Reed switches and the track as a common return

[playmofire]

I'm planning to introduce some reed switches into a layout and I've seen reference to wiring them up using the track as a common return. However, I haven't found any explanation as to how this is done. Can anyone explain how to do it, in simple terms, please?

 

[dutchelm]

If you decide to use the same common return as the track you must use a completely independant power supply for the reed switches. Whilst it is possible its better to keep things separate if only for fault finding.

 

[korm kormsen]

i am talking simple DC here. (without a second "C")
using the LGB colours, i had on my last layout blocksections with different transformers.
blue was common for all transformers, while red was interrupted between the different transformers.

the white (common) of the AC transformer to the users (switch motors etc) i put on the blue lines/rails as well. the black and orange wires between transformer and switch (reed or other) and between switch and user i had separated.

 

[playmofire]

If you decide to use the same common return as the track you must use a completely independant power supply for the reed switches. Whilst it is possible its better to keep things separate if only for fault finding.

I was planning to power the reed switches from the controller outlets for accessories.

 

[playmofire]

i am talking simple DC here. (without a second "C")
using the LGB colours, i had on my last layout blocksections with different transformers.
blue was common for all transformers, while red was interrupted between the different transformers.

the white (common) of the AC transformer to the users (switch motors etc) i put on the blue lines/rails as well. the black and orange wires between transformer and switch (reed or other) and between switch and user i had separated.

Hmm, my electrical knowledge is limited. I can wire up plugs about the house and connect up points and signals. I'm really asking, which wires are connected to where, if that helps.

 

[dutchelm]

If you are using the auxiiary output from the main controller it is quite posible that everything comes from the same transformer winding. In that case using the track common for other purposes should be avoided as it is quite likely you will cause a short circuit. The track common return can be either polarity DC depending on the direction & the reed switches are AC.

 

[korm kormsen]

in this case blue and red come from the DC transformer(s) to the rails.
white goes from AC transformer (accesory outlet) to switchmotors, etc.
black goes from AC transformer (accesory outlet) to reed.
orange goes from (one of the) reed outlets to switchmotor.

i would not try to make blue and white together as common, if they come out of the same transformer/controllier.
(i prefer to fry meat or chips, not electronics...)

edit:
the orange wires from one "left" connected and one "right" connected reed can/should/must be joined before they go into the switchmotor.
all whites can be common together.
all blacks can be common together.

2nd edit:
one set of reeds ("left" and "right") can be connected to one or two switchmotors.
switchmotors with the additional switch are used for powering/unpowering blocks.

3rd edit:
http://kormsen.info/lgb-manual.pdf

 

[playmofire]

Thanks everyone for your input and, Korm, for the link. Using the rail as a common return seems rather complicated so I won't follow that route.

 

[minimans]

It's not complicated once you get your head around it, it actually simplify s the wiring and saves a ton of wire!

 

[playmofire]

It's not complicated once you get your head around it, it actually simplify s the wiring and saves a ton of wire!

Saving wire was my aim, but, with no criticism intended of those replying, the verbal explanations do sound complicated. Maybe a simple wiring scheme for, say, two reed switches wired with the rail as a common return and showing power sources would help me understand more.

 

[minimans]

I gave my copy away but in the LGB EPL instruction book there are some very good diagrams and tips for just this very thing

 

[korm kormsen]

easy enough?

 

[playmofire]

Thank you. The top diagram I have found on page 117 of the LGB Manual. The other two, I take it, are amended versions you have created showing alternative ways of using the rail as a common return using different outlets on a transformer. I'll study them closely.

 

[korm kormsen]

yes.

a word about saving:
if you want to save money, use your one controler/transformer and all wires as described by LGB.
if you want save on wires (less spagetti under the layout) you should pay for seperate transformers for DC rails and AC switches.

 

[playmofire]

yes.

a word about saving:
if you want to save money, use your one controler/transformer and all wires as described by LGB.
if you want save on wires (less spagetti under the layout) you should pay for seperate transformers for DC rails and AC switches.

Thanks, that's useful to know.

 

[James Day]

Gordon,

Good luck with what you are proposing to do.

I like what Korm has said re the colour coding of the wires! Sticking to the LGB colours really helps!

I usually run my automation schemes from LGB control boxes. That way I can switch the automation on and off as desired using the yellow box and over-ride the last setting of the point or whatever using the orange one.

For fault finding each automated point etc is treated as a self contained circuit and is normally centred on a locally placed home-made distributor board near where the action actually is. I use modified food storage tubs to keep the water out.

I have always used completely seperate transformers for each function: traction, automation and lighting.

James

 

[playmofire]

Thanks, James.

Here's a plan of my thoughts. The train would run one way passing in front of the station and the other way using the loop. I'm planning to use of Clive Heathcote's electronics, and thinking of uprating the, to 2amp. Is that necessary?

There will be a station stop.

 

[minimans]

The diagrams Korm referenced are for trains running in the same direction, you will need to basically double up for trains in opposite directions. this will complicate matters as length of siding and placement of reeds will become very important! If you don't have a copy of the LGB EPL manual I would suggest hunting down a copy as it does show the correct methods of running trains in both directions at the same time. If your using track power with LGB loco's you will have to reverse the wiring to one of the Loco motors to enable reverse running or the Loco will go in the same direction but bunker first if you see what I mean...............

 

[minimans]

Oh and on a power supply I would suggest using a 5 amp supply for the EPL system and even with that possibly a LGB EPL booster. When running trains in opposite direction's it's extremely important that the points throw reliably 100% of the time!! it gets very interesting otherwise. Make sure you use an adequate size of cable to carry the switching current. On my garden I was able to run six trains in opposite directions using the EPL system and very impressive it was too until a point would fail to switch then it got interesting in a bad way. Not trying to put you off in any way but you will need to be very careful in planning and fitting the wiring whichever way you choose to wire it, common return or separate return.

 

[playmofire]

The diagrams Korm referenced are for trains running in the same direction, you will need to basically double up for trains in opposite directions. this will complicate matters as length of siding and placement of reeds will become very important! If you don't have a copy of the LGB EPL manual I would suggest hunting down a copy as it does show the correct methods of running trains in both directions at the same time. If your using track power with LGB loco's you will have to reverse the wiring to one of the Loco motors to enable reverse running or the Loco will go in the same direction but bunker first if you see what I mean...............

I have a copy of the World of LGB and also The Big Train Book.

As regards running, the line is a single track branch line and will be operated by a single loco, although I may add a separately powered shunting area at each end later.