Tip: 4275 4276 4277 4278 Coach LED Lightingmembers.ozemail.com.au/~rossstew/rms/pdf/4275_4276... · 4276 2nd class, 2x 4277 2nd class coaches and 1x 4278 baggage car which will allow

Tip: 4275 4276 4277 4278 Coach LED Lighting Date: 24-10-2018

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Hi All,

All the coaches were manufactured over an eight year period 1991-1998. I have 2x 4275 1st class, 2x

4276 2nd

class, 2x 4277 2nd

class coaches and 1x 4278 baggage car which will allow me to make up a

seven car train.

The warm white LED lighting installed in the coaches is very even and controlled by an old 6080

decoder. If I have sparked your interest please read on.

4278 Baggage Car Lighting

The baggage car with LED lights on has the 6080 decoder with collector shoe and wheel contacts and is

the power source for the entire train of seven coaches.

The collector shoe and wheel contacts are mounted on the rear bogie. I used gel super glue to glue two

rolled IC pins as a socket to the coupling pocket. Please note that the coupling should be removed when

the glue is used to prevent gluing the coupling into the coupling socket.

The wires on the socket are protected with heat shrink tube. You will also notice I have protected the

wires from rubbing on the axle by gluing heat shrink tube close to the axle as shown yellow arrow. It is

most important that the axle doesn’t rub on the heat shrink tube causing drag to the coach. This method is

used for each coach.



4278 Baggage Car continued

Electronic Component Placement in the Baggage Car

On the left I drilled a 2mm hole through the

dividing panel (yellow arrow) and threaded the

wires from the collector shoe (black wire) and the

wheel contacts (brown wire). For the wires on the

right from the coupling socket the free ends will be

soldered onto the lighting PCB.

All wires from the decoder and diode bridge rectifier are soldered to a small interconnection Vero board

strip glued with hot melt glue as shown.

The 6080 decoder was set to address code #46. I removed the motor wires and the reversing coil centre

black wire. The assembled diode bridge and 470uF capacitor with two rolled IC pins for sockets for the

+plus (orange arrow) and negative (black arrow) supply as shown above were soldered to the LED

lighting Vero board see below.

Decoder Wiring Diagram

The two yellow wires from the decoder were soldered together for the F0 function which will operate in

the forward or reverse direction.

Wiring Diagram Baggage Car LED Lighting

Current Consumption for 7 Cars

The baggage car uses 6mA and each coach requires 13mA so the total current consumption for the train

is 84mA which is well within the capabilities of the 6080 decoder.

6080 F0

470uF

35V

Decoder

~ ~ 15Vdc

+Plus

-Neg

+Plus

-Neg

1k




The Vero board lighting strip 140 mm length only requires three warm white PLCC2 LED’s at a spacing

of approx. 63mm with the centre LED to be mounted in the centre of the car. The copper foils under the

LED’s have been cut using a 3mm drill. One 1k resistor is used for the current limiting of the LED’s and

on the foils +Plus and –Neg you can see the connection location for the wires to the capacitor and the

wires for the coupler socket connector.

There +Plus is linked across to the anode of the LED on the right hand side and all LED’s have the

cathode and anode orientation shown. The left end of the resistor is soldered to the cathode of the LED

and the other end of the resistor is soldered to the –Neg foil strip.

The reason the LED’s are mounted on the edge of the PCB is to try and maintain the centre line of the car

as the capacitor stands higher that the PCB.

I constructed two 17.5mm PCB stand offs from Vero board and soldered them in place to be a close fit on

the car divides (red arrows)

Note on the other cars I found it was easier to super glue the stand offs to the LED PCB.

Finally I held the LED PCB with stand offs with hot melt glue then soldered the wires from the capacitor

and coupler socket to the PCB

140

Wires to capacitor Wires to coupler socket

k a k a k a




Light Reflector/Diffuser 4278

The reflector is made from 80 GSM plain printing paper. I marked where the ribs that support the window

inserts from the curved part of the roof are and using scissors cut in from the edge 4mm.

Once all cuts have been made the reflectors can be inserted into the roof section of the coach without the

need for any glue. The window inserts support the paper and are a nice snug fit.

With the reflector/diffuser in place the car can now be clipped together once more.

180

34



Coach General Notes

The car on the left has a socket connection and the car on the right has the plug connector.

As a rule I arrange all the coaches in the order I want the train to be assembled. This allows me to decide

which end I want to have the electrical plug and socket and to make sure I get the +Plus side on the same

side for the entire train to make joining the coaches consistent.

The body shells of each type of coach are keyed and will only fit the chassis one way so it is essential to

get the orientation correct. I chose to get the white toilet windows facing me as I assembled the coaches

into the train formation. This allowed me to place the plug connector at the left end and the socket

connector on the right hand side of the coach.

The wires must have freedom of movement and heat shrink tube is used to support the wires which allow

movement as well, see red arrows.

Coupling Modifications

As the electrical cables pass underneath the couplings I removed the

portion of the uncoupler bar (marked in orange) at the location of the

red arrow using side cutters. This allows for easier connection of the

plug and socket but also allows you to still uncouple the coaches.



Coach General Notes continued

PCB for Power Supply and LED Lighting (typical)

Four PCB’s required for 4275 and 4276

Two PCB’s required for 4277

Six lighting strips total with the above dimensions are required. PCB photos are not to scale in this article.

Each LED is equally spaced about the centre of the lighting strip. Under each LED the copper foil has

been cut to allow a series circuit for each group of three LED’s see diagram below. See the (a) and (k)

orientation for the two groups of three LED’s.

The LED PCB is used to mount the PLCC2 warm white LED’s and to supply power through the coach.

The black arrow is the –Neg connection and the cathode of the LED’s at each end of the strip connects to

the 1k limiting resistor. The orange wire is the +plus supply. In the middle of the PCB (red arrow) there is

a small wire link between the +plus and the anodes of the two LED’s, refer to wiring diagram below.

Wiring Diagram Coach LED Lighting (typical)

+Plus

-Neg

1k 1k

220

200

a k a k a k k a k a k a




Light Reflector/Diffuser 2x 4275



The reflector is made from 80 GSM plain printing paper. I marked where the ribs that support the window

inserts from the curved part of the roof are and using scissors cut in from the edge 4mm.

Once all cuts have been made the reflectors can be inserted into the roof section of the coach without the

need for any glue. The window inserts support the paper and are a nice snug fit.

205

205

178

34

34

34




4275 Lighting Arrangement


For coaches 4275 and 4276 I drilled a 1.5mm hole under the seat at each end of the seat detail to allow the

wires to enter the toilet area so they would remain hidden from view.

I constructed two 17.5mm PCB stand offs from Vero board for each coach and super glued the stand offs

to the LED PCB at the locations shown.

In the center of the pcb I super glued a spacer which just rests on the top of the seat head rest.

Finally I held the LED PCB with stand offs with hot melt glue then soldered the wires from the plug and

socket connectors to the PCB.





For the coaches 4277 no hole is required as there is a slot under the seat at each end of the seat detail to

allow the wires to enter the toilet area so they would remain hidden from view.



What is the difference with and without reflector/diffuser

The photos below tell the story. You will notice I have the LED’s pointing up away from the coach

interior see pages 8-9. The LED light is reflected and diffused giving a very even light intensity through

out the coach.

4275 without reflector

4275 with reflector

The above two photos have the same camera exposure.



A Different Viewing Angle of all the Coaches

4275

4276

4277

4278

Other examples of coach lighting can be found under my Tips section.

As always enjoy your model trains.

Documents

Tip: 4275 4276 4277 4278 Coach LED Lightingmembers.ozemail.com.au/~rossstew/rms/pdf/4275_4276... · 4276 2nd class, 2x 4277 2nd class coaches and 1x 4278 baggage car which will allow