Relays to switch direction and such stuff

It's not absolutely clear what you mean.  Are you saying that you have a track that is not a loop, and you want something like a trolley to move one direction across the layout, then stop at the end, and reverse to cross back the other way, revers when it gets to that end, and keep doing that?  If not, I don't understand the situation.  If so, a relay won't help you with an AC power O-gauge train since you can't reverse the polarity of AC power: best to get a trolley with auto reversing bumpers: they work very well.

Yes that is want I'm looking for but I want to run a short train, an engine and a couple of cars about 25 feet across the back of the layout with out having to run the controls.

These bumpers you speak of.. can they do what  I want to do ?

If you don't want to use a trolley or gang car which reverse when the bumper on the car hits a fixed stop z-stuff makes an electronic reversing unit for any engine with an e-unit in it, the DZ-1240 will do auto reverse, intermediate stops and blow the horn.

Scotie

Thanks! I  think that's what I'm looking for..I cant really do another loop (well I could but I'm trying to be good) but a straight elevated  track  to the rear of the layout would work and I wanted to be able to turn it on and let it cycle... Again thanks  

without sound like a dummy.. what is a "e-unit" ?

Electromechanical or electronic reversing unit.  It's what cycles O gauge engines to go in different directions.

Common e-units in the postwar and modern era have Forward, Neutral, and Reverse cycles, although there were older lower-priced engines made in the past that had Forward and Reverse only with no neutral, and some were made with Forward only.

Another option. If the motors are DC then remove the reverse unit completely and apply DC to the track.  Use sensors at each end to trip a relay and reverse the DC voltage on the track.

http://www.dallee.com/Timed_Stop_AC.htm

With this little unit, you can avoid the use of relays, rewiring your trains, changing your power supply, installing bumpers, using trains you don't want to use, and fretting about anything you don't understand. It is designed to do exactly what you want to accomplish. 

It interrupts track voltage according to a prearranged plan, so that the train will automatically stop, pause, reverse, (optionally make stops along the route) and continue to the other end of the track, where the steps are repeated. 

All Lionel post war and the other makes that are compatible with them have a reverse unit inside. It is called an "E" unit, and can be electromechanical (like a relay) or electronic. Either way, the E unit stops, reverses and starts the locomotive in response to track power interruptions. The Dallee control unit takes advantage of this feature and interrupts the track power automatically.

By checking the archives of this and other forums, you can get an education on train matters. Here is a thread about E units.

http://www.modeltrainjournal.c....php?f=2&t=12661

Please keep us apprised of your progress. Good luck!

The Dallee unit Arthur links should work and relies on current sensing devices.

It can also be done with outside insulated rails used for detection and relays.

One method is to remove the E unit and run everything off DC. At the end of each side,a timer is tripped and polarity is reversed with a DPDT relay or a DPDT twin coiled latch relay.

It can also be done with the traditional E unit if it is not the style that reverts back when power is removed to start in forward. Relays are used with a timer where they are pulsed briefly to interrupt power it to neutral at the end,then pulsed a second time and the train moves in the opposite direction after a set time. With additional relays a interim stops can also be made to happen.  With this set up it is wise to have a dead section of track at the end or a safety relay to cut power if for some reason the E unit does not cycle or cycles wrong.

Dale H

Dale is right as always go with it.Nick

The TMCC Action Recorder Controller should handle that for the new line.

(if you are using cab-1) Cab-2 Legacy has it included.

http://www.lionel.com/Products/Finder/ProductDetail.cfm?ProductNumber=6-14181&expandBranch=0&Keywords=&CategoryID=115&RailLineID=&CatalogId=

I do not have drawing software. So I will try a hand drawn explanation. This is a reverse circuit for a standard 3 position E unit or an electronic one that retains memory of its previous state. Click to enlarge

Parts used

3, SPDT relays. 10 amp or more contacts 24VDC coils

1, Bridge rectifier 4 amp or more 50 volts or more

3, capacitors 1000 uf 35 volt electrolytic. C2 and C3 have to be large enough to pulse the E unit,this varies with relay coils used but this value should provide about a 1 second duration.

1, Mars Timer module,model 32391, delay on make, has adjustable pot up to 8 minutes delay

5, 1n4001 diodes or suitable substitutes.

1, 18 ohm or 33 ohm half watt resistor. This slows capacitor charge a bit to reduce relay contact arcing when the capacitor charges (when the relay coil is not energized)

A separate transformer is used to power relays and timer. Most any train transformer. It can not share a common with the track transformer.  The minus of the bridge rectifier shares a common with the track transformer drawn here as "U"

"A" goes to the center rail power through the NC contacts of relay 3. So power is on the track unless relay 3 is energized.

The relay transformer set at 18 volts AC is in series with a bridge rectifier. Filter capacitor C1 boost voltage to 24VDC for timer and relay coil power.

The red wire + 24VDC goes to goes to the 3 relay coils and to the +s of C2 and C3 in series with a small value resistor.

IR1 and IR2 are insulated outside rails. They are connected together. Train wheels complete the circuit and immediately energize relay 1 providing - DC to Coil 1 and - DC power to coil 2 after the delayed set time of the Mars timer module.

When relay 1 or relay 2 is energized Their respective capacitor,C2 or C3 is discharged into relay coil 3,momentarily energizing it. Diodes D1,D2 keep capacitors separated. Not shown for clarity,diodes are placed  across all 3 relay coils opposing flow for spike suppression.

The system is started when the train is in the center area,moving one way or the other. Then the power is turned on to the relay system. When the train crosses IR1 for example at the end on the line,relay 1 is energized and C2 is discharged into coil 3. Relay 3 contacts momentarily break the power to the center rail. The e unit is cycled into neutral. When the timer times out. Relay 2 is energized and C3 is discharged into coil 3. The track power is again momentarily interrupted the e unit cycles into its opposite state. the train moves in the other direction. It vacates IR1,the timer is reset and the capacitors are charged,the process is repeated when the train arrives at IR2,it reverses back. The process will continue until power is removed. then the whole thing will have to be started again,cycling the e unit once with the transformer in the conventional manner.

I would add an additional relay as an emergency shut off at the ends,but I am trying to show the basic idea. Additional relays can be added for soft start,stop and block signal logic.

Parts would cost maybe $40 for this basic circuit.

mars timer modules are inexpensive and durable. Coupled with relays ,most timing functions can be done in model railroading. Further applications for the timer are here

www.jcstudiosinc.com/BlogShowThread?id=481

Dale H

Hi Garry, Dale's drawing will do the trick but let me warn you unles you have his know how it can be a little daunting of a project. Besides I have built such a sequencing  circuit and believe me though it was a fun project I could of ordered the Dallee switch for less money with alot less time invested.

In fact, I have such a project in mind and it's Dallee for me.

well,,, I got the dz 1240 unit .. I tried to hook up the unit using sensors I had...  failed miserably... man am I disappointed. Im sure its my error.. I think I need to get the 1070 sensors...   I just cant cut track at this point because its already down and in a hard to reach spot...

talk about wasting a day....

For 3 rail, the outside insulated rail method is cheaper to use and much more dependable than IR detectors. The DZ unit should work for you however..

Dale H

I wanted to post the update of what I was trying to do here.... three point wye with sensors at each end and a z stuff board controlling the movement.. Thanks to Dennis (Z stuff) for servicing my 1240 board.... Kinda neat ... just set the throttle and forget it !!