The output voltage for the TCS M1 headlamp function is 100mA. As others have suggested, a 1K ohm resistor for LED usage would be right. I recently replaced the DZ123 decoder that was in my trackmobile with TCS's M3 decoder and I used 1K ohm SMT resistors for the outputs with LED's and all works great.
TONY
"If we never take the time, how can we ever have the time." - Merovingian (Matrix Reloaded)
Depending on track voltage. Usually 12 to 16 volts. Cacole gave you the info that is most helpful. I also use a 1K 1/4 watt resistor for my LEDs. Here is as couple links to get you started.
http://www.members.optusnet.com.au/nswmn2/DCC.htm
http://www.wiringfordcc.com/intro2dcc.htm
Pete
I pray every day I break even, Cause I can really use the money!
I started with nothing and still have most of it left!
The function output on the blue wire is 12 Volts DC. For an LED headlight I use a 1,000 Ohm resistor in either of the leads (white or blue).
Also keep in mind that an LED is polarized so the blue wire must connect to the LED positive lead. If you don't know how to determine the polarity of an LED, there are on-line sources that explain it if you type a phrase such as 'LED Polarity' into Google or other search engine.
Here's the Wikipedia entry about LEDs and their polarity:
I'm currently installing a TCS M1 decoder in an N scale loco (Concor 4-8-4) and need to know the output voltage of this decoder's headlamp function and what would be a good LED/resistor combo for this application.I can handle DC but my electronic knowledge is quite limited.Thanks.