Lovely job.
I see with your onboard Capicitors there are some other bits in the wiring. Diodes and is there something else? Could you do a wiring schematic so that I can understand how the setup works. May be the solution to an itinerant Piko Kamel that I have.
JonD
This is the test version, you can see pretty much all there is to it. The two wires go in parallel with the motor. The capacitors are polarity sensitive, so there is one for each direction. The diodes protect them from reverse polarity.
I used a pair of 47,000uf capacitors since that was what I could get cheaply, but the effect would still be noticeable with less. A larger capacitance would give an even greater momentum effect, but you might need a current limiting resistor to stop the power supply being overloaded by the inrush current. A bonus feature is the intermittent high current draw when running over a piece of dirty wire makes some very realistic trolley pole sparks.
One thing I might try is having another set of capacitors connected in parallel across the power supply output as well. That way they would carry the momentary inrush currents and allow the on board capacitors to recharge faster in conditions where there is only intermittent contact. Needless to say all this high currents and arcing and stuff is not friendly to delicate electronics, so if you're using a loco with a sound module or something make sure it's well protected!
