Sorry about the late reply, thanks for all your help, it is greatfully appriciated, when I get the chance I will work on it.
Many years ago I used a constant voltage lighting circuit with a 1.5 volt bulb and a four diodes. It produces 1.4 volts DC. Never tried it with a LED which requires around three volts.
http://www.mrollins.com/constant2.html
Rich
If you ever fall over in public, pick yourself up and say “sorry it’s been a while since I inhabited a body.” And just walk away.
The old motor got power from somewhere, one side of the loco and the other side of the tender was a common way to do it. Those power sources are the feeds for your new motor.
A bulb could tap into those power feeds and you would be good to go. The LED is a bigger problem, because there is a polarity that must be observed. If the power is backwards, it will not light and may damage the LED over the long term. This was recently discussed in lighting passenger cars or cabeese, but since I do not run DC, I did not pay attention.
For DCC, a 1K resistor is plenty, and it does not matter to which lead of the led it is connected.
Henry
COB Potomac & Northern
Shenandoah Valley
There have been lots of modelers in here that have repowered their locos, even small ones like yours, and I'm sure someone will pick up on this and help out.
Is the Marx and DC now? I know nothing about them.
Mike.
My You Tube
Hi I've been wanting to retrofit a Marx HO 0-4-0 tender locomotive to have a modern DC electric motor, I have 6 I bought off amazon, by EUDAX they are 12 volts DC... I bought the train set for $40 off eBay, the motor in the set didn't work at all, it was a non runner.
I wanted to add a resistor and eventually and LED to the "running board", I have some ideas that I'd like to do to the engine, but that's for diffrent discussions on diffrent parts of these forum threads.
I have been having a hard time finiding the "right" wiring diagram to use for wiring up the locomotive... (I have been thinking about even using a diagram from the RC car industry, but so far I haven't been a whole lot successful) I'm not sure where else to look.
I am not sure a 10kohm resistor would work??? I don't really want to fry the resistor and the light. I have a variety of resistors to use that I got for $10 on Amazon, 0ohm to 1Mohm
Any help would be appriciated. I am a bit of a newbie in this. I am Not new to the Hobby, but new at wiring locomotives from scratch.