C1 4700uF 35V capacitor

C2 100nf ceramic capacitor

BR1 W10 package bridge rectifier

U1 LM78xx voltage regulator, value will determine DC output voltage

Q1,Q2 2N2222 NPN transistor or equivalent

R1,R2 10k resistor

The following components are only needed for the dim output in the reverse direction

VR1,VR2 10K trim pot, 3386 case

D2,D3 1N4007 diode

Assembly should be fairly self explanatory. The regulated DC portion of the board will work equally well on AC or DC track power and can be used as a standalone supply, and the board is marked for cutting if needed. For operation on DC track voltage, This circuit has outputs to drive LEDs at a constant voltage (depending on the choice of voltage regulator. I use 5V). It can also power small lamps, up to the current rating of the transistors used. There are two on/off outputs, one for each direction, and another two bright/dim outputs. If the dim output is not needed, the trim pots and diodes may be omitted. Either track power polarity or LED outputs may safely be swapped to reverse the direction of the outputs. I recommend installing pin headers for the connections, but wires can be soldered directly to the board if desired.