3.3K is not out of line, especially with SMD LEDs going in somethign small like a marker where you definitely don't want it shinign out the back. I DO use 1K resistors for all standard headlights, but in my Steart AS-16 they were too bright so I added another 1K in series, and it's still PLENTY bright. Not sure why theyw ould be any difference that say my Proto Geeps, they have the same Miniatronics Yel-Glo LEDs (I replaced the orange Stewart ones), and both use TCS decoders, although the Geeps have T1s and the AS-16s have DP2X. Stewart must have better quality (optically more clear) light pipes going ot the headlights.
It's amazing how bright some LEDs are these days,. On the Yelo-Glo, a 1K resistor is about 10ma, right int he middle of the rating which is 20ma max. You'd think it might be slightly dim, but it's not. Still PLENTY bright even with 2K of resistence. 1K is SAFE at HO and N scale track voltages, but more may be needed in some situations.
-_Randy
Modeling the Reading Railroad in the 1950's
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locoi1sa If there is no reverse light in the tender then a T1 using the yellow wire and remapped to F1 would work. Wiring them to the headlight would disable the dimming feature of the decoder. Depending on the required voltage for the LEDs 3.3K resistors seem steep. My normal resistor value is 1K for LEDs. You can save yourself some wiring by running the markers in series with on resistor. Just my Pete
If there is no reverse light in the tender then a T1 using the yellow wire and remapped to F1 would work. Wiring them to the headlight would disable the dimming feature of the decoder. Depending on the required voltage for the LEDs 3.3K resistors seem steep. My normal resistor value is 1K for LEDs. You can save yourself some wiring by running the markers in series with on resistor.
Just my
Pete
At first I thought they were 1.5 volt led's after looking up the info on them they are 3.2-3.4V, So the VR1.5 is out of the question. Also I am using the rear light function on the decoder for the tender light. I think I will end up using the TX4 and use the purple ang green wires for the makers and map them so that they work on F1. There wont be any sound in this loco. And the reason for the 3.3K resistors is the gentelman in the link I got the idea from said he used I beleive 2.2K resistors and the markers were a little brite, and if he were to do it again he would use at least a 3K resistor. These led's are tiny, I need a magnifying glass just to see the solder tabs ,And I have 20/20 vision.
I don't think you want to use a VR1.5 decoder (voltage regulator) . It will only suppply 1.5 volts, and that will not light up any LED's that I know about. Most LED's require about 2.3 to 3 volts to make work.
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I started with nothing and still have most of it left!
I am installing marker lights on one of my Bachmann Decapods. I will be using the 0603 leds. Here is where I got the idea. http://schutzer.net/Markers/Marker_page1.htm I can not fit the circuit board set up he used in the boiler, NO ROOM. I am going to run wires to the tender. I have already swapt out the incondecent head lamp with a Miniatronics 12-625 surface mount yeloglow led. I originally had a TCS T1 decoder in this unit until the motor fried "locked up" and took out the decoder. TCS replaced the decoder no questions asked Nice guys. Any way I was wondering if I should use the T1 and add the markers to the headlight function, the markers will have a 3.3K resistor to each of them. Or I have a T4X and a VR1.5 decoder and regulator I could use. I have completly eliminated the circuit board in tender , but I will be using the tender to loco conectors that came on the units plus one more connector hidden in tender to run the marker light wires. So there is plenty of room in tender for all options. I was just wondering which would be the best way to go.
All opinions are welcomed. Thanks, Truck.