LED recommendations

[Graeme Dunbar]

Have you considered a trying a latched hall effect device. I have used un-latched device for turntable index reference position quite succesefully.

Good thinking Phil!

I see one on Farnell has 20 mA open collector output which would be more than enough for a tail light and perhaps enough for low current carriage lighting in small 009 coaches. There must be many or at least several other similar devices that would do the job too. It could be smaller and neater than a reed switch too.

I've used them as sensors but not as to switch 'power'. There is a trick where they are set by momentary passing of a magnet and then reset after they have been read by turning the power off and on again, for e.g. train detection.