Self-contained lighting system for passenger cars

A modeler named Jim Betz developed a flicker-free circuit that uses a modern "super capacitor" to store track power and compensate for poor electrical contact. The circuit works on both DC and DCC, although I have not personally tried it. More information is available here:

http://www.members.optusnet.com.au/nswm ... ree_JB.htm

A capacitor would give constant lighting on a DC system. But DCC uses an AC voltage, and a capacitor would act as a short.

What about if a bridge rectifier was put between the capacitor and the tracks? so that the capacitor was on the DC side and only got DC volts going to it, and then the lights were powered from there?

Hi All,

See my post earlier in this thread on first page. Re; full wave bridging recifier and capacitor and light bulbs.

Guys, did you actually look at the circuit diagram and info I linked to? Jim Betz's circuit does contain a bridge rectifier for that very purpose.

BTW, capacitors only act as a short in low-frequency AC situations, because there has to be enough time for it to charge. When a high-frequency AC signal is put through a capacitor, the effect is like an open circuit, since the pulses are too quick to pass much charge to the capacitor.

I always prefer a low tech approach that anybody could build which is easy to maintain.

I prefer an independent source of energy for lights that would not put any kind of a drain on the source for locomotive power. Since real trains have all kinds of connections between the cars which most models lack, what about connecting wires between the cars, with a common, cheap, easy to purchase and replace battery, concealed in the baggage car up front?

D/

But then you still need to replace the battery. I hate anything with batteries, and would much rather see it operate off track power to 1) save time 2) be easer to maintain.

I was thinking the same thing. a battery pac in a B unit, or baggage car. I would only use rechargables, maybe AAA or AA. I think you could solder wires to the battery contacts on one of those little wall chargers, and just plug a small mini plug into the end of the car to charge.
Many trains get all their power from the locomotives. I was on an Amtrak one time, when the car suddenly went dark, a couple minutes out of Washington DC. The conductor just happened to be a little ways down the aisle, taking tickets. He had a hand held radio, and he said "We just lost all train power. Stop the train". After a short conference with the engineer, he announced, "we are backing into the station for repairs". It was a broken power cable from the loco to the train. We must have backed up a good three miles. Took about 45 minutes to repair or replace the cord. By then, we were six hours behind schedule.

Question: When hooking up multiple LEDs, are they hooked up in series, or parallel? I've been an incandescent light bulb kind of guy, all my life. Trying to catch up.

LEDs can be done either way. If you do searches for LED calculators they can show you how to connect LEDs in series or parallel for things like, running a bunch of 3v leds, off a 12v power source, with no resistors involved. The following source is a good place to start.

http://www.theledlight.com/technical.html

I rarely see voltages mentioned with regard to LEDs. Just that you must use this or that resistor.

Just checked that site. Thanks so much. Pretty much answers everything.