bantam blue comet LED project

I have a few questions with regards to the positions of the choke, CAP, resistor, basically which side.  see my diagram.  I have set things on the paper and labled the sides with corresponding color side.  The resistor has the yellow band/silver band.  The capacitor has the light blue line on the one side.  (see my indication) The choke is a silver band on one side.  I tried to line up from your diagram (john).  I circled something I am not clear with on your diagram too.  what is that? (pic 2)

The resistor and the choke have no polarity and go in either way.  The capacitor stripe goes to the negative side of the circuit.  The diode band faces away from the track feed, the + side of the power is developed on the banded end of the diode.  The anode (positive) side of the LED(s) faces the + side of the power supply.

john, you mentioned a diode.  is the flickering setup have one?  is that what I circled?

Anytime you have AC feeding the LED's, you should have a diode.  The diode is indeed what is circled.

I see now. I did purchase them thanks john! 

 in the diagram is the power going in the top wherebthe choke and diode is?  And the bottom is the outgoing. So connect the purple wire to the top feed in the circuit according to your diagram?  Thanks

Correct.  I just realized that you're driving this from the headlights, the circuit is designed to run from track power.  If you're running from the PS/2 headlight voltage, you can leave out the choke and diode, you just need a resistor of 150 ohms and the capacitor for filtering after the resistor in this case.  The resistor value changes because you have two LED's in parallel.  If you use all the parts, you can connect it directly to track voltage with the 470 ohm resistor.

oh yeah, ill test it.  its ready to attach hook up wires.  I will test it, it it goes ok, ill leave it alone.  Ill then coat the wires with liquid tape.  I hope the motor flywheel doesn't touch.  I think it will be ok, but until its all in there

ill hook it up and video the setup running and post it later.  wish me luck!  lol

You're not supposed to need luck for this kind of project!

https://www.youtube.com/watch?v=AAVZY9F0ynI&list=UU_lca3Q0uAVuf0skoq-2vnQ&feature=c4-overview

Eureka! It works!  hard to see in the video as you described at one time.  now packaging it into the boiler area.  a little bending and it will work ok. I coated all the wires thick with liquid tape. a nice product for this type of circuit.  I plan to coat the inside of the housing with liquid tape in the areas of contact too.  I think the rubbery coating will stick nice and prevent any rubbing or contact. 

  You're now the expert.

chriss, saw your post about the ca setting slowly.  I used to play with r/c airplanes and we had, and I still use, a product called kicker.  It makes ca glue set up in seconds and doesn't affect strength much.  used it a lot to fix planes in the field after crashes so the whole day wasn't ruined!  Thank you for the post, I gutted my blue comet for its electronics but after following your post I may modify it and put it back together.

one note it may turn some plastics hazy

I heard about that stuff, but I was not in any hurry.  it did cloud up the plastic that I used in the facing to attach the LED to, but it looks better clouded almost etched. thanks for the tip though if I need it to set fast, ill get some of that.  you mix it like an epoxy?  1:1?  chris

CA will cloud clear plastic, or any plastic for that matter.  The accelerant will really cloud plastic, I only made that mistake once!

It's the fumes from CA curing that cloud the plastic, I've had good luck around plastic by ventilation to disperse the fumes.  Nowadays, I use canopy glue if I'm working around windows or other finished plastic.

no better than epoxy, just super glue it like normal and then quick little spray of kicker and it sets right now!!  for a couple bucks saves a lot of time.  

well, im not sure what the heck is the issue, I taped the connections to prevent the shell contact, used wire ties to set things well together. 

Now, ok, turned the TIU on. no lights!  good,  turned on engine from remote, all is good, lights on.  Now moving, they flicker a little, like a loose wire or something simultaneously, so maybe the feed connections or something.  the lights are shakey.  thats what im saying.  not flashing.  ill youtube the video I took and post it.

Chris

Can you sketch out exactly how you wired them?

john, see here, I tapped the purple off that smoke unit lead, and the other off the headlight.  because when I tried both headlight sources, I got nothing unless I did not touch something correct.  Now, my other engines, there is a purple off that headlight and the blue comet is blue wires.  mmmmm. 

I bet my issues stem from voltage draw on that purple wire leading off the smoke unit.  until the smoke unit puffs, I bet that is the flickering, the chuffs, signal and the constant chuff when the engine stops.  I need another source of power I bet and it should be ok then.  your thoughts?  thanks

The purple lead to the smoke unit heater is the common for the headlight and the heater.  One of the headlight leads should be purple as well.  If that's not how it's wired, something is wrong.

are you able to blow up that pic above. I have 2 lightblue wires for the headlight leads and that purple one you can see is off the smoke unit. that's the ones I tapped. 

hmmm... 

here is the other thing:  I can move the engine on the track side to side a bit (shifting it) and the lights will go on and off. am I grounding out?  or maybe one of my wires is truly touching the shell still.  ill keep searching also.  maybe I missed one.

Chris

If moving the engine like that stationary causes flicker, I'd look for that cause!

As far as the wiring, I was looking at the upgrade kit colors, but the headlight shares a common with the heater on any standard PS/2 steamer wiring scheme.  Question:  Can you turn the headlight on and off from the remote? 

If you open up the engine and disconnect the tether, you can use a meter to find the common connection between the heater and the headlight wiring.

If you have any wire touching the shell, that can be a death-blow for PS/2 electronics, there is NO common DC ground to the frame like TMCC.

Chris, The Purple Positive voltage is generated off Diodes on the bottom of the PCB at the rear of the engine.  Motor power is used to create it.  Even of both wires are blue to your headlight, one traces back and merges with the purple.

The purple wire will have about 24VDC on it if track voltage is 18VAC.  If you return for you flicker is on the return for the headlight, than you have a resistance in parallel with the flicker circuit and your limiting the voltage to around 6V or less via PWM.  Maybe it won't run right on that.

Now why the lights flicker on and off (all of them?) when you move the engine, means your losing your AC input.  Do both pickup rollers have good continuity?  Wheels clean?  G

I guess my statement that they were common wasn't sufficient?

Nope,  Now he know where and how it is generated.  G

Ok simple, the one part of flickering led was touching she'll even though the liquid stuff was all around it. So, regular tape onto area and all is good.  Engine is good. see my YouTube channel . I'll link Saturday morn.

Great, and it's good you found it before you cooked something.

Whenever possible, I use heat-shrink on all connections.  I try to cover everything I can.

Yes, I thought the liquid would cover it, but, not doing that again alone.  I had shrink tube too, should have used it. 

 western maryland will be done different

My primary use for liquid tape is to secure LED lighting and block the back light from them inside the shell.  I don't count on it for heavy duty insulating.

Hi Chris,

Nice work detailing your Blue Comet 4-6-2. I have another suggestion for you. See the sketch.

hey thats a great idea!  ill have to look into that

For those insulating chores, I tend to use two layers of Kapton tape.  The adhesive on that tape will last a lot longer, it's also a lot thinner and will work anywhere electrical tape works.  I don't doubt the electrical tape serves the purpose, it's just that the adhesive on it doesn't seem to stand the test of time.

As you say, to each his own.