A frequent, sometimes heated topic of debate is upgrading to LED lighting in the headlight of vintage American Flyer, Lionel, or Marx trains. It shows how sometimes a little knowledge can be a dangerous thing. You have several options for LEDs in old electric trains, and not all of them are expensive or difficult.
Specialty retailers like Town and Country Hobbies sell screw-in replacement LED bulbs with an E10 base for vintage trains. It’s also possible to wire up your own circuit. You can also take your chances on cheap 12V E10 LED bulbs from Ebay.
Advantages of LEDs
LEDs have several advantages when it comes to electric train applications. LEDs consume two watts less than a conventional bulb. That leaves two watts for other uses. If you have a headlight in your locomotive and lighted cars, all that wattage adds up fast. Converting to LEDs can let you get by with a smaller transformer.
The other advantage is that a properly wired LED will last a lifetime in this application. An undervolted bulb will too, but getting more brightness and a lifetime of use and lower wattage is a compelling combination.
Cheap and easy first: Random 12V E10 LEDs
The fights always start with someone talking about how they bought the cheapest 12V E10 LEDs they could find on Ebay and put them in their engines. Then the questions flood in about what they did to make the bulb work. The person who did it says they didn’t do anything to make it work, and the fight begins. Because everyone knows LEDs are DC and they don’t work on AC current.
Do LEDs work on AC?
Actually, only half that statement is correct. A little knowledge can be a dangerous thing. LEDs are indeed DC. But they still work on AC. Feeding them AC just reduces their life expectancy. How much it reduces their life expectancy depends on the LEDs, and the cheapest listing on Ebay isn’t going to give you the information you need to figure it out.
So it’s a crapshoot. If you feel lucky, buy it and see. Some hobbyists report they’ve gotten more than a year of service out of their LEDs. That’s a start. What’s important to note is that it can work, and the bulb doesn’t fail right away. If you want a cheap, plug-in-and-go solution, you can take a chance on these.
Improving your chances with 12V LEDs
The sad thing about these arguments, though, is that if you’re worried about it, it’s not super difficult to make the 12V LEDs work. Just find the circuit that supplies power to your headlight and add a diode to it. Even a cheap 1n4001 diode is overkill for this application. As a bonus, the diode will reduce the amount of power reaching the LED by about .7 volts. If you’re worried about overvolting your LED, since track power can run 14, 15 or even 18 volts, you can use a suitable number of diodes to reduce the voltage.
No matter how you do it, you can convert a lot of locomotives with $10 worth of diodes. And then you don’t have to worry about whether your random LEDs include the circuitry necessary for AC.
Rolling your own LED circuit
If you’re willing to do some wiring though, you can just make up your own LED circuit, wire it in however, position it in front of the lens, and leave out the bulb.
I’ve seen a lot of people overcomplicate this circuit, so let’s keep it simple. Connect a 1n4001 diode to the long leg of the LED with the arrow on the diode facing the LED. Connect an 820 ohm resistor anywhere in the circuit that’s convenient. Before the diode is fine. After the diode is fine. On the other leg of the LED is fine. The direction it faces doesn’t matter either.
That’s it. Buy the cheapest white 3mm LED you can find on Ebay, along with a supply of 1n4001 diodes and 820 ohm resistors, and you can make up as many LED circuits as you want or need. Warm white LEDs cost around 20 cents in quantity. 1n4001 diodes also cost about 20 cents in quantity. The resistors cost about 10 cents in quantity. So you should be able to build up 25 circuits for $12.50, not counting the cost of your solder.
Just connect a wire from the part of the circuit feeding the long leg of the diode to the pickup on the locomotive, and connect the other leg to ground. It’s an easy modification for anyone who knows how to solder, and it’s easy to undo if you ever want to return the locomotive to stock condition.
Using a prebuild LED
If you want a truly plug and play solution that doesn’t involve any modification or any questions, stores like Town and Country Hobbies sell screw-in LED bulbs with all the necessary circuitry to run on AC. They’re more expensive than the random Ebay sellers and you’ll pay shipping, but the cost has become much more reasonable in recent years as LED costs have come down. Town & Country’s warm white 1447 replacement is a suitable match for most American Flyer, Marx, and Lionel locomotives. If yours happens to have a bayonet base, use the 1445 replacement.