Tech tips Controllers

“cd” conversion for O27 switches

Most good quality O gauge remote control switches have a feature where if a train is heading into a switch the wrong way the switch will change directions automatically to accommodate the train so it won’t derail. This is a really cool feature but is lacking in most all O27 remote control switches. Why? I think it is more because the manufactures wanted to show more value to the O gauge stuff. That plus to do the job right there needs to be an electrical switch installed in switch to indicate on the remote control when the No D Rail feature is activated.

So anyway. Converting a old style O27 remote control switch to have a NO D Rail feature is quite simple. There is a tech tip on the site that will show you how to do it. Once you have done that, you will discover a problem associated with your conversion. When a train hits your NO D RAIL section on the switch or an external track, it does it job by activating a solenoid on the switch which is responsible for making the switch turn. When the train exits the switch the power is removed from the solenoid and the world is right again……except. While the train is going thru the switch the solenoid is fully powered, drawing juice, and often will make an irritating buzzing sound. And if you happen to park your train on the NO D RAIL switching the power will again be sent to the solenoid constantly. Eventually the switch mechanism will heat up to the point where it can self-destruct. That issue becomes worse if you have modified the switch as we do for all of our O27 switches to operate from high power accessory voltage.  If you use normal center rail power to run the switch, the current draw will also slow down the train, and the more it heats up, the slower the train will go.

The solution….

If your switches are not set up for constant accessory power to make the switch work, that needs to be done. Not just for this purpose, but they just work a lot better than trying to run them on center rail power. On some switches like the hump backs or the 1122’s that chore is pretty tricky. There are lots of articles on the web as to how to do it. We here at TinMan, make those modifications on all the switches we sell that do not have it before we sell the switches. We also have a service to modify your switches if you like. FYI there are some switches, for example all the Marx switches that are already set up for accessory power, as well as some of the K lines. Virtually all the remote switches we sell today either are set up for accessory power, or we have modified them to do so. However once we have done that we have the problem of over heating etc.

The solution! A really smart guy “Rob Nelson” came up with an idea of adding a cd circuit to the accessory power that operated the switches. How it worked was the switches were actually operated by a capacitor discharging.  If a car was parked on the No D Rail track the capacitor would not recharge, and therefore would not damage the switch. Once the car was removed, the capacitor would recharge in a matter of seconds, and was ready once again to operate the switch again. Not bad eh?  We were so impressed by all all this creativity, we now include accessory power and NO D Rail capability with all the O27 switches we offer. In addition we now include the CD system in all of our “red button” controllers, at no extra charge. We just cannot take credit for the invention so we have named these controllers the “Bob Nelson Controllers”   Just our way of recognizing a really smart guy, who willingly shared his invention to anyone who was interested. If you are still around Bob, our sincere thanks to you. 

How convinced are we with this new system? We now include the Rob Nelson CD system with all our red button controllers, including with switches that include the red button controller.

How its done:

The system is really quite simple. It is comprised of 3 electrical components. Which are:

  1. A diode which converts the AC voltage from the accessory power to the switch to DC
  2. A resistor, which goes in series with the diode.
  3. A large capacitor which then goes in series with the diode, and is also hooked up to the switches solenoids. (the solenoids is what actually makes the switches turn direction).

How it works, is the AC voltage is converted to DC voltage and then goes thru the resistor and diode and charges the capacitor. What is a capacitor? For this discussion it is like a rechargeable battery, except once turned on it drains down to nothing in a matter of a fraction of a second. It then stays dead until it can be recharged again. The discharging of the capacitor operates the switch mechanism. The resistor in series prevents the recharging until the ground connection from either the controller or the NO D Rail system is removed. Once the ground connection is removed the capacitor recharges in a matter of a second or two and is ready to operate the switch again. In the meantime, while being energized, once it has operated the switch it draws almost no current from the transformer, stopping the buzzing and the issue of potential over heating of the switch. Pretty cool eh?

The TinMan/Rob Nelson system:

We now add the CD parts into our O27 switch controllers for all our switches that have been modified for accessory power. No wiring changes need be made by the customer. Because our controllers can operate 2 switches at once, we had to add some extra components to the design, and it works super well. It actually improves the action of the switches, and they switch a lot faster with the CD system than they do without. They work best with an accessory power input of at least 14 volts. We include these mods to all the controllers that will be used with our modified switches, and we offer a new “CD” controller for those who have switches that were already modified.

So there you have it, now you are an expert in CD systems for model railroad O27 switches!

What’s the scoop about the “cd” conversion for O27 switches?

It all started here……..

Most good quality O gauge remote control switches have a feature where if a train is heading into a switch the wrong way the switch will change directions automatically to accommodate the train so it won’t derail. This is a really cool feature but is lacking in most all O27 remote control switches. Why? I think it is more because the manufactures wanted to show more value to the O gauge stuff.

So anyway. Converting a old style O27 remote control switch to have a NO D Rail feature is quite simple. There is a tech tip on the site that will show you how to do it.  Once you have done that, you will discover a problem associated with your conversion. When a train hits your NO D RAIL section on the switch or an external track, it does it job by activating a solenoid on the switch which is responsible for making the switch turn. When the train exits the switch the power is removed from the solenoid and the world is right again……except. While the train is going thru the switch the solenoid is fully powered, drawing juice, and often will make an irritating buzzing sound. And if you happen to park your train on the NO D RAIL switching the power will again be sent to the solenoid constantly. Eventually the switch mechanism will heat up to the point where it can self-destruct. If you use normal center rail power to run the switch, the current draw will also slow down the train, and the more it heats up, the slower the train will go.

The solution….

Step one:

If your switches are not set up for constant accessory power to make the switch work, that needs to be done. Not just for this purpose, but they just work a lot better than trying to run them on center rail power.  On some switches like the hump backs or the 1122’s that chore is pretty tricky. There are lots of articles on the web as to how to do it. We here at TinMan, make those modifications on all the switches we sell that do not have it before we sell the switches. We also have a service to modify your switches if you like.  FYI there are some switches, for example all the Marx switches that are already set up for accessory power, as well as some of the K lines.

Step two:

Once you have your switch modified for accessory power you can add the “CD” system to the power that goes to the switch. This idea originally came from a really smart guy that participates in some of the O gauge train forums. Sorry, but I cannot remember his name. His system was to add a few electronic components to be installed between the transformer and the switch. These parts consisted of a large capacitor, a diode, to convert the transformer AC voltage to DC and then charge the capacitor. A  resistor needs to be put in between the diode and capacitor. How it worked, is the AC voltage is converted to DC voltage and then charges the capacitor. What is a capacitor? For this discussion it is like a rechargeable battery, except once turned on it drains down to nothing in a matter of a fraction of a second. It then stays dead until it can be recharged again. For our purposes, the discharging of the capacitor operates the switch mechanism. The resistor in series prevents the recharging until the ground connection from either the controller or the NO D Rail system is removed. Once the ground connection is removed the capacitor recharges in a matter of a second or two and is ready to operate the switch again. In the meantime, while being energized, once it has operated the switch it draws almost no current from the transformer, stopping the buzzing and the issue of potential over heating of the switch. Pretty cool eh?

The TinMan system:

We now add the CD parts into our O27 switch controllers for all our switches that have been modified for accessory power. No wiring changes need be made by the customer. Because our controllers can operate 2 switches at once, we had to add some extra components to the design, and it works super well. It actually improves the action of the switches, and they switch a lot faster with the CD system than they do without. They work best with an accessory power input of at least 14 volts. We include these mods to all the controllers that will be used with our modified switches, and we offer a new “CD” controller for those who have switches that were already modified.

So there you have it, now you are an expert in CD systems for model railroad switches!

UPGRADE CONVERSION FOR LIONEL SWITCH CONTROLLER

The technical prowess shown by the original Lionel team was amazing considering what they had to work with in the early part of the 20th century, however some things older is not necessarily better. One for sure is the original rubber wire cable that came with the O22 and other switches. 1st unless you were building a midget layout, the cable is way too short. Next after just a few years the cable becomes brittle and eventually is unusable. If you run bootstrap power you will need a separate cable for that. Then if I want to run power taps for the track, another cable. Sooo, if I have to run a cable to control the switch, why not have it do a lot more? This conversion will also provide constant switch bootstrap power, an additional power tap for the center rail of the track, and all normal switch and remote control functions The only parts you will need are:
15 feet or so of 4 conductor cable. A 2.5mm power plug, to replace the boot strap, soldering iron, some solder and about 10 minutes of your time. If you wish a kit will be available soon from TinMan3rail.com for about 10 bucks with shipping, and includes the wire, 2.5 mm plug, with wires soldered on, and 15′ of cable. If you need more than the 15′ cable, or 3′ to the transformer, let us know and we will extend it for you to your specs
This cable is to be wired to the transformer. This cable is to be wired to the switch.

The transformer cable is about 3′ long and is stripped of the insulation at the 3′ mark about 3″ worth.
The red and black wire go all the way from the transformer cable thru the longer right cable untouched.
The green wire is pulled out of the 4′ piece of cable, and wired to the solder terminal next to the green light . The white wire is cut 1/2 between the 2 rolls of cable. The white wire that is part of the transformer cable is wired to the switch solder lug. The white wire from the long cable is soldered to the red light bulb solder lug.</p>
The end of the 3′ cable:
The red wire goes to accessory power that you would normally run to the boot strap.
The black wire goes to the track power terminal that is connected to the center rail of the track the switch is hooked to.
The white wire is hooked to the common terminal on the transformer. </br>
The long cable
The red wire will go to the center terminal of the 2.5mm plug.
The black wire will go to the outside (barrel) connection of the 2.5mm plug.
The 2.5 mm plug will go directly into the 022 switches. For some of the newer switches, you need to use a 2.1mm.
The green wire goes to the right screw down terminal on the switch assembly.
The white wire goes to the left screw down terminal on the switch assembly (if your switch works backwards reverse the green and white wires).
The center terminal of the switch is not used. Originally it provided a ground to the remote control switch, which is now being provided directly from the transformer.