Anyone using capacitors to get their DC or DCC (non-sound) locos across switch gaps or over cheap track? I was curious as to the usability of a small capacitor that would give a second or so of (recent) track-level voltage to keep locos moving smoothly.... would provide some non-throttle based "inertia" to those of us still dinking around with "ancient" DC.... Crazy, right? Not something I'd likely put to use, but hey- curiosity killed the cat... not the 3am ponderous goof with a tumbler of iced, peaty 12-year. I recall a certain Kato/Atlas GP30 (now gone darnit) that would literally coast 1-5 inches (depending on speed) and for some odd reason, still light up the directional led's as well, on any DC source after power was cut. Never did figure that one out....
The capacitors used in DC locomotives are used to reduce electronic noise (static on the TV or radio). They don't contribute to the motor just reduce the spikes in the current. They are required by Japanese law. They are not large enough to store enough power turn the rotor even a fraction. Flywheels keep the motor spinning after the power is cut. Larger flywheels keep the motor spinning longer. The flywheel also slows the spin of the motor so a locomotive starts moving smoothly. EMD E series locomotives have the heaviest flywheels as they have so much space under the body. From full power to a break in the power I've had one travel five or six feet with a full passenger load. On the other hand the NW2 stops instantly after it crosses a power gap. Any electric motor will turn into a generator when the armature is spun by a force other than electricity. That's why the lights stay on after the power is cut. A capacitor on a DCC locomotive keeps the decoder powered while going over gaps or dirty spots in the track. The decoder is sensitive to breaks in power that the cheapest DC loco would ignore. Since the decoder actually controls the amount of power going to the motor any glitch would be like pulling and then quickly replugging your computer. The capacitor keeps enough power so the decoder can keep going through the micro gaps. Larger capacitors store more energy and so will bridge larger gaps. But the ones in N scale do not have enough power to keep the motor turning.
And that's all I needed to know! Well there goes my million dollar idea ; ) I'm gonna buy another of those GP30's, maybe in GN. I miss that loco, despite its Autobahn-capable top speed.... (that's for us car guys... trekkies might say "warp 9"?)
