Eliminating Flickering

[richg1998]

alloboard

     What type of capacitor would be recommended for purchasing and how will I wire and integrate it into the existing interior lighting?

You offered very little in exactly what you want to do.

Adding a capacitor is not as easy as you think it is or want it to be. DC or DCC layout, though probably the same components.

You definitely need a lot more electronic knowledge.

http://www.awrr.com/lighting.html

Commercial product.

http://www.dccconcepts.com/index_files/DCCflickerfree.htm

Store the links in Favorites.

Rich

[BroadwayLion]

LION uses 48 wheel pickup. Wheely!

 

[rrinker]

 That circuit needs a little more help, mainly with some small capacitors on the regulator to keep it from oscillating, and there needs to be a resistor to keep the super cap from having too much inrush and frying the regulator.

 On one of the DCC groups on Yahoo is a circuit by Mark Gurries that has a capacitor wired to provide light power to prevent flickering, and it is also wired with the approriate resistor and diode to prevent an inrush surge when the power is first applied.

 And then there is the mechanical best practices - pick up on all 8 wheels (or 12 if 6-wheel passenger trucks)  instead of just 2 wheels on the front truck and 2 wheels on the back. With 8 or 12 wheel pickup and track in decent shape, the lights shouldn't flicker, no extra parts needed.

                             --Randy

 

[BroadwayLion]

There was an article in the April issue of MRR (oh about 10 years ago or something) which will do what you want. I tried it but it did not do what I wanted. I wanted the lights to stay on in my cars while the train stopped in the station, which this circuit did not do.

 

HERE is the LION'S circuit for LEDs in the passenger cars.

1) A full wave rectifier is installed so that the DC provided always has the correct polarity regardless of which way the train is going. [All Electronics part number FWB-11]

2) A 5 V dc regulator is used so that only 5 volts reaches the circuit. This is necessary because the capacitor that I use is limited to 5 volts. [All Electronics part number 7805T]

3) 0.22 FARAD Super Capacitor goes across the circuit like a rechargeable battery. [All Electronics part number CBC-19]. Additional capacitors may be added for longer time.

4) 1/4W 510Ω Resistor (1 for each LED) [All Electronics part number 291-510]

5) LEDs... I buy mine at Menards, Wallmart etc also sell them as Christmas lights. pull the lamps out and throw away the wires. You can get yours elsewhere if you want to pay more. You can add as many lights as you need. I generally put 3 LEDs in each car.

 

BUYER BEWARE: I have not built "THIS" circuit. I have built a similar circuit with a smaller capacitor, and that will stop flicker, but will not keep the lights on for 30 seconds.

They used to have a 12 volt / 1 Farad capacitor, but those are no longer in stock. I did buy the ones indicated above, but have not installed them yet.

Maybe electronics experts can comment on my circuit.

BTW: Most Capacitors ARE DC devices, and not AC devices. There are several kinds for different applications. but mostly you can think of them as little batteries.

ROAR

[Texas Zepher]

alloboard

     What type of capacitor would be recommended for purchasing and how will I wire and integrate it into the existing interior lighting?

It depends if the system in question is using DC, DCC, DCS, AC, Railcommand, or some other tyhpe of power.    With straight DC or AC power, something will have to be added to block the electricity from running back out into the track and consequently into the locomotive.   With DCC, DCS, and railcommand type systems a capacitor put directly across the rails will degrade the digital signals, so some sort of separation and filtration has to be added. 

With the new LED lighting a stand alone battery in each lighted car is not a bad option.

For units that draw power from the track, I add a circuit that trickel charges a battery.  The battery is what powers the lights.  There are problems with a battery too because if left on too long they can overcharge.   Without an on-off switch these units can cause problems it they sit unpowered for long periods of time as the battery will totally discharge and take a while to bring back up to intended lumination levels. 

The simplest capacitor circuit is a full wave bridge rectifier with the AC side toward the track.  The lamp is connected to the DC side with the capacitor/battery is in parallel.  As an earlier poster noted a capacitor in this configuration will draw a lot of current on start up and can be interpreted by a command control system as a short circuit.  It is therefore a good idea to add a current limiting resistor.   I like to use 1.5V bulbs so the same resistor is used to limit current and provide ballast to the circuit.   If the resistor is put on the AC side the diodes do not have to do as much work, lengthing their life.   With LEDs the resistor has to be between the capacitor/battery and the LED.  

Tto answer your original question, we would have to know not only type of power but size and type of lighting that is flickering.

[hobo9941]

Just adding a simple capacitor on a DCC system will result in a short. Capacitors pass AC and block DC.

[simon1966]

It is not really just a case of adding a capacitor.   You really need to build a supply circuit.   The precise nature of that circuit will depend on the lighting that you are using, LED's or different current bulbs.   A google search for "flicker free lighting circuit for DCC" provide several web sites and sample circuits.  An example of such a link with a lot of good material is  http://www.dccconcepts.com/index_files/DCClightgeninfo1.htm  read up on the subject a bit and determine if you have the skills and tools to accomplish what you want to do.

[alloboard]

     What type of capacitor would be recommended for purchasing and how will I wire and integrate it into the existing interior lighting?