Capacitor Installation

[RkyGriz]

Greetings all. I installed two sets of capacitors in my Jackson Sharp passenger cars one capacitor per LED lighting strip for a total of 2 in each car. I installed them by soldering wires to them and then soldering the wires to the +- terminals on the LED strips. I tested my connections with a 9 volt battery as I went along. Everything seemed to be working. The capacitors charged quickly and held a charge that kept the LED's lit for over a minute. Believing that everything was in order, I wired up the LED/capacitor assemblies to the wires on the trucks, put the cars on the tracks, and ran the train. The lights started flickering immediately and turned off the immediate second I turned off the power to the tracks. Before, when I used the battery to test the connections those LED's stayed lit. What went wrong? The tracks were thoroughly cleaned before I tried to operate the train, so I know that it wasn't caused by dirty tracks. Here's a link capacitors and the bridge rectifiers that I purchased on Ebay:
http://www.ebay.com/itm/381038554102?_trksid=p2060353.m2749.l2649&var=650359890389&ssPageName=STRK%3AMEBIDX%3AIT
http://www.ebay.com/itm/261422215574?_trksid=p2060353.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT
Also, I'm still unsure about how to wire the rectifiers into my wiring . Does anybody have a picture they could share on how it's done? I've found some schematics online but they don't make any sense to me.
Thanks!

[Joe Satnik]

RG,

Take the loco off the tracks (lit cars only on tracks) and try:

Forward power until the LEDs are satisfactorily bright, off (until the LEDs die),

Repeat for reverse power.

Let us know your results.

Thanks.

Sincerely,

Joe Satnik

[Joe Zullo]

The can type caps you probably used are polarity sensitive (the only work in one polarity). If you keep applying power in the wrong polarity they will blow up (literally). For track power and LEDs you need to have a bridge rectifier with the input from the track power and the output to the caps and LEDs. That way the polarity to the caps and LEDs is always in the correct polarity.

[RkyGriz]

I did as you asked , Joe, and the LED's remained lit after power was turned off to the track. They currently only work one-way, so reverse power had no effect on them. I then placed a loco on the tracks and it's obvious that the loco is draining the capacitors. But why? They're 25v 1000Uf. Is it that the storage capacity is too small for this application, or am I missing something? I'm still waiting for the bridge rectifiers, but I'm not sure how to rig them and at  this point I'm considering trashing the whole lighting project and just leaving the cars dark as I'm not willing to fork out a small fortune just to buy 9 volt batteries to keep these cars lit. I can recover some of my losses for the track power parts on Ebay. Either that, or I may reconvert them back to incandescent bulbs which , while they may still flicker, will at least work in both directions without having to add bridge rectifiers. At this point I''m still open to using LED's in my cars, but I'm also getting frustrated with LED's since they do not work in both directions without all of this extra trouble and expense.
Thanks Joe.

[tom p]

Much more is needed than just a capacitor. 1) the track polarity may change 1s a full bridge rectifier is needed. 2) the voltage will change on the track depending upon speed. I use 12 v strip leds, thus put a 12 volt regulator inline. 12 v LEDs will operate down to about 7v these are polarity sensitve also. 3)finally a smaller capacitor is put in line between the voltage regulator, be carefull about polarity. The diodes in the rectifier will stop any reverse current to the track.  I make these up using a cut piece of circut board with  linear traces. 4 holes wide and 6 long being sure to cut the approprate trace that between the bridge rectifer and capacitor.

[Joe Satnik]

RK,

Here's a simple forward and reverse circuit showing only one resistor and LED pair:

Left wheel pickups  ---->-- Bridge (~ac)

Right wheel pickups ---->-- Bridge (other ~ac)

Bridge (+) ----->---- (+) ------->----Resistor-->-- anode
                           Capacitor                                LED
Bridge (-) -----<----- (-) ------------<------------ cathode

Hope this helps.

Sincerely,

Joe Satnik

[RkyGriz]

Thanks Joe. I should be able to get this done. It seems to me that the locomotive itself is responsible for draining the capacitor of power. I thought that it might have somehow been associated with the power switch but now I'm thinking that it may be caused by my transformer as it's an older a Lionel 4060 transformer that was built in 1988 from The Gold Rush starter set. I think that it may be either 1 or 1.5 amps and perhaps that's not enough power to accommodate the locomotive and the lights in the passenger cars. What do you think: should I buy a different, more powerful transformer and if I do, will it stop the LED's from flickering? Or, do I need a different solution? Here's a video that I made last might of the train and its' problem:
https://youtu.be/g2NHBrHmvKA

[NarrowMinded]

You definitely. need diodes installed between the pickups and capacitors otherwise the capacitors will drain to the other electronics through the track.

NM-Jeff

[RkyGriz]

Thank you for the tip Jeff. Does it matter what kind of diodes are used or are they pretty generic?

[Joe Satnik]

Ken,

Re: Passenger Car Video.

How many wheels per car are picking up?

If you have good rail-to-wheel electrical contact on multiple points,

and good wheel-to-pickup electrical contact on multiple points,

your lights should not flicker at all.

Clean your track, clean your wheels, and fix your pickup wipers.

When that is complete, then improve your circuitry.   

However, until you get a properly wired diode or diode bridge

between your pickups and the electrolytic cap, do not run in reverse. 

(If your LEDs are lit under forward track power, you are safe.

i.e., you will not blow up the electrolytic capacitor.)

Hope this helps.

Sincerely,

Joe Satnik