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Well, the costs for shipping of one resistor is pretty steep in comparison to the price of the part, I'll agree.   OTOH, I buy in bulk, so shipping is not a major part of the price.  I don't see any local places around me that have any assortment of electronic components, so it's either mail-order or nothing.

One way you can minimize the issue of going for "one" capacitor or resistor is to buy an assortment.  There are tons of resistor and capacitor assortments available for a few bucks, that gives you readily available parts in most common values.

. . . and therein lies the problem -- to solve almost *anything* electronic, it seems you need either ready access to retail-level components, *or* you need to start stocking up like you're about to open one of the (late, lamented) RS stores, with heaps of spare parts and a lot of salvaged scrap. Hey, I've already slid down enough rabbit holes after finding and resurrecting my childhood Marx train set's rolling stock -- I can't afford the cost of "saving more money" by stocking up on electronic components, too!

FWIW, that's what I find most valuable about these types of forums -- exchanging information, expertise and occasionally hardware with fellow hobbyists who've specialized in areas that you haven't.

Well, if you're only going to do a couple simple electronic projects a year, then buying as needed will probably work for you.  I need to have components available, and the cost is not that great, so I have them available.

Oh, I fully agree, John. However, the alternative 'solution' I've found works for me so far is to avoid mixing toy trains and electronics to the extent practicable, if at all possible!

It's not that I'm a Luddite in general -- I greatly appreciate and sometimes envy what progress has been made in our mutual hobby since we were kids (less so the price tag that usually attaches!), but I and a number of our like-minded fellow hobbyists have decided to employ "old school" solutions whenever practicable, but with the flexibility to employ modern gear when the spirit moves us. For instance, after first adding a pair of legacy Marx crossing gates and then a pair of Marx crossing warning flashers to my layout in the traditional fashion, I decided I wanted crossing bell sounds, too (to be honest, trying to impress the grandkids! ). So, I found a guy who puts together track voltage-powered train sound modules, and got him to do a custom pair of such modules with a crossing bell clip, powered in parallel to the crossing gate isolated rail. The mini-speakers I mounted under the layout in a couple of toilet paper tube section mini-enclosures, and the overall effect was just what I hoped for without appearing radically different from a typical layout 'back in the day'.

How about this "old-school" approach...no high-tech semiconductors required!

154 flasher low tech alternatives using AC relay

Place the xmas flasher bulb in series with a 12V AC-coil relay.  I figure a xmas bulb drops about 2V when "on."   So the 14V Accessory AC would be split 12V AC to the relay, and 2V AC to the flasher bulb and the relay would turn on when the flasher turns on.  Then the SPDT contacts of the relay would alternate power to the 154 bulbs.

OK, there are some details such as managing the voltage split between the relay coil and the bulb...but that could be fine-tuned by using one or more existing "regular" bulbs placed in series or parallel with the relay coil.

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  • 154 flasher low tech alternatives using AC relay

Stan, I think you're right on the money! As you say, you'd need to find a relay with a current draw compatible with the flasher bulb (otherwise, the flasher would promptly burn out or fail to heat properly, or the action of the relay might be impaired), but a couple of minutes of experimentation (as I did with the incandescent bulb) should tell the tale. Now, where can I find a cheap SPDT relay to play around with?

Goodness, eBay and many overseas vendors have tons of relays available for peanuts.   You just need to figure out roughly what specifications you need.

Well, I didn't make much progress searching eBay, but I did find a two-pack of 12 volt relays on Amazon: https://smile.amazon.com/Ulinc...ps%2C111&sr=8-28 Do you think this might work? It's a 12 VDC relay, but I see no reason why AC at track voltage (especially in series with a flasher bulb, as Stan's schematic shows) wouldn't work just as well, and the inclusion of a socket and leads with the relays would make installation a lot easier. I couldn't find anything in the specs about the amperage requirements for the relay's coil (to see if it's in range of what the flasher could handle), but I doubt it's excessive, and the amperage rating on the control circuits is *way* more than sufficient.

@Steve Tyler posted:

...

I did find a two-pack of 12 volt relays on Amazon: https://smile.amazon.com/Ulinc...ps%2C111&sr=8-28 Do you think this might work? It's a 12 VDC relay, but I see no reason why AC at track voltage (especially in series with a flasher bulb, as Stan's schematic shows) wouldn't work just as well, and the inclusion of a socket and leads with the relays would make installation a lot easier....

Applying 12V AC to a 12V DC-coil relay will chatter/buzz the relay contacts as the AC voltage switches polarity.

12V AC-coil relays are out there but harder to find.  Yeah, if you use the search term "12V AC relay" on Amazon, it thinks you're looking for an automotive Air Conditioner (AC) relay and you just go around in circles!

Here's a "genuine" 12V AC-coil relay on eBay, R10-5A10-12, but widely available such as DigiKey...and even available thru Walmart of all places!   You can socket it but that's another component.

12v ac relay socketable

Hmm.  The math is a little more involved than simply using coil resistance.  That is, resistance as measured by a multimeter is relevant for DC operation.  The datasheet for the AC coil relay doesn't even tell you the coil resistance and instead specifies 2VA (Volt-Amps) as coil power.  Cutting to the chase, the AC coil current when applying 12V AC would be 167mA (= 2VA / 12VAC).  It's that coil winding that mucks things up; in techno-speak we're dealing with Impedance instead of Resistance.  Gets pretty nerdy. OK, hold that thought.

Back to your 12V DC-coil Amazon relay.  I did not see the coil resistance either but found what appears to be a similar automotive relay that actually provides some useful parameters such as 80 Ohms coil resistance:

automotive relay

So applying 12V DC to the 80 Ohm coil, the DC current should be 150 mA (= 12V / 80 Ohms).

OK, so tying together the technical tidbits, the good news is we're at least on the same page as the operating currents are similar... albeit apples and oranges (i.e., AC vs. DC).  I'll address that later if anyone is still awake.

In any case, if trying to design the circuit, choose components, etc., we need to know the parameters of the flashing bulb.  I actually scrounged around and found some old incandescent xmas strings but no flashing bulbs.  However I found some bulbs I had extracted from a toy truck powered by 2 D-cells (i.e., 3V) that had flashing and fixed lights.  I'll use this as a proxy for your xmas flasher bulb.

flashing bulb from 3V toy truck

I can see now that trying to "crack open" a flasher bulb to fiddle with the bimetallic element would be a fool's errand.  Anyway, I got some DC measurements.  At 2V DC, current when on was 240mA (or 8.3 Ohms).  At 3V DC, current when on was 320mA (or 9.4 Ohms).  It would not flash below ~2V; I did not run it much more than 3V so as not to burn it out.  The key is one can get "useful" data with a meter measuring DC parameters because a bulb is not a coil.  The "fixed" bulb that are about the same brightness measured 120mA at 3V DC (or 25 Ohms).

So I see (at least) 2 directions you can take:

1. Stick with a "genuine" AC-coil relay.  Make some measurements on your flasher and fixed lamp bulbs with a meter to get their DC parameters.  Then do the math.  I think the numbers are in the ballpark such that you can balance the voltage split between the AC-coil relay and the flasher bulb by placing a few fixed-bulbs across the AC-coil...but I'm getting ahead of myself.  At $10+ for just the relay, I think this approach is kind of spendy.  But it would be "old-school" as a relay might be age-appropriate for a Marx era layout.

2. Try to get a DC-coil relay to work in an AC environment.  This is what I'd do as 12V DC-coil relays are widely available and inexpensive.  However, as I see it, you would need some 10-cent diodes which presumably violates the old-school approach?

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  • 12v ac relay socketable
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Last edited by stan2004

First off, what bulb are you using?  The bulb will determine what relay will work and what voltage you need to run at.  That's a very high power relay, I suspect it's coil current will be too much for most flasher bulbs.

Well, the flasher bulbs I have are all from one or another of the many mini-incandescent-bulb serial Christmas light sets we've had over the years,  most of them long gone. However, being a pack rat by nature, I've tended to keep the red-tinted flasher bulbs usually included with the spares for such sets, which can be substituted for any other bulb in the string to cause the whole string to flash. Since such strings had from 35 to 100 bulbs in series, I guesstimated that the flasher bulbs were rated to handle between a bit over one to about three volts. In an early experiment, I used first one and then two AAA batteries to light a flasher, so based on the brightness, I'd guess it was from a 35 or 50 light string.

What I came to realize, though, is that "voltage" is secondary to the amount of *current* flowing, which is a function of the overall resistance offered to the power supply. It's been more than a half century since I had to work precisely with Ohm's Law, but some of the basic relationships stayed with me, I guess.

In this case, the voltage is accessory or track AC, so say 10-15 volts. In my two-bulb experiment, the (low voltage rated, low resistance) flasher was placed in series with the (relatively high voltage rated, high resistance) other bulb, and as it turned out, the flasher did not add enough resistance to unacceptably dim the other bulb, and the other bulb added enough resistance to allocate enough of the voltage away from the flasher to prevent it from immediately burning out.

Frankly, I don't have enough information to reliably predict the result of running any relay in series with a flasher bulb, which is why I'm inclined to fall back on the "redneck" method -- just plug it in and see what happens! At worst, the flasher will go up like a flashbulb, or the relay will not reliably activate . . . or if Murphy is on vacation,, it might even work! 😉

While this is all fun and the like, it seems more like a snipe hunt than a useful exercise!  There are so many better ways to build a flasher, and $10 for the relay seems way out of line!

Well, no snipe hunt (as in, search for a non-existent creature, at the prompting, and to the vast amusement, of bystanders) was intended, just a request on my part for a simple, cheap, preferably old-school solution to a fellow hobbyist's desire to alternately flash two old-school small incandescent bulbs on a warning bar (similar to, or possibly salvaged from, an old crossing warning light set). Maybe I missed it, but so far I've seen no "better ways to build a flasher" proposed that didn't involve having a deep parts bin, considerable soldering and assembly experience, and/or a lot of cash, in some combination. Salvaging a pair of leftover Christmas light flashers and wiring them in series with the lights to be "blinked" so far seems by far the easiest and cheapest solution, albeit with much less than perfect alternation of the flashes. If there's any better solution, old school or not, well under ten bucks, I'm all ears . . .

Now, can I interest anyone in a used left-handed smoke shifter?

The flasher modules work on incandescent bulbs or leds.    I have 6 Marx signals and they work great.  They flash alternately and I was able to adjust the speed to what I felt comfortable with.  My modules can handle 4 signals or eight bulbs each.  I do understand the fun of building your own flasher, after all this is a hobby but for me plug and play was the best option

Do you have a meter that can measure current?  OK if it is DC current as you have a 3v DC battery.

I think it will be hard to find a cheap AC coil relay unless you get lucky at a swap meet or surplus store.

You are probably more likely to find a surplus or cheap 12v DC coil relay.  In which case add a few 10 cent diodes (one unique part) and I think it would work. I can elaborate if diodes are permitted.

Let the snipe hunt begin!

Here we have a 12V DC-coil relay driven by 4 diodes (i.e., a bridge rectfier).  The 3V flasher bulb I had lying around is performing the timing.  3 regular bulbs in a string are placed across the relay coil to balance the voltage splitting so the xmas flasher bulb gets enough current to do its thing.  Yes, it takes a few seconds to start the action when the flasher bulb first turns on (warms up).  This looks like a mess since I just used alligator-jumpers to connect everything but it's fairly simple.

Everything is powered by 14V AC.  The relay steers 14V AC to two bulbs in the upper left simulating the 154 bulbs.

By all means go spend $10, $15, $20 (plus shipping) or whatever for an assembled and tested flasher module.

But if snipe hunting is part and parcel of your enjoyment/amusement of our eclectic hobby, then here you go. 

Last edited by stan2004
@PLCProf posted:

If I were determined to stick with this idea, I think I would use 12 VDC relays and a 12 VDC wall wart and be done with it.

Agreed.  The xmas flasher bulb will flash equally well with AC or DC, doing its thing to interrupt/cycle the voltage to the relay.  The key point being a 12V DC relay is like a 50 cent or $1 part...and the wall-wart may be sitting in your attic or basement so that's "free."

Or.  If you have a source of 12V DC, then you could use a wig-wag automotive flasher relay discussed earlier in a linked thread.  But IIRC wig-wag automotive relays are maybe $10 or so...

Last edited by stan2004
@Steve Tyler posted:

Well, no snipe hunt (as in, search for a non-existent creature, at the prompting, and to the vast amusement, of bystanders) was intended, just a request on my part for a simple, cheap, preferably old-school solution to a fellow hobbyist's desire to alternately flash two old-school small incandescent bulbs on a warning bar (similar to, or possibly salvaged from, an old crossing warning light set). Maybe I missed it, but so far I've seen no "better ways to build a flasher" proposed that didn't involve having a deep parts bin, considerable soldering and assembly experience, and/or a lot of cash, in some combination. Salvaging a pair of leftover Christmas light flashers and wiring them in series with the lights to be "blinked" so far seems by far the easiest and cheapest solution, albeit with much less than perfect alternation of the flashes. If there's any better solution, old school or not, well under ten bucks, I'm all ears . . .

Now, can I interest anyone in a used left-handed smoke shifter?

Agreed whole heatedly.

There's nothing more frequent, on any thread on this forum, than the comment "in my opinion your wasting your time", or the insinuation of same.

Steve, I 'd like to thank you, profusely, for your original post, your comments above in summary, and especially for getting us to expend significant energy on something not that is not that terribly important, and perhaps more easily solved in a more modern way.

Yes it probably was a poor use of a limited resource -- but it was also a lot of fun.

Now where did I put my box of vacuum tubes?

Mike

Agreed whole heatedly.

There's nothing more frequent, on any thread on this forum, than the comment "in my opinion your wasting your time", or the insinuation of same.

Steve, I 'd like to thank you, profusely, for your original post, your comments above in summary, and especially for getting us to expend significant energy on something not that is not that terribly important, and perhaps more easily solved in a more modern way.

Yes it probably was a poor use of a limited resource -- but it was also a lot of fun.

Now where did I put my box of vacuum tubes?

Mike

Thanks for the sentiment, Mike, and I'll see your vacuum tubes and raise you a DIY relay! Well, at least the attempt . . . 20220620_220602

Not having anything remotely resembling a suitable relay, neither as a discrete part nor in something I'd be willing to sacrifice to the effort, I decided to go full old-school science project and wind my own (an homage of sorts to my paternal grandfather who, as an auto mechanic in the early 20th century, looked down his nose at mechanics who just *replaced* ailing generators, rather than *rewinding* them!). So, with a bolt secured through a paint stirrer and about twelve feet of the smallest diameter wire I had at hand wound around it, I made my very own electromagnet! Initial tests with a single AAA battery were promising, and the coil easily attracted steel strips and other items. However, when I connected the flasher and bulb in series with the coil, the magnetic field being generated dropped to the point that it was too weak to move a relay contact. *sigh* Obviously, more windings and thinner insulation (and probably a *much* better design (or designer)!) would be needed before any of the rest of the relay design issues could even be tackled.

"Sorry, sir, the snipe evaded capture yet again!" 😜

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@JohnActon posted:

Search  for  "Flasher Board" on ebay.  OR, search " 1X Compact Circuit Board Flasher to Flash Crossing Signal

Alternately"

FLASHER

Looks like an economical solution - $9 each including shipping for one, $15 for two.

A couple of observations / questions from someone who isn't an electronics guru:

1) Input says 3-12v DC.  If the crossing signal is initiated by an insulated track section (sends AC from the track), is it correct to assume that a relay and DC power source are also needed to provide the appropriate input voltage? 

2) Output is 3-12v DC to power LEDs.  If the signal has incandescent bulbs, what else needs to be added between the output terminals and the bulbs? 

@Steve Tyler posted:

Thanks for the sentiment, Mike, and I'll see your vacuum tubes and raise you a DIY relay! Well, at least the attempt . . .

Not having anything remotely resembling a suitable relay, neither as a discrete part nor in something I'd be willing to sacrifice to the effort, I decided to go full old-school science project and wind my own ( 😜

Well if you really want to build your own flasher, see the attached step-by-step instructions for building thermal time-delay relays. Just arrange one to control itself!

Easy!Relays ARelays BRelays C

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  • Relays A
  • Relays B
  • Relays C
@PLCProf posted:

Relays C

@PLCProf,

Excellent.  Thank you.

And what fine publication did this article come from?

(Why do I ask? Relevance, even this far into the future -- I like the "Long Tongs" in the second article, and then the technique described in the article on the last page, "Electric Switches Close Automatically",  was just mentioned in another thread here on the forum within the last few days.)

Mike

@PLCProf,

Excellent.  Thank you.

And what fine publication did this article come from?

(Why do I ask? Relevance, even this far into the future -- I like the "Long Tongs" in the second article, and then the technique described in the article on the last page, "Electric Switches Close Automatically",  was just mentioned in another thread here on the forum within the last few days.)

Mike

1952 edition of "The Boy Mechanic," by the publishers of Popular Mechanics.

*whew*

Boy, look away for a moment, and everything goes crazy!

First, my heart-felt thanks to all who took the time to consider my dilemma, and especially those who took the time to contribute and/or comment. I'm constantly amazed at the depth of expertise that's available and freely offered to others in our mutual hobby, even to and by those who are "rollin' on different rails"! I continue to be amazed at all the (sometimes *very*!) different ways our mutual hobby can be enjoyed, but if there's *anything* I've learned over the nearly seventy years I've been (on and off) "playing with trains", it's that there's really no wrong way to do it, as long as you're being sincere and tolerant of others.

Second, I'd like to try to summarize my takeaways from among the many suggestions offered:

- One option would be to purchase a pre-built flasher module, with such additional power source and control wiring as needed to alternately flash two lights (such as a crossing warning light set). The chief advantages are fidelity, providing a (sometimes adjustable-rate) true alternate flashing signal to the lights that activates almost immediately, and the fact that they are (at least somewhat) available off the shelf on-line. The downside is the cost (reportedly between $15-25 each, plus shipping).

- Another option is to build your own flasher system, using modules, circuit boards and/or components and one of several possible circuit designs. Again, fidelity is at least potentially an advantage, and depending on the state of your scrap bin, it may be cheaper (to a *lot* cheaper!) than the pre-built version. OTOH, not everyone has the skills to put all this together, and if everything has to be purchased retail, any cost advantage over pre-built can quickly diminish or vanish.

- A final option is some sort of old-school electro-mechanical lash-up, ranging from repurposing scrap relays (or purchasing or even building new versions), to what I settled on as my personal solution, repurposing old Christmas light flashers. The downside may be the time and effort needed to "roll your own", and in many cases the loss of fidelity due to the lack of true alternate flashing can be an issue.

So, here's a video of final solution to my quest in action, attached. In the final installation, the flasher board will be mounted on one side of a mobile crane, and my correspondent's salvaged light bar will be mounted on the other . . . assuming he doesn't come up with a better idea! The test video just temporarily simulated the salvaged light bar with a Marx crossing warning light set (we're both into legacy Marx stuff, if you couldn't tell!).

Having started this whole thread, I now declare this 'snipe hunt' officially at an end! Unless, of course, it ain't . . .

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20220621_230321
@Mallard4468 posted:

Looks like an economical solution - $9 each including shipping for one, $15 for two.

A couple of observations / questions from someone who isn't an electronics guru:

1) Input says 3-12v DC.  If the crossing signal is initiated by an insulated track section (sends AC from the track), is it correct to assume that a relay and DC power source are also needed to provide the appropriate input voltage?

2) Output is 3-12v DC to power LEDs.  If the signal has incandescent bulbs, what else needs to be added between the output terminals and the bulbs?

1) If DC power source is a wall-wart, simply connect the DC common to your track AC common.  Then, when a train wheel axle triggers the insulated track section, it will provide the DC common to the module.  Then you do not need a relay.

2) I found what appears to be the module on eBay but there is scant technical information on how much power is can control.  My guess is it is for LEDs (NOTincandescent bulbs).  A diagram:

Untitled


shows the addition of an external current-limiting resistor with a comment that you need to do so for higher DC voltages.  This implies there is/are on-board current-limiting resistors to allow direct LED hookup at lower DC voltages.  That tells me it would not work with high-current (relative to LED) incandescent bulbs.

So to use this specific module to drive bulbs, you would need to buffer/amplify the outputs.  It's not expensive ...maybe $2 in parts (plus shipping!) but means messing with tiny components (e.g., transistors, resistors) and probably firing up the soldering iron.  There are pre-built transistor buffer modules with screw-terminals and such but by the time you add up the costs you're better off with a previously discussed off-the-shelf or DIY solid-state flasher module that can directly drive incandescent bulbs.

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  • Untitled

It was Steve who suggested I try this, as (since RC went out of business) online flashers are a bit pricey, unless you want to shop overseas, and good luck with that. I had to paint the bulbs themselves flat black as to not have any unwanted illumination destroying the 'effect' of my lighting arrangement. As to the bridge lighting, I painted the bulbs red just below the red tips the bulbs came with. So now we have a new use for those old, unwanted Christmas lights.

I have quite a few of these 'insulated track sections' on my layout, that run a variety of accessories by both Marx and Lionel. I run mostly Marx legacy, but I do have a new Lionel 2-6-4 complete with circuit board, and have had no problems with either the locomotives, or the accessories. So, IMHO, I would say you're good to go.

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