Modern DPDT Switches for 1122 turnouts

[lionelsoni]

You're right about SPDT instead of SPST.  I have edited that error out.

Because we're using the capacitive discharge circuit, we must use DC to power the turnout.  All it is is the electrolytic capacitor charged to about 16 volts (or whatever it takes to throw the turnout, probably more than 12) powering the turnout coils and the latching relay coils (which will be wired in parallel with the turnout coils).  When you throw the turnout, you get voltage from the capacitor for a short time, until it discharges.  That is what protects the turnout coils from burning out.  There is no harm in giving the relay a little extra voltage for such a short time, even though it is rated at 12 volts.

You can make your own DC supply if you want from a small train transformer.  This is very simple to do and would give you the ability to adjust the voltage if you need to.  This requires a bridge rectifier and another electrolytic capacitor.  The only thing you will need 12 volts DC for is the LEDs, which will be controlled through the relay contacts; so that can be a separate HO-type power supply.

The first step will be rewiring the turnout.

[Civil War]

 I got the LEDs today. They are wonderful. Very small. I will only need about a 3/16" hole in my panel for them. If anyone needs LEDs in red, green or yellow check out these:

Blue Sea Systems

[Civil War]

 Bob,

 I got my SPDT momentary toggle swithces to day. I think they will work very well and are pretty small.

We have gone back and forth on the turnout modification so I just want to be sure I have it right before I start on that part of the project. Below is what I have. Let me know if this is correct.

Normal 0

Modifying the turnout:  Take off the switch-machine cover and drill out the rivets that hold the plastic top to the steel bottom.  There are two rivets on the switch machine, but only one goes through to the bottom.  The bottom of the frog is the second; and the bottom of the common terminal is the third.  Pry up the tabs that hold the outside rails to the turnout, but only enough to get the bottom plate off, since they will break easily.  Identify the two wires, one from each coil that connect to the center rail.  Unsolder them and resolder them to an insulated wire.  Insulate the solder joint.  Find or make a path for the new wire out of the turnout in a place where it will not be pinched.  Drill and tap the frog, starting at the bottom end of the post that you drilled off, for a 6-32 screw.  Go ahead and drill and tap it all the way through to the top.  Put the turnout back together, using machine screws to replace the rivets and a flathead screw to hold the frog on, just long enough to come flush with the top of the frog casting.  The common terminal is no longer needed and can be replaced by a simple screw.

The capacitive-discharge circuit is very simple (not for me).  It is an electrolytic capacitor, about 4700 or 5000 microfarads), with its positive terminal connected to the outside rails and its negative terminal connected to the new wire that you installed.  The capacitor's negative terminal is also connected to one side of a number-53 lamp.  The other side of the lamp is connected to a 16-volt (approximately) DC supply, whose positive side is returned to the outside rails.

I am getting a couple of Tyco HO transformers. They should work for the DC power source. If I have this correct I can modify my first turnout. Then I will be ready to start on the toggle switch, latching relay and diodes. I went to Radio Shack today and they only had one diode in stock but will have more on Wednesday. I will need two correct, one for each indicator light? I plan to make up a small temporary control panel to operate one turnout to make sure everything works as expected, then it will be easy to modify all the other turnouts. I'm going to take pictures and write up a step by step proceedure. Thanks for your time and help.

 

Normal 0

[lionelsoni]

It's a good thing you posted that.  It should read, "The other side of the lamp is connected to a 16-volt (approximately) DC supply, whose positive side is returned to the outside rails."  I thought I had swapped all the "positive"s and "negative"s earlier; but I missed that one.  By the way, do you think the Tyco will put out enough voltage?  You need a good 16 volts.

You don't need diodes for the indicators if you run them from one of the DC supplies, set to 12 volts.

[Civil War]

 Bob,

Thanks for clearing that up. Here is the listing for the transformer. It says it has an 18 V DC output. Do you think this will do the job?

Transformer

[lionelsoni]

Yes.  It looks promising.

[servoguy]

I just went through a bunch of 1122s and manual equivalents. All of them had bad electrical connections. Some looked like they had been wet, and some were pristine. It didn't matter. They all had loose electrical connections. I recommend you solder all the connections before you reassemble the switches. Work quickly because the plastic does melt a little. The rivet in the center of the fat center rail needs to be soldered at both ends. I used a 4-40 screw for the frog with a pan head screw which fits nicely into the depression in the bottom cover plate. When you drill and tap the hole, use a little WD-40 for cutting oil, and it will drill and tap much easier. I also replaced the ground terminal because I am not adding Bob's cap discharge modification. To do this, I polished the metal tab that sticks out of the motor housing and also polished the area of the stud that would be soldered. Then I soldered the stud to the metal tab. Then here is the tricky part. I put a thumb nut onto the stud and used a pair of channel locks to hold the stud tightly into the bottom cover plate. The channel lock jaws are slightly offset so I could have one jaw on the thumb nut and the other on the bottom cover without covering up the hole where I was going to solder. Then holding the channel locks in one hand and the soldering gun in the other and having the solder draped over the edge of the table, I was able to do this 3 handed operation by myself. You can check your work by making sure the cover is held tightly by the soldered terminal. I also soldered two of the tabs that hold the outside rails in place to make a good connection between the outside rails. I had one switch that had the ground terminal broken off and it was lost. I soldered a 4-36 pan head screw to the bottom cover and made a new terminal. The thumb nut holds it tight to the metal tab coming out of the switch motor. Bruce Baker

[Civil War]

 I got both the transformers for 99 cents. I'll check them out when I get them. They also have an AC output so I might be able to power some small accessories or lights with them.

 

[Civil War]

Civil War

The capacitive-discharge circuit is very simple.  It is an electrolytic capacitor, about 4700 or 5000 microfarads), with its positive terminal connected to the outside rails and its negative terminal connected to the new wire that you installed.  The capacitor's negative terminal is also connected to one side of a number-53 lamp.  The other side of the lamp is connected to a 16-volt (approximately) DC supply, whose positive side is returned to the outside rails.

 

 

Bob,

 OK I got the turnout apart with no damage. My question is: Do I need two capacitors, one for each of the two wires from the coils? Should I run the wires that I attached to the coil wires all the way to the control panel and attach them to the capacitors or should I locate the capacitors below the table at each turnout?

I should have my DC transformer in a few days and we can start working on wiring the toggle switches and latching relays. I am taking pictures of every step of the procedures so I can document the process. I'll post them here once I have one complete working new turnout.

 

[lionelsoni]

The two wires, one from each coil, which were connected to the center rail inside the turnout remain connected to each other after you disconnect them from the center rail and both get connected to the negative terminal of a single electrolytic capacitor associated with that turnout.  I locate mine under the table at the turnout, since both its connections are handy there; but you could put it wherever is convenient for you.

Have you been able to identify the negative capacitor terminal?  The minus-sign symbols are often inside circles which are themselves inside a stripe with an arrowhead pointing at the terminal.

[Civil War]

lionelsoni

Have you been able to identify the negative capacitor terminal?  The minus-sign symbols are often inside circles which are themselves inside a stripe with an arrowhead pointing at the terminal.

 

Bob

Yes I see the markings. I received my two HO transformers today. One does not have any DC output. The other has 18 Volt DC output, but it is all or nothing. It is either 18 Volt or nothing. There is no variation of the voltage from the control handle. This doesn't sound normal. Is this OK? 

Below is a picture of the inside of my turnout. As I understand you I connect a new wire (22 gauge OK?) to the two wires from the coil that I will unsolder. The new wire is routed outside and connected to the Negative end of the Capicator. Once this is done I should be able to put the turnout back together, correct?

 

Thanks

[lionelsoni]

No, those are the wrong wires.  Notice that they are connected to the control rails, which are the short outside rails that make the non-derailing feature work.  Leave them where they are.  Instead, unsolder the other two wires that are both connected to the center rail.  Then connect both of those two wires to the wire that will come out of the turnout.  Yes, 22 AWG is fine for that.

Be sure to insulate the new connection adequately, and route the wire where it will not get pinched or cut when you put the turnout back together.

I just now went back and looked at the picture of the supplies that you bought.  They are Tyco 899Bs.  I couldn't find any description of the circuit; but I'll bet they are 18-volt supplies with a rheostat in series with the output.  That's the traditional HO way of doing things.  Measuring the voltage with a voltmeter, you wouldn't see any variation, because of the high impedance of the voltmeter.  If that's the case, you can use the one that works with no problem; just turn it all the way up.  The full 18 volts will probably be fine for powering the capacitive-discharge part.  I think that the 18-volt output is a clue that they are intended for slot cars, not trains.

You will need a 12-volt supply to power the LED assemblies that you bought.  If you can find a similar supply meant for HO trains, it should have a 12-volt output, which would work with your LEDs.  Making your own LED circuits, designed to run on the 18 volts or whatever AC or DC supply you want to use is also still an option, instead of getting another HO supply.

[Civil War]

 Bob,

 OK, I edited the picture in my last post. It only looks like one wire, but are there two wires? I'll look for another power source. Will I be able to use just one HO Train transformer for all my LED indictor lights? 

[Civil War]

 I found another transformer that looks like it puts out 12 volts. Can you take a look?

Transformer

[lionelsoni]

There should be two wires.  It looks like they may be in a single insulating sleeve.

That supply looks like it should work.

Have you drilled and tapped the frog yet?  Do you know how to do that, or would you like some detailed instructions?

[Civil War]

lionelsoni

Have you drilled and tapped the frog yet?  Do you know how to do that, or would you like some detailed instructions?

 

 I haven't drilled the frog yet, but that wil be no problem. I just need to get to the hardware store to get a new drill bit of the correct size. Thanks.

[lionelsoni]

I have used a 7/64 inch drill for 6-32 x 3/8 inch flathead Phillips screws.  I recommend drilling from the bottom, all the way through the frog, then threading the entire hole.

[Civil War]

 Thanks again, another good tip. I have been away all weekend, but tomorrow I will pick up a new drill bit and the 6-32 screws. I already have the taps. I used to do a lot of machine work, so this shouldn't be too hard. Do you know what the frog is made of? Is it brass (unlikely) steel or a pot metal?

 

[servoguy]

The frog is die cast zinc. It is soft but it will weld to the drill bit. WD-40 works well for cutting oil. If you cut it dry the bit may weld to the frog and break off. Don't ask how I know these things. Bruce Baker

[lionelsoni]

Oil is a good idea.  I've never had a bit break in one; but the tap gets stopped easily.  Do a lot of back-and-forth, back the tap out frequently and clean out the chips, and don't try to advance more that about a quarter-turn without backing up a few turns.

[Civil War]

 Success!

 The frog is drilled and tapped. The Negative end of the capacitor is soldered to a lamp socket and to the new wire from inside and the new wire is routed out the bottom of the turnout base. There was a nice slot so I didn't have to drill a hole. Will the lamp always be on, or will it only be on when the capacitor is charging? I used a lamp socket so I can change the bulb easily when it burns out.

When you say the Positive side of the capicator is attached to an outside rail does that mean I can connect it to any outside rail or to a buss wire under the table that connects to the outside rails? 

 

I should have my new 12V transformer in a couple of days. Then I will be ready to connect the toggle switch to the turnout and to the indicator lights. 

Thanks

[lionelsoni]

Any of the above; that is, connect the positive side of the capacitor to any outside rail other than the two control rails or to any wire or transformer post that is connected to the outside rails.

Then you can go ahead and connect up the 18-volt supply that you already have, since that's the one to use to charge the capacitor.  Connect the positive side of the supply to the outside rails, or etc.  Connect the negative side of the supply to the free terminal on the lamp.  The lamp will light only when the capacitor is charging.  Then put a truck on the track over one or the other of the control rails, to test the capacitive discharge operation.

[Civil War]

lionelsoni

Then you can go ahead and connect up the 18-volt supply that you already have, since that's the one to use to charge the capacitor.  Connect the positive side of the supply to the outside rails, or etc.  Connect the negative side of the supply to the free terminal on the lamp.  The lamp will light only when the capacitor is charging.  Then put a truck on the track over one or the other of the control rails, to test the capacitive discharge operation.

 

Something is amiss. I conntected the Negative from the Capacitor to the new wire to the turnout coils. The Positive side of the Capacitor is connected to one side of the lamp and to the outside rail. (I used a track connector CTC)

The other side of the lamp is connected to the Negative side of the Transformer. The Positive on the Transformer is connected to the outside rail via the same CTC track connector. The transformer is not marked positive or negative, but when I put my meter to the terminals with the negative lead on #2 and the positive lead on #1 it get an 18 Volt reading. I am assuming that #1 is positive and #2 is Negative.

 When I apply power, the lamp goes on. How long does it take to charge the capacitor? I thought it would be pretty quick. When I run an engine's front trucks onto the control rails nothing happens. I have power on the track via a 1033 Lionel Transformer. The lamp for the turnout indicator lantern lights up. I do hear a very faint buzzing from the turnout coils. 

 Have I wired this correctly? Could it be that the turnout I selected is no good? 

Thanks for your patience with me with this. I'd love to get this right so I can start on the toggle switch and latching relay part of this.

 

[lionelsoni]

You have it wired wrong.  Neither lamp terminal should connect to the outside rails.  Only the + terminals of the capacitor and the 18-volt supply connect to the outside rails.

Capacitor:  + to outside rails, - to new wire and one lamp terminal

18-volt supply:  + to outside rails, - to other lamp terminal

I don't know your meter; but you're probably right that 1 is positive.

The lamp should fully charge the capacitor in 1 2/3 seconds.

[Civil War]

 Got it right this time. Works perfectly. It is amazing how the turnout snaps into place when the truck hits the control rails. The Capacitor charges up just like it should. This is so much better than using track AC power. Can't thank you enough.

I should have my new 12 volt transformer in a couple days, maybe tomorrow. I have a SPDT toggle switch. I assume of the three terminals on the switch two go to the turnout and the center one I'm not sure what goes to it. I have a latching relay. It is 12 volt DC. It is a SPDT, but I am confused (as usual) because it has six terminals on the bottom. There is a black band at one end. Does this indicate polarity? The pins on the bottom are numbered 1  3  6 on one side and 12  10  7 on the other. 1 and 12 are at the end with the black band. Does this tell you anything?

I also have one red and one green LED lamp. 

[lionelsoni]

Congratulations!  You're right, the two outer terminals of the switch go to the two insulated turnout terminals.  The center switch terminal goes to the outside rails generally.  The switch does the same thing as the truck axles; it connects one or the other of the control rails to the outside rails generally.

Your relay has 3 terminals for the coils and 3 terminals for the contacts.

[Civil War]

 Bob,

 Below is a schematic of the latching relay. It is Greek to me can you tell me what gets connected to each of the pins? This is exactly how my relay is numbered. This came from the seller's web site. I got my new 12 volt transformer today but I forgot it at work so will have to test it tomorrow.

 

[lionelsoni]

You saved me the trouble of looking up the relay diagram--great!  Pins 1, 3, and 6 are the operating coils, which will be connected in parallel with the turnout coils.  Pin 3 is common to both coils, so it gets connected to the new wire that you installed, or to the negative terminal of the capacitor, which is the same thing.  Notice that it requires a negative polarity, which is why we installed the capacitor and the 18-volt power supply the way we did.  Pins 1 and 6 get connected to the same insulated terminals of the turnout to which you connected the SPDT switch.  (You did try that out, right?)

We will use pins 7, 10, and 12 to connect the LEDs, one or the other, to the 12-volt supply.  There are two equally good ways to do this; but here's one:  Connect the negative terminal of both LEDs to the negative terminal of the 12-volt supply.  Connect relay pin 7 to the positive terminal of the 12-volt supply.  Connect pin 10 to the positive terminal of one LED and pin 12 to the positive terminal of the other LED.  If the colors don't match the turnout position the way you want, swap the LEDs.

[Civil War]

lionelsoni

You saved me the trouble of looking up the relay diagram--great!

 

That is the least I could do. you have given me a lot of help on this project, and I am learning a lot about train wiring from it. Thanks. I checked out my new 12 volt transformer today and it seems to be ok. It has a set of constant 12 volt DC terminals on the side as well as a set for cab 1 and cab 2. It also has a set of AC terminals. I will probably use the constant DC terminals. The cab 1 & 2 rheostats don't seem to work well. As soon as I start to turn the knobs they both go right to 12 volts and there isn't much variation in voltage output. Is this normal with these old transformers? Every one I get seems to work this way. No matter, It will work well for what I need. When I get home tonight I will complete the wireing of my first turnout and see how it works. I'm building a little sample control panel so I can see how it all works. Can't wait to see the turnout snap back and forth and watch the LEDs change from red to green. This is going to be so cool. Thanks again. I'll let you know how it turns out.

 

[willpick]

Most of the early HO power packs use a rehostat(variable resistor) to control the output voltage. If you do not have  a load(engine) connected to the power pack, the output will read 12V. Also, the DC is just rectified AC-- no filtering. For what you intend to use them for, they will work just fine.