A Coach electrical system
This is a project for mainly the H0 and N scales. This interior lighting system produces constant light regardless of speed direction. Depending of what engine is used it is also possible to create lit bulbs while the train is standing still.
Bulbs L1-L3 should be low voltage types (1.5 – 2.0 volts) while R1 is 2 kohms and R2 is 22 ohms. Both transistors are preferrably BC 337. All 4 diodes are 1N4001 types or one rectifier bridge for 1 amp could be used.