I'm considering adding a 450 signal bridge to the layout but do not want to use Lionel contactors. I have succesfully used insulated tracks on other accessories but it appears that the signal bridge is more complicated from what I've been able to find on the net. Can anyone provde a wiring diagram using insulated track and any other components required??
There is a simple way to operate a signal from a control rail, which I have described a number of times on the forum, using only an extra incandescent lamp. Here is a description based on an individual 153-type signal:
Connect the green lamp's terminal to the layout common, that is, the outside rails generally. Connect the red lamp's terminal to the supply, whether the center rail or a separate accessory supply. Connect the signal's common (the terminal connected to both lamps) to the control rail. Then connect an extra lamp in parallel with the red lamp, that is, effectively between the supply and the control rail. The extra lamp should have the same voltage rating as the signal lamps but draw twice the current. When the signal lamps are number 53s, as they often are or could be, a number 57 is ideal as the extra lamp. An alternative is to use two extra lamps in parallel, of the same type as in the signal.
This arrangement is not possible for a signal bridge, since there is only one common shared between the two signal heads, which is the bridge structure itself. You would have to isolate at least one of the signal heads from the bridge so that you have separate common connections to the two heads.
A couple of hears ago, I was surprised to come across almost the same idea in an old book I was reading. [Raymond F. Yates, Making and Operating Model Railroads, D. Appleton-Century, New York, 1943] It was attributed to Albert C. Kalmbach, the founder of the very company that sponsors this web site. The difference was that he used an ordinary resistor in place of the extra lamp. Lamps work much better in this circuit because the current that the lamp draws varies as the .55 power of voltage, not proportional to it as with a resistor (Ohm's law). So the voltage across the lamp increases almost as the square of the current. The number-53 lamp draws 120 milliamperes at 14 volts; so putting a number 57, which draws twice that, in parallel with the red lamp means that the red lamp gets only 1/3 the current that the green one does when they are in series. Because of the near-square-law behavior of the incandescent lamps, that means that the red lamp gets only about 1/7 the voltage of the green lamp, or about 1/8 of the total voltage. Furthermore, since an incandescent lamp puts out light proportional to the 3.5 power of voltage, the red lamp in that circumstance is only about 1/1000 as bright as the green one.
Bob Nelson
Sounds complicated for the 450 to work properly. Would a newer Lionel #14093 Single Signal Bridge or 153 block signal be a better option??
It's entirely your choice, whether you want to insulate one of the 450's signal heads or change to individual signals.
I don't have a 450, so I don't know how the heads are attached. I can imagine something like replacing a metal screw with a nylon one. Can you or someone else show us how they go together?
srguy I'm considering adding a 450 signal bridge to the layout but do not want to use Lionel contactors. I have succesfully used insulated tracks on other accessories but it appears that the signal bridge is more complicated from what I've been able to find on the net. Can anyone provde a wiring diagram using insulated track and any other components required??
Trying to figure how to get the green to go off and then just let the red come on. using the contactors where when the pressure of the engine comes it disconnects from the up position which would be green and connects to the bottom which turns on the red the only problem I see is you need the green to get turned off when you get to the isolation area of the track so the red will come on or you will have both on when you get to the part the red come on in the isolation track area. Thats the reason lionel uses the 153C to do this and to do it as dual tracks you could use 2 to do this one for each side.
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The method I described uses the single contact to the control rail to turn off the green, by shorting out the green lamp, and turn on the red, by connecting the red lamp across the supply voltage. It's really a very simple circuit and uses no extra electronics, except for a single additional lamp per signal head.
You wouldn't happen to have a wiring diagram??
accessoryvoltage----------------(or center | | rail) | | --- --- / \ / \ |extra| | red | | #57 | | #53 | |lamp | |lamp | \ / \ / --- --- | |control | |(signalrail------------------| common) | | --- / \ |green| | #53 | |lamp | \ / ---transformer |commmon |(outside--------------- rails)
Thanks Bob ... I'm assuming that this diagram is for the 153. If I go with the 450 and somehow isolate the second signal, will this diagram apply to the isolated signal as well or will another ground be necessary?. Also, what are you using to house the # 57??? Would you locate under the board??
Jim
The problem is that the point that I labeled "signal common" is the same for both signal heads on the bridge, whereas each signal head's common needs to be connected to a different control rail. So you need to isolate one of the heads from the bridge. Then the bridge continues to serve as the common connection for the other signal head and gets connected to its control rail, while a new wire that you connect to the now-isolated signal head gets connected to its control rail.
Of course, you can isolate both signal heads from the bridge if you like and add a new wire to each one. This would prevent operation of one signal if the bridge accidentally gets connected to the transformer common, perhaps by a derailed train crashing into it. But there's really no harm in that. (The accidental operation, not the crash!)
You can hide the extra lamps. (Remember that you need one for each signal head.) Or, you can use them somewhere on the layout to light something up, perhaps a billboard or a floodlight tower. Most observers won't notice that some unrelated accessory lights up at the same time that the signal goes red.
I have been trying to figure out how the signal heads are mounted. It looks, from the information I have, that each one has a 4-36 x 1/8" screw into its bottom through a hole in the top or bottom chord of the top truss. I'm thinking that you might use a #4 nylon washer between the head and the chord and replace the metal screw with nylon. Unfortunately, it will be hard to find anything but a 4-40 screw. But if the nylon screw is no longer than needed, you may be able to force it far enough into the hole in the signal head to do the job.
Another possibility is to drill and re-tap the hole in the head for a 6-32 nylon screw. This might also require drilling out the holes in the chord unless they are already a little oversized.
By the way, it looks like the stock lamps are number 53s, which Lionel calls 53-301 or L53(R), and 53-302 or L53(G).
Hi, I'm a new member and I have a question. I'm trying to wire a 153 signal by following your written instructions and using the diagram above,. When I put the wire from the green lamp on the transformer common or (outside rail) and put the wires from the red lamps on the transformer voltage or (center rail) both lamps are lit. When the signal common is applied to the control rail (insulated rail) both green and red lamps are still lit. Am I'm doing something wrong. I have tried all different combination's of bulbs. Thanks for any help you can give.
Have you connected the extra lamp, the number-57 in the diagram, between the supply voltage and the control rail? It's not there for looks. It's what turns off the red lamp when there's no train on the control rail.
Hi, Thanks for your quick reply.Yes I have the extra bulb(s) between the supply voltage and the control rail. Still not getting it I don't have a #57 bulb so I tried a # 363 a #1445 18v and 2 #53's wired together and the red is still on but not as bright as the green. When I jump the control rail the extra bulbs light along with the red on the 153 but the green is still on but not as bright as the red. I guess I'm using the wrong bulbs or am I still doing something wrong?
Of course, a SPDT relay driven by the isolated track section would do the trick just fine.
Of course, that would require the complexity of a relay and independent power supply.
Rob
ADCX Rob Of course, that would require the complexity of a relay and independent power supply.
No, if you use a supply other than the track voltage, whether with a relay or with the lamp trick, you can still sense the train completely independently of the track voltage. The independent supply must share its return with the track supply. If the relay supply is AC--an accessory supply on the same transformer that powers the trains, for example--then the relay must be an AC relay, or a (cheaper) DC relay with a bridge rectifier to allow it to operate on AC. Otherwise, a DC relay requires a DC supply, which cannot be made from that accessory supply but must use a separate transformer.
The lamp trick doesn't care whether its supply is AC or DC, nor whether it is the track voltage or an accessory voltage.
Thanks for all the info, but getting back to the lamp trick, why is the red still on (very dim) with the bright green and the green still on (very dim) with the bright red? By the way talking about the 450, I put a rubber washer on the screw that mounts the signal head that runs down to the leg with only 2 terminals and then ran a separate ground wire and attached it to the same mount screw (outside of washer) and both signals work independently of each other. I was hoping to use the lamp trick to operate the 450 also.
Sorry I can't help much on how to wire up a 450 as I just used a simple toggle to go from green to red, avoiding any track power connection.
But one thing I can advise is to swap the bulb positions so the green bulb is on top and the red bulb is on the bottom. Railroads use high green and low red instead of a traffic signal setup with red on the top and green on the bottom.
Every single 450 I've ever seen comes with a red bulb on top and the green bulb on the bottom. Easy to swap the bulbs, but you'd think someone would figure this out over all the years this particular style signal bridge has been issued.
Best pic I could find that sort of shows the 450 on our layout:
Matt from Anaheim, CA and Bayfield, COClick Here for my model train photo website
The green should be completely off. The red will be on but should be very dim. What lamps are you using, both for the signals and for the extra lamp in parallel with the red one?
Hi bob, I was using (without realizing) a pre 1950 #153 signal with a resistor. So I got out another one (without a resistor) and used #1445 bulbs with 1extra lamp, but it works better (red was dimmer.. almost not on) with 2 extra lamps. It did works as you described. I just ordered some #53's and #57's and I'll be changing them all out.
Thanks
Jim, did you ever hook up the 450 using Bob Nelson's approach? If so, what did you use to isolate the second signal from the bridge and what did you do to create the common for the second signal?
Thanks, Swede
Thanks for the prompt response, Srguy. I want to try Bob Nelson's approach to the second signal. Guess I'll try to cobble something together. I just haven't figured out how to secure the new common to the signal and separately secure the signal to the bridge. If I find a solution, I'll post it.
Again, thanks for your response.
Swede
The first signal, wired per Bob Nelson's suggestion, works perfectly. On the second signal, I soldered a new common wire to one of the two bulbs, adjacent to one of the two nubs that secure the bulb in the lamp socket. I fished the wire through a hole in the side of the signal body provided by Lionel as part of the bulb locking mechanism and ran it out the base and connected it and the other two wires as per Bob's suggestion. Unless activated when a car enters the isolated zone, the green light is bright and the red light is very dim. When activated, the green light is totally extinguished and the red light is bright. The third bulb, in parallel with the red bulb, is the same for each signal. I will add a second parallel lamp to the second signal to see if the problem goes away.
What lamp types are you using, both in the signals and as the second lamps?
Thanks for the quick response, Bob. I am using 53's for the signals and 1891's for the parallel bulbs.
That should work: They're both 14-volt lamps, and the 1891's current (240 milliamperes) is specified to be twice that of the 53. Since you've got exactly the same circuit for both signals, but one works and the other not quite, my guess is that at least one of the lamps is out of spec. But adding a second parallel lamp should surely do the trick.
Had a chance to add a second parallel 1891 bulb this evening but got the same result. Having the dim red is not the end of the world but something is wrong with the wiring.
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