Blinking Mars Light on Atlas F3 Diesel

I think that was the Atlas attempt at a MARS light.  It should actually be a real MARS light, but I think that's the way it works.

thanks - that explains it - will be enjoying the engine - appreciate your help

If you'd like a real MARS light, there are excellent LED based simulators available.

I don't have an Atlas engine with a Mars light - but I just bought a Mars light board and LED from Dallee to install in one of my FP-7s (in S gauge).  These single LED systems are set up to mimic a Mars light as seen when standing in front of the train (at least up to the point of impact...) -- that is, you will see a variation in light from full intensity to lower intensity (as opposed to a 'blink', which is presumably on-off-on-off, etc.) to simulate the horizontal swing of the light from side to side. I'm guessing that is the way the Atlas light is set up.

Ngineering makes a similar, one LED device; they also have a three-LED headlight that actually mimics the side-to-side light swing by sequentially lighting the LEDs, which are mounted side-by-side-by-side horizontally.

- Rich

GRJ's right. It replicates the MARS lights found on certain prototypical diesels (and a few steamers), and is supposed to be on when the engine moves forward. It more or less pulsates rather than just blinks. These lights served as an additional warning of an appoaching train. Lionel and MTH also incorporate a similar MARs light on some of their engines.

The Ngineering single led board works great but needs DC to power it; same for the 3-led version but putting together the leds for it in the way suggested in the instructions requires a very high level of soldering skill (which I have not got). Ngineering sell a very small DC power source that can handle up to about 14 VAC input. There are other DC power modules that can handle AC input; GRJ makes a number of these.

3rd Rail used to use a “blinker” led circuit in their diesels equipped with Mars lights but now have adapted the Ngineering single led module. I expect Atlas just used a blinking led. Not very convincing when you’ve seen the real thing or the more prototypical lighting effect boards available. Lionel and MTH have put some very convincing Mars lights in some but not all of their models.

There was a Forum thread a while back about exactly when a Mars light was used and how by various railroads. Practice was not uniform but for many streamliner diesels the Mars light was at the front above the headlight and intended to alert oncoming traffic or any that crossed the track. Most 3rail O gauge diesels simply have the Mars light activated when in forward motion.

I used to ride the CA Zephyr to and from college, waaaay back in the day, and I'd ride in the dome car until the conductor would come and kick me out (back to my coach seat) - you'd see the beam from the Mars light swing from one side of the track to the other (just guessing, but once every few seconds).  So a one-LED light isn't going to mimic that 'swing' but you will see a variable light intensity output.

I have an Atlas-O Santa Fe Fairbanks-Morse Erie-Built diesel that has a simulated Mars light in the upper bezel.  On that locomotive Atlas used a dual LED that simulates the side to side action of the Mars oscillating headlight (which actually moved in a figure-8 pattern).  Atlas wired it so that it is operating anytime the headlight (which is in the lower bezel) is switched on.

I have the MTH NP F series and I have upgraded my Atlas CBQ F2/3 to PS3 as well. BTW I left the stock speaker in the Atlas.

Just for comparison here's what the mars light looks like under DCS

So I'm curious what the stock Atlas board's mars light looks like?

I don't remember as I yanked it right out to run on my layout under DCS.

I'll be darned. I made a video way back then! Doooh!

great ideas, explanations from all of you - appreciate the responses/help!

ted

The new Atlas F units I've seen imitate a Mars light pretty well. Sadly for a while some of the Lionel Legacy F units which should have been equipped with a Mars light were produced as just two headlights. (which is far less impressive then the Atlas units ;-) The Lionel set we have with the Mars light looks good. Saw the MTH Chicago Great Western F units from a few years back, strong mars light effect there too.

Hey Joe,  thanks for your often posted video clips of your equipment in these threads. Those MTH lights look great!

Joe - thanks for the videos -- I gather you did not change out the actual mars light, just swapping out the Atlas controller for the DCS?  I can't tell very well from the videos, but the Mars light does look like it swings from side to side - as opposed to simply periodically changing light intensity?

Here are some other O-scale MARS lights:

Top of picture is the prototype. (photo removed 8/18/19) You can see the side to side motion of the light. I was using it to set the timing of a 555 timer fade/throb LED circuit I breadboarded (bottom of picture).

555 circuit installed in a 90s Lionel PA-1

Lionel Legacy F3

 The best of the bunch is the Atlas Erie-builts using dual fade/throb bulbs to simulate the side to side motion.  The Ngineering product has a similar effect.

Bob

going from my poor memory here, I believe the MTH uses just one bulb/LED.

IIRC Williams had a really good Mars light effect in their E7's.