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Discussion Boards => HO => Topic started by: BaltoOhioRRfan on October 26, 2014, 04:45:13 PM

Title: 2-8-0 Wiring problem
Post by: BaltoOhioRRfan on October 26, 2014, 04:45:13 PM
I changed the headlight position on a 2-8-0 and am adding details to it for a specific road, and I'm not sure what happened but when i wired up the new LED light and all, it works if i apply power to the new wiring, but when I place it on the track the light doesn't work. I'm guessing there is a break in a wire somewhere and was going to hook up the headlight to the motor leads...will this cause any problems on DC operation?

Here is how she looks so far....she will not be C&O anymore.
(https://fbcdn-sphotos-f-a.akamaihd.net/hphotos-ak-xap1/v/t1.0-9/10382733_792147174142074_7783558615421357120_n.jpg?oh=16548f44da3e9865b400f7bb1e985864&oe=54EC61E3&__gda__=1421141311_4294ae45bc1d8d9e495974d4a54e10bd)
Title: Re: 2-8-0 Wiring problem
Post by: Joe Satnik on October 26, 2014, 05:27:23 PM
Hi, Beano.

DC block or DCC operation?

Does it light when you run in reverse?

Thanks.

Joe

Title: Re: 2-8-0 Wiring problem
Post by: BaltoOhioRRfan on October 26, 2014, 05:34:21 PM
It would be just plain DC for now. I'll have a pro rewire for DCC if i go that route.

It doesn't light at all, only when I directly apply power to the wiring hooked up to it. so i'm guessing the problem is a connection in the harness connections or the pcb connection.
Title: Re: 2-8-0 Wiring problem
Post by: BaltoOhioRRfan on October 27, 2014, 09:56:38 PM
Ok, new problem.

I isolated the problem to the plugs, so I hard wired to the PCB bored. I added two resistors in the tender on the headlight wires. Now it wont work unless I bypass one, is two resistors too much? I've got one on each side since I couldn't remember which side of the bulb was positive and negitive.
Title: Re: 2-8-0 Wiring problem
Post by: jonathan on October 28, 2014, 06:57:46 AM
Balto,

While it is normally recommended that the resistor be wired on the negative side, you can actually get away with it on the positive side.  You will need to bypass one of the resistors.

If you used two 1K ohm resistors, the light may be so dim that you can't see it, rather than it not working at all.

Regards,

Jonathan
Title: Re: 2-8-0 Wiring problem
Post by: BaltoOhioRRfan on October 28, 2014, 07:31:00 AM
Thanks jon, was hoping you would get in on this. I;ll remove one of the resistors tonight. They are 1.2 ohm per digitrax instructions. 
Title: Re: 2-8-0 Wiring problem
Post by: Irbricksceo on October 28, 2014, 11:37:07 AM
2.4Kohm? Thats a lot of resistance. yeah, use only one.
Title: Re: 2-8-0 Wiring problem
Post by: BaltoOhioRRfan on October 28, 2014, 08:47:27 PM
this dang thing keeps providing more questions then answers headlight would not work with a resistor, took it out, now the bulb appears to be burnt out.

my new question is....is it possible to destroy a resistor with too much heat?
Title: Re: 2-8-0 Wiring problem
Post by: BaltoOhioRRfan on October 28, 2014, 09:20:19 PM
Here is the resistors I'm using....i put in a new LED already, and if i attach a lead to the resistor and apply power the light is VERY VERY dim, looks like its off even. but if i move the lead to after the resistor, the light comes on.......i'll even add a photo on how i have the resistor soldered in

(https://fbcdn-sphotos-f-a.akamaihd.net/hphotos-ak-xpa1/v/t1.0-9/10731213_793109394045852_4160508958422489309_n.jpg?oh=f9e8fbec3aa45b80b34241c304108d28&oe=54DE39E6&__gda__=1421094750_7cc56cbc04fcda328bc80dd0ba532e7f)

are these too strong? Does the 2-8-0 already have some resistance built into the PCB bored?

(https://fbcdn-sphotos-h-a.akamaihd.net/hphotos-ak-xfp1/v/t1.0-9/1911892_793109390712519_8808175192263279221_n.jpg?oh=f60db46aa35418d0fefaffd78bb25b4c&oe=54F1B607&__gda__=1424759196_4f33964f47d757ebe76489e5f8c69b7a)

The light works if I place a lead in front of it(closer to the bulb) but if i place it behind it....nothing tho I did get it to come on extremely dimly
Title: Re: 2-8-0 Wiring problem
Post by: Doneldon on October 28, 2014, 11:54:20 PM
Quote from: BaltoOhioRRfan on October 28, 2014, 08:47:27 PM
my new question is....is it possible to destroy a resistor with too much heat?

Balto-

You can destroy anything with enough heat but that's not your problem. If you put 12 - 14 volts through your LED without
a resistor you burned it out for certain. You may have seen a short, very bright flash as the LED blew.
                                                                                                                                                      -- D
Title: Re: 2-8-0 Wiring problem
Post by: jonathan on October 30, 2014, 09:36:29 AM
Ballto,

Going back to your original post.  Are you insulating your wires after the headlight?  The frame halves are still live if I remember correctly.  You could be shorting the light if any of the wires to LED leads are toucing the metal frame halves.

Depending on the version of your 2-8-0, they came with standard bulbs and there should be no resistors on the PCB for the headlight.  Polarity is key here.  Try reversing the wires for the headlight.  The original wire leads are not color coded for + or -.  You will have to experiment a bit to figure out which lead is positive.  Just a couple of thoughts for you.

Regards,

Jonathan
Title: Re: 2-8-0 Wiring problem
Post by: BaltoOhioRRfan on October 30, 2014, 10:21:00 AM
I got her back together and headlight working. As for insulating jon I covered the weight with electrical tape and taped one wire in place on the shell covering it and letting the other float free.

Anyone want to guess the road name?(https://scontent-b-iad.xx.fbcdn.net/hphotos-xpf1/v/t1.0-0/s480x480/10653678_859372747429528_8773990396228642525_n.jpg?oh=5ecaa4ee10b6da193548c79c2be82756&oe=54F82029)
Title: Re: 2-8-0 Wiring problem
Post by: jonathan on October 30, 2014, 11:11:38 AM
Well,

Due to the F/W Heater on the smokebox, I would guess MA&PA.

Other Mid Atl/Northeast roads that used the heater: CB&Q, Erie, C&O (G-7 I think), New Haven and NYC.

Don't recall ever seeing one on a Beano.

Regards,

Jonathan
Title: Re: 2-8-0 Wiring problem
Post by: BaltoOhioRRfan on October 30, 2014, 12:06:41 PM
Quote from: jonathan on October 30, 2014, 11:11:38 AM
Well,

Due to the F/W Heater on the smokebox, I would guess MA&PA.

Other Mid Atl/Northeast roads that used the heater: CB&Q, Erie, C&O (G-7 I think), New Haven and NYC.

Don't recall ever seeing one on a Beano.

Regards,

Jonathan

I think I told you at the train show as well......but yep gonna be a Ma & Pa eather 42 or 43since I only see photos of 41 without the heater
Title: Re: 2-8-0 Wiring problem
Post by: jbrock27 on October 30, 2014, 12:11:56 PM
...they came with standard bulbs and there should be no resistors on the PCB for the headlight.  Polarity is key here.

I beg your pardon Jonathan, but if you are talking about incandecent bulbs ("lamps", right Roger? ;))   then why would polarity matter?
Title: Re: 2-8-0 Wiring problem
Post by: jonathan on October 30, 2014, 12:28:53 PM
Oh, I was referring to the switch from a "lamp" to an LED.  :)
Title: Re: 2-8-0 Wiring problem
Post by: jbrock27 on October 30, 2014, 05:28:39 PM
 :)

Got it, thank you J.  Sorry I misundertood which one you were referring to.  Yes, polarity is important to determine when you want the LED lit.

Do you steam guys usually have the headlight stay on when the loco is moving in reverse or do you set it up to go off?
Title: Re: 2-8-0 Wiring problem
Post by: jonathan on October 31, 2014, 06:28:28 AM
With conventional 'lamps' I use a zener diode so the reverse light only comes on in reverse.  With an LED, I just wire it with reverse polarity so the light only comes on in reverse.

Regards,

Jonathan
Title: Re: 2-8-0 Wiring problem
Post by: jbrock27 on October 31, 2014, 06:44:16 AM
Thank you Jonathan.  I did not know about the use of the zener diode.  Good tip.
Title: Re: 2-8-0 Wiring problem
Post by: Joe Satnik on October 31, 2014, 05:04:01 PM
Jonathan,

Why a Zener (as opposed to a regular diode with a higher PRV)?

What Zener voltage?

Joe
Title: Re: 2-8-0 Wiring problem
Post by: jonathan on November 01, 2014, 06:17:41 AM
Honestly I don't know the answers.  I get them at Radio Shack for 99 cents a pair. They're small and they work. That's my "why".   :)

Regards,

Jonathan
Title: Re: 2-8-0 Wiring problem
Post by: Joe Satnik on November 01, 2014, 11:32:56 AM
What Radio Shack part number?