What am I doing wrong? - DPDT Relay & Rectifier wiring for 2 trains on 1 loop

[lionel2986]

Hello everyone,

I am still trying to run two trains on one loop and am having problems. I am trying to use the following diagram:

Here is the Relay that I am using:

URL=http://s7.photobucket.com/user/budgetrc/media/relaydiagram-1.jpg.html][/URL]

Here is the rectifier I am using:

Here is my wiring:

Now, my relay looks a little different than the one in the diagram (it is a square, not inline). I have two ~ terminals for the A/C power. One goes to the transformer, and the other goes to the insulated - track in the following block to send a signal and activate the relay. I was told it doesn't matter if plus or minus is on either terminal because the polarity doesn't matter with AC on a rectifier. I found this hard to believe, but maybe it's true.  Also, I have a red wire coming out where #8 is in the original photo but it is not attached to anything (I was using it to troubleshoot). It seems that when I adjust the transformer C control, and D control, I can get the relay to activate the Red or Green light depending on how much power comes out either post (as if they are fighting each other). Any idea? I'm not sure if my relay's internal wiring is equal to the diagram I found online that I'm using as a model. I was up until 2:30am doing this so perhaps I wasn't thinking clearly, but I'm still having problems. Also, I am using only 1 ground terminal on the transformer. I assumed that I didn't have to use two like in the above diagram because they are common and it doesn't matter?

Thanks

Thanks for all your help.

[lionelsoni]

You haven't shown the relay contacts on your wiring diagram; and the terminal numbers on the relay package, which does show the contacts are illegible.  So I don't think we can say for sure that you wired it right.

From the pictures, I can't tell for sure that the bridge is wired right.  (It's much bigger than you need; but that doesn't matter.)  It looks like there's something on the ~ terminals besides the wires.  Maybe it's blobs of solder. 

The reason that the wiring of the ~ terminals can be either way is that the rectifier is completely symmetrical.  Look at the diagram on its package.  Each ~ terminal is connected to an anode and a cathode--you can't tell them apart.  In any case, neither ~ terminal is "plus" or "minus", and none of the transformer's terminals and none of the rails are "plus" or "minus".

The U terminals are indeed connected together on all the postwar transformers, like the Z and ZW transformers.  Do you have a real transformer or a modern "ZW"?

[lionel2986]

Hello,

I am working on getting you better photos. What do you mean by "real" transformer? I have the new ZW from around 2004 with the 180watt bricks (when it first came out). I understand the rectifier now.

[lionel2986]

The numbers are:

1           2

3           4

5           6

7           8

The relay pins show

1           2

3           4

5           6

L           R

[lionel2986]

I checked the wiring and i think its ok. Here are my symptoms. When I have a train in the adjacent block, the axels cause a flickering signal (Im using a lamp to diagnose this). So it's like the relay is fighting itself as the power from the adjacent block outside rail cuts out for a milisecond. Perhaps my axel wheels are dirty, but can I make this smoother somehow with a capacitor or something to hold energy for the millisecond that insulated outside rail power going to the relay might cut out as the wheels roll?

Also, the accessory terminal on my zw powering the relay via bridge rectifier throws the signal and relay back to green even if the adjacent block is occupied when I bring power below 9-11volts. Does this sound right? I had no idea I needed to "tune" voltage going to the relay to make it function properly.

So my track is slightly dirty and or my wheels are causing a flickering in the isolated ground power to activate the relay. I just need to know if I can fix this with a capacitor or something so I don't have to buy entirely new track. 027 has always flickered the passenger cars from time to time with me, so I'm not sure it's best conducting. O usually works flawless even if it's dirtier than 027. Perhaps there is greater surface area?

[lionel2986]

I searched other forums and it looks like I'm describing relay chatter and a capacitor could be the solution.  I assume the capacitor gets installed somewhere in the isolated ground to relay circuit?

I've also discovered a Philips screw on the back of the relay after reading they can be adjusted to fix chatter. Is this the right way of solving this or should I install capacitors? As the relay chatters i see small sparks on the track wheels as they roll indicating arcing. I'm not sure adjusting the relay Philips screw will fix this, and I don't want to touch that "factory setting"  until I know what I'm doing. 

If I install capaciors do I need resistors? I wonder why that wasn't indicated in the above diagram from toy train review? It's turning from simple to rather complicated and I have 8 more to go. This is just the first and I want to make sure I get it right before I proceed to the rest. Thanks!

[steve24944]

I have several relays for block signals on my layout.  I put a capacitor between the bridge rectifier and the relay.  See my picture below. The bridge rectifier is on the left, the relay is on the far right.   I have used a Radio Shack 1000uF 35v.  The end of the capacitor with the rib is the positive - the arrows point towards the negative.  I find using terminal blocks makes the wiring easier - no soldering the connections so you can un-do connections.  I do solder my wire end connectors to the wires. From the bridge rectifier run your pos and neg wire to the terminal block,  bend the leads from the capacitor so you can  wrap them around the screws on the terminal block - positive ends of the capacitor to the positive wire from the bridge rectifier, and same for the negative side.  

To connect to the relay and the bridge rectifier I use radio shack female wire end connectors,  they slip on the the contact tabs on the relay nicely.   Looks like the bridge rectifier you are using you can bend the leads and wrap around the screw on a terminal block.  So if needed you can disconnect the wires from the relay or bridge rectifier as you mess around with stuff.  I have all the parts on a wood bracket under my layout.  The bracket can be unscrewed and lowered to the floor if I need to do any work.  Make sure you have long enough wire slack to do so.

When my train enter the block the relay holds the signal at red until the train leaves the block.

Steve

[lionel2986]

Very nice! That is what I'm looking to achieve. I've never done anything like this before, so I have a dumb question:

I have my signal lamps connected to terminal "C". This terminal must be set to atleast 9 volts for me to see the bulb illuminated with the cover on.

I have my bridge rectifier connected to terminal "B" which needs to have atleast 10-11 volts of power for it to switch to red if the block is occupied.

Finally, my track positive power (terminal A) needs to be set to atleast 10-11volts for the light to turn green when the block is not occupied. If track power is below 10 volts, while the other terminals are atleast 11volts, the light turns red even if the block is not occupied. I don't understand this. Why does the track positive affect my relay functioning? It is ac and does not get converted to dc because it bypasses the bridge rectifier and goes directly to the relay. Shouldn't track voltage have no effect on relay functioning? I just want to make sure this is all wired correctly. I remember lionelsoni advising against connecting different terminals to the same circuit, so I want to avoid this and damaging or burning something since I'm using three different terminals here. I want to make sure they are not connected to each other, but if track power (terminal a) and terminal b both effect the relay's throw, maybe I did something wrong?

Thanks

[steve24944]

You refer to the A B C D posts on your transformers.   You have said that A post is your track power - OK Fine.   The A post goes to the center rail, the outside rails are connected to U post.   Your B post ( set at 10-11 volts ) goes to the AC side of the bridge rectifier, the wire from the insulated control rail goes to the other AC side of the bridge rectifier.  The DC side of the Bridge Rectifier to contacts 7 + 8 on the relay.   So now when you roll a car onto the control rail, the relay should close, remove the car the relay should open.  ( No track power from post A )  The relay is being energized from post B, the car on the control rail closes the connection back to the U post.  

If the relay functions as described above,  now its a matter of getting power to your signal lamps.  Are you using a Lionel 153 block signal with red + green bulbs ?   

From your photo I'm not sure how you have your relay wired.  Looks like you have the DC side of the bridge rectifier soldered to contacts 7 + 8 for the coil on the relay.

On one side of the relay you are running the signal lamps.  I'm going to say the left side.  From your transformer C post run a wire to contact 5 on the relay .  Contact 1 on the relay goes to the green lamp connection on the signal, contact 3 goes to the red lamp on the signal.   Run a wire from the transformer U post to the common on the signal,  which is the center post on the 153.

So when the track is clear the relay is open and lamp power goes through contact 1 to the green lamp.  when the track is occupied, the control rail closes the relay and lamp power goes through contact 3 to the red lamp.

First make sure the relay opens and closes by a car being on the control rail.    Then connect the signal to the relay and see if the signal changes from green to red when a car crosses over the control rail.  If the red + green lamps come on in the wrong order, you can just swap the red - green wires on the signal base.

If the signal is working properly at this point,  now you can use the other side of the relay contacts to control the power to the center rail you are using to stop the train at a red signal.   Run a connection from A post ( which is your power to the center rail to run the locomotive ) to contact 6 on the relay.  From contact 2 on the relay run wire to the center rail you insulated with fiber pins.

So .... when track block ahead is clear, relay is open and power goes to the green lamp and the isolated center rail.  When the track block ahead is occupied, the relay is closed, power goes to the red lamp and no power to the center rail stopping a train at the red signal.   When the first train clears the block ahead the relay opens again, back to a green signal and power to the isolated center rail allowing the second train to proceed.     Turn off your e-units so the locomotives are only going forward, or the locomotive will be in neutral ( or reverse ).

So ..... First get the relay to go on - off by the control rail.      Second, get the signal lamp to change.    Then,  get the isolated center stop rail to go on - off with the the change in the signal.

One step at a time

Steve

[lionelsoni]

Assuming that relay terminals 1 through 8 on the relay-package wiring diagram are actually 1, 4, 5, 8, 9 12, 13, and 14, respectively, it seems that you have it wired right.

What I meant by "real transformer" is a magnetic circuit with windings on it, which is essentially what postwar transformers are.  Many of the modern "transformers", although they have a transformer or several inside the box, also contain computers and other electronics, whose operation the manufacturer keeps secret.  That is why I routinely avoid trying to diagnose their problems on the forum.  There should be no interaction between the controls of a traditional transformer, like the original ZW, if that were what you were using to power your relay scheme.  With the new phase-control "ZW" all bets are off; so I won't try to guess what's happening.

(It would be nice if Lionel would refrain from reusing for their products names that already denote something, like ZW, standard, and Pul-Mor.)

[lionel2986]

What type (specs) of resistor should I use? I see that you have two. Do I need two or one? Thanks!

[steve24944]

lionel2986

What type (specs) of resistor should I use? I see that you have two. Do I need two or one? Thanks!

Depends on what lamp or bulbs you are using for your signals.  The relay block set-up I have shown in that picture is for some searchlight signals that I scratchbuilt.  I use a Red-Green multi-color LED for the lamp ( Radio Shack # 276-0028 ) And I think the resistors are 470-Ohm 1/2 watt.  The power for the LED Signals is 6 volt DC from a cheap HO train transformer.   If you are using a Lionel 153 2 bulb Block Signal,  Then you just need to run your 12 volt accessory voltage to the signal.

Steve