How to fix flickering lights on a Pullman coach

[Skelton Junction]

Hi.

As the title says; a coach’s internal illuminations flicker when in motion and sometimes don’t work when stationary ( the others in the rake work fine).

I’m hoping it’s an easy fix, thank you in advance for your advice

Al.

[ntpntpntp]

Probably dirty wheels or intermittent pickups. Perhaps one of the springs is loose around the axle? Also check for bad wiring joints.

A better fix is to add a smoothing circuit with some power storage. Assuming Hornby don't fit something as part of the factory install? Typically a bridge rectifier (so it works in either direction of travel), feeding a capacitor and resistor charging circuit which then feeds the lights. so a bit like a DCC "stay-alive".

There are commercial units and home-brew designs for this purpose, or do an internet search for "flicker-free model railway coach lighting".

[P-Henny]

Assuming LED, then factory fitted lighting should already have a bridge rectifier for bi-directional operation. Probably a voltage regulator IC too, to give even brightness over a range of track voltages when operated on an Analogue layout.

As well as the obvious (already mentioned) i.e pick-up reliability. It should be easy enough to identify the output of the driver circuit feeding the LED lamps by tracing wires etc and put an Electroytic cap (if one doesn't already exist) across it to act as a stay alive. Or if one does exist, replace it with one with a higher uF value.

If there is a voltage regulator IC, I would expect it to give a 3v or 3.3v output. If this is the case any cap that is added doesn't have to be a high voltage rating to minimise size for maximum uF capacity.

The above is based upon what I have found inside my own factory lit coaches (00 scale not TT).

[Skelton Junction]

Crikey, the amount of dirt on the wheels was phenomenal, betweem cleaning them and ensuring the pickups were in contact seems to have provided a return to functionality.

Appreciated.

[ntpntpntp]

Crikey, the amount of dirt on the wheels was phenomenal

 

 

This is why in discussions about track cleaning I always stress that as well as the track it's equally important to clean ALL wheels on locos and rolling-stock regardless of whether or not they actually pick up power grinning

[Rallymatt]

I have noticed my MK1s pull up dirt and crud like nothing on earth! Although they are illuminated it’s via battery packs inside so no pickups involved. And on another note, the centre non driven axle of my Piko BR 130 is always the dirty one.