Adding LED lights to older Bachmann plus dc locomotives Issue

[brokenrail]

Hello,
I have a question regarding LED lights.For starters I installed some white LED lights in my gp 30 with the proper resistor to make them directional after hard wiring the locomotive since it was a older split frame.They work well directional ,but the light that goes out on the back side of the engine will flicker.I did some research and found that I am missing a capacitor in the circuit to absorb the spikes generated by the motor and in time will blow the LED lights.Someone said to put a capacitor across the motor leads to absorb the spikes .Can anyone recommend the right type to use polarized ,non polarized ,???Thanks.
Johnny Adam

[jbrock27]

Depending on how much of a "flicker" could be caused by dirty wheels.  How are they?  If they are dirty and you need a method to clean them, just let me know.

[brokenrail]

Hello,
The wheels are clean and it runs like a Swiss watch.The pickups were all tuned ,adjusted and everything was wired and soldered in.The flickering is on the reverse light only either direction.So if it is going in reverse  the forward light flickers when it should be out.And when going in reverse the forward light flickers a bit and should be out.Thanks
Johnny Adam

[electrical whiz kid]

are you using this engine wired for a DCC module, or are you using this engine without having installed a DCC module?

Rich C.

[richardl]

Hello,
I have a question regarding LED lights.For starters I installed some white LED lights in my gp 30 with the proper resistor to make them directional after hard wiring the locomotive since it was a older split frame.They work well directional ,but the light that goes out on the back side of the engine will flicker.I did some research and found that I am missing a capacitor in the circuit to absorb the spikes generated by the motor and in time will blow the LED lights.Someone said to put a capacitor across the motor leads to absorb the spikes .Can anyone recommend the right type to use polarized ,non polarized ,???Thanks.
Johnny Adam

Show us the circuit you are using. Right now I am assuming this is strictly a DC loco operation with DC power pack.

I do remember the constant lighting using 1.5 volt bu;lbs many years ago but have not seen a circuit to do this with LED's which as you know have a little higher voltage requirement.

Rich

[jward]

if this is dcc keep in mind that capacitors stop dc and pass ac. the dcc waveform is a form of ac. bettter to use the function leads of the decoder for your lighting, as intended by the manufacturer of the decoder.

if this is a dc locomotive, use a non polarized capacitor. remember that, while you are only using one polarity to run your locomotive, you reverse that polarity every time you change direction.

[brokenrail]

It is a simple circuit of two - 3 mm Led lights .One for the front and 1 for the rear and ONE 800ohm 1/4 watt resistor that is all you need to make it work .The

led's take 3 volts to light.They reverse direction perfectly ,nice and bright.I am using DC .  I have seen in automotive applications on the air compressor magnetic

coil they use a capacitor to protect the sensative low voltage electronics from the voltage spike created when the coil is turned off and on ,but they do not reverse polarity in this 12 volt dc circuit like we do with our model trains in dc.I have noticed that Bachmann uses some type of capacitor on there new motors ,but looks can be deceiving
Johnny Adam.

[richardl]

Ok that sounds good. Does make sense. Reverse the polarity and the LED's switch on and off.
The only locos with caps on the motors I have seen are some the DCC ones.

Rich

[jbrock27]

The flickering is on the reverse light only either direction.So if it is going in reverse  the forward light flickers when it should be out.And when going in reverse the forward light flickers a bit and should be out.

Ok JA, this is a little different than what you first stated....

They work well directional ,but the light that goes out on the back side of the engine will flicker.

I have done the same as you just not with a split frame and run DC as you, and the only occasions I get an LED flickering in the opposite end than the direction of travel is when the wheels are dirty.  And it is also veerrrrrry brief and hardly noticeable if you were not looking directly at it.  It was, I believe Mr. Banner, who explained why this happens, some time ago in a post here.

So based on your response, that leaves checking your soldered connections, I believe.  No need for any CAPS; using the LED and proper resistors hooked up the correct legs of the Light Emitting Diode for the directions you want them to light in should work fine.  Any other electrical junk in between those 2 things?

[jbrock27]

...or, if not in between the LED and resistor, is anything in line with them?

[Len]

Here's a circuit for a basic directional light set up using LEDs. The capacitor is nonpolarized to deal with the polarity reversals when changing direction.



Len

[jonathan]

I've wondered if this question would ever come up again.  I posted about it in the past.  I have also read the explanation about motor spikes and dirty track/wheels causing the reverse light flicker.  I also have this flicker on my DC locomotives with LEDs installed.  Clean track and wheels will only go so far to alleviate the issue.

The capacitor sounds like a good idea.  I have not tried it yet.  Didn't even know there was such a thing as a non-polarized capacitor. 

Sounds like a future project.  Until then, I've learned to live with the flicker. I feel your pain, Johnny.

Does the schematic mean the capacitor goes on the common light wire?  I never could read those things. 

Regards,

Jonathan 

[Len]

it gets wired exactly as shown. The wires to the LEDs are as long as need to get them in the right locations for your loco. If that was an old style schematic, there would be big black dots where the wires cross or touch, indicating a connection.

Here's an example of a nonpolarized .5uf capacitor that will work fine for this circuit: http://www.amazon.com/CAPACITOR-POLYESTER-FILM-RADIAL-POLARIZED/dp/B007Z7JE6W Also available from many other sources, so you might want to shop around for the best price.

Len

[jbrock27]

Interesting, way back when, when I asked for direction here on directional lighting, I was told it was not necessary to use any thing other than the LEDs and appropriate strength resistor.  So that is what I have been doing w/o issue outside of the hardly noticeable "flicka" and again, only when the wheels are dirty.  Once clean, no issues.  And only one model, an SD9, does the flicka happen with any frequency.  Again, this is not a split frame loco; don't know if that makes any difference or why it even would.

And on 2nd thoughts, I think it was Joe Satnik who once explained the electrical reason(s) for the flicka effect.

[brokenrail]

Here's a circuit for a basic directional light set up using LEDs. The capacitor is nonpolarized to deal with the polarity reversals when changing direction.



Len

Thank you for sharing this.I have seen that the opposing LED  flicker will eventually blow the led and this has happened to me over time.