double signal bridge

[Anonymous]

I was about to purchase #14094, the double signal bridge, when I noticed that in the Lionel Catalog it does not mention that it works with insulated track sections. I e-mailed Lionel and they said it does not work with insulated track but only with a 153c contactor. What makes this different than other signals that work with insulated track? What is a 153c contactor and how is it wired? I liked this bridge because it would cover a mainline and a parallel siding.

[mpzpw3]

A 153 contactor is a pressure sensitive "switch". As a train passes over the 153, contact is made by the weight of the train and the curcuit is completed. The reason the signal bridge won't work with an insulated section of track is because the light needs to turn from red to green ( or green to red, whatever). An insulated section just turns an item "on", but can't shut an item off at the same time. The easiest way to wire the signal bridge is to wire it into a remote- controlled turnout. I think relays are required for any other installation other than the 153 or through a switch.

[Anonymous]

I guess I am confused. I thought that when a train passed into an insulated section it turned the signal on, and it went off once the train left the section. How do you wire the double signal bridge into a remote switch, because I do have those available to use.

[Big_Boy_4005]

The contactor acts as an SPDT type of switch. This allows the lights to change from green to red when the train passes. There are other methods of achieving this effect, all of which have been discussed here in the not too distant past.

Here is a link to one of those topics.

http://www.trains.com/community/forum/topic.asp?TOPIC_ID=26500

[Anonymous]

I have used a relay system to operate my double signal bridge. these work much better than the 153 C. How ever you need an insulated track for the relay coil. It is not really hard to do.

[spankybird]

Hi bobbohn,

I have a single bridge from K-Line that works off an insulated rail. The light stay red until the train comes, then the red goes very dim and the green come on.

I am not sure if K-line still makes this. It is several years old (like ’97).
tom

[lionelsoni]

Tom, are you sure it isn't the other way around? Usually toy signals are green until the train passes, then red. If so, I suspect that they used a scheme much like I described on that other thread; although they probably used a resistor instead of a third lamp, which would account for a dim glow from the red light when the green is on.

Unfortunately, it is difficult to use my trick with a double bridge which uses the frame of the bridge as the return for both signal heads, since the common point between the lamps needs to be connected to the control rail rather than grounded. Is that the case with your bridge, Bob?