For any of you out there that would like to make an LED MARS light I have one that works very good.
I found a great LED 2mm clear white round top LED that works great through the lens of a 5mm LED.
The 2mm LEDs are flat sided and are easily glued together.
I don’t understand the reasoning behind using two LEDs. Real Gyralights and Mars Lights were just a single bulb, just each brand had it’s own method of rotating the bulb.
Mark.
Some did use a red emergency lamp that would automatically engage when the train went into emergency. UP, Santa Fe and maybe Burlington come to mind.
ATSF_mars by Edmund, on Flickr
Maybe Mel has one LED of each color?
Otherwise, I get great oscillating headlight effects with just about any of the better decoders and a single LED.
Regards, Ed
I placed the LEDs horizontal, both are clear. Using two alternating LEDs gives a very realistic looking sweeping effect as the locomotive rolls past scenery and on the track in front of the locomotive, much like the real locomotives I watched as a kid.
I filled the area where the small LEDs connect to the 5mm lens with Testors Clear Parts Cement & Window Maker so that I could paint the assembly black without dinging the forward light from the two smaller LEDs. I paint all of my Led headlights black behind the lens to prevent light splash on the track under the locomotives. It also prevents light splash through the locomotive cab windows.
I use the Single Row 1X40 & Dual Row 2X40 pin Socket Connector Strips for pretty much everything so that I do not need to solder directly to the LEDs. The connector strips have the standard electronic component spacing of .1” and the .02” diameter LED leads simply
So the two smaller LEDs are one white and one red ?
Mark.
Both of the 2mm LEDs are clear. They are glued together on a horizontal plane. In the MARS decoder configuration they alternate with a modulated pulse. The alternated pulse makes them look like a single light in motion. The light from the 5mm LED lens appears to sweep from left to right. The illumination from the MARS light on the scenery near the track also looks like a light sweeping from side to side as if it was a single light moving like the real thing. A single LED only flashes, it doesn’t look like it’s moving.
Mel
Modeling the early to mid 1950s SP in HO scale since 1951
My Model Railroad
http://melvineperry.blogspo
Do the two LEDs flash out of phase with each other ?
Mark.
Yes, The MARS and Gyralite DCC decoder function is an alternating output giving the LEDs a sweeping action.
Mel
Modeling the early to mid 1950s SP in HO scale since 1951
My Model Railroad
http://melvineperry.blogspot.com/
Bakersfield, California
I understand the functionality of each function / feature, I’m just having trouble wrapping my head around how you got each LED to flash out of phase with the other. Or, do they both actually flash the same together ? That would work well IF they are opposite phased to each other, but I’m not aware how you would do that. (?)
Mark.
Sounds like it works!
I’ll try it next time.
could you make a video of it working and show it to me/us?
Mark:
I don’t have experience with decoders other than MRC and Digitrax and both of those manufacturers MARS and Gyralite functions are as you describe it “opposite phased to each other” or as I refer to them as alternating.
Charles:
I tried making a video but I lack a lot in that department, I made several tries but the LEDs wash out and just look like a blob of light.
Mel
Modeling the early to mid 1950s SP in HO scale since 1951
M
Unfortunately then, your lack of experience is hampering your answer to my question.
To be out of phase with each other, each of the LEDs would be attached to their own function output. To be “out of phase” means one would ramp up and flash bright, then the other would. As one is ramping up, the other is flashing it’s bright pulse, then vice-versa.
I’m assuming then, based on your claim, this is not the case and both LEDs are connected to the same function output (?) and both pulse identical with each other.
Mark.
Mark:
You and I aren’t in sync. I’m using function F1 (Green) for one LED and function F2 (Violet) for the other LED. F1 call it the right LED ramps on as F2 left LED ramps off, then the process reverses. They alternate, slow on slow off creating a sweeping effect from left to right.
I’m trying to make a video but photography is not my thing.
Mel
Modeling the early to mid 1950s SP in HO scale since 1951
My Model Railroad
Ok - now I got it. Geeze, talk about brain freeze … must be the long week-end.
One last clarification … one is set as a Mars light and the other is set as a Gyralight ? I can see how that would work well with the larger lens helping to blend the two. Will have to try this …
Mark.
Ok I think I have a video, this is the best I could do.
I hope it works. I don’t see anything in preview.
If not here are a couple of links to my Google Drive.
https://drive.google.com/file/d/1BpyxY12gIfkm04Y_jRph5xdahu4MJ7Mb/view?usp=sharing
https://drive.google.com/file/d/1eNeaVDaz62aWw2OHf1pAWyKdJ8dEwFfJ/view?usp=sharing
Mel
Modeling the early to mid 1950s SP in HO scale since 1951
Mark:
I’ve tried it with one Gyralite and one MARS and that works too. It looks good using both on Gyralite but I happen to like it better in the MARS configuration.
Mel
Modeling the early to mid 1950s SP in HO scale since 1951
My Model Railroad
http://melvineperry.blogspot.com/
Bakersfield, California
I’m glad we got into it, I have been having sound programming problems and during my failure at photography my sound problems went away??? I had been changing the F1 & F2 settings around and something fixed my sound. I had wanted to turn off the accessory sounds, Air/Break sounds, and I had left the CV settings at 1 and now I can barely hear them.
Thanks Guys!!!
Mel
Modeling the early to mid 1950s SP in HO scale since 1951
My Model Railroad
http://melvineperry.blogspot.com/
Bakersfield
Thanks for the video !
To be honest, I’m really surprised they alternate like that. Not that I’ve ever had the need to have two functions both on Mars at the same time, I just assumed they would both flash together at the same rate. That’s pretty slick that they alternate like that !
Thanks for bearing with me …
Mark.
Many years ago before DCC I built up a MARS alternating flasher circuit for my diesels using a LM555 timer, by using the two outputs of the timer for alternating flash I use the ramp drive portion to drive a third LED and it looked better than the Decoder MARS outputs. One of the caps needed to be non polarized for the slow on off and a non polarized cap is huge and it was difficult to find enough room for it to fit. It’s much easier to use the Decoder circuit.
Mel
Modeling the early to mid 1950s SP in HO scale since 1951
My Model Railroad
http://melvineperry.blogspot.com/
Bakersfield, California
Mel,
You have shown us a very clever setup and the video is intriguing.
Could you show us a video of what the effect looks like when looking at an approaching engine? I think that would be the most convincing view.
Thanks!!