Older engine nib. From conversions to dcc on the internet no mention of changing the headlight bulb for an LED. Required or not to change. Probably less power consumption if I do
That depends on the decoder you would plan on installing into one. Some decoders come with built-in resistors for LEDs; others don't. I would always assume you would need to add resistors unless your decoder manual states otherwise.
Tom
https://tstage9.wixsite.com/nyc-modeling
Time...It marches on...without ever turning around to see if anyone is even keeping in step.
ndbprr Older engine nib. From conversions to dcc on the internet no mention of changing the headlight bulb for an LED. Required or not to change. Probably less power consumption if I do
The TCS website shows a conversion from DC to DCC using a T1 non-sound decoder. There is no mention of changing the factory installed incandescent bulbs for a different voltage incandescent bulb or an LED.
I very recently converted a Proto 2000 GP9 from DC to DCC, and in that case the instruction sheet specifically cautioned against using the factory installed incandescent bulbs and suggested replacement with 12 volt incandescent bulbs. Turned out, the DC lighting board only put out 1.5 volts after the rail pickup voltage passed through a series of resistors on the light board.
The Proto 2000 E7A instruction sheet doesn't mention anything about replacing the factory installed incandescent bulbs.
I would suggest that you use a voltmeter to test the amount of voltage on the output tabs on the DC lighting board. I need to do the same thing.
Rich
Alton Junction
richhotrainThe TCS website shows a conversion from DC to DCC using a T1 non-sound decoder. There is no mention of changing the factory installed incandescent bulbs for a different voltage incandescent bulb or an LED.
I was looking at that very same TCS page, Rich. I noticed that TCS did not opt for replacing the incandescent headlights that came with the E-unit for anything else. So that makes me wonder if those bulbs were 12V. And the how-to page also included optional TCS decoders MP4-1" and DP5 for the installation; both of which support 12V bulbs.
No, the bulbs are not 12V, but the decoder is reatinign the facotyr board, and that includes driving the circuit for the Mars light that flips between the two filaments. Usually you only have 7 wires in an 8 pin decoder socket - 2 track, 2 motor, headlight, rear light, and function vommon (bluw). the blank pin is what allows you to plug the decoder in backwards and not fry anything. But if you take one of the extra funtions na route it to the normally blank pin, it feeds power to the Mars light circuit on the P2K board.
As usual, with such things I remove the factory board. Actually, I just bypassed it -0 removed the palstic caps and soldered the wires to the decoder's wires, for the one I did. That way you just have to cut the wires and put them back in the lugs and put the plastic caps back on and the loco is exactly as it was out of the box. There is plenty of room back there under the shell. For a Mars light one, I would repalce it all and use an LED. A deocder that can run LEDs for functions, eith adding my own resistor or with one built in, can create a much more effective Mars light effect than that silly dual filament bulb - which is also not easy to get replacements for if it burns out. That's why the P2K factory board in those locos is so complex, with transistors in addition to the expected diodes for directional constant lights - the extra circuitry is an oscillator circuit to alternate between the two filaments in the Mars light bulb.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
Thanks for that detailed follow-up explanation, Randy. That answers the question of whether or not to replace the two factory installed incandescent bulbs.
If the incandescent bulbs are replaced with LEDs, any recommendations as to specifics. In other words, are there specific types of LEDs to be used? I assume resistors will be needed on the LEDs.
Rich,
On a few of my DCC conversations I hand-drilled out the back of the headlight lens 1/4" with a 0.116" (#32) drill bit. A 3mm LED bulb fits snuggly (press fits) into the hole so it doesn't need any glue. And it can be removed later in the event that it should ever burn out. A piece of black heatshrink over the base of the LED also helps to reduce the amount of light leakage in the cab area.
This link shows how I added a rear backup light to a Walthers SW1 switcher. I used the identical technique on the 5/32" OD styrene tubing. Perhaps it could be incorporated into an LED installation for the E7 if the tubing can be glued to the surface below the incandescent bulb pictured on the TCS installation page.
FWIW...
Tom, thanks for those tips on LED installations. The photos on that link that you furnished are very helpful, and your installation is clean and elegant.
I made an LED replacement for the Proto dual filament bulb.I chopped off the lens of a 3mm clear LED and attached two 1.8mm LEDs to the lens.My LED Mars light driven off a MRC decoder.
https://drive.google.com/file/d/1BpyxY12gIfkm04Y_jRph5xdahu4MJ7Mb/view?usp=sharing I couldn’t figure out how to post the video. Mel My Model Railroad http://melvineperry.blogspot.com/ Bakersfield, California I'm beginning to realize that aging is not for wimps.
This has been a very helpful discussion on what makes the Mars light work with the intended effect. I had not realized that it is a dual filament incandescent bulb that makes it work.
That is why I asked about the use of an LED to achieve the same Mars light effect. Does it require the use of a special type of LED to achieve this effect, or will a "standard" LED do?
rrinkerNo, the bulbs are not 12V, but the decoder is reatinign the facotyr board, and that includes driving the circuit for the Mars light that flips between the two filaments. Usually you only have 7 wires in an 8 pin decoder socket - 2 track, 2 motor, headlight, rear light, and function vommon (bluw). the blank pin is what allows you to plug the decoder in backwards and not fry anything. But if you take one of the extra funtions na route it to the normally blank pin, it feeds power to the Mars light circuit on the P2K board.
Just what I did to an P2K E6. There is a diagram on the Digitrax web site that shows which wire to relocate.
https://www.digitrax.com/tsd/KB894/proto-2000-e6e7-mars-light-installation/
Mike.
My You Tube
mbinsewi Just what I did to an P2K E6. There is a diagram on the Digitrax web site that shows which wire to relocate. https://www.digitrax.com/tsd/KB894/proto-2000-e6e7-mars-light-installation/
I haven't yet used my voltmeter to test the voltage output to the light tabs. Does anyone know with certainty the voltage of the two factory installed incandescent bulbs (i.e., Mars light and headlight) on these two types of locomotives (E6/E7)?
richhotrainThat is why I asked about the use of an LED to achieve the same Mars light effect. Does it require the use of a special type of LED to achieve this effect, or will a "standard" LED do?
I'm slowly working on an F7a&b set. I'm going to try using 2 peco or nano size prewired LEDs, and wire them to the ditch light function, and change what ever CV's are involved to make the lights alternate, hopefully giving me the mars light effect.
The F7 A has 2 headlight openings. The top will be the constant headlight, and the bottom will be the mars light effect.
The Digitrax decoder I'm using, which includes sound, has the instructions for wiring and setting CV's for the alternating ditch lights.
I have not tested the P2K bulbs for voltage.
richhotrain Does anyone know with certainty the voltage of the two factory installed incandescent bulbs (i.e., Mars light and headlight) on these two types of locomotives (E6/E7)? Rich
Does anyone know with certainty the voltage of the two factory installed incandescent bulbs (i.e., Mars light and headlight) on these two types of locomotives (E6/E7)?
I have a replacement Proto MARS bulb that I bought before Walthers and the package is marked 3.6 volts but it is very dim at 3.6 volts and looks correct at 6 volts at 40ma. Mel My Model Railroad http://melvineperry.blogspot.com/ Bakersfield, California I'm beginning to realize that aging is not for wimps.
A standard single LED will work as a repalcement, you don't need to use two. Most any decoder has a lighting option that flashes the attached LED in a pattern that looks like a Mars light.
Thanks for those replies, Mel and Randy.