Hornby power rail - electrical what is it query

[john new]

Embarrassed to ask this but - I have just laid a circle of Hornby train set track to do some winter indoor testing. On the power feed rail there is a plastic clip over the copper power connections which some of the wheels were catching on and derailing*. I removed it as the quick fix to find a white electrical thingy underneath across the feeds.

 

Firstly what is it; secondly what does it do and thirdly, more seriously, on other layouts with standard, analogue wiring and lots of switched individual sections is it worth adding a whatever it is across the outputs from the controllers?

 

* the wagon in question brand new, first running session. Back to back to be checked.

Edited October 10, 2018 by john new

[Trains4U]

It’s a small capacitor

Similar to what you’ll find across the terminals of a loco motor.

 

It is supposed to help reduce TV interference (though I’m not sure if it makes any difference these days)

 

These can’t be used with digital. Which is why Hornby sell a “Digital” power track, which is the same as the standard one, but without the capacitor.

[john new]

It’s a small capacitor

Similar to what you’ll find across the terminals of a loco motor.

 

It is supposed to help reduce TV interference (though I’m not sure if it makes any difference these days)

 

These can’t be used with digital. Which is why Hornby sell a “Digital” power track, which is the same as the standard one, but without the capacitor.

 

Thank you.

 

A modern form of TV Suppressor had been my guess as on my collectable H Dublo 3 rail and some other old locomotives there is one wired across the brush leads etc., on the motors but they aren't there on modern one's. I will leave it on this but won't bother elsewhere unless I note any interference on our radio and TV etc. I don't normally use the power clip type set-up but this is a temporary rig so I can get everything out of the storage boxes, test it and see what needs repairs.