the dispatcher or signalling

equipment, still allows traffic to pass; for example, if a green lamp is burned

out, but the indication to be displayed is "clear", the signal can detect this and

display a cautionary aspect using a different lamp or lamps, allowing traffic to

proceed at reduced speeds without stopping.

In the UK, most filament-type colour light signals are equipped with lamps

having two filaments. When the main filament fails, the auxiliary filament

automatically comes into use. Failure of the main filament is indicated to thetechnician (but not the signalman), who will then arrange for the lamp to be

replaced. Failure of both filaments, resulting in a 'dark' signal, is indicated to the

signalman, inside the signal box; also, the previous signal may also be restricted

to no more than a yellow warning aspect.
http://en.wikipedia.org/wiki/Light-emitting_diodehttp://en.wikipedia.org/wiki/Light-emitting_diode


33/34


34/34

buffer first with a buffer stripping tool, and then remove the 5cm of 250umcoating.

6. Place the fusion splice protection sleeve. Put a fusion splice protectionsleeve onto the fiber being spliced.

7.

Clean the bare fiber. Carefully clean the stripped bare fiber with lint-freewipes soaked in isopropyl alcohol. After cleaning, prevent the fiber from

touching anything.

8. Fiber cleaving. With a high precision fiber cleaver, cleave the fiber to aspecified length according to your fusion splicers manual.

9. Prepare second fiber being spliced. Strip, clean and cleave the other fiberto be spliced.

10.Fusion splicing. Place both fibers in the fusion splicer and do the fusionsplice according to its manual.

11.Heat shrink the fusion splice protection sleeve. Slide the fusion spliceprotection sleeve on the joint and put it into the heat shrink oven, and pressthe heat button.

12.Place splice into splice tray. Carefully place the finished splice into thesplice tray and loop excess fiber around its guides. Ensure that the fibers

minimum bending radius is not compromised.13.Perform OTDR test. Perform a OTDR test of the splice and redo the splice

if necessary.

14.Close the splice tray. After all fibers have been spliced, carefully close thesplice tray and place it into the splice enclosure.

15.Bidirectional OTDR test (or power meter test). Test the splices with anOTDR or power meter from both directions.

16.Mount the splice enclosure. Close and mount the splice enclosure if allsplices meet the specifications.

Documents

New Report Training