I’ve been wanting to upgrade the headlights in my HO Scale DC locos’s for while. I know there are ready to install kits out there but I want to do it all myself. I have Proto 2000’s (1) GP7’s & (3) GP9’s & (2) IHC Steam engines (1 Pacific & 1 Husdon) as well as (1) IHC GG1.
I the diesels I want install the bright Led’s & in the GG1 & Steam engines the not so bright type with the yellow tinge to them.
Anyone have any info for me, perhaps a parts list or model #'s to purchase led’s & such. If you have a scematic or wireing diagram for installing these that would be helpful too. Any how too’s or advice is welcome… Thanks in advance for the help!
Go to http://www.mouser.com/ and request their catalog. They are one of the best electronic parts houses around. For lighting clinchfield station or loy’s toy’s has a lot of bulbs and LEDs you can use . The problem with LED’s is that you’ll have to use two of them for one light or one of them with two sets of diodes per light and resistors which is going to be hard to get all of this into a locomotive shell. An LED allows the current to flow one way. Another solution is to use incandecent bulbs. they will stay lit no matter which way the locomotive is traveling.
The best solution is to go to a DCC system. That way you can instruct the decoder to run the bulbs any way you choose.
Here is a website that has some good simple electrical DC circuits in it
Just hook up a wire to each electrode on the LED. If it lights up in the wrong direction, just reverse the wires. Most people also use a resistor in the wiring circuit to lower the current going to the LED.
Unless the LED is put in series with the motor it HAS to have a resistor. I have seen a few LED’s that have built in resistors, but make certain that is what you have before installing it without one. With no resistor the diode will pass as much current as is possible, that is usually more than it can deal with and will burn out. An LED is not a light bulb and electrically does not behave as one.
Generically, 1K usually works ok. Lower it if it doesn’t light soon enough, raise it to make it last longer and/or make it dimmer.
I thought many of the units (P2K) you mentioned already had directional lighting (and resistors for 1.5V lighting). But when going from scratch, no, just reverse the LED leads to get it to light in the opposite direction.
Well you have a tinge bit of a problem. Actually several.
LEDs operate on a low voltage. You go over it you’ll burn them out PDQ. You can hook up a resistor for your maximum track voltage, but that means your lights will go out early if you go slow. You can use resistors, dropping diodes, voltage regulators, or full bridge rectifiers. The later two will allow you maintain a consistant voltage, but take up considerable space. This is why a lot of these electronics are stuffed into the tender.
As already said, LEDs are diodes, which means they work only one way. You reverse the polarity of the track you have a problem. (Again a full bridge rectifier will take care of this.)
Recently model manufacturers have become more apt to making their equipment DCC ready. So they installed dropping diodes/rectifiers to the headlight. So they can run at low voltage and high voltage without burning out the light. You would just need to add a little more resistance to the line to reach the proper voltage for the lamp.
I can send you the mathematics to calculating the proper resistor, but it can get complex. You’ll need to know the resistance across the LED, the LED operating voltage, and the original bulb voltage.
This one is for bulbs. To use it with LEDs, remove the top and bottom diodes, leaving four diodes. Wire the LEDs where the bulbs are. If the LED does not light up, switch the leads.
Resistor fed LED’s among other things grow brighter and dimmer with speed, and Voltage regulators require 5 v. to do their work.
Much simpler is a series pair of diodes feeding a parallel pair of 1.5 volt grain-of-rice bulbs in series with the motor. If you don’t know the difference in ‘parallel’ and ‘series’, buy a kit with black yellow, and white wires.
GOR bulbs fit in a Diesels twin-beam headlight holes, are the correct color, and are also constant brighness. Add a Shottky diode if you want directionality.
I don’t have any IHC engines, but Proto 2000 comes with 1.5 CV directional lighting.
If you are going non-DCC, aka DC, then this is the method I agree with the most. Its the simplest, but seriously impacts your loco’s ability to creep. The only true way to get around this involves some pretty serious tinkering with your power supply. My $0.02 is follow the KISS method and use the diodes or go with a battery operated setup (Yelch)