Hi Guys:
Here is an American Flyer question I have about controlling the track voltage at remote locations using a Flyer five-digit 350 watt (#22090) AC transformer. Let's say that I have one Flyer #22090 transformer to run several trains through multiple blocks. Is there a way that I can slow down and stop a train within a given block without disturbing the operation of other trains that are running off of the same #22090 in other blocks? Would it be safe to use a rheostat at a given block to do that? I'm thinking that the rheostat would then be turned up all the way to deliver whatever voltage is coming out of the #22090 when re-starting the train and driving it into the next block. It sounds simple enough but I don't know the physics of it all and don't know if that would be safe. I want to find some American Flyer way to do this and I don't want to use any modern technology from any other source. Rheostats were available in the '50's.
Thanks,
Timboy
That should work fine.
Bob Nelson
Thanks Bob! I think I finally have this worked out to have the kind of vintage Flyer layout I want with a small central command and some select remote areas I can put under local control briefly to perform an operation or two. I'll use the rotary dimmer switches available for household incandescent lighting. They will certainly be robust enough. I can get them for about $12 each from Leviton's. They also have a push-button on/off feature that will be very nice and it should be easy to work them into the landscape. Since most of my layout will be track running though wide open counrty-side, I'll only need 4, but I'll pick up a couple to dial in my two vibrating mat accessories from a dedicated accessory transformer and to regulate some overhead track lighting on it's own dedicated circuit as well. Even though I'll have a lot of running track, I'll only be running at the very, very most 3 trains at any one time, so a single high-wattage Flyer transformer dedicated to the track only should do the trick.
Thanks again,
Tim, those aren't rheostats! They're phase-control dimmers designed for 120 volts. I wouldn't expect them to work at toy-train voltages.
A rheostat is a variable resistor. They were commonly used with toy trains in the early days, particularly with batteries, which are of course not adjustable, but also with transformers. I know that prewar Lionel rheostats are easy to find and cheap ($5); so I would think that Flyer rheostats are also out there, although I've never noticed one. Would you consider using a Lionel if that's all you can find?
Oh! It's so hard to know the difference in those esoteric things. Prewar Lionel? Well, I hadn't planned on using any prewar items from any manufacturer, not even Chicago Flyer. I really do want to keep this a post-war Flyer-pure layout. Since rheostats existed in the 50's, I rationalized that I could use present-day ones, since I'm using present-day plywood, paint, screws, wire, etc. Are the ones that Radio Shack sells for volume control not engineered for toy train use? The period on my layout will be late 40's - early 50's. The top toy train manufacturers blurred the line somewhat back then. The early Flyer Log Loader is actually O-gauge sized. I won't be entirely closed-minded to using a prewar Lionel device, I would just like to avoid doing it if possible.
I think I understand what those dimmers do. They don't vary the voltage to a light bulb, they turn the voltage on/off extremely quicky so the bulb can't light up fully. No wonder they can't be used with flourescent fixtures! Maybe what I need to do is tear apart an old #8B Flyer transformer into it's primary and secondary coils and feed the track voltage through the secondary coil with it's wiper. I looked on eBay at some prewar Lionel rheostats and they are just as bulky; too bulky. Gotta be a better way...
The more I read from various Internet "how-to" sources, the more confused I get. Now I find out that there are at least TWO different ways that light dimmers work. The "old" style is a rotary wheel which actually IS a variable rheostat. The "new" style is the one that turns the current on/off extremely fast, tricking the light bulb. While the "old" style generates heat due to resistance, I'm thinking that it actually might work in my application.
Remember that you are trying to "dim" a much lower voltage (15 versus 120 volts) and a higher current (about 2 versus .5 amperes) than a light dimmer is intended for. So, if you could find a true rheostat meant for that purpose, it would probably have too high a resistance and too low a current rating for your purpose.
The biggest rheostat that Radio Shack sells is rated at 25 ohms, 3 watts. That's only about 350 milliamperes, which is way too little.
I looked up a few likely rheostats in the Mouser catalog; but they are all around $50. My (postwar) Flyer service manual doesn't show any rheostats, but that's not surprising.
Bob,
Okay. Thank you. I appreciate your thought and research on this. $50 per device IS too much. The bare minimum I would need would be four. The idea is local control of a loco when the transformer is on the other side of the room. Local control in my application means slowing the loco down, stopping it, reversing it's direction and backing it up at a reduced speed. What if I wired an appropriately rated resistor with two toggle switches. One toggle switch would direct the track voltage through the resistor, slowing the loco down - say by half. The other toggle switch would break the circuit, stopping the loco. That would enable me to cycle the reverse unit, then get the loco going in reverse at a reduced speed. The reduced speed is necessary to get it into a siding safely, without slamming it in at full speed. The Gilbert factory used a ceramic resistor in their "lockout eliminator", so that door was opened. All I would be doing would be to use a different resistor value.
Servoguy:
Hmmmmmmmm. Could be a good lead. Thanks! Worth checking into. My "fallback" plan is to establish 6 mini-control stations strategically placed around the layout - as though there was a club with 6 members running the layout; one member per mini-station. At first, I thought I would need 12 blocks to control this beast. Now I think I can cut that "club" down so that 6 blocks or 6 mini-stations would work nicely. I already have one mini-control station. Five more to go. Each station would have a #8B transformer controlling the train in that block. Advantage: train gets passed off to a "fresh" transformer when passing to another mini-control station. Disadvantage: voltage spikes could be a theoretical problem. My high-level quest is to have an all-Flyer vintage layout with a more dynamic control than was commonly achieved in the 50's, but using all 50's technology. Whew! Good luck to me! Fire extinguisher at the ready...
The toggle switch idea sounds like it would work. If you want, you could use a just one single-pole-double-throw-center-off switch. The fast and slow positions would be separated by the off position; but it's pretty easy to flip a toggle switch faster than the train can react. In any case, my impression of the way you plan to use it is that you would switch from fast to slow before the train arrives in the block, in which case the intermediate stop position is no problem at all.
Here's a possible resistor, Ohmite D100K25R. It's 25 ohms, 100 watts, and adjustable: http://www.ohmite.com/catalog/pdf/210_series.pdf It's in stock at Mouser, for about $17. Interestingly, it's nearly the same size as a Lionel rheostat, suggesting that we're in the right ballpark. The adjustment feature could save you a lot of trial and error.
I just checked the Skycraft website that Bruce mentioned; but I didn't see anything suitable.
Timboy, What you want to do is possible but difficult to do safely with what is available. Some of the old timers took the approach of assigning a transformer to an operator and using a rotary selector switch to connect that transformer to whichever block his train occupied. This way multiple operators could run their assigned train anywhere on the layout from a central location. The option suggested earlier of locating a transformer at each block and connecting it through a DPDT or SPDT switch will work . It provides the option of central or local control for these blocks. To your original question of a rheostat, there is a reason the old Lionel units would be large, they have to dissipate a lot of wattage as heat. For example an AF two motor PA unit plus some lighted passenger cars is likely at least 4 to 5 Amps. To be safe the rheostat would need to be rated close to 50 Watts, a very large unit when air cooled. The HO guys can use much smaller rheostats since they need only around 10 Watts.
The resistors in the AF lockout eliminators could be much smaller since the were basically just passing enough current to keep the e-unit from cycling, not run the train
If you decide to use the switches there are three styles in both SPDT and DPDT. First is the three position center off style. Then there are two position switches that are either "make before break" or "break before make." I would use the center off style.
Tom
Guys: Thanks to all for the contributions to this thread! I believe we have at least two possible work-arounds to my dilemma and they both involve the use of a master transformer of high wattage to initiate trains running around the layout. For local control of the trains: 1) use of toggle switches and a resistor to slow a train down and cycle the reverse unit in a given block and 2) use of a toggle switch to cut out the master transformer and insert a local transformer to control the train once it is in the block. I believe that both will work well and both are safe approaches. If I have the space to build mini control areas at various key locations, then I believe I'll go for the #2 approach. I'll further refine that approach by also having a dedicated household circuit around the underside of the layout and use a simple on/off switch for the local transformer. No need to have it on all the time when it's not in use. But when it is on, the toggle switches will re-route the track circuit there as outlined above when needed. Only concern here is, should I also have the local transformers phased with the master transformer and just use an insulated gap on the variable voltage rail (keeping the base post rails contiguous) - or should I keep the local transformers out of the loop completely and use insulated gaps to break both rails? Keep in mind that the local transformers will only come into play once the train is in the selected block and I decide to park it there to perform some RR function.
For what it's worth, I had good results using some old Lionel rheostats to vary the speed from flat to a climb uphill, another flat raised run, and then back down again. There are 4 blocks on this layout. Track is just the O27 3-rail. I mostly run a newer Williams engine on this layouut with no problems. On Bob Nelson's advice, there is also virtue in not having the train cross from one block to another run by a different transformer.
The rheostats are easy to hide under the table, so no one even sees what I am using. I like them because they are cheap, pretty simple, and effective. Bob Nelson and others suggested using a series of resistors too, but these simple rheostats allow me to fine tune the blocks pretty easily. These old Lionel rheostats are so cheap that you might experiment with a couple first to see what you think.
jjm: You make a worthy argument for their use. Thanks!
Guys: Is this rheostat too heavy?
http://cgi.ebay.com/150-Watt-Ohmite-Rheostat-Ceramic-Model-L-350-Ohm-NIB-/160460950564?cmd=ViewItem&pt=LH_DefaultDomain_0&hash=item255c37cc24
There doesn' seem to be any shortage on eBay!
I'm still confused over how many ohms and watts a rheostat should be for my use with a 300 watt transformer, capable of delivering up to +-18 volts, with up to three Flyer open-frame motors and reverse unit coils drawing.
There are several Lionel rheostats on eBay right now, but unless I missed something, I can't find any specs on them listed. Here they are:
http://cgi.ebay.com/VINTAGE-LIONEL-TRAIN-RHEOSTAT-NO-81-88-LOT-2-/400133270567?cmd=ViewItem&pt=Model_RR_Trains&hash=item5d29cd2c27
I do not know enough about electrical stuff to say if the ceramic one in your link would work.
I used the Lionel 81s or 95s. I did not the 89s, which are for battery operation. You can usually find the rheostats in decent shape for $5 to $10 on eBay.
These things are pretty old, and it would not surprise me if the wires are wrapped in asbestos (maybe I don't want to know!), but they work fine for me.
Servoguy: Thanks! Looks like a little gold mine. The only problem is - I don't know what I want! I have no clue what the specs on a rheostat would be for my application. I don't want to take a shotgun approach and try one of everything until I get it right. I took a look at my benchwork and determined that it would not be difficult or obtrusive at all to have four little stations where a #8B transformer would reside with a toggle switch or two. Two of them can be on my already-established mini-control panel; one on each side of a #19B "master transformer". One can be at the end of my newly-constucted peninsula and one can be worked into the landscape on the other, far end of the layout. I can live with this approach. After all, it's all Flyer! LOL
Three-hundred-fifty ohms is way too much resistance. The Lionel rheostats are about 12 ohms. Postwar Flyer draws a little less than Lionel. So you could go up a little on the resistance, perhaps to 16 or 20 ohms. The power rating for the rheostat is the square of the maximum current times the resistance. So, for example, a 12-ohm rheostat for a train that draws about 2 amperes should be rated at about 50 watts (2 x 2 x 12).
Ironically, although increasing the resistance would seem to reduce the current and allow you to use a lower-power rheostat, it actually increases the power rating needed. This is because, at the high-speed end, the current flows through less of the resistor and you are using only a small part of the total power rating. For example, a 10-ohm rheostat set to 1 ohm with a 1-ampere load needs to be rated at 10 watts (1 x 1 x 10), because 1 watt is being dissipated in 10 percent of the resistor, which can handle only its tenth of the total power rating . But a 20-ohm rheostat set to 1 ohm used with the same load needs to be rated at 20 watts (1 x 1 x 20), because, although it is also dissipating 1 watt, that watt is being dissipated in only 5 percent of the resistor, which can handle only 1/20 of the total power rating.
So, if you used the 350-ohm rheostat with a 2-ampere load, you would need a ridiculous 1400-watt power rating! Otherwise, it would burn out the first time you went to anything like full speed. On the other hand, you want to have enough resistance to be able to slow the train down to a reasonable speed--but no more than that!
Thanks, Bob for pursuing this. Interesting that the very spec needed on a rheostat for this application would be the one that is near impossible to find. Apparently, this is a direction that no one has ever seriously taken with American Flyer trains. Hard to imagine that in the past 60+ years, the concept of using a local transformer when needed never got developed in this gauge and I can't imagine running a large Flyer layout any other way! Well, DCC makes everything like this moot in today's hobby, but I'm not going down that road with vintage Flyer. Been there; done that. It's silly. Why not just buy new S Gauge and let it go at that. I think the concept of using toggle switches and local transformers is sound enough; not a perfect solution - but workable. After all, they ARE toys.
Interestingly AF facilitates local train control with a dedicated transformer. If the track layout is configured with all tracks in an area you want to control locally fed from a yard lead or a double ended passing siding the AF turnouts set to "2 Train Operation" and use of a fiber pin or two provide the selective power control automatically without any additional control switches. Many AF operators have set up their layouts this way. Two rail AF does make reverse loops more complicated but the selective power routing built into the turnouts by Gilbert sure make some of what you want to do really easy.
What about a 22 ohm, 4.4 amp rheostat?
http://cgi.ebay.com/Cenco-Air-cooled-Laboratory-Rheostat-22-OHMS-4-4-Amps-/150472534198?cmd=ViewItem&pt=LH_DefaultDomain_0&hash=item2308dca8b6
fredswain What about a 22 ohm, 4.4 amp rheostat? http://cgi.ebay.com/Cenco-Air-cooled-Laboratory-Rheostat-22-OHMS-4-4-Amps-/150472534198?cmd=ViewItem&pt=LH_DefaultDomain_0&hash=item2308dca8b6
Bob Nelson or others can answer this best, but it looks like a winner to me. Still, I think you can find the old Lionel rheostats a little cheaper.
fredswain: I think that is about the right spec, since a dual-motor Alco could draw 3.25 amps. It's bulky, but it could be installed well under the layout with a brass rod attached to the wiper and a slot in the layout for the lateral movement. I'm watching that auction to see what, if any bids get placed. Thanks for pointing me to it! I have a feeling that my plan for using local transformers is the direction I'll end up going, because in the end, it's retains it's All-Flyer status.
I'll re-iterate what my "local transformer" plan is. I'll have one or two trains going around the layout powered by a #19B "master transformer". At four locations, I'll want local control. When a train is headed towards a block where I'll want that local control, I'll walk over there and energize a #8B transformer. A toggle switch will re-route track power within that block from the #19B to the #8B before a train enters that block. It will be key to get that #8B set as close to the voltage as the #19B is. An in-line AC voltmeter (the kind that is on the #19B) could prove beneficial. Never-the-less, there will be a momentary voltage spike in the loco as it crosses over the insulated gap, but I have never experienced a problem with that. Now that the loco is under the local control of the #8, I can do whatever I want with it - probably back it into a siding to set out or pick up a car or two. Then I'll get it going back up to the mainline speed that the #19B established and let it cross another insulated gap and get picked back up by the #19B. There will again be a momentary voltage spike. Then I'll re-route the track power in that block back to the #19B for the next train that will just roll through it and I'll de-energize the local #8B. There is no sense in having it remain energized until the next time I decide to use it. Is this a perfect plan? No. Will it work? Yes. It is the best solution to my needs that I can find that is all Flyer.
That would probably work on a Flyer layout. One would need to try it with a variety of engines to see how they respond. There is a difference between styles of engines in how much current they draw at part load. A Rheostat (or Potentiometer) is not a great way to control AF trains. A transformer outputs a constant voltage at a given setting for any load between zero and its rated output. A rheostat is simply a constant resistance at a given setting. So the voltage at the track is always a function of the load applied. At no load the track voltage will read the transformer voltage at any rheostat setting. If for example the rheostat setting is at 5 ohms, the transformer output is 16 volts and a 3 ohm engine impedance is on the track then the measured track voltage will be 6 volts. If the engine leaves that block and just the 150mA caboose light is present then the voltage will immediately show almost 16 volts at the track. Rheostats apparently worked well with the large standard gauge trains and much of the early O gauge equipment. The AF motors have a very non linear impedance with load and voltage and even that varies quite a bit between engine styles. It is my opinion that a rheostat will be very difficult to use in a satisfying way with AF engines.
That definitely works. You probably will not need the voltmeter since the AF transformers are pretty uniform in their voltage output at a given "speed" setting on the case. If you can get them a 15B makes a great local control complement to the 19B on the mainline.
Tom: Thank you. I think it is a sound and novel approach, given what I have to work with. The #19B can handle two trains and I probably will run two at times. This is a very large vintage American Flyer layout I am building and I am trying to marry how we would have done it in the early 50's with how it could be done today by just using vintage components. The 50's part is of course, the vintage trains and train components and loop running. The today part is designing a model RR in the around-the-wall shelf style with true 3-D realistic to-scale scenery and with the concept of also being able to run them in a more prototypical way as part of an operating session. Since the op sessions will be one-man, I had to come up with a way to control them at various points as I walk around. So - I could just set one or two in motion and oogle them, sipping on a Scotch; or I could perform a freight-car forwarding procedure as well, maybe with a passenger train also making a run on a timed basis. I believe that when all my scenery is completed, I'll enjoy watching a single train weave it's way through "miles" of open country-side, making a stop or two as needed for a function. That is pretty much how real trains are, to my knowledge.
#15B transformers are available. The question is how much do I want to pay for one. Top on the list is the #19B, of course. I'll have to collect the #15B transformers over time, but that will be fun to upgrade from the #8B one-by-one as I go along. I only need four, so it's doable.
Thanks to Bob for all the technical information on rheostats and help over the past months in understanding the safety concerns in using multiple transformers.
Thanks to everyone who has had input into this thread so far. This has been an important thread for me and I hope others have learned from it as well.
Timboy, I really admire what you are creating for a layout. I look forward to hearing about the end result. If only i had more space... And you had to bring up the scotch; I suppose now I will have to sip some single malt and ponder where to create the space for something bigger than an 8X12!
Tom: Thanks! I am having the time of my RR'ing life building this one! I'll keep this forum and my blog updated as I make progress. In all lack of modesty, I think I'm making history with this build in one regard because I don't know of anyone who has ever created a large home-based Flyer layout by making a spline subroadbed out of homosote! I believe the great Kolosseus layout used a girder grid construction and cookie-cutter subroadbed.
I think you could do a terrific layout in an 8X12 space! Wasn't the classic Gilbert dealer display layout that size or a little smaller? Here's a link to it:
http://www.geocities.com/theupstairstrain/1950_Factory_Layout.html
I have often thought of re-creating one of the classic Gilbert Flyer layouts - to the smallest detail - as fun and a tribute.
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